Does resection of small liver metastases from colorectal cancer improve survival of patients?

Because the size of metastases greatly affects their detection, we retrospectively investigated the influence of the size of liver metastases on survival after hepatic surgery. The subject group study consisted of 77 patients who underwent liver surgery for metastases from colorectal cancer. The survival rate after hepatic surgery was analysed using multivariate Cox's proportional hazards model with the following variables: (1) size of dominant metastases (Small: < 3 cm; Medium: > or = 3 cm and < 6 cm; Large: > or = 6 cm); (2) synchronous versus metachronous resection; (3) solitary versus multiple metastases. The size of dominant metastases (p = 0.035) and synchronous versus metachronous resection (p = 0.0009) were independently associated with survival after liver resection. No association was found, however, for solitary versus multiple metastases. The survival of the Large group was much poorer than that of the Small group (p = 0.0168) and that of the Medium group (p = 0.0205), with statistically significant differences. No statistically significant difference was seen between the Small and the Medium groups (p = 0.7963). This study showed that long-term survival following resection of metastases was much poorer when metastases were 6 cm or greater in diameter. With regard to metastases less than 6 cm in diameter, resection of the smallest of these (less than 3 cm) did not appear to improve survival.