Molecular oncology. Molecular profiling of the tumor is a step towards personalized cancer treatment. Differentiated thyroid cancer

As a result of the progress of new scientific areas of molecular biology, molecular genetics and genetic engineering a huge step forward has been made, which now allows us to ask nature questions that were previously impossible to ask. It is about understanding the most fundamental foundations of such phenomena as cell division and differentiation, as well as the causes of the mechanism of their violations.

In a specific application to one of the most topical and exciting problems facing humanity - the problem malignant tumors- we can talk about the emergence of a new science - molecular oncology. Her striking success in the field of studying the molecular mechanisms of oncogenesis and the molecular basis of the cancer phenotype is associated with the use of unique research methods inherent in her.

The book "Molecular Oncology", which is being published and is offered to readers, is devoted to summing up the first results and presenting the achievements of this young science. It clearly traces the continuity of the basic principles and postulates of classical theoretical oncology, primarily in the main issues: the polyetiology of the onset of tumors and the multi-stage nature of this process.

However, solutions are already given at another level of organization of living matter - the molecular one. This book- the first and only so far in our country. It was written by authors who are directly and actively working in this field, which predetermined the depth of understanding of the given specific facts and the constructiveness of generalizations. The idea of ​​the universality of the molecular mechanisms of oncogenesis runs throughout the book.

This idea follows naturally from the analysis carried out by the authors latest research the main types of carcinogenesis: chemical, physical, biological, the basis of which, as the authors convincingly show, is one and can be expressed in fundamentally general molecular terms.

Separate chapters are devoted to each of these types of oncogenesis. Chapter 1 turns the reader to the origins of theoretical oncology, to its classic studies of the beginning of this century. Chapters 2 and 3 are devoted to the molecular mechanisms of chemical and viral carcinogenesis, respectively.

The first three chapters mentioned logically precede the final chapters 4 and 5, the true core of the book.

It is in these chapters that facts and ideas are presented in a concentrated form, symbolizing the essence and spirit of modern theoretical oncology - molecular oncology. Her achievements inspire confidence in the final victory of the human mind over a serious illness.

"Molecular Oncology"
I.F. Seitz, P.G. Knyazev

To a critically thinking observer, modern theoretical oncology may appear to be a flowering tree, but not a fruitful one. Such an impression is to some extent justified and is due to a clear imbalance of huge intellectual efforts and material investments, on the one hand, and modest practical outputs, on the other. Still remain unclear both the nature of malignant neoplasms and the primary stimulus that initiates an inevitable chain ...

Over time, the identification of the carcinogenic properties of chemical agents has become only a matter of technology, and there has been a clear shift in research focus from routine testing for carcinogenicity to the study of the mechanism of oncogenic action. In this case, along with significant successes, considerable difficulties were revealed. Successes concerned the purely chemical side of the problem: the need for activation of the original carcinogens was established, metabolism, interactions were studied ...

How does the invasion of fragments of chemical carcinogens into DNA result in uncontrolled growth and transformation of cells? The theory of chemical carcinogenesis, in order to take a new and decisive step forward, needs some kind of scientific event, similar in significance to the discovery of reverse transcriptase in oncovirology. In the theory of chemical carcinogenesis, such an event has not yet occurred. However, you can expect…

The main success of oncovirology today should be considered the discovery of oncogenes - discrete material genetic elements in the DNA structure of cells responsible for the induction of malignant tumors in humans and animals. This line of research is the most promising in modern theoretical oncology. Oncogenes have been found in the genomic DNA of not only animals, but also humans, and the likelihood of their involvement in tumor induction…

Even I. M. Sechenov in 1860, in the theses of his doctoral dissertation, wrote that in the present state of the natural sciences, the only possible principle of pathology is molecular. Now one can only marvel at this providence. Today molecular oncology stands at the threshold of the mystery of cancer. It is she who owns the most outstanding successes in the field of theoretical oncology in recent years. These include the following…

If molecular biology in the most concise interpretation can be characterized as a science that expresses and explains complex general biological phenomena in terms of the properties and interactions of molecules, then molecular oncology, of course, is designed to reveal the molecular mechanisms of the process of carcinogenesis and the characteristics of tumors. This book attempts to summarize the progress of this young science. All the greatness of progress in the knowledge of tumors in our ...

The use of gene transfer and molecular cloning techniques has made it possible to establish some of the most important, central determinants of the cancer process. These determinants are oncogenes and their products are oncoproteins that act both on the structure and functions of cells and affect the regulatory mechanisms of biochemical reactions. Many of these functions of oncogenes and oncoproteins are still unknown, however, with the current level of knowledge, they ...

The oncoprotein p21cras, during cell transformation, apparently significantly affects the bioenergetics of the cell and the transmission of the regulatory signal from cell membrane into the core. There is also no doubt that the p2jcras oncoprotein in its multifunctional action in the process of malignancy of the target cell, it cooperates with the functions of other activated proto-oncogenes. For some steroid hormones, such as glucocorticoids, a mechanism has been established for transmitting their information from a specific ...

