Basic Informations Basic Informations

Basic Informations

What is cancer?

Cancer is a large group of diseases that begin with the uncontrolled proliferation of abnormal cells, invading nearby tissues, and/or moving beyond their usual boundaries to spread to other organs. The latter process is called metastasis and is the leading cause of death from cancer. It is also called a malignant neoplasm or tumor. Hematological cancers arise from blood or bone marrow tissue.

Cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020. Approximately 300,000 children aged 0-19 years are newly diagnosed each year. According to the 2020 data, the mortality rate for cancer in Turkey is 120 per 100,000 persons. The most common cancers in our country are breast, lung, colon, rectal, cervical, ovarian, stomach, and pancreatic cancers in women, and lung, prostate, colon, rectal, stomach, and pancreatic cancers in men.

While 30-50% of cancers are preventable, the cancer burden has been increasing worldwide, putting enormous physical, emotional, and financial pressure on individuals, families, communities, and healthcare systems. In countries with strong healthcare systems, survival rates for many types of cancer are increasing thanks to accessible early diagnosis, quality treatment, and care.

Reference: Cancer. World Health Organization.

What is oncology?

Oncology is a branch of medicine that studies the formation, causes, diagnosis, treatment, and association with genetics of existing tumors in the body. Surgery, radiotherapy, chemotherapy, hormone therapies, biological treatment methods, and targeted therapies are used alone or in combination for cancer treatment. Treatment is usually carried out by a team led by a medical oncologist. The initial treatment is generally known as first-line treatment. The treatment administered before the first-line treatment is neoadjuvant treatment. The treatment given after the first-line treatment is referred to as adjuvant treatment. Chemotherapy administered after surgical treatment is adjuvant therapy. Many experimental treatment methods have been tested in clinical studies. Cancer treatment is increasingly requiring specialized expertise.

Reference: Ministry of Health, General Directorate of Public Health. What are Cancer Treatments?

What is chemotherapy?

Chemotherapy is a type of cancer treatment that uses anticancer drugs to kill cancer cells or control their growth. It can be used alone or in combination with surgery and radiotherapy for cancer treatment.
The goal of chemotherapy in cancer treatment varies depending on the type and extent of the disease. The goals of chemotherapy are as follows:

• To treat the disease
• To control the disease by preventing the proliferation of cancer cells and slowing their spread.
• To increase the quality of life of the individual by eliminating the complaints and symptoms associated with the disease.
• To reduce disease recurrence when administered after surgery or radiotherapy
• To facilitate local treatments to be administered before surgery or radiotherapy.

While chemotherapy attempts to destroy cancer cells in the body, it also affects normal cells, leading to side effects. Potential chemotherapy-related side effects and the severity of these side effects vary depending on the drugs used and individual sensitivity. The normal cells most affected by chemotherapy drugs are the cells that proliferate most rapidly in the body. Among these cells that have the ability to proliferate rapidly are hair, blood cells that develop in the bone marrow, and cells in the digestive system. For this reason, the most undesirable effects of drugs are seen on these systems. Despite that, these cells proliferate in a short time due to their rapid proliferative and regenerative properties, eliminating these adverse effects of chemotherapy. The most common potential side effects of chemotherapy are as follows:

