The fact that you have been on the pill intermittently is not of any relevance in relation to your risk of developing cancer. You do not say what type of cancer your relatives suffered from. Genetic factors can influence the development of some forms of cancer. For example a genetic marker has been identified for particular forms of breast cancer. If there were a strong family history of breast cancer then testing for the presence of the genetic marker could be appropriate. If on the other hand your relatives suffered from different forms of cancer then testing for genetic markers is unnecessary. One of the most important things for you to do in relation to reducing your overall risk of developing cancer is to ensure that you do not smoke. Smoking is one of the greatest risk factors for developing all forms of cancer.