Molecular pathology of lung cancer studies the totality of morphological and molecular genetic features of this tumor. At the same time, the most important aspects problems are the determination of biomolecular and histogenetic markers of cancer, as well as the pathology of apoptosis in lung cancer.

Biomolecular markers of lung cancer are diverse, apparently coincide with markers of non-radiation lung cancer and are represented by various genes, proteins, hormones and other molecules.

Cellular oncogenes in lung cancer. In the pathogenesis of lung cancer greatest value have cellular oncogenes of four families: myc, ras, bcl, erb-B.

The myc family of cellular oncogenes - c-myc, L-myc, N-myc - is represented by immediately reacting genes and encodes cellular regulatory proteins that induce proliferation and suppress differentiation. It was found that in the absence of growth factors, an increase in c-myc expression does not lead to cell division, but to apoptosis, which can be inhibited by bcl-2. Amplification of c-myc is found in 10-25% of lung cancers, while L-myc and N-myc are found only in neuroendocrine lung tumors (10-30%). Determination of increased expression of myc oncoproteinins is recorded much more often.

L-myc expression is found only in the group of neuroendocrine lung tumors, and c-myc expression in both the group of small cell and non-small cell lung cancer. In the group of small cell lung cancer, a significant correlation of L-myc and c-myc expression with the presence of metastases and tumor size was established.

The ras family of cellular oncogenes often undergoes changes during tumor growth. The genes encode the synthesis of p21 proteins, which have GTPase activity and bind to GTP and thereby affect the transmission of the growth signal to the cell. Mutations that activate the ras genes and are localized in codons 12, 13, and 61 are described. Most often, K-ras mutations are found in lung cancer, which are inherent only in non-small cell lung cancer, in contrast to small cell lung cancer. The frequency of K-ras mutations in lung adenocarcinomas is up to 30%, and in squamous cell lung cancer only 3%. The association of K-ras mutations with smoking has been shown.

K-ras mutations were found in lung precancer - atypical hyperplasia of the alveolar epithelium. Expression of p53 has been described in the same foci. Correlations were found between higher expression of this oncoprotein with glandular differentiation of lung cancer. High expression of ras protein products was also recorded in foci of lung adenomatosis and in oval and slit-like epithelial structures in scars.

The bcl-2 family consists of bcl-2, bax, bak, bclXL, bclXS, protein products which are able to form homo- and heterodimers, which sometimes have a diametrically opposite effect on the proliferation and apoptosis of tumor cells. The most studied of this family, bcl-2, is localized on the inner membrane of mitochondria, as well as in the nucleus, stimulates cell proliferation and inhibits apoptosis, probably due to antioxidant activity. On the contrary, bax proteins, whose transcription and synthesis is regulated by p53, block proliferation and stimulate apoptosis of tumor cells. BclXL inhibits apoptosis and stimulates proliferation, while bclXS, on the contrary, induces apoptosis. Thus, the balance between the protein products bcl-2 - bax, bclXL-bclXS and determine the shift of the balance towards proliferation or apoptosis in the tumor.

Suppressor genes in lung cancer. The role of suppressor genes in the development of tumors is reduced to blocking apoptosis and removing their suppressive effect on cellular oncogenes, which ultimately ends with the activation of proliferation. To realize the effect of damage to suppressor genes, the changes must affect both alleles of the gene, since a mutated suppressor gene is always treated as intact as recessive to dominant. For example, a mutation or deletion of one of the alleles of a suppressor gene must be accompanied by a loss or change in the other allele.

Suppressor genes in lung cancer are relatively well understood. The most common chromosome deletions are known, affecting the following regions: 3p21-24, 17p13, 13q14, 9p21-22 and 5q21. The 3p21-24 deletion occurs most frequently: in small cell cancer - in 100% and in non-small cell - in 85% of cases. But not a single suppressor gene is localized in this zone. Other sites correspond to known suppressor genes. So, for example, p53 is localized in 17p13, the retinoblastoma gene is located in 13q14, p16 INK4B(MTS1) and p15 INK4B(MTS2) - 9p21-22. The functions of most of these genes are well known and are associated with the control of the G1 phase of the mitotic cycle and/or apoptosis. Their inactivation causes the development of apoptosis. The detection of genome damage in the area of ​​localization of suppressor genes at the stage of precancerous changes indicates the involvement of these genes in the early stages of tumor growth. Currently, a number of new suppressor genes have been described that appear to be important for the development of lung cancer and are localized on chromosomes 1 and 16.

The p53 gene is exposed to the most frequent changes with tumor growth. Wild-type p53 (natural) is a transcription factor with multiple functions, including regulation of cell transition from G1 to S-phase, DNA repair, and apoptosis following genome damage. A deletion of one of the alleles (17p13) in combination with a point mutation in the other allele is a genetic rearrangement observed in most malignant tumors. The mutated p53 actually acts as a cellular oncogene, stimulates the proliferation of tumor cells and induces the formation of antibodies that are detected in the blood of patients. The latter served as the basis for the development of immunodiagnosis and immunotherapy for lung cancer.

