Unit UNIT - - - NUTRITION IN CANCER Promotion: In the promotion phase, the initiated cells multiply and a new abnormal tissue with no useful function is formed. This is called “neoplasm”. Promotion takes place by a continuous exposure of the initiated cells to promoting agents. Carcinogenesis INITIATION Carcinogen Genetic change Promoted Cell Normal Cell Initiated Cell Malignant Cells Malignant Tumor Genetic change Genetic change PROMOTION PROGRESSION Fig .
Genetic mutation of a normal cell to a cancer cell Progression: During the progression phase, the abnormal tissue grows and leads to the development of a fully malignant tumor. This tumor has the capacity to invade normal tissues which may ultimately lead to the spread of cancer to other parts of the body. This is called as “metastasis.” A Cancer that has spread to other parts of the body is said to have “metastasized”. A tumor is an abnormal growth of cells that serves no purpose.
There are two types of tumors : Malignant and benign tumors A benign tumor is a non-cancerous tumor that does not spread to other parts of the body. A malignant tumor is a cancerous tumor that may spread to other parts of the body . Classification of cancer Cancers are of four main types based on the type of cell that produces it. They are carcinoma, sarcoma, lymphoma, and leukemia.
. Carcinoma is cancer of the epithelial cells that line the digestive tract, urinary bladder and the uterus. . Sarcoma is cancer of the soft tissues of the body, such as muscle, fat, nerves, tendons, blood and lymph vessels.
. Lymphoma is cancer of the lymphoid tissue. This includes the lymph nodes, bone marrow, spleen, and thymus gland. .
Leukemia develops from the white blood cells and also affects the bone marrow and spleen. The most common cancers in men are that of the lung, colon, pancreas, liver and prostrate gland. In women, cancer of the breast, ovary, cervix, uterus and colon are common. Besides this, cancer can occur in any part of the body like the thyroid gland, stomach, oral