Background and objectives: It is now established that liver resection is beneficial for metastases from colorectal cancer. Nevertheless, a surgical margin estimated at less than 10 mm at preoperative imaging is considered an absolute contraindication to surgery by some, and a relative contraindication by others. The true impact of the width of the margin on the prognosis is unclear.
Methods: From 1984 to 1996, 196 patients underwent curative hepatectomy for liver metastases and were studied prospectively. Surgery was to be curative (or a complete R0 resection) and mortality was to be avoided. Of these 196 patients, 136 had surgical margins of less than 10 mm. Sixty-eight percent had multiple liver metastases and 15% had extrahepatic metastatic lesions. Clinical and pathological factors were studied specifically and a multivariate analysis was carried out.
Results: Overall 5-year survival rate of these 136 patients (taking into account postoperative mortality which attained 1.5%) was 27.8% and the disease-free survival was 22.9%. The surgical margin was 0 mm in 30 cases. The sole prognostic factor was the discovery of unsuspected (resectable) extrahepatic lesions at laparotomy (P < 0.001) ; the width of the free margin had no significant effect. However, in the multivariate analysis of prognostic factors for the entire series (269 hepatectomies), three powerful parameters were identified : (1) the curative nature of resection (P = 0.0007), (2) less than 20% of liver involvement (P = 0.002), and (3) a free margin exceeding 9 mm (P = 0.02). A correlation was found between narrow margins and extensive disease (high number of metastases, bilateral sites, and extended hepatectomy). There was also a greater likelihood of microscopic satellite lesions within 10 mm around the metastases.
Conclusions: The prognostic impact of the width of the surgical margin should not be overestimated. Hepatectomy for liver metastases can procure long-term survival, even in patients with supposedly poor prognostic factors. Resection is justified as long as it is complete and the risks are minimal.