The mutation causes conformational changes in the p53 protein, and it accumulates in the cell nuclei, which makes it possible to determine it by immunohistochemical methods. On the contrary, wild-type p53 is considered to have a very short half-life (20 min) and therefore cannot be determined immunohistochemically. Inactivation of p53 in lung cancer occurs in about 70% of cases. Studies on the correlation of p53 expression with survival are controversial. In general, if such an action exists, it is very insignificant. The association of p53 with malignant transformation is also unclear. At the same time, experimental data show that upon activation of wild-type p53, growth slows down and apoptosis develops, which can lead to reversal of the malignant phenotype.

There is evidence for the significance of the p53 mutation in the early stages of lung carcinogenesis. Mutant forms of p53 are never detected in reserve basal cell hyperplasia or squamous metaplasia without signs of dysplasia. In p53 dysplasia, mutations are detected in 12-53% of cases, and in cancer in situ, in 60-90% of cases in studies of tissue surrounding lung cancer. Detection of p53 in more than 20% of cells in dysplasia foci is a marker of irreversible precancerous changes. However, p53 mutation is not a necessary phenomenon in lung cancer, and therefore the absence of p53 is not a favorable prognostic factor. Moreover, neither the accumulation of p53 nor its mutation exhaust the molecular mechanisms through which p53 can be inactivated in tumors. Disruption of p53 function occurs when it interacts with other proteins that regulate the mitotic cycle - p21, Mdm2, bax.

The Rb gene is localized in the 13q14 site, which is deleted in 80% of small cell lung cancer cases (as often as in retinoblastoma), encodes a 110 kDa nuclear phosphoprotein, and controls the exit of the cell from the G1 phase. Hypophosphorylation of Rb leads to cell blockade at the G1 stage and apoptosis. Inactivation of Rb in tumors is achieved by the loss of one of the alleles and the mutation of the second allele of the gene.

Thus, inactivation of the p53 and Rb suppressor genes is more important for the development and progression of small cell lung cancer.

Growth factors, growth factor receptors and binding proteins in lung cancer. In the progression of cancer lung factors growth play important role, providing tumor growth with the help of autocrine and paracrine stimulation.

Adhesive molecules and extracellular matrix in lung cancer. Adhesive molecules, integrin receptors and the extracellular matrix of lung cancer have a modulating effect on tumor cells and ensure the growth, invasion and metastasis of the tumor, as discussed in the previous sections of the lecture.

The first phase of tumor invasion is characterized by a weakening of contacts between cells, as evidenced by a decrease in the number of intercellular contacts, a decrease in the concentration of some adhesive molecules from the CD44 family, etc., and, conversely, an increase in the expression of others that ensure the mobility of tumor cells and their contact with the extracellular matrix. On the cell surface, the concentration of calcium ions decreases, which leads to an increase in the negative charge of tumor cells. The expression of integrin receptors, which provide attachment of the cell to the components of the extracellular matrix - laminin, fibronectin, and collagens, is enhanced. In the second phase, the tumor cell secretes proteolytic enzymes and their activators, which ensure the degradation of the extracellular matrix, thereby clearing the way for invasion. At the same time, the degradation products of fibronectin and laminin are chemoattractants for tumor cells that migrate to the degradation zone during the third phase of invasion, and then the process is repeated again.

Histogenetic markers various types lung cancer. Lung cancer is represented by tumors of various histogenesis. AT last years all histological types of lung cancer are divided into small cell and non-small cell, which differ not only in morphological manifestations, but also clinically, response to chemotherapy and life prognosis of patients.

Small cell lung cancer is also characterized by specific biomolecular markers from the group of cellular oncogenes, suppressor genes, and growth factors. In addition, small cell carcinoma is also distinguished by signs of neuroendocrine differentiation. In more than 90% of cases, tumor cells express both chromogranin and pancytokeratins. Chromogranin is found in the form of granules in the cytoplasm of tumor cells. The number of chromogranin-positive cells and the level of expression varies depending on the degree of tumor maturity.

Non-small cell lung cancer is a heterogeneous group of tumors belonging to different histogenetic groups: squamous cell carcinoma(markers are cytokeratins and keratohyalin), adenocarcinoma (mucus cytokeratins, surfactant), as well as large cell carcinoma, which can be represented by both poorly differentiated adenocarcinoma and poorly differentiated squamous cell carcinoma.

Lecture equipment

Gross preparations: bronchiectasis and pneumosclerosis, chronic obstructive pulmonary emphysema, cor pulmonale, honeycomb lung with idiopathic fibrosing alveolitis, lung silicosis, central lung cancer, lung cancer metastases to the adrenal glands.

Micropreparations: chronic obstructive bronchitis, bronchiectasis and pneumosclerosis, chronic obstructive pulmonary emphysema, cor pulmonale, restructuring lung vessels with secondary pulmonary hypertension, idiopathic fibrosing alveolitis, sarcoidosis, lung silicosis, peripheral lung cancer, squamous cell lung cancer, lung adenocarcinoma, small cell lung cancer.

