Knowing Cancer

Common Cancer

Haematological Cancer

Breast Cancer

Nasopharyngeal Cancer

Liver Cancer

What is CANCER?

Doubling Times

Causes of Cancer

For many cancers, no definite cause is known and there is no single cause. There are, however, 4 groups of aetiological factors we now know:

(1) Viral Carcinogenesis
Two DNA viruses, the hepatitis B and human papilloma viruses, are responsible for hepatocellular and cervical cancers respectively. Other common viruses directly linked to human tumours include Epstein Barr virus (EBV), Human Herpes virus, Human Immunodeficiency virus, Herpes Simplex virus.

(2) Chemical Carcinogenesis
Chemical Carcinogenesis is an important cause of cancer and can be implicated by certain lifestyles. For example, cigarette smoking and exposure to chemicals in the community or workplace such as asbestos cause lung cancer, dye causes bladder cancer and benzene causes marrow tumours.

(3) Radiation
Radiation damages cellular contents especially DNA. Radioactive isotopes, X-rays and nuclear waste can cause cancer especially some types of leukemia. The main radiation hazard is sunlight, which causes most of the skin cancers.

(4) Hormones
Different hormones and their related growth factors play a variety of roles in carcinogenesis in a number of malignancies including cancer of the breast, endometrium, prostate, ovary, thyroid, testis and bone. In these sites, the cancer results from excessive hormonal stimulation of relevant target cells.