Cancer is not a new disease. The word cancer is derived from karkinos, Greek for crab. Worldwide, 13 per cent of deaths can be directly or indirectly attributed to cancer. The apparent increase in numbers is due to the population explosion, increased longevity, improved diagnoses and better communication. Everyone knows someone who has cancer.

In developed countries, cancer is picked up early because of awareness and subsidised screening programmes. Treatment is effective and a large number of people survive. This is not the case in our country. Here, cancer is diagnosed late because of fear, ignorance or lack of facilities. In the coming decade, 70 per cent of cancer deaths worldwide will occur in developing countries.

There are more than 100 types of cancer with different symptoms. The patient may notice the presence of a swelling. The abdomen may get swollen. Lymph nodes may enlarge and appear in various parts of the body. The diagnosis is difficult when the symptoms are vague, like chronic fatigue, weight loss, hoarseness of the voice, difficulty in swallowing or breathing or non-specific muscle and joint pains.

All cancers are due to mutations in the genes and damage in the chromosomal structure of the body. These alterations in cell structure allow them to grow rapidly with no regulation. Normally, tumour suppressor genes prevent this abnormal growth. Genetic damage is corrected by inherent repair genes. Cancer sets in when these genes are either damaged or dysfunctional.

Genes may be defective from birth. If this is balanced by a normal gene, the person may not get cancer. In others, the abnormal gene may cause cells to grow at a certain age. The cancer then manifests itself. Many members of a family may carry the gene and eventually develop cancer. If the defect is in a particular gene they will all have the same type of cancer, such as breast cancer. If it is in the tumour suppressor gene or repair genes, the affected members will have different kinds of cancer. Not all people who have a defective gene will develop cancer. The environment and lifestyle also play a part in it.

Genetic mutations may occur as a result of chronic inflammation or viral infections (Human Papilloma Virus, Hepatitis B virus, Epstein-Barr virus.). It can occur as a result of imbalanced hormones, excessive exposure to ultraviolet light or prolonged contact with or intake of cancer causing chemicals.

Although cancer can occur at any age, the risk increases with age and the incidence rises sharply after 65. Other risk factors are unhealthy habits such as tobacco (chewing, snuff, smoking) use, being exposed to second-hand cigarette smoke and having more than two drinks a day (in men; one in women). Consumption of food additives such as sodium monoglutamate, preservatives and some food colours is dangerous. Exposure to chemicals like benzene or working with asbestos are risk factors.

Cancer is diagnosed by a comprehensive physical examination, followed by appropriate blood tests, X-rays, scans and biopsies of suspicious lesions. There is no universal test for cancer.

Accurate and early diagnosis usually results in successful treatment. The tumour may be surgically removed. This may be followed by radiation and chemotherapy. Pain, infection and other complications may require adjuvant palliative care. Some cancers require stem cell treatment. In others, biological therapy is used whereby the body is taught to recognise and attack cancer cells.

Alternative medicine has not been proven to have an effective cure for cancer. But yoga, hypnosis, acupuncture, acupressure or massage can help the patient cope with it.

Dr Gita Mathai is a paediatrician with a family practice at Vellore. Questions on health issues may be emailed to her at yourhealthgm@yahoo.co.in