All these possible factors involved in the development of cancer not only work together but can do so in a multistage process; meaning that different factors can influence carcinogenesis at different times but still in conjunction with each other. The development of colorectal cancer is an example of such a process that combines both oncogenes and tumor suppression genes acting at different times but influencing each other and contributing to the development of cancer. And since these are genetic influences, they can " sometimes appear to 'run in families..'," or be carried by members of the same family. ("Genetic Testing for Hereditary Cancer Syndromes") in fact, there are a number of types of cancers that seem to cluster in familial groups; like breast, ovarian, and prostate cancers.

Since certain types of cancers are caused by genetic factors that can be found in familial groups, members of these groups should be aware of the possibility of developing cancer. For instance, if several members of the same family develop the same type of cancer, or a rare type of cancer, there may be inheritance factors at play....

In fact, any type of cancer related problems within multiple members of the same family may be an indication of some type of familial genetic tendency toward cancer. With this in mind an individual who feels that their familial group may have a predisposition toward cancer may want to have regular cancer screenings, particularly for familial-linked cancers. Screening for cancer should involve a series of tests directed at the type of cancer that the individual's family exhibits and usually should begin at early adulthood. But it is vitally important that those between the ages of 35-50 be screened as this is the time when individuals are most susceptible to inherited cancers. Finally, if cancer is detected the individual should immediately seek out an appropriate treatment, one that is the least invasive but most effective possible.
Works Cited

"Genetic Testing for Hereditary Cancer Syndromes." National Cancer Institute. Web. 4

June 2013. http://www.cancer.gov/cancertopics/factsheet/Risk/genetic-testing

"What are Oncogenes." News Medical. Web. 5 June 2013. http://www.news-medical.net/