Pattern of Recurrences and Metastases after a Curative Resection for Primary Colorectal Cancer

ABSTRACT

PURPOSE: We aimed to verify the pattern of recurrences or metastases after a curative resection for primary colorectal cancer. METHODS: From the prospective colorectal cancer database of Asan Cancer Center, 2,810 paitents who underwent a curative resection for primary colon (1,295) or rectal (1,515) cancer between October 1995 and December 2003 were studied retrospectively. Patients were followed for more than three years or until disease recurrence. Risk factors considered were age, gender, site of primary tumor, stage, histologic differentiation, and lymphovascular invasion. The mean follow-up duration was 60+/-29 months. RESULTS: Overall recurrence occurred in 546 patients (19.4%). According to stage, the recurrence rates were 4.7% (20/423) in stage I, 10.8% (128/1,185) in stage II, and 33.1% (398/1,202) in stage III. More than 70% of the recurrences occurred within 2 years of surgery. The most common metastatic site was the liver in colon cancer and the lung in rectal cancer. In colon cancer, recurrence was more common in left than in right colon cancer (P=0.012). In rectal cancer, local recurrence was the most common in lower rectal cancer and was more common in patients receiving abdominoperineal resection than in those receiving a sphincter-preserving operation. The liver was the most common site of metastasis within 2 years postoperatively, but metastasis to lung was significantly increased after the second postoperative year. Factors such as sex, T category, N category, and location of the primary tumor were identified to be independent risk covariates for recurrence. CONCLUSIONS: Patterns of recurrences differed according to the characteristics of the primary tumor and varied with the follow-up period.