A new scoring system to classify patients with colorectal liver metastases: proposal of criteria to select candidates for hepatic resection.

Background: Although many studies have reported the beneficial effects of hepatic resection for colorectal liver metastases on survival rates, it is still difficult to preoperatively select good candidates for hepatectomy.

Methods: Fifteen clinicopathological features, which were recognized only before or during surgery, were selected retrospectively in 81 consecutive patients in one hospital (Group I). These features were entered into a multivariate analysis to determine independent and significant variables affecting long-term prognosis after hepatectomy. Using selected variables, we created a scoring formula to classify patients with colorectal liver metastases to select good candidates for hepatic resection. The usefulness of the new scoring system was examined in a series of 70 patients from another hospital (Group II).

Results: Multivariate analysis, i.e., Cox regression analysis, showed that serosa invasion of primary cancers (P = 0.0720, risk ratio = 2.238); local lymph node metastases of primary cancers, i.e., Dukes' C (P = 0.0976, risk ratio = 2.311); multiple nodules of hepatic metastases (P = 0.0461, risk ratio = 2.365); nodules of hepatic metastases greater than 5 cm in diameter (P =0.0030, risk ratio = 4.277); and resectable extrahepatic distant metastases (P = 0.0080, risk ratio = 4.038) were significant and independent prognostic factors for poor survival after hepatectomy. Using these five variables, we created a new scoring formula to classify patients with colorectal liver metastases. Finally, our new scoring system classified patients in Group II and Group I well, according to long-term outcomes after hepatic resection.

Conclusions: Our new scoring system to classify patients with colorectal liver metastases is simple and useful in the preoperative selection of good candidates for hepatic resection. Although many studies have reported the beneficial effects of hepatic resection for colorectal liver metastases on survival rates, it is still difficult to preoperatively select good candidates for hepatectomy.