  • Fatigue: It is one of the most common side effects arising after treatment. Fatigue can be secondary to a broad variety of causes, such as anemia or the patient's sense of burnout. If the cause is anemia, fatigue can be eliminated by blood transfusion, and if it is secondary to psychological reasons, the help of an expert can be sought.
  • Nausea and Vomiting: Nausea and vomiting are some of the most concerning issues for patients before treatment. Nausea and vomiting secondary to chemotherapy may occur immediately after treatment or a few days after the completion of treatment. Sometimes, patients may experience nausea called anticipatory nausea before starting treatment. The complaint of nausea and vomiting is a condition that can be prevented or minimized thanks to newly developed drugs.
  • Hair Loss: Some chemotherapy drugs can cause temporary hair loss. The extent of hair loss varies depending on the type and dose of the drug used. In general, hair loss occurs 2-3 weeks after the initiation of treatment. This is a temporary process; the hair will start to regrow 3-4 weeks after the treatment is completed.
  • Decrease in Blood Values: While receiving chemotherapy, a decrease may occur in red blood cells, white blood cells, and platelets in the body. This is because the drugs suppress blood production in the bone marrow. Red blood cells are the cells that carry oxygen, and in the case of their deficiency, symptoms such as weakness, fatigue, and palpitations occur. White blood cells are involved in the body's defense against germs, and when their number decreases, the individual can get infected very easily. Platelets are responsible for blood clotting. Bleeding such as easy bruising and easy nasal and gingival bleeding can be seen in the body when their number decreases.
  • Mouth Sores: Chemotherapy drugs can sometimes cause inflammatory sores in the mouth. Patients should pay attention to their oral hygiene, avoid drinking very hot or very cold drinks, and moisten their lips with creams to minimize mouth sores. Furthermore, patients can consult their primary physician for additional treatments for oral wounds.
  • Diarrhea and Constipation: Depending on the type of chemotherapy drug used, patients may experience diarrhea or constipation. These complaints can be eliminated by diet and various simple medical therapies. However, sometimes diarrhea may be much more severe than expected and require intravenous fluid support to be given. In such a case, the primary physician should be informed.
  • Skin and Nail Changes: Some chemotherapy drugs may cause symptoms such as dark, flaking, red or dry skin, dark and brittle nails. In this case, irritants such as cologne and alcohol should be avoided. Dressing can be done with warm water and simple moisturizers can be used. These complaints are generally not severe and improve over time, but if the current symptoms are severe, the primary physician should be informed.

Reference: Ministry of Health, General Directorate of Public Health. What are Cancer Treatments? Chemotherapy.

What is radiation therapy?

Radiation therapy, also known as radiotherapy, has started to be used to treat cancer patients right after Wilhelm Conrad Roentgen's discovery of X-rays in 1895. In parallel with the advancements in physics and computer technology, modern radiation therapy methods have been developed in recent years.

Radiation therapy can be administered to cancer patients in radiation oncology clinics as a single method, or it can be administered simultaneously or sequentially with surgery and chemotherapy. Radiation therapy is administered to 52% of all cancer patients at some stage of treatment.

Radiation therapy begins with the evaluation of the patient by a radiation oncologist and the decision of using it. After the simulation process, planning and physical calculations are made with the participation of physics engineers trained in radiation. The procedure is carried out by radiation technicians under the control and supervision of expert physicians and physics engineers.

Ionizing radiation is used for radiotherapy. Its goal can be summarized as destroying cancer cells and reducing the tumor size. Ensuring to keep the normal tissues that can be affected by radiation at a minimum level is one of the main goals of planning.

Reference: Ministry of Health, General Directorate of Public Health. What are Cancer Treatments? Radiation Therapy.

What is hormone therapy?

Some cancers such as prostate and breast cancer grow and develop in the body in the presence of certain substances called hormones.

Hormone therapy is used for the treatment of breast, prostate, and reproductive system cancers by changing the amount of hormones in the body.

For example, tamoxifen reduces the amount of estrogen in the body and is used for the treatment of hormone-sensitive breast cancer.

Hormone therapy also has potential side effects, which usually disappear with the completion of treatment. Side effects depend on the drug used and vary between men and women.

Reference: Ministry of Health, General Directorate of Public Health. What are Cancer Treatments? Hormone Therapy.

What is targeted therapy?

These agents bind directly to proteins in cancer cells, thus unlike chemotherapy drugs, they only kill cancer cells without affecting healthy cells.

Examples of targeted therapy are imatinib, gefitinib, and erlotinib. Most targeted therapies are also experimental and are used in combination with other treatment modalities.

Reference: Ministry of Health, General Directorate of Public Health. What are Cancer Treatments? Targeted Therapies.