19: Outcomes from Selective Hyperthermic Intraperitoneal Chemotherapy for Colorectal Cancer Patients in the Post-PRODIGE 7 Era

Introduction: Despite critical reception, the PRODIGE7 trial raised questions on the utility of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with metastatic colorectal cancer (mCRC). At our center, HIPEC became selectively offered for disease progression on or inability to tolerate preoperative chemotherapy. In this study, the perioperative and oncologic outcomes of broadly offering HIPEC are compared to those managed with selective HIPEC in the post-PRODIGE7 era.


Methods: All mCRC patients going for CRS at a single center between 2010-2023 were included. After the PRODIGE7 results were shared on June 4, 2018, patients were offered HIPEC selectively when demonstrating disease progression on or inability to tolerate a full course of first line systemic chemotherapy. In cases when patients had stable disease, response, or tolerated a full course of preoperative chemotherapy, CRS without HIPEC was offered, reserving HIPEC to manage future relapse as “second line” therapy. Fisher’s exact test examined the association of treatment strategy with long-term survival ( >2Y from CRS) as well as clinicopathologic and perioperative variables. Kaplan-Meier methods estimated overall (OS) and recurrence-free survival (RFS).


Results: Of 330 cases undergoing CRS, 94 had mCRC, 52 were managed in the pre-PRODIGE7 broad CRS+HIPEC era, and 42 in the post-PRODIGE7 selective era with 12 undergoing CRS+HIPEC. No deaths occurred within 90 days, but there were 41 (78.8%) and 18 (42.9%) deaths on follow up, 43 (82.7%) and 23 (54.8%) recurrences, and 27 (51.9%) and 18 (42.9%) long-term survivors in the broad and selective eras, respectively. More patients in the broad era had prior abdominal surgery (95.7% vs 61.1%, p< 0.001), but there was no difference in median peritoneal carcinomatosis index [13 (range=0-26) vs 12 (range=2-39), p=0.752]. After a median follow up of 22.0 months, the median OS for the broad CRS+HIPEC, selective CRS, and selective CRS+HIPEC groups were 25.3 (95%CI=16.7-40.2), 33.7 (95%CI=17.4-not reached (NR)), and 36.8 months (95%CI=10.6-NR), respectively (p=0.802, Figure). Similarly, median RFS for the broad CRS+HIPEC, selective CRS, and selective CRS+HIPEC cohorts were 8.3 (95%CI=6.7-15.6), 19.9 (95%CI=5.4-NR), and 17.1 months (95%CI=3.7-32.7), respectively (p=0.655).


Conclusions: With-holding HIPEC did not lead to significantly worse perioperative or improved long-term outcomes. Long-term outcomes may improve with further follow up of selectively treated CRS+HIPEC patents.