Background: Hereditary non-polyposis colorectal cancer (HNPCC) is a dominantly inherited syndrome characterized by the development of colorectal cancer (CRC) and other carcinomas. Our aim was to evaluate tumour parameters and survival in HNPCC.
Methods: One hundred and eight Danish HNPCC patients were compared with 870 patients with sporadic colorectal cancer.
Results: The median age at CRC diagnosis was 41 years in the HNPCC group. HNPCC patients had significantly more carcinomas located to the right colon (68% against 49% in controls), more synchromous tumours (7% versus 1%), more metachronous CRC after 10 years (29% versus 5%), more localized carcinomas (62% versus 39%), and significantly higher crude cumulative 5-year survival (56% versus 30%).
Conclusions: CRC in HNPCC behaves differently compared to sporadic cases concerning age of onset, frequency of multiple lesions, and location. The metastatic tendency is less than in sporadic CRC and the survival is better.