Electronograms: chronic obstructive pulmonary emphysema (obliteration of alveolar capillaries), lung adenocarcinoma, small cell lung cancer.

In recent years, methods of molecular and genetic research have been developed and put into practice. malignant cells. These studies allow us to determine the degree of aggressiveness of the tumor and, as a result, the appointment of the most appropriate cancer treatment in Germany.

In some cases, it is worth limiting yourself to only surgical intervention and the disease will not return even without the use of chemotherapy and radiation. It is also possible to analyze certain cancer cell growth receptors, blocking which with special antibodies can prevent their further reproduction.

In addition, in modern oncology, it is possible to determine mutations (genetic damage) in the enzymes of tumor cells, which are responsible for whether a given tumor is amenable to certain chemotherapy or not.

We offer you to send us by mail a block with the pathology of your biopsy or operation even without coming to Israel or Germany. On the basis of the ‹‹Genomics›› laboratory, we carry out genetic and molecular analysis of the material, after which, based on the nature of the tumor, leading oncologists in Israel and Germany will provide you with specific recommendations in the treatment of cancer to achieve the most effective result with the least harm to the body.

‹‹OncotypeDX›› is not an experimental study. The results of these tests are based on observation of patients over 8 years. They are widely used in the largest cancer centers in the world and have saved hundreds of thousands of people from the use of ineffective chemotherapy.

What tests exist and who are they suitable for?

Oncotype DX for Breast (Breast) Cancer

1.a) Oncotype DX ® breast

‹‹Oncotype DX ® breast›› is a diagnostic test that is performed after surgical treatment of breast cancer. Suitable for menopausal women invasive cancer breast, with estrogen - receptor - positive (ER +) and HER 2 -negative tumor with unaffected lymph nodes.

The ‹‹Oncotype DX breast›› test provides additional information with which physicians make decisions about the course further treatment.

This is due to the fact that the results of the study determine the degree of aggressiveness of the tumor, the chance of recurrence and the need for chemotherapy.

The ‹‹Oncotype DX›› test presents necessary information in addition to standard tumor characterization measurements such as tumor size, tumor grade, and lymph node status, which are traditionally used by clinicians for evaluation. In the past, based on these parameters, a decision was made on the tactics of further treatment. With the advent of the ‹‹Oncotype DX breast›› test for 21 genes, physicians have an effective tool that indicates the degree of effectiveness of a chemotherapeutic or hormonal treatment.

To date, the results of the Oncotype test are the most important test in deciding whether to use chemotherapy in the treatment of breast cancer, it fundamentally changes the decision compared to what was used in the past without its use. Since the types of tumors are different for everyone, it sometimes happens that a small tumor with unaffected lymph nodes can be very aggressive. Therefore, intensive chemotherapy is necessary. On the other hand, in cases where this is not the case, with the ‹‹Oncotype›› you can save yourself from unnecessary chemotherapy and side effects associated with her.

Below we present the stories of several patients who have benefited from the ‹‹Oncotype DX›› test.

Susan, aged 59, a routine mammogram revealed cancer.

After surgery to remove the tumor and biopsy of the lymph nodes, Susan underwent a series of examinations, including PET/CT, to assess the extent of the spread of the cancer. She was relieved when all those tests came back negative, but Susan wanted to make sure her illness wouldn't come back. After hearing about ‹‹Oncotype DX ®›› from a friend, Susan asked her doctor if the test was right for her. The initial tumor findings were suitable for the test, as her tumor was estrogen receptor positive and lymph node negative. Susan's doctor was very surprised when he saw the result of ‹‹Oncotype DX››, it was 31, which indicates a high risk of cancer recurrence, and chemotherapy is necessary additional treatment in this case. Based on the result of the ‹‹Oncotype DX›› test, Susan's attending physician recommended several rounds of chemotherapy, which she started immediately to avoid possible relapse diseases. Before the test, Susan's doctor was sure that chemotherapy was not needed, but after learning about high risk return of the disease, changed his mind.

A commercial airline pilot with 27 years of experience, Diana, 50, discovered a small lump in her left breast during a self-examination.

A tissue biopsy confirmed her worst fears. Diana's cancer took the form of multiple small tumors scattered across her breasts. She was immediately operated on - the entire breast was removed. Although the tumors themselves were very small, Diana's doctor could not confidently rule out the need for chemotherapy based on standard measures such as tumor size and stage. Diana was worried about her future health and work safety. "Because I'm small, there has been concern that I'm less able to withstand the severe side effects of chemotherapy," Diana said. "In addition, the airline has been vigilant about the health of its pilots, and a cancer diagnosis could mean a permanent suspension from flying."

Seeking information, Diana's doctor turned to Oncotype DX for a genomic analysis of her illness. About a week later, Diana learned that her result was 13, suggesting that she has a lower risk of relapse (return of the disease). During the conversations with her doctor, she felt confident, she was able to avoid chemotherapy and its side effects without increasing the likelihood of a recurrence of the disease, and she was able to continue her career and active lifestyle. In addition, she was able to keep her long hair, which she raised from the age of 23. "Thirteen is mine lucky number currently," Diana said.

