CRS and HIPEC for PMP—Use of the LC-CUSUM to Determine the Number of Procedures Required to Attain a Minimal Level of Proficiency in Delivering the Combined Modality Treatment

The learning curve for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for pseudomyxoma peritonei (PMP) which peaks at 90 procedures for the surgeon may take several years to reach. The cumulative summation (CUSUM) test of the learning curve (LC-CUSUM) was used to assess the safety of the procedure (minimal level of proficiency for the surgeon) in terms of morbidity, mortality, and completeness of cytoreduction and early oncological failure before the peak of the learning curve had been reached. The limits for h0 and h1 were set based on the results of large series of such cases published before. From 2011 to 2016, 77 patients with PMP underwent CRS and HIPEC. The mean peritoneal cancer index (PCI) was 28 and 75% of the patients had a CC-0/1 resection. The grade 3–4 morbidity was 42.6% and the mortality was 5.2%. The 5-year overall survival (OS) was 62.3% and the 3-year disease-free survival (DFS) was 71%. The LC-CUSUM analysis showed that for in-hospital mortality, acceptable limits are reached after the 57th case, after the 38th case for the grade 3–4 morbidity and CC-2/3 resections both and after the 70th case for early oncological failure. The number of cases required to attain a minimal level of proficiency for each prognostic variable is different. Using the CUSUM test, surgeons can analyze their performance and determine the areas in which they need to improve before the peak of the learning curve is reached. These outcomes reflect the performance of the multidisciplinary team and not the surgeon alone.