The impact of family history of colon cancer on survival after diagnosis with colon cancer.

Background: The impact of family history of colon cancer on survival after diagnosis with colon cancer is generally unknown. It is possible that family history is indicative of a genetically inherited form of disease which may alter survival.
Methods: The Utah Population Database was used to evaluate survival after diagnosis with colon cancer among 2236 first primary colon cancer cases. This database includes detailed information about family history and is linked to the Utah Cancer Registry to obtain tumour information.
Results: Stage at diagnosis was the primary factor associated with death from all causes and from colon cancer. An older age at diagnosis, being female, and having a tumour in the ascending segment of the colon also were associated with poorer survival, although after adjusting for stage at diagnosis these associations disappeared. Having a family history of colon cancer had little impact on survival patterns although there were suggestions that men who were diagnosed at age < or = 55 were more likely to die from all causes as well as colon cancer if they had a sibling with colon cancer (hazard rate ratio [HRR] 2.50, 95% confidence interval [CI]: 1.03-6.10) relative to men > 55 without a sibling with colon cancer.
Conclusions: From these data it appears that the major factor which increases survival is being diagnosed at an early stage of disease. These data also suggest that younger men who have a sibling with colon cancer may have a different form of colon cancer which increases their risk of dying.