The test is suitable for menopausal women with invasive breast cancer, estrogen receptor positive (ER+) and HER-2 negative tumors, with normal lymph nodes. It is performed on a tissue sample of a removed tumor during surgery.

1.b) Immunohistochemical test of ER, PR, HER-2 receptors in tumor cells

Genetic analysis Fish-response to the antibody ‹‹Trastuzumab›› (Herceptin).

Immunohistochemical study: checking the tumor for special proteins - receptors located on the surface of tumor cells and being a target for drugs.

Analysis of estrogen, progesterone, HER-2 receptors allows us to establish their sensitivity to hormone therapy and to a specific antibody ( biological drug, not chemistry, a new generation of oncological drugs).

A tumor DNA test that tests genes in tumor cells for antibody susceptibility. Herceptin (Fish reaction) is suitable in 20-25% of breast cancer patients. This medicine significantly increases life expectancy in metastatic disease and prevents the return of the disease after surgery.

The above tests are suitable for both initially detected tumors at any stage, and for metastatic tumors.

1.c) CYP2D6 test

After the operation, many women are shown prophylactic treatment to prevent further relapse. If there are estrogen receptors and progesterone receptors in the tumor tissues, then menopausal patients are often prescribed hormone therapy, tablets ‹‹Tamoxifen›› for 5 years.

Recent studies have found a specific enzyme in liver cells that activates the drug ‹‹Tamoxifen›› in active substance‹‹Endoxifen››, which destroys cancer cells.

Therefore, the effectiveness of the drug is largely determined by the degree of activity of the liver enzyme CYP2D6, and the activity of the enzyme is determined by the genes of the patient.

This genetic test detects mutations in genes associated with the CYP2D6 enzyme, and allows you to accurately assess the degree of enzyme activity and the effectiveness of the drug Tamoxifen ››.

Definition of CYP2D6 genetic code helps in choosing the right hormonal treatment and provides an opportunity to predict the effectiveness of the use of ‹‹Tamoxifen›› individually for each patient.

From medical literature it is known that 7-10% of the population of Europe and the USA have an ineffective enzyme, in these cases ‹‹Tamoxifen›› is an ineffective medicine.
It is very important to find those women for whom ‹‹Tamoxifen›› treatment is not suitable due to inefficient drug metabolism caused by low CYP2D6 enzyme activity. These patients are at increased risk of recurrence of breast cancer when taking ‹‹Tamoxifen››, and they need to take other hormonal drugs.

The test is intended for patients who are expected to be prescribed ‹‹Tamoxifen››, at an early or metastatic stage of the disease. The analysis is carried out using the patient's saliva.

2. Oncotype DX ® colon for colon cancer

2A. Oncotype DX®colon is a diagnostic test that is performed after the surgical removal of colon cancer. The ‹‹Oncotype DX colon›› helps men and women with colon cancer learn more about biological features tumors and determine the likelihood of recurrence. Combined with other pieces of information, the results of the ‹‹Oncotype DX colon›› trials can help patients and their physicians make personalized decisions about whether or not to use chemotherapy in the treatment of colon cancer.

One of the main problems in the treatment of patients with colon cancer is to determine the risk of recurrence of the disease after surgery and assess the need for postoperative chemotherapy in order to reduce the chance of recurrence.

Oncotype DX provides a new way to assess the risk of recurrence in stage 2 colon cancer (without lymph node involvement) and enhances the ability to make informed decisions on an individual basis.

You have recently been diagnosed with stage II colon cancer without lymph node involvement and have been surgical resection. Do you and your doctor have to make a decision about chemotherapy?

The ‹‹Oncotype DX›› test provides the necessary, additional information based on the genomic features of the tumor, which doctors use when making decisions about treatment tactics. It also indicates the likelihood of recurrence. The ‹‹Oncotype DX colon›› test provides information in addition to standard data such as tumor stage and lymph node status, which physicians and their patients traditionally use to assess whether the disease is likely to recur. In 15% of cases, the tumor of the colon is absolutely non-aggressive, and in this case, chemotherapy only brings harm to the body, because. the disease will never return.

Below are answers to the most frequently asked questions about the ‹‹Oncotype DX colon››

1. What is the ‹‹Oncotype DX colon›› test?

‹‹Oncotype DX colon››- tests colon cancer cells by looking at the activity of 12 human genes in order to assess the likelihood of the return of colon cancer in patients with early stage colon cancer with intact lymph nodes.

2. Who is the ‹‹Oncotype DX colon›› suitable for?

Men and women with newly diagnosed stage II colon cancer.

3. How does the ‹‹Oncotype DX colon›› test work?

The DNA that makes up the cell is extracted from tumor samples and then analyzed to determine the degree of activity of each of the 12 genes. The results of the analysis are calculated using a mathematical equation to convert the value into a numerical result.
This result corresponds to the probability of colon cancer recurrence within 3 years of initial diagnosis among individuals with early stage(second stage) colon cancer who underwent surgery to remove the primary tumor.

