Is ulcerative colitis associated with survival among older persons with colorectal cancer in the US? A population-based case-control study.

Background: While ulcerative colitis (UC) is a risk factor for colorectal cancer, the association of UC with survival after colorectal cancer has not been studied in an older population.

Aims: The objective of our study was to compare the survival of colorectal cancer between persons with and without UC.

Methods: All cases of colorectal cancer (CRC) in persons 67 and older residing in a SEER catchment area and enrolled in the Medicare between 1993 and 1999 were assessed. We identified diagnosis of UC using ICD-9 codes on Medicare outpatient, office, and inpatient claims in the 2 years prior to the date of diagnosis. We used Cox proportional hazards model and Kaplan-Meier curves to compare survival between individuals with UC and CRC (UC-CRC) and sporadic CRC RESULTS: We identified 47,543 cases of colorectal cancer. Cases with UC-CRC tend to be diagnosed at earlier stages compared to sporadic CRC (42 vs. 37% local (TNM stage 1 and 2) and 11 vs. 17% distant spread (TNM stage 4), respectively; P value = 0.04). Controlling for age, gender, race and stage, diagnosis of UC did not affect the 3-year survival for CRC.

Conclusions: Colorectal cancers tend to be diagnosed at earlier stages among persons with UC, but there is no difference in 3-year survival rates for colorectal cancer among individuals with and without UC.