Treatment of Isolated Peritoneal Recurrences in Patients with Colorectal Peritoneal Metastases Previously Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Colorectal peritoneal carcinomatosis (PC) is preferably treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Peritoneal recurrence of disease after treatment can occur without distant metastases, with a variety of treatment options. This study aimed to evaluate the management of isolated peritoneal recurrence after primary CRS-HIPEC. In two tertiary referral centers, all patients who underwent CRS-HIPEC for colorectal PC between 2004 and 2015 and who developed isolated peritoneal recurrences were retrospectively evaluated. Location, treatment of peritoneal recurrences, and curative or palliative treatment intent were reported, and univariable and multivariable Cox regression analysis and survival analyses were performed. Of 414 patients treated with CRS-HIPEC for colorectal PC, 106 patients (26%) developed isolated peritoneal recurrence. Forty-three patients (41%) were treated with curative intent and 63 (59%) were treated with palliative intent. Median overall survival (OS) in the patients treated with curative intent was 24.7 months (interquartile range [IQR] 12.1-61.7), compared with 7.6 months (IQR 2.5-15.9) in those treated with palliative intent (p < 0.001). In the patients treated with curative CRS (n = 17) and curative second CRS-HIPEC (n = 15), median OS was 51.7 months (IQR 14.4-NA) and 29.0 months (IQR 18.1-63.0), respectively (p = 0.620). The latter group had a significantly higher region count (median 1 vs. 3; p < 0.001). Postoperative complications and hospital stay did not significantly differ between first and second CRS-HIPEC. After CRS-HIPEC for colorectal cancer, approximately one of four patients will develop isolated peritoneal recurrences. A substantial amount of these patients can be safely treated with curative intent yielding long-term survival.