Comparison of Survival between Patients with Hereditary Non Polyposis Colorectal Cancer (HNPCC) and Sporadic Cancer

Background: Hereditary non polyposis colorectal cancer (HNPCC) appears to have a better prognosis thansporadic cancer. In the present study we evaluated the clinical outcomes of HNPCC patients with their sporadiccolorectal cancer counterparts arising from the general population recorded in a population-based cancer registryin Iran. Patients and methods: The population studied consisted of 121 individuals including 61 patients withsporadic colorectal cancer and 60 with HNPCC who were followed-up between 2003 and 2008 in TaleghaniHospital Tehran. The subjects with HNPCC were screened according to Amsterdam criteria II and BethesdaGuidelines. Subjects with sporadic cancer had no familial history of colorectal cancer. Observed survival wasestimated using the Kaplan-Meier method and compared with the log rank test. Multivariate analysis wasperformed using Cox’ regression analysis.
Results: In the HNPCC group, 85.0% showed tumors in the colon, vs.68.9% in the sporadic cancer group. The 5-year survival was 82.5% in the HNPCC study group compared withonly 56.4% in the sporadic colorectal cancer group (P=0.044). The age distribution at diagnosis of sporadicpatients was significantly higher than HNPCC patients (mean 50.1 years vs 44.3 years P=0.008). The hazardratio for sporadic cases was 2.93 (95% CI 1.06-8.11) compared with the HNPCC group (P=0.038).
Conclusion:Our findings corroborate the results of previous studies which showed overall survival of colorectal cancer inpatients with HNPCC is better than with sporadic CRC patients.