Direct surgery with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for patients with colorectal...

Neoadjuvant chemotherapy is widely used in treatment of peritoneal metastases from colorectal cancer, but there is little scientific evidence for this approach. This study aimed to study survival in patients treated with direct surgery with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), i.e. without neoadjuvant chemotherapy.

Patients with histopathologically confirmed peritoneal metastases from colorectal cancer that underwent first-time CRS-HIPEC with complete cytoreduction (CC0 or 1) at Karolinska University Hospital 2012-2019 were included. Patients with synchronous extraperitoneal metastases were excluded if not treated before end of follow-up. Factors associated with overall survival (OS) and disease-free survival (DFS) were evaluated using the Kaplan-Meier method and Cox regression models. The multivariable models were adjusted for sex, age, synchronous/metachronous peritoneal metastases, peritoneal carcinomatosis index (PCI), extraperitoneal metastases and the pathological tumor (T) and lymph node (N) stage of the primary tumor.

In all, 131 patients underwent complete CRS-HIPEC for peritoneal metastases without neoadjuvant chemotherapy. The median OS and DFS were 40.3 months and 12.5 months, respectively, in patients treated with direct surgery. In the multivariable model, PCI≥16 was the only variable associated with decreased OS, whereas elevated PCI, metachronous development of peritoneal metastases and synchronous extraperitoneal metastases were associated with decreased DFS. Age was not associated with an impaired prognosis.

Patients who underwent direct surgery with CRS-HIPEC had a good prognosis, with a median OS of more than 3 years. The results from this study question the need of neoadjuvant chemotherapy in all patients eligible for CRS-HIPEC.