what is cancer and chemotherapy?

Cancerous Tumor

What is cancer?

Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites through blood or lymph (the clear fluid that bathes body cells).

Tumor or tumour literally means "swelling". However, the term is now primarily used to denote abnormal growth of tissue. This growth can be either malignant or benign.Cancer spread from the primary tumor through the lymph nodes to other sites.

Origins of cancer

Cell division or cell proliferation is a physiological process that occurs in almost all tissues and under many circumstances. Normally the balance between proliferation and programmed cell death is tightly regulated to ensure the integrity of organs and tissues. Mutations in DNA that lead to cancer disrupt these orderly processes. The uncontrolled and often rapid proliferation of cells can lead to either a benign tumor or a malignant tumor (cancer). Benign tumors do not spread to other parts of the body or invade other tissues, and they are rarely a threat to life unless they extrinsically compress vital structures. Malignant tumors can invade other organs, spread to distant locations and become life-threatening.

Chemotherapy

Chemotherapy is a cancer treatment that damages cancerous cells, causing them to stop dividing.Chemotherapy also affects normally dividing cells in the body, such as those in the skin, digestive tract and blood. For this reason, a patient may become quite sick as a result of chemotherapy treatment.

This treatment commonly has adverse side effects that may include the temporary loss of the body's natural immunity to infections, hair loss, digestive upset, and a general feeling of illness. Chemotherapy may be taken by mouth or it may be put into the body by a needle inserted into a vein or muscle.

Chemotherapy may be given in many forms including: pill, injection, or by catheter. The drugs enter the bloodstream and travel through the body killing mostly cancer cells, but also some healthy cells.

Ramneek Maan Singh