Familial colorectal cancer: a concept revisited

Objective  The family history of patients with colorectal cancer (CRC) shows an increased risk of disease although evident inherited syndromes are demonstrable in only a small percentage of patients. The purpose of this study was to identify factors that might suggest an inherited component in the transmission of CRC.
Method  The study monitored 880 consecutive patients between 1980 and 2005 treated for CRC.
Results  Familial adenomatous polyposis (FAP) was found in only one patient, and a classical mutation of hereditary nonpolyposis colon cancer was found in only two patients. The risk assessment was possible mainly because of factors such as early onset CRC, the presence of multiple primary tumours and a high risk family history. Considering these 36 more patients were suspected to be high risk and referred for further genetic testing. At least one first-degree relative with CRC was reported in 140 patients. In 49 patients, CRC was diagnosed before 50 years of age. Multiple primary tumours, colonic or extra colonic, synchronous or metachronous were found in 136 patients.
Conclusion  Our study suggests that if only patients with identified mutations are taken into consideration, then the percentage of evident hereditary colon cancer is very low, but this percentage quickly increases if we make marginal adjustments to the identifying criteria. It seems that it is the physician's clinical suspicion, more than the fulfilment of rigid criteria, which plays a fundamental role in the timely identification and a subsequent focused treatment of patients with hereditary CRC.