Individual learning curve of cytoreductive surgery for peritoneal metastasis from colorectal cancer: A process with an impact on survival.

BACKGROUND: This study aimed to assess the learning curve (LC) of cytoredutive surgery (CRS) of peritoneal metastasis (PM) from colorectal cancer (CRC). Information about learning curves is important for developing teaching tools and well-structured training programs for the implementation of this complex procedure in new healthcare centers. The aim of this study was to estimate how many procedures an inexperienced surgeon must perform (the length of the learning period) in order to demonstrate an acceptably low rate of locoregional recurrence.

METHODS: All consecutive 74 patients with CRS for CRC performed by a novice surgeon between 2012 and 2017 in a tertiary cancer center were included. The learning curve was calculated by a cumulative sum control chart (CUSUM) graph. Two groups were formed based on the length of the learning period and were compared on overall and disease free survival.

RESULTS: The risk of locoregional recurrence decreased after surgeons had performed 19 cases, suggesting a learning period of this length. Overall survival and postoperative morbidity were not significantly different between learning and proficiency periods. Multiple linear regression analysis showed that the learning period and peritoneal cancer index are the only factors affecting disease free survival. A second learning period was observed in cases where patient care became more complex.

CONCLUSIONS: This study confirms that learning period has negative impacts on disease-free survival. An initial experience supervised in specialized centers allow to have a short learning curve for CRS for peritoneal metastases for CRC.