Recurrence and malignancy rates in a benign colorectal neoplasm patient cohort: Results of a 5-year analysis in a managed care environment

OBJECTIVE: To estimate the apparent recurrence rates of benign neoplasms an d the development of malignant colorectal neoplasms over a 5-yr period in a high risk managed care population. METHODS: Using the CPT and ICD-9 CM codes, a cohort of subjects with benign neoplasms were identified with a colonoscopy in 1992 from a longitudinal c laims database (MarketScan). Three groups of subjects (benign neoplasms wit h polypectomy, benign neoplasms without polypectomy, and no neoplasms) were evaluated. Five-year recurrence rates of benign or new malignant colorecta l neoplasms were determined for the baseline benign neoplasms with polypect omy and no neoplasm groups. For the benign neoplasm without polypectomy, on ly rates for malignancy were evaluated. RESULTS: Of 16,293 subjects at baseline, 39.50% were diagnosed with benign and 5.50% with malignant neoplasms. The 5-yr cumulative incidence of benign neoplasms in subjects without an index neoplasm (n = 8,967) was 7.92% comp ared to the recurrence of 40.93% in subjects with a benign neoplasm and pol ypectomy (n = 4,046) at baseline (p < 0.001). The 5-yr cumulative incidence rates of malignant colorectal neoplasms in the no neoplasm (n = 8,967) and benign neoplasm groups (n = 6,438) were 1.81% and 2.55%, respectively (p < 0.005). A lower 5-yr malignancy rate was observed in benign neoplasm group with polypectomy (2.17%) compared to the benign neoplasm group without pol ypectomy (3.18%) (p < 0.05). CONCLUSION: The high recurrence rate of benign colorectal neoplasms and a h igher incidence of colorectal cancer in subjects at high risk (history of b enign colorectal neoplasm) highlight a healthcare opportunity for surveilla nce and/or interventions to reduce the morbidity associated with colorectal neoplasms. (Am J Gastroenterol 2001;96:2761-2767. (C) 2001 by Am. Coll. of Gastroenterology).