Receipt of colorectal testing prior to colorectal carcinoma diagnosis

Abstract

BACKGROUND: Among patients with established colorectal carcinoma, the prior use of procedures for colorectal carcinoma screening is unknown. In addition, the association of disease stage at the time of diagnosis with previous procedure use has not been studied previously at a population level. METHODS: The Surveillance, Epidemiology, and End Results tumor registry files identified 5806 patients age >or=70 years with an initial colorectal carcinoma diagnosis in 1999. Medicare claims data from 1995 through diagnosis were extracted and identified receipt of fecal occult blood testing (FOBT), sigmoidoscopy, colonoscopy, and barium enema. Time intervals were divided into >6 months prior to diagnosis and <or=6 months of diagnosis as probable screening versus diagnostic indications, respectively. RESULTS: The most commonly performed procedure was colonoscopy (63%), but most colonoscopic examinations were within 6 months of diagnosis. Only 44% of patients received >or=1 procedures >6 months before diagnosis, with FOBT the most frequent procedure (36%). Colonoscopy was performed in only 6% of patients prior to the 6-month peridiagnostic period. Compared with patients who underwent no procedures or who underwent procedures only within 6 months of diagnosis, those who underwent procedures >6 months earlier presented with earlier stages of carcinoma. CONCLUSIONS: The receipt of colorectal procedures in the interval >6 months prior to a diagnosis of colorectal carcinoma was low, suggesting the under use of screening in this population. The association of procedure use with earlier stage at presentation as well as unmeasured benefits in reducing carcinoma incidence suggest beneficial effects of this testing.