Incidence and therapeutic implications of synchronous colonic pathology in colorectal adenocarcinoma.

BACKGROUND: The presence of synchronous benign and malignant colonic pathology may influence the magnitude of surgery for colorectal adenocarcinoma. The aim of this prospective study was to quantitate the need for a more extensive surgical procedure because of synchronous pathology in colorectal cancer patients.
METHODS: Between 1984 and 1996, 235 consecutive patients were treated for colorectal adenocarcinoma. Preoperative survey of the colon in 228 patients included colonoscopy (91%) and double contrast barium enema (35.7%). Seven patients were excluded for incomplete preoperative survey because of perforating or obstructing colon carcinoma or acute ulcerative colitis.
RESULTS: One hundred four patients (45.6%) had the following synchronous colonic lesions: benign polyps (68 patients, 29.8%), diverticular disease (30, 13.1%), ulcerative colitis (10, 4.4%), synchronous adenocarcinoma (8, 3.5%), and Crohn's colitis (3, 1.3%). Pathologic examination demonstrated three additional synchronous adenocarcinomas for a total of 11 patients (4.9%). Twenty-five (11%) required more extensive surgery than dictated by the primary cancer. Of these 25 patients, 17 had a benign or premalignant condition associated with their carcinoma and 8 had a synchronous carcinoma. Seventeen patients underwent a sphincter-saving procedure. Of the remaining eight patients requiring sphincter ablation, seven were needed because of a synchronous nonmalignant lesion, rather than because of the primary tumor.
CONCLUSIONS: In our patient population, the incidence of synchronous colorectal lesions was 45.6%. Synchronous colorectal cancer occurred in 4.9%. In 11%, the presence of synchronous colorectal lesions made the surgical procedure more extensive than that dictated by the primary cancer, and in 3%, the need for a sphincter ablating procedure was dictated by a synchronous nonmalignant lesion.