Background: Surgical resection of primary colorectal cancer (CRC) in patients with stage IV disease at initial presentation remains controversial. Although bowel resection to manage symptoms such as bleeding, perforation, or obstruction has been advocated, management of asymptomatic patients has not been well defined. Patient-dependent factors (performance status, comorbid disease) and extent of distant metastases are among the considerations that impact on the decision to proceed with surgical management in asymptomatic stage IV CRC patients. We postulated that selected patients might benefit from elective resection of the asymptomatic primary CRC. The extent of distant metastases was objectively measured by several methods to identify potential prognostic variables that may help guide patient selection in this population.

Study design: We reviewed hospital and colorectal service databases for the years 1996 to 1999. Stage IV patients who had colorectal resections with gross residual metastatic disease were identified (n = 209). Among these 209 patients, 82 patients operated on for symptoms (obstruction, perforation, bleeding, or pain) were excluded, leaving 127 patients who underwent elective resection of their asymptomatic primary CRC. Over the same time period, 103 stage IV patients who did not undergo resection were identified. Data on patient characteristics and clinical management were collected. A radiologist performed an independent review of available CT scans to assess extent of liver disease. The chi-square test was used for analysis of categoric data and Student's t-test for continuous variables. Survival was determined by the Kaplan-Meier method and distributions compared by the log rank test. Multivariate analysis was performed using Cox regression.

Results: The resected group could be easily distinguished from the nonresected group by a higher frequency of right colon cancers (p = 0.03) and metastatic disease restricted to the liver (p = 0.02) or one other site apart from the primary tumor (p = 0.02). Resected patients had prolonged median (16 versus 9 months, p < 0.001) and 2-year (25% versus 6%, p < 0.001) survival compared with patients never resected. Univariate analysis identified three significant prognostic variables (number of distant sites involved, metastases to liver only, and volume of hepatic replacement by tumor) in the resected group. Volume of hepatic replacement was also a significant predictor of survival in Cox multivariate regression analysis (p = 0.01). Subsequent to resection of asymptomatic primary CRC, 26 patients (20%) developed postoperative complications. Median hospital stay was 6 days. Two patients (1.6%) died within 30 days of surgery.

Conclusion: Stage IV patients selected for elective palliative resection of asymptomatic primary colorectal cancers had substantial postoperative survival that was significantly better than those never having resection. Limited metastatic tumor burden and less extensive liver involvement were associated with better survival and a higher likelihood of benefit from elective bowel resection in asymptomatic patients with incurable stage IV CRC.