Stratifying risk factors for follow-up

INTRODUCTION: The selection of patients for individualized follow-up and adjuvant therapy after curative resection of colorectal carcinoma depends on finding reliable prognostic criteria for recurrence. However, such criteria are not universally accepted, and follow-up is often standardized for all patients without regard for each individual's level of risk of recurrence. Such a system of follow-up is not cost-effective. METHODS: A comparison of operative findings, pathologic features, and follow-up data of 1,731 cases of nonrecurrent colorectal cancer (821 colon, 910 rectum) with 357 cases of recurrent colorectal cancer (164 colon, 193 rectum) following potentially curative surgery was made, and results were analyzed to ascertain criteria for stratifying follow-up according to risk factors. RESULTS: Single-factor analysis showed that Dukes staging and tumor invasion were significantly associated with recurrence in both rectal and colon carcinoma. Tumor fixation and grading were additional significant factors in rectal cancer. Recurrence rates, time to recurrence, site of recurrence (locoregional vs. distant), and pattern of metastatic spread were not significantly affected by original tumor site. Recurrence was not significantly affected by patient age and gender. Individual surgeon performance in this series had also no significant effects on tumor recurrence. With multivariate analysis only, Dukes staging and tumor invasion into adjacent tissues were found to be independent adverse prognostic factors for recurrence. CONCLUSIONS: Dukes staging and tumor penetration into adjacent tissues are the only significant adverse prognostic factors for tumor recurrence of colonic and rectal carcinoma. Tumor grade and tumor fixation are additional adverse prognostic factors in rectal cancer. Guidelines for follow-up may be based on these factors and follow-up thus stratified according to risk of developing recurrence.