Outcomes of Combined Peritoneal and Local Treatment for Patients with Peritoneal and Limited Liver Metastases of Colorectal Origin: A Systematic Review and Meta-Analysis.

Background: Almost half of all colorectal cancer (CRC) patients will experience metastases at some point, and in the majority of cases, multiple organs will be involved. If the peritoneum is involved in addition to the liver, the current guideline-driven treatment options are limited. The reported overall survival ranges from 6 to 13 months for the current standard of care (systemic treatment). This study aimed to evaluate morbidity and clinical long-term outcomes from a combined local treatment of hepatic metastases with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) used to treat peritoneal metastases.
Methods: A systematic search was performed in PubMed, Embase.com, Web of Science, and Cochrane. Studies evaluating the clinicopathologic data of patients who had both peritoneal and hepatic metastases treated with CRS-HIPEC were included provided sufficient data on the primary outcomes (overall and disease-free survival) were presented. The quality of included studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS).
Results: Patients treated for peritoneal and liver metastases (PMLM group) had a pooled mean survival of 26.4 months (95% confidence interval [CI] 22.4-30.4 months), with a 3-year survival rate of 34% (95% CI 26.7-42.0%) and a 5-year survival rate of 25% (95% CI 17.3-33.8%). Surgical complications occurred more frequently for these patients than for those with peritoneal metastasis only (40% vs 22%; p = 0.0014), but the mortality and reoperation rates did not differ significantly.
Conclusion: This systematic review showed that CRS and HIPEC combined with local treatment of limited liver metastasis for selected patients is feasible, although with increased morbidity and an association with a long-term survival rate of 25%, which is unlikely to be achievable with systemic treatment only.
(© 2021. The Author(s).)