Is Ulcerative Colitis Associated with Survival Among Older Persons with Colorectal Cancer in the US? A Population-Based Case-Control Study

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