How can we detect cancers at an early stage?

Q: I am 22 years old and quite healthy. But I have one little problem. Recently, I met a few people who have cancer. I know that these peoples do not smoke, drink or eat non-vegetarian foods. I too do not drink alcohol, do not smoke and do not eat non-vegetarian food. I am now a days afraid that I too might be afflicted with cancer in near future. How can we detect cancer at an early stage itself and how to prevent cancer?

A:There are only few cancers for which screening tests are available like carcinoma cervix or carcinoma breast. Some cancers can be screened if there are high risk category with family history like ca colon, breast. You can undergo routine through health check ups with some of the hospitals, which provide such packages.