Improved Survival with Experience: A 10-Year Learning Curve in Hyperthermic Intraperitoneal Chemotherapy and Cytoreductive Surgery.

Background: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an aggressive locoregional treatment for peritoneal carcinomatosis (PC). Studies demonstrate improved perioperative and oncologic outcomes at high-volume centers.

Methods: This study retrospectively analyzed all patients with PC from various malignancies who underwent attempted CRS/HIPEC at the authors' institution from 2007 to 2017. Clinicopathologic, perioperative, and oncologic outcomes of early (2007-2012) and late (2012-2017) experience were compared, and multivariate analyses for factors predictive of perioperative and oncologic outcomes were performed.

Results: The study enrolled 388 patients (157 early and 231 late). The late experience contained more appendiceal low-grade mucinous neoplasms (LGMNs; 21% vs 9%) and had a lower Peritoneal Cancer Index (PCI; 10 vs 16). Moreover, achieving a similar rate of CC-0/1 required fewer organ resections, involved shorter operations (298 vs 347 min), and had lower estimated blood loss (EBL) (400 vs 200 ml) (p < 0.05). More procedures were aborted (20% vs 3%; p < 0.01). The late experience had fewer ICU admissions (13% vs. 55%) and a lower perioperative mortality rate (0% vs 3%) (p < 0.05). In the multivariate analyses, PCI and number of organ resections were independent predictors of multiple perioperative outcomes [EBL, operating room time, intensive care unit (ICU) admission, ICU length of stay (LOS), overall LOS]. Survival was significantly longer in the late cohort (median overall survival: NR vs 31 months; progression-free survival: 22 vs 11 months; p < 0.01), even after control for tumor histology.

Conclusions: At the authors' high-volume center, with increased surgeon and institutional experience over time, perioperative and oncologic outcomes have improved significantly for patients undergoing CRS/HIPEC for PC.