Primary tumor location as a predictor of the benefit of palliative resection for colorectal cancer with unresectable metastasis

Abstract

Background: It is still under debate that whether stage IV colorectal cancer patients with unresectable metastasis can benefit from primary tumor resection, especially for asymptomatic colorectal cancer patients. Retrospective studies have shown controversial results concerning the benefit from surgery. This retrospective study aims to evaluate whether the site of primary tumor is a predictor of palliative resection in asymptomatic stage IV colorectal cancer patients.

Methods: One hundred ninety-four patients with unresectable metastatic colorectal cancer were selected from Sun Yat-sen University Cancer Center Database in the period between January 2007 and December 2013. All information was carefully reviewed and collected, including the treatment, age, sex, carcinoembryonic antigen, site of tumor, histology, cancer antigen 199, number of liver metastases, and largest diameter of liver metastasis. The univariate and multivariate analyses were used to detect the relationship between primary tumor resection and overall survival of unresectable stage IV colorectal cancer patients.

Results: One hundred twenty-five received palliative resection, and 69 received only chemotherapy. Multivariate analysis indicated that primary tumor site was one of the independent factors (RR 0.569, P = 0.007) that influenced overall survival. For left-side colon cancer patients, primary tumor resection prolonged the median overall survival time for 8 months (palliative resection vs. no palliative resection: 22 vs. 14 months, P = 0.009); however, for right-side colon cancer patients, palliative resection showed no benefit (12 vs. 10 months, P = 0.910).

Conclusions: This study showed that left-side colon cancer patients might benefit from the primary tumor resection in terms of overall survival. This result should be further explored in a prospective study.

Keywords: Colorectal cancer; Primary tumor site; Unresectable liver metastases.

Fig. 1

Flow chart for selecting asymptomatic colorectal cancer patients with unresectable metastasis who received palliative resection of the primary tumor or chemotherapy only

Fig. 2

Kaplan–Meier curves for 5-year overall survival (OS) in different prognostic subgroups. a OS in different CA199 level groups. b OS in different CEA groups. c OS in different liver metastasis diameter groups. d OS in palliative resection and chemotherapy only groups. e OS in different histology groups. f OS in different primary tumor location groups. g OS in different number of liver metastasis groups. h Cox hazards regression analysis for 5-year OS in the entire cohort

Fig. 3

Kaplan–Meier curves for 5-year overall survival (OS) in different primary location subgroups. a Palliative resection shows no benefit in stage IV right-side colon cancer patients. b Stage IV left colorectal cancer patients show a benefit from palliative resection