Oncology: what it is and what types of cancer diseases exist

For many people, "oncology" is associated with fear, and that fear gets in the way of understanding something simple: what a diagnosis means, how a cancer disease differs from cancer, and which examinations help detect it. Below is an explanation of the basic concepts.

What oncology is and what it deals with

Oncology is a branch of medicine that studies benign and malignant tumors, the mechanisms and patterns of their origin and development, as well as methods of prevention, diagnosis and treatment. It is an entire field: oncohematology deals with tumors of the blood, oncogynecology with tumors of the female reproductive system, oncodermatology with skin tumors, and neuro-oncology with brain tumors. Cancer diseases are a vast and heterogeneous class of diseases: they are systemic and affect all organs and systems of the human body.

Is oncology cancer or not: basic concepts

In everyday speech, "oncology" is often used as a synonym for cancer, but the concepts do not coincide: oncology is a field of medicine, cancer diseases is a general term for tumors, and cancer is a malignant tumor. Normally, the body produces new cells as needed, replacing dead ones; sometimes the process malfunctions: new cells grow when they are not needed, and old cells do not die on time. The excess cells form a mass — a tumor. Benign tumors are not cancer; malignant ones are cancer: their cells grow into neighboring tissues, can break away and spread to other parts of the body, that is, metastasize.

A cancer diagnosis is often perceived as a death sentence, but far from all even malignant tumors lead to death: cancer cells and microtumors regularly arise in every person's body and die under the action of antitumor immunity.

How a cancer disease develops

Cancer is a genetic disease: it is caused by changes in genes, or mutations. Some of them a person inherits from parents, others arise during life. Normally the body gets rid of damaged cells before they become cancerous, but with age this ability declines. Risk may be increased by ultraviolet radiation, smoking, dietary patterns, age, heredity, excess weight, alcohol, certain viruses and asbestos. Why cancer arose in a particular person is usually unknown.

What types of cancer diseases exist

There are more than 100 different types of cancer, and it can start almost anywhere in the body: in organs, blood, bone marrow, the immune system. Most often it is named after the place where it started: lung cancer — in the lung, breast cancer — in the breast.

• Carcinoma is the most common type: it is formed by epithelial cells covering the internal and external surfaces of the body.
• Sarcoma is cancer that starts in the bones and soft tissues.
• Hodgkin lymphoma and non-Hodgkin lymphoma affect the lymphatic system, part of the immune system.
• Leukemias, myeloma, myelodysplastic syndrome are tumors of the blood, bone marrow and hematopoietic organs.

What cancer screening is

Cancer screening is the examination of people without symptoms: it helps find changes at an early stage. Screening programs include, for example, cervical screening, mammography and bowel cancer screening.

How a diagnosis is made and when to see a doctor

There is no single test that detects cancer: the set of examinations depends on the symptoms. The doctor asks about the medical history and about relatives with cancer diseases, performs an examination, may order blood tests and imaging examinations, and to determine the nature of the changes — a biopsy: examination of tissue, cells or fluid. If symptoms may be a sign of cancer, the doctor refers the patient for urgent examinations to a specialist at a hospital.

General signs that may be a sign of cancer: a new swelling or lump anywhere in the body, severe sweating (especially at night), a persistently elevated temperature, unusual fatigue, unexplained bruises and bleeding, unusual pain, weight loss without effort or loss of appetite.

A cancer diagnosis in itself is not a reason to call an ambulance. 103 or 112 — if bleeding starts (blood in vomit, blood from the rectum), hemoptysis appears or severe shortness of breath.

Most such symptoms are very common and caused by other conditions: their presence does not mean cancer. But it is necessary to get checked: when detected early, cancer is often easier to treat. Cancer often does not cause pain, so there is no need to wait for it; people see a doctor if symptoms do not resolve within a few weeks. Information about types of cancer and support can be sought from specialized organizations and from the treating doctor. This material is for reference and does not replace consultation with a doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer