Staged or simultaneous resection of synchronous liver metastases from colorectal cancer - a systematic review

A systematic review of the literature was undertaken to estimate the differences in length of hospital stay, morbidity, mortality and long-term survival between staged and simultaneous resection of synchronous liver metastases from colorectal cancer to determine the level of evidence for recommendations of a treatment strategy. A Pub-med search was undertaken for studies comparing patients with synchronous liver metastases, who either had a combined or staged resection of metastases. Twenty-six were considered and 16 were included based on Newcastle Ottawa Quality Assessment Scale. All studies were retrospective and had a general bias, because the staged procedure was significantly more often undertaken in patients with left-sided primary tumours and larger, more numerous and bi-lobar metastases. Analyses of primary outcomes were performed using the random effects model. For the reason of the heterogeneity of the observational studies, no odds ratios were calculated. In 11 studies, there was a tendency towards a shorter hospital stay in the synchronous resection group. Fourteen studies compared total perioperative morbidity and lower morbidity was observed in favour of a combined resection. Fifteen studies compared perioperative mortality, which seemed to be lower with the staged approach. Eleven studies compared 5-year survival, which seemed to be similar in the two groups. No randomized controlled trials were identified, and hence a meta-analysis was not performed. The evidence level is II to III with grade C recommendations. Synchronous resections can be undertaken in selected patients, provided that surgeons specialized in colorectal and hepatobiliary surgery are available.