Background: Cytoreductive surgery (CRS) is a technically demanding procedure, and there is considerable debate about its safe application. This study investigated the learning curve for CRS and the clinical outcomes of consecutive patients treated by a single surgeon at a single institution.Methods: We collected 251 consecutive patients who underwent CRS for peritoneal metastases by a single surgeon at Fondazione Policlinico Universitario A. Gemelli IRCCS, between January 2016 and December 2020. The learning curve was estimated using the cumulative summation analysis (CUSUM) for operative time (OT). Risk-adjusted CUSUM (RA-CUSUM) charts were developed using a composite variable (surgical failure), defined as the occurrence of at least one of the following events: major postoperative complications (Clavien–Dindo grade ≥3), blood loss ≥500 mL, incomplete cytoreduction. Three learning phases were thus derived from the RA-CUSUM analysis, and were compared in terms of perioperative outcomes.Results: CUSUM-OT showed that the operation time improved significantly after the 161^th case. RA-CUSUM analysis allowed to break the CRS learning curve into three different phases: phase 1, “the learning phase” (cases 1–99), phase 2 “the experienced phase” (cases 100–188), and phase 3, “the mastership phase” (cases 189–251). The rate of major postoperative complications decreased significantly over the three phases (p = 0.019). Operative time decreased significantly as well (p = 0.031) and was significantly shorter in phase 3 with respect to the other two phases (phase 3 vs phase 2: 420 min vs 500 min, p = 0.017; phase 3 vs phase 1: 420 min vs 503 min, p = 0.021). Blood loss consistently decreased throughout the three phases (p = 0.001). The rate of incomplete cytoreduction was significantly lower in phase 3 than in phase 2 (4.8% vs 14.6%, p = 0.043).Conclusion: The CRS failure rate stabilized after the first 99 cases, and the complete surgical proficiency was achieved after 189 cases. A standardised and mentored learning model is a safer strategy to shorten the learning process, to reduce morbidity and mortality, to improve oncologic outcomes.

Systemic chemotherapy offers poor control over peritoneal disease, maybe as a consequence of restricted drug availability within the abdominal cavity. Locoregional chemotherapy may overcome these shortcomings but its administration is limited to a few patients with confined peritoneal spread. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) emerged in the last years as a novel method of intraperitoneal drug administration. We report a meta-analysis of published studies on PIPAC safety and pathological anti-tumoral efficacy on PC from various tumor entities, with the aim of providing more evidence to support further research. This systematic review and meta-analysis were designed, conducted and reported according to the PRISMA statement. An overall pathological response rate of 43.7% was calculated on a total of 668 patients who underwent 1480 PIPAC cycles across the 20 studies. Pooled severe adverse events rate (CTCAE grade 3-4) was 10% and seven deaths across all studies were reported, of which only four were related to PIPAC. PIPAC is a safe procedure which has a relevant anti-tumoral activity on peritoneal carcinomatosis. Further studies, even in the early stage of disease, are awaited to assess the clinical benefit of PIPAC. This review may serve as a reliable basis for future research.

Introduction: At the time of diagnosis, 15–20% of gastric carcinomas are in stage T4 or T4b. Furthermore, 5–20% of patients undergoing potentially curative surgery suffer from synchronous or metachronous peritoneal metastases. To date, neither surgery nor systemic chemotherapy successfully controls peritoneal dissemination, offering a limited impact on survival. Peritoneal metastases are in fact responsible for death in around 60% of gastric cancer patients. Several Eastern studies in the past have focused on hyperthermic intraperitoneal chemotherapy (HIPEC) as a prophylactic measure in patients with serosal extension, nodal involvement, and positive peritoneal fluid cytology. Therefore, a new multimodal therapeutic strategy based on aggressive surgery plus new locoregional treatment may prolong survival in this particular clinical scenario. Methods: This study compares the efficacy of prophylactic surgery (radical gastric resection, appendectomy, resection of the round ligament of the liver, and bilateral adnexectomy) plus hybrid CO2 HIPEC system versus standard surgery in patients with T3-T4 N0-N + gastric adenocarcinoma. Patients will be randomly assigned (1:1 ratio) to the experimental arm or standard surgery. The primary endpoint is to establish the difference in disease-free survival between the groups. The secondary objective is to compare the safety and tolerability of prophylactic surgery plus HIPEC CO₂ versus standard surgery. Discussion: Considering the poor prognosis of patients with peritoneal dissemination from gastric cancer, a prophylactic strategy to prevent peritoneal metastases may be beneficial. In patients with gastric cancer at high risk of peritoneal carcinomatosis, we propose aggressive surgical treatment with radical gastrectomy, removal of organs at risk of harbouring tumour cells, and HIPEC. Trial registration: ClinicalTrials.gov NCT03917173. Registered on 16 April 2019. Protocol version: v1, March 27, 2019. Protocol number: IRFMN-GCC-7813. EudraCT number: 2019–001478-27.