4. How long does testing take?

It usually takes 10 to 14 calendar days from the time the pathology arrives at the laboratory. The results of the study come in the form of a number on a scale from 0 to 100, and indicate the degree of likelihood of a relapse.

The ‹‹Oncotype DX colon›› is the doctor's advanced tool for assessing the severity of colon cancer and assisting in personalized treatment.

2B. Mutation testing in the K-RAS-Test is suitable for patients with metastatic colon and rectal cancer

One receptor that is characteristic of colon tumors is the epithelial growth factor receptor or epidermal growth receptor EGFR. These growth factors with a specific growth receptor trigger a chain of reactions that promote the development and division of the tumor cell. Changes, mutations (genetic failures of the code that determines the structure of the receptor), activation of EGFR receptors, can lead to constant uncontrolled cell division - these are necessary prerequisites for the appearance of malignant tumors. Determination of the EGFR receptor (a gene that can lead to cancerous transformation) is the target receptor for targeted treatment of tumors of the colon and rectum.

The drug - the antibody ‹‹Erbitux›› (Setuximab) blocks these receptors and thus prevents further division and growth of malignant cells.

What is K-RAS?

One of the "actors" involved in the chain of events. The action occurs after the activation of the EGFR family protein. The K-RAS receptor, this protein is a link in the chain of division signals in cells, which ends in the cell nucleus.

When there is a mutation in the K-RAS receptor, even if the EGFR receptor is blocked by the Erbitux›› antibody, it will still occur chain reaction cell division, bypassing the EGFR receptor link, in other words, the antibody will be absolutely ineffective.

On the other hand, if there is no mutation in K-RAS, then the biological drug ‹‹Erbitux›› gives a statistically significant improvement in the survival of patients with metastatic disease. In 55-60% of cases, no mutation is observed, that is, it is possible to treat with an antibody.

Complex treatment with ‹‹Erbitux›› in combination with chemotherapy allows to reduce metastases, and in the future, in some cases, they may surgical removal which can lead to full recovery.

If 10 years ago, patients with the fourth metastatic stage of colon disease lived an average of a year, now they live 3-5 years, and in 20-30% of cases a complete recovery is possible.

Thus, the test for the presence of a mutation in K-RAS helps to assess the degree of effectiveness of treatment with biological drugs in metastatic colon cancer.

The test is suitable for patients with metastatic colon and rectal cancer.

To conduct the test, you need a block with tissue from a biopsy tumor or a sample from a removed tumor.

3. Checking for EGFR mutations - non-small cell lung cancer

On tumor cells of non-small cell lung cancer, there are growth receptors responsible for the process of cell division.

Special enzymes that transmit signals for cell division are called tyrosine kinase.
Tyrosine-Kinase inhibitors are targeted drug therapies that block signals that promote tumor growth. These new drugs, small molecule tyrosine kinase and epidermal growth factor receptor (EGFR) inhibitors (Erlotinib (Erlotinib), Gefitinib (Gefetinib) were originally developed for use as second-line therapy after chemotherapy failure.

Under these conditions, Erlotinib showed an increase in survival rate, with an outcome magnitude similar to second-line chemotherapy, but without severe side effects. Since this is a targeted therapy, specific cancer cells are affected without harming normal cells, thus not harming the body.

Clinical studies have shown a correlation between the presence, activation of specific mutations in the T3 region of the EGFR receptor, and an increase in the activity of small molecule drugs - Erlotinib and Gefitinib. The presence of a mutation was found in 15-17% of patients, and instead of heavy chemotherapy with side effects, an antibody in tablets is suitable for them. The antibody can be given as the first line of treatment for metastatic disease. This drug can inhibit the growth of a tumor for years, as it blocks the tumor growth receptor.

The test is suitable for patients with non-small cell lung cancer with metastases, both before the start of any chemotherapy, and when the disease progresses during treatment. It is carried out on the biopsy block or on the material obtained during the operation.

4. New survey - Target Now (Target check)

Just as there is a difference between different people, it also exists between different malignant tumors, even if they are of the same origin, from the same organ.
So, for example, breast cancer may respond to hormone treatment in one woman, and another woman will not respond to them. Today, with the development of medicine, tests have been developed that help doctors choose treatment individually for each patient, thereby significantly increasing the effectiveness of treatment and reducing the risk of unwanted side effects.

What is Target Now?

This is a study conducted on the material of cancerous tissue removed during an operation or biopsy.

Research checks potential targets in tumor cells for various drugs.
In accordance with these goals (the presence or absence of certain receptors, mutations or their absence) allow the doctor to choose one or another drug that kills a specific tumor.

The test determines in cancer cells big number molecules that can be used as a site of action or target, chemicals and/or various biological antibodies. Molecular changes may indicate the expected good efficacy or ineffectiveness of a given treatment.

results this study were published in 2009 at the annual meeting of the American Association for Cancer Research. The test was carried out on 66 patients suffering from metastatic cancer. Based on the results of the Target Now test, patients were selected necessary treatment, after the standard treatment used for their disease proved to be ineffective.

