These are simple measures for early cancer detection before it destroys the organ and spreads to surrounding areas. Different cancers require different methods to detect them in the early stages. For example, breast cancer can be detected by mammography by the time it has grown to the size of a pea. It can also be detected when it is about lemon size by carefully feeling for it in a systematic way by self-breast examination. Mammograms require specialised X rays requiring expert analysis and are recommended only once a year. Hence, regular self-breast cancer check on a periodic basis is the most practical way of detecting breast cancer signs.
However, the same methods do not apply to colon cancer screening. Colon cancer starts as a small growth within the colon. There are no easy scans or physical examinations to access such a small growth in an internal organ. Most cancers have raw surfaces due to uncontrolled growth, from where they ooze blood. This can be detected in the early stages by checking to stool for minute quantity of blood by the ‘occult blood test’. Another method is by directly checking the insides of the colon for small growths called polyps. This requires a trained doctor to do colonoscopy. The advantage is that this can detect those growths which are not bleeding, unlike the occult blood test which detects only bleeding cancers. Moreover, bleeding can also occur from other non- cancerous conditions of the colon. But colonoscopy being a hospital procedure, stool occult blood test is popular as a simple initial screening test for colon cancer screening.