What are the risk factors for cancer?

A risk factor is anything that may increase a person's chance of developing a disease. A risk factor does not necessarily cause the disease, but it may make the body less resistant to it. The following risk factors and mechanisms have been proposed as contributing to the development of cancer.

Lifestyle factor

Smoking, chewing tobacco, taking gutka and pan masala, high- fat diet, lack of exercise or exposure to chemicals (cancer-causing substances) in the work place over long periods of time may be risk factors for some adult cancers.

Genetic factors

Family history, inheritance, and genetics may play an important role in some adult and childhood cancers. It is possible for cancer of varying forms to be present more than once in a family. Some gene alterations are inherited. However, this does not necessarily mean that the person will develop cancer. It indicates that chance of developing cancer increases. There are two important types of genes that, when mutated, can cause cancer-tumour suppressor genes and oncogenes.

Environmental Hazards

During the course of a day, we are continuallyexposed to things that damages our DNA. Things that damage the DNA are called carcinogens, and they include: Tobacco, Car exhausts fumes, the sun, Natural and man made radiation, asbestos, pesticides, fertilizers.

Many of these things cause damage because they react with the molecules in our cells to form free radicals. Free radicals are highly damaging molecules, and can wreck havoc on the sensitive machinery inside a cell.


Age is an important factor for cancer. Cancer can occur at any age, but the risk of developing cancer increases with age. Over 70% of all newly diagnosed cancers occur in people aged 60 years or more. This is because the longer we live, the greater the number of potentially cancer causing mutations in our DNA.


Some viruses are linked to certain types of cancer. Possibly, the virus alters a cell in some way. This does not mean that these cancers spread from person to person like an infection, and does not mean that everyone infected with these viruses will develop cancer.