The study found that molecular targets can be detected in 98% of cases.

In addition, adjusted treatment based on the results of the ‹‹Target Now›› test in one third of patients was found to prolong the time to disease progression by 30% compared to past treatment before the Target Test. Many patients have been extended life for many months and even years. It must be emphasized that we are talking about patients who were not helped by many drugs prescribed according to the scheme generally accepted for their disease.

From the results of Targeted Testing, it was found that their particular tumor is often treated with drugs that are usually not suitable for their type of cancer in the general group.

This study indicates that the Target Now test can detect drugs that are personally appropriate for a given tumor, which is difficult to determine in any other way today. A targeted test now allows for optimal adjustment of individual drugs before starting cancer treatment.

This study is suitable for patients with metastatic disease of any organ who have not responded to previous treatment.

To conduct the study, it is necessary to have tissue from a biopsy or after surgery.

5. Mamma Print - a test to determine the risk of breast cancer recurrence

MammaPrint is a diagnostic test to assess the likelihood of recurrence, which can predict the possible occurrence of recurrence of breast cancer within 10 years after treatment of the primary tumor.

MammaPrint is the only test of its kind that received FDA approval in February 2007.

The results of this test allow you to choose a technique after surgical treatment. If there is a high risk of recurrence, chemotherapy is indicated.

According to FDA recommendations, this test is indicated for patients under 61 years of age, without affected lymph nodes, with a tumor size of less than 5 cm. MamaPrint is also effective in hormone-dependent breast cancer and in other types of malignant tumors.

This test is based on the analysis of 70 oncogenes associated with breast cancer. The analysis of these genes makes it possible to predict with great accuracy how a particular malignant tumor will behave in the future, this will allow the attending physician to select the necessary treatment with great accuracy.
The test is performed on tumor tissue taken during a biopsy or after surgical removal.

MamaPrint is the first highly individualized diagnostic test.
Today this method is very popular, for the sake of diagnostics with its use, many patients from the CIS countries come to Israel.
To take this test, you need to come to Israel for a few days, undergo a biopsy or surgical operation as the test requires fresh tissue samples. After that, you can go home or wait for the diagnostic results in Israel. It will take about 10 days to wait.

Treatment in Israel with the "Cancermed" center is the organization of high-quality medical care.

We are completing a series of articles on oncological diseases.
Today I will tell you in detail what molecular testing is and how it affects the diagnosis.

In the photo: Vladislav Mileiko, head of the department,
biomedical holding "Atlas".

To understand how it works molecular diagnostics and what place it occupies in oncology, you must first understand the mechanisms that occur in the tumor.

Molecular processes in a tumor

Mutations in proto-oncogenes and suppressor genes responsible for cell division and death cause the cell to stop following instructions and synthesize proteins and enzymes incorrectly. Molecular processes are out of control: the cell is constantly dividing, refusing to die, and accumulating genetic and epigenetic mutations. Therefore, malignant neoplasms are often called a disease of the genome.

Hundreds of thousands of mutations can occur in tumor cells, but only a few contribute to tumor growth, genetic diversity, and development. They are called drivers. The remaining mutations, "passenger" (passenger), in themselves do not make the cell malignant.

Driver mutations create different populations of cells, which provides tumor diversity. These populations or clones respond differently to treatment: some are resistant and relapse. In addition, the different sensitivity of clones to therapy can lead to a radical change in the molecular profile during treatment: even cells that are insignificant at the beginning of the population can gain an advantage and become dominant at the end of treatment, which will lead to resistance and tumor development.

Molecular Diagnostics

Driver mutations, changes in the number or structure of proteins are used as biomarkers - targets for which treatment is selected. The more targets are known, the more accurate the choice can be from potentially efficient schemes treatment.

It is not easy to separate driver mutations from the rest and determine the molecular profile of the tumor. For this, the technology of sequencing, fluorescence in situ hybridization (FISH), microsatellite analysis and immunohistochemistry is used.

Next-generation sequencing methods can identify driver mutations, including those that make a tumor sensitive to targeted therapy.

With the help of FISH technology, sections of chromosomes on which a certain gene is located are tinted. Two connected multi-colored dots are a chimeric or fused gene: when, as a result of rearrangement of chromosomes, sections of different genes are joined together. This can lead to the fact that the oncogene will fall under the influence of the regulation of another more active gene. For example, the fusion of the EML4 and ALK genes is of key importance in the case of lung cancer. The proto-oncogene ALK is activated under the influence of its rearrangement partner, which leads to uncontrolled cell division. The oncologist, given the rearrangement, may administer a drug that targets the activated ALK gene product (crizotinib).

Fluorescent in situ hybridization (FISH).

Microsatellite analysis shows the degree of damage to the DNA repair system, and immunohistochemistry - protein biomarkers located on the surface, in the cytoplasm and nuclei of tumor cells.

All of these studies are included in New Product biomedical holding "Atlas" - Solo test. With the help of such a test, the oncologist obtains information about the molecular profile of the tumor and how it affects the potential effectiveness. a wide range anticancer drugs.

