What are Carcinogens? Explain three main types of Cancer along with main danger signals of Cancer.

Explanation

1. Physical, chemical or biological factors which cause cancer are called as carcinogens.
2. Cancer. It is uncontroled proliferation of the cells. Cancer is of three main types regarding the tissue affected.
(1) Sarcomas. Sarcomas affect the tissues derived from mesoderm such as connective tissues (bones, cartilages, tendons, adipose tissue), lymphoid tissue and muscles.
(a) Lymphomas. Lymphomas are the cancers of the lymphatic tissues. They appear in the lymphatic nodes, spleen and reticuloendothelial tissues.
(b) Lipomas. Lipomas are tumors formed in the adipose tissue.
(c) Osteoma. It is the cancer of bones.
(2) Carcinomas. Carcinomas affect the epithelial and glandular tissues. They include breast cancer, lung cancer, pancreatic cancer, stomach cancer.

(3) Leukaemias. Leukaemias result from excessive formation of WBCs in the bone marrow and lymphatic nodes, increasing their number in the blood.
Besides the above, highly malignant tumours form from primitive embryonic tissue in infants and children. These include tumours of eyes, kidney and cerebellum.
3. Possible danger signals. Cancer can be treated if detected in its early stages. Therefore, one should consult a doctor if any of the following symptoms are found-
(1) Unexplained loss of weight.
(2) Unexplained low-grade fever.
(3) Unexplained reduction or loss of appetite.
(4) Persistent indigestion or difficulty in swallowing.
(5) Persistent changes in bladder or bowel habits.
(6) A swollen or sore throat which does not heal easily.
(7) Any wound that does not heal in a normal time.
(8) A lump or hard tissue which changes or grows larger.
(9) Bleeding from any body opening.
(10) Progressive change in the colour of a wart or mole.
(11) Persistent hoarseness or cough.
(12) Excessive loss of blood in menses in women or loss of blood outside the normal date.
The above symptoms may or may not mean cancer and should not cause undue worry. In our country, the major form of cancer in men is the mouth and throat cancer and in women is uterine-cervical cancer.