Outcomes of Stable Lung Colorectal Metastases on Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Background Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) have demonstrated benefit in patients with colorectal peritoneal metastases (CRPM). Traditionally, extraperitoneal disease is considered a contraindication to CRS/HIPEC. Stable lung metastases in patients with colorectal cancer often have an indolent course, while the presence of untreated peritoneal metastases poorly affects short-term survival. We sought to evaluate the outcomes of patients undergoing CRS/HIPEC for peritoneal disease with known stable lung metastases. Methods We retrospectively reviewed our prospectively maintained CRS/HIPEC database. In 2017, we adopted a policy of considering patients with stable lung metastases for CRS/HIPEC as part of multidisciplinary treatment. We compared the oncologic outcome and safety of CRS/HIPEC with peritoneal only (PM) against patients with peritoneal and lung metastases (PLM). Results Our database includes 570 patients with CRS/HIPEC of which 174 with CRPM that underwent CRS/HIPEC, 18 with preoperatively diagnosed peritoneal and lung metastases. The demographics of the PM and PLM group were similar with the exception of operative time that was longer in the PLM group. Median PCI of the cohort was 7, similar in both groups (p = 0.89). Three-year overall survival (OS) of PLM patients was 68%, compared to 71% in PM (p = 0.277). Three-year progression-free survival (PFS) rate was 20% in PLM and 23% in PM (p = 0.688). Conclusions Presence of stable lung metastases from colorectal cancer in patients with CRPM does not appear to affect the outcomes of CRS/HIPEC. Patients with stable lung disease should be considered for CRS/HIPEC after multidisciplinary discussion.