Very few things happen in life, which are as overwhelming and as devastating as the diagnosis of cancer. The very first question invariably asked by the patient is, “Why me? What did I do to deserve this?”
Every year, more than 1 million people are diagnosed of cancer in India, and there are around 3 million cancer survivors at any given point in time. There are several risk factors associated with the development of cancer. If a person has got one or more of these risk factors, his likelihood of developing cancer is more than the person without them. However, cancer is a result of a complex interaction between the individual and the environment he lives in. Having a risk factor doesn’t mean that the person will surely develop cancer, and many patients of cancer do not have any known risk factors.
Most of the risk factors are lifestyle related and can be reduced by adapting to a healthier lifestyle. Risk factors that cannot be changed are age, sex and a family history of cancer.
- Advancing age: Cancer is more common in individuals of more than 50-55 years of age. However it can affect any age group, including infants.
- Tobacco use: Tobacco use is the single largest preventable cause of cancer and cancer related death. 40 per cent of all cancers and more than 85 per cent of lung cancers are tobacco related. Tobacco is also a major cause of cancers of the mouth, voice box, food pipe, stomach, kidney, pancreas, bladder and leukemia. Non-smokers exposed to environmental tobacco smoke are at an increased risk of cancer. Smokeless tobacco like chewing, snuff, etc., cause cancer of the mouth and oesophagus. Quitting smoking reduces the risk of cancer.
- Ionizing radiation / UV radiation: This can increase the risk of cancer. Electromagnetic radiation used in mobile phones is possibly carcinogenic. It is advisable to reduce its usage, or use hands free and speaker options.
- Chemical carcinogens: People who are exposed to certain chemicals like benzene, asbestos, vinyl chloride, etc., in the workplace, are at a higher risk of cancer.
- Viruses and bacteria: Certain viral and bacterial infections can increase cancer risk.
- Human papillomaviruses (HPVs): HPV infection is the main cause of cervical cancer. It may also be a risk factor for other types of cancers.
- Hepatitis B and Hepatitis C viruses: Liver cancer can develop after many years of infection with hepatitis B or hepatitis C.
- Human immunodeficiency virus (HIV): HIV is the virus that causes AIDS. People who have HIV infection are at a greater risk of cancer, such as lymphoma and a rare cancer called Kaposi sarcoma.
- Helicobacter pylori: This bacterium can cause stomach ulcers. It can also cause stomach cancer and lymphoma in the stomach lining.
Prevention of these viral infections is the best way to prevent associated cancers. Practice of safe sex, screening of blood for contamination, use of vaccines (against hepatitis B virus and human papillomavirus) can prevent these cancers.
- Hormones: Prolonged use of hormone replacement therapy in post- menopausal women can lead to increased risk of breast cancer.
- Family history of cancer: History of cancer in first degree relatives (parents, brother, sister) increases the risk of cancer in an individual. Breast cancer susceptibility gene mutations (BRCA1 and BRCA2) can lead to very high (60-80 per cent) risk of developing breast cancer or ovarian cancer in the affected individual and can also run in families. The features that suggest familial cancer are:
- Cancer at an early age
- Two or more relatives with the same cancer
- Multiple cancers in the same individual
- Alcohol: Long term alcohol consumption may increase risk of cancers of mouth, throat, oesophagus, liver and breast. Smoking along with alcohol further increases the risk.
- Poor diet, lack of physical activity, being overweight: These factors may increase the risk of cancers of colon, uterus, prostate and breast. A healthy diet high in fibre, vitamins, minerals, exercise, and optimal body weight help in reducing the risk.
Many of these risk factors can be avoided. If you think you have an increased risk of getting cancer, discuss with your doctor for reducing the risk. For a risk factor that cannot be changed, he might suggest an aggressive surveillance and screening for early detection and cure.