Hyperthermic Intraperitoneal Chemotherapy in Platinum-Sensitive Recurrent Ovarian Cancer: A Randomized Trial on Survival Evaluation (HORSE; MITO-18)

PURPOSE To investigate whether the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) to secondary cytoreductive surgery (SCS) without neoadjuvant chemotherapy has a benefit on progression-free survival (PFS), as opposed to SCS alone in patients with platinum-sensitive recurrent epithelial ovarian cancer (platinum-free interval, >6 months). METHODS This was a multicenter randomized phase III study. Random assignment was performed at the time of surgery in cases with residual tumor ≤0.25 cm. HIPEC with cisplatin (CDDP) 75 mg/m 2 for 60 minutes at 41.5°C was administered at the end of surgery in the experimental arm. Both groups received postoperative platinum-based chemotherapy. The primary end point was PFS. The safety profile and postrecurrence survival (PRS) were the secondary end points. RESULTS A total of 167 patients underwent random assignment, 82 patients to SCS plus HIPEC (experimental arm) and 85 to SCS alone (control arm). The median follow-up was 83 months (IQR, 64-102). The median PFS was 23 months (95% CI, 17 to 29) in the group that underwent surgery alone and 25 months (95% CI, 18 to 32) in the group that underwent cytoreductive surgery with HIPEC. The probability of PRS at 5 years was 61.6% (95% CI, 50.8 to 72.4) in the SCS group and 75.9% (95% CI, 66.5 to 85.3) in the SCS plus HIPEC group. The incidence