Solo researchers are examining up to 450 genes and biomarkers to evaluate how a tumor might respond to more targeted cancer drugs. For some of them, biomarker analysis is dictated by the manufacturer. For others, they use data from clinical trials and recommendations from international communities of oncologists.

In addition to selecting targets for targeted therapy, molecular profiling helps to detect mutations that, on the contrary, make a tumor resistant to a particular treatment, or genetic features that are associated with increased toxicity and require an individual selection of a drug dose.

For research, biopsy material or paraffinized blocks of postoperative material are used.

Molecular profiling provides additional information about the disease, but it is not always applicable to the choice of treatment. For example, in situations where standard therapy is sufficiently effective or indicated surgery. It is possible to identify clinical situations where such a study may be most useful:

• A rare type of tumor;
• Tumors with unidentified primary focus(it is not known where the tumor that metastasized originally appeared);
• Those cases where a choice of several options for the use of targeted therapy is required;
• The possibilities of standard therapy have been exhausted and experimental treatment or inclusion of the patient in clinical trials is required.

Solo project specialists consult oncologists or patients and suggest whether a test is needed in this case.

Precision Medicine and Clinical Research

Usually in medical practice apply general strategies to treat patients with a specific diagnosis. For small cell lung cancer, one strategy is used, for non-small cell lung cancer, another. For oncological diseases, this method is not always suitable. Due to differences at the molecular level, even with the same type of tumor, patients may receive ineffective or unnecessary treatment.

With the increase in research and the invention of targeted drugs, the approach to cancer treatment has begun to change. To increase the relapse-free period and life expectancy of the patient, it is necessary to take into account the molecular profile of the tumor, the body's response to medications and chemotherapy (pharmacogenomics), to know the main biomarkers.

Precision medicine can significantly improve the prognosis of a particular patient, avoid serious side effects of oncological drugs and significantly improve the patient's quality of life. But this method also has disadvantages.

Targeted drugs are on the rise and have two major limitations: most molecularly targeted agents provide only partial suppression of signaling pathways, and many are too toxic to be used in combination.

Imagine that you are an architect of Moscow. Standing in front of you not an easy task- Solve the problem of traffic jams during rush hour by building one bridge. Molecular mechanisms can be compared with the movement of machines, and the bridge - main drug which should solve the underlying problem. It seems that several drugs (a series of bridges) targeting the major molecular disturbances may solve this problem. But the toxicity of drugs increases and can be unpredictable.

We have gained a better understanding of the molecular processes of malignant tumors, but the current methods of introducing precision oncology into clinical practice are far behind. To speed up the study of targeted therapy, scientists have developed two new approaches - Basket and Umbrella.

The essence of the Basket method is that patients with a certain biomarker are selected for the study, regardless of the location and name of the tumor. In May 2017, the FDA approved such a treatment for a biomarker called high microsatellite instability (MSI-H) or mismatch repair defect (dMMR).

Molecular disorders differ not only in different patients but also within the same tumor. Heterogeneity - a big problem in oncology, for which the Umbrella study design was developed. For the Umbrella method, patients are first selected according to the type of malignant neoplasms, and then genetic mutations are taken into account.

Such studies help not only to collect information about the effect of targeted drugs - sometimes it the only possibility for patients who do not respond to standard treatment with registered drugs.

Clinical example

We decided to give an illustrative example of what the use of advanced molecular profiling might look like.

A patient with skin melanoma and liver metastases consulted an oncologist. The doctor and the patient decided to do molecular profiling in order to get more full information about the disease. The patient was biopsied and tissue samples sent for analysis. As a result of diagnostics, several important genetic disorders were found in the tumor:

• Mutation in the BRAF gene. Indicates activation of the RAS-RAF-MEK oncogene signaling pathway, which is involved in cell differentiation and survival.
• Mutation in the NRAS gene. Indicates additional activation of the RAS-RAF-MEK signaling cascade.
• An inherited variant of the TPMT gene. Indicates the features of metabolism anticancer drug"Cisplatin".

Based on the results of clinical studies and recommendations, we can come to the following conclusions:

• The BRAF inhibitors (Vemurafenib) may be potentially effective, moreover, the presence of an NRAS mutation may serve as an additional reason for prescribing a double blockade of the signaling cascade - a combination with MEK inhibitors (Trametinib).
• Although there is no approved therapy that directly targets the NRAS oncogene, mutations in it are known to increase the likelihood of successful treatment when prescribing immunotherapy (Ipilimumab and Pembrolizumab).
• The hereditary genetic variant in the TPMT gene indicates an increased individual toxicity of Cisplatin, which requires dose adjustment when prescribing platinum-containing regimens.

Thus, the doctor gets the opportunity to navigate among options treatment based not only on the clinical parameters of the patient, but also taking into account the molecular features of the tumor.

Molecular diagnostics is not a panacea for all cancers. But this is an important tool for the oncologist, which allows you to approach the treatment of malignant tumors from a new perspective.

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