Question

What is cancer? Explain any four types of cancer in brief.

Answer 1

When tumours are formed due to unorganized and uncontrolled division cell, then it is called cancer.
Types of cancer: Cancer is not a single disease but a complex of many diseases. Today about 200 distinct types of cancer have been recognized. These are grouped into four main types:
(1)Carcinomas: The tumours which are made up of epithelial cells of ectodermal or endodermal origin are called carcinomas e.g. solid tumours in nerve tissues of body surfaces or their attached glands. It includes breast, skin, cervical and brain carcinomas.
(2) Sarcomas: The tumours which are made up of connective tissue cells of mesodermal origin are called sarcomas. e.g. solid tumours growing from connective tissues, bones, cartilages, and muscles. It constitutes only about 2% of human cancers.
(3) Lymphomas: Cancers in which there is is excessive production of lymphocytes and lymph nodes and spleen are called lymphomas e.g. Hodgkin's disease. It constitutes about 5% of human cancers.
(4) Leukemias: It is cancer of blood characterized by the excessive number of W.B.Cs (leukocytes) in the blood (neoplastic growth). these cells invent into bone marrow, lymph nodes and the spleen. It is more frequent in the children of age group 5 to 7 years but it occurs at any age. Acute leukemia causes death. It has no sure remedy. It constitutes about 4% of human cancers.