Research in context
Evidence before this study
We searched PubMed from Jan 1, 1980, to Jan 1, 2012, for studies with the terms “second-look surgery”, “peritoneal carcinomatosis” or “peritoneal metastases”, and “colorectal cancer” or “peritoneal malignancy”. We found no randomised trials published during this time.
Only two prospective studies have been reported investigating systematic second-look surgery in patients at high risk of developing colorectal peritoneal metastases, and one retrospective study in patients after initial resection of peritoneal carcinomatosis from appendiceal malignancy. For patients at high risk of colorectal peritoneal metastases, the previous studies showed that peritoneal metastases are diagnosed during second-look surgery in 55% of patients, and that prolonged survival can be obtained with this strategy.
An updated search done on Jan 1, 2018, found no further relevant randomised trials.
Added value of this study
To our knowledge, this is the first reported phase 3 study to evaluate systematic second-look surgery plus hyperthermic intraperitoneal chemotherapy (HIPEC) in patients at high risk of colorectal peritoneal metastases.
Implications of all the available evidence
This randomised phase 3 study (PROPHYLOCHIP) does not support a disease-free survival or overall survival benefit from systematic second-look surgery plus oxaliplatin-HIPEC in patients at high risk of colorectal peritoneal metastases. However, an important point raised by this study is that this at-risk population should be recognised, and that all medical staff should be aware of this risk and systematically look for signs of colorectal peritoneal metastases during routine surveillance.