New guide to cancer treatment: Genetic testing
Today, many genetic changes specific to cancer cells are being discovered and many new drugs are developed by this means. In the light of genetic tests, targeted cancer treatment that protects healthy cells can be planned. In addition, the risk of developing many cancers can be estimated with the help of genetic tests and precautions can be taken before the disease develops. Although its incidence is gradually increasing in our age, cancer, which is moving away from being a ‘relentless disease’ with the treatment methods that are developing day by day, can be briefly defined as the uncontrolled division of cells. Emphasizing that the studies on the treatment of cancer continue at full speed, Medical Oncology and Internal Diseases Specialist Assoc. Dr. Mehmet Metin Şeker; He draws attention to the fact that genetics has made very important contributions to the treatment of cancer. Stating that the goal of scientists is to ‘control uncontrollably proliferating cells’, Assoc. Dr. Candy; He gave information about the developments in the field of genetics, the most important guide of cancer treatment:
UNCONTROLLED DIVISION: Cancer; It can be defined as the general name of diseases characterized by uncontrolled division and proliferation of cells in our organs or tissues. This uncontrolled proliferation in cells is caused by permanent changes in the genes that control the division, growth and survival of cells.
Personalized cancer treatment applied with molecular and genetic tests is more successful.
LIFE THREATENING: These cells, multiplying uncontrollably, can be life-threatening in many ways:
- Cancer cells multiply uncontrollably, replacing normal cells and preventing organs and tissues from performing their functions.
- Growing cancer cells put pressure on the vessels and impair the blood supply, that is, the nutrition of the organs.
- Growing cancer cells press on the nerves and cause severe pain.
- Cancer cells multiplying uncontrollably go to other organs through blood vessels and may impair their function.
- Cancer cells disrupt the functioning and normal functioning of the whole body and cells with the hormones and other substances they secrete.
New drugs in the light of genetics
TREATMENTS THAT PROMISE: Cancer cells, which cause such important effects in our body, must be quickly removed from the body or neutralized. For this, some treatment methods are applied. Today, very promising and promising developments are being recorded in the treatment of cancer. In cancer treatment; Surgical (surgery), radiotherapy (radiation) and chemotherapy (drug) treatment methods are applied successfully.
NORMAL CELLS DON’T DIE: Although all drugs used in cancer treatment are generally referred to as chemotherapy; Today, chemotherapy refers to agents that directly cause cell death. These drugs damage cell DNA or cell membrane in general and cause cell death. They show these effects in rapidly dividing cells. In other words, while killing cancer cells, they also affect normal cells such as hair, skin, nails, bone marrow and mucous cells, which have the capacity to divide rapidly, and cause very serious side effects.
Is genetic disposition a risk factor in the formation of cancer? Can it be detected by gene testing?
GENETIC SCIENCE GUIDE: In the most important goal of scientists; In order to get rid of these sometimes fatal side effects and to treat cancer more effectively, it is necessary to develop drugs that only affect cancerous cells. For this purpose, genetic features specific to cancer cells are being investigated and many genetic changes specific to cancer cells are now being discovered. In this way, many new drugs are being developed.
Genetic tests that guide cancer treatment
The most commonly used genetic tests that guide cancer treatment can be listed as follows:
- EGFR GENE: Mutations in the EGFR (Epidermal Growth Factor Receptor) gene, one of the genes responsible for cell growth, cause an increase in the gene copy number. This condition is most common in lung, head and neck, and pancreatic cancer. Today, some drugs have been developed that bind to the EFGR-1 receptor and prevent this receptor from working, that is, prevent the growth of the tumor. EGFR-1 mutation analysis should be performed before treatment in patients to whom these drugs will be used.
- HER-2 GENE: The HER-2 (Human Epidermal Growth Factor Receptor-2) gene, which is normally found on the surface of many cells; controls cell growth. However, in some cancers such as breast, stomach, lung, ovary (ovary), uterus (womb), the number of copies of the gene that determines the level of HER-2 increases and causes cancer cells to multiply much faster. Today, the increase in the HER-2 gene is detected by newly developed methods, and patients with an increase are given drugs that prevent the HER-2 receptor from working. In this way, much more successful results are obtained in cancer treatment.
- RAS GENE: In some cases, mutations occur in the RAS gene responsible for cell growth, and this gene constantly produces growth and division signals. This mutation is seen in many cancers such as large intestine (colorectal), lung, head and neck cancer. Patients carrying this mutation have resistance to some drugs. Because; Patients who are planned to use these drugs should undergo a RAS mutation test before treatment and these drugs should not be given to patients with mutations.
- ALK GENE: Anaplastic Lymphoma Kinase (ALK) gene; It is responsible for the synthesis of ALK receptors, which are especially important for the development of brain and nerve cells. However, in some lung cancer patients, the ALK gene and the EML-4 gene combine to form the EML4-ALK fusion gene. These patients; Some ALK inhibitors respond very well to drugs, thus achieving much longer life spans.
- BRAF GENE: In case of mutation in the BRAF gene, which encodes the protein named BRAF, which has an important role in cell growth; The BRAF protein is constantly active and constantly generates signals for cell growth. This causes both the development of cancer and the faster course of the existing cancer. The effect of BRAF mutation in many cancers such as large intestine (colorectal), lung and malignant melanoma has been clearly demonstrated. For this reason, drugs have been developed that prevent the BRAF protein from working.
New target in cancer therapy: P53 gene activation
Preventive treatment can be applied with early diagnosis.
The contribution of genetics to cancer is not limited to helping the right drug selection. The risk of developing many cancers can now be predicted with the help of genetic tests. Some treatments can be applied to people at high risk before the disease develops. The most recent example of this is the BRCA gene test. Since the risk of breast and ovarian cancer is quite high in people with this gene, conservative surgeries may be recommended.