Bowel surveillance patterns after a diagnosis of colorectal cancer in Medicare beneficiaries

Background: Postoperative colon surveillance has been recommended for patients with a diagnosis of local/regional colorectal cancer. The extent to which these recommendations are followed in practice is poorly characterized. Patterns of surveillance after surgery for colorectal cancer were determined by using a large population-based database. Methods: This is a retrospective cohort study with cancer registry data linked to Medicare claims. Identified were 52,283 patients treated for local/regional colorectal cancer between 1986 and 1996, and surveillance patterns through 1998 were determined. Surveillance patterns were analyzed by using survival analysis and by computing the proportion of surviving patients who underwent procedures during 4 time periods after treatment: 2 to 14 months, 15 to 50 months, 51 to 86 months and more than 87 months. Results: Median times to first through fifth surveillance events were 20,14,15,15, and 15 months, respectively. For 17% of the cohort there was no surveillance event. Younger patients were more likely to undergo surveillance. Surveillance patterns were not affected by stage. The proportions of the cohort that underwent no surveillance during the 4 respective time periods were 54%, 52%, 60%, and 69%. The percentages of patients who underwent surveillance annually or more frequently in the latter 3 time periods, respectively, were 19%, 10%, and 5%, or 11% overall, treating the data for the 3 events as a whole. Over the period from 1986 to 1998, the proportion of patients who had no surveillance procedures gradually decreased, whereas the proportion of those who underwent procedures annually or more frequently remained relatively constant. Conclusions: During the period from 1986 to 1998 there was low utilization of postdiagnosis colon surveillance in a substantial proportion of elderly patients with a diagnosis of local/regional colorectal cancer. Over time there was a trend toward increasing receipt of any surveillance procedures. The percentages of patients undergoing surveillance annually or more frequently did not change between earlier and later periods.