About Familial Bowel Cancer
Most colorectal cancers arise sporadically, that is out of the blue and with no strong family history. In these particular cases this is due to a gene defect, or multiple gene defects, that are not inherited and therefore not passed on from generation to generation. It is not known what causes these gene defects to arise but certainly an environmental factor that can be dietary or other chemical agent is the most likely culprit. However in a minority of patients that develop colorectal cancer, this is due to a gene defect that can be passed on from one generation to the next. Families that give a strong history of colorectal cancer occurring throughout successive generations are likely to possess this defective gene and under these circumstances genetic testing is certainly advisable. If an individual is found to be positive for one of these genes then the rest of the family needs to be tested and counselled appropriately.