Cancer Screening and Prevention
Introduction
- Cancer is emerging as major public health problems in India.
- It has a long latent period and needs specialized infrastructure and human resource for treatment.
- India has a high burden of preventable communicable diseases and will offer competition for the resource allocation.
The major risk factors are
- Tobacco,
- Dietary habits,
- Inadequate physical activity and alcohol consumption.
- This offers the prospect for integrated primary prevention strategies
- Major categories of cancer are
- Carcinoma
- Arises from the epithelial cells lining the internal surface of various organs (e.g. mouth, oesophagus, uterus)
- Sarcoma
- Arises from the mesodermal cells constituting the various connective tissues (e.g. fibrous tissue, bone)
- Lymphoma, myeloma and leukemia
- Arising from the cells of the bone marrow and immune system
- Carcinoma
Cancer Patterns
- There are lot of international variations in the pattern of cancer which are attributed to a number of factors such as:
- environmental factors
- food habit
- lifestyle
- genetic factor
- inadequacy in detection and reporting of cases
Environmental factors
- Tobacco
- Tobacco in various forms of usage can cause cancer of lungs, larynx, mouth, pharynx, esophagus, bladder, pancreas and probably kidney
- Cigarette smoking is now responsible for more than 1 million death each year
- Alcohol
- Excess intake of alcohol can cause esophageal and liver cancer
- Beer consumption may be associated with rectal cancer
- Alcohol contributes about 3 % of all cancer deaths
Dietary factor
- Smoked fish is related to stomach cancer
- Dietary fiber to intestinal cancer
- Beef consumption to bowel cancer
- High fat diet to breast cancer
- Food additives and contaminants have fallen under suspicion as causative agents
Occupational exposures
- These includes exposure to benzene, cadmium, arsenic, chromium, vinyl chloride, asbestos, polycyclic hydrocarbons, etc.
- The risk of occupational exposure is said to be increased if the individual also smokes cigarette
- Occupational exposure is usually reported 1-5% of human cancer
Viruses
- Hepatitis B & C - hepatocarcinoma
- HIV infection – kaposi’s carcinoma
- AIDS – non Hodgkin’s lymphoma
- Epstein – bar virus – Burkitts lymphoma and naso – pharyngial carcinoma
- Cytomegalovirus – Kaposi’s Sa
- Pappiloma virus – cervix cancer
- Human T cell leukemia virus – T cell leukemia
Parasite and lifestyle habits
- Parasite
- May be a cause of cancer
- Schistosomiasis can produce Ca of bladder
- Customs, habits and life style
- May be associated with an increased risk of cancer
- Smoking and lung cancer
- Tobacco and beetle chewing and oral cancer
Genetic factors
- Genetic influences have long been suspected
- Retinoblastoma occurs in children of the same parent
- Mongols are more likely to develop leukemia
- There is probably a complex relationship between hereditary susceptibility and environmental carcinogenic stimuli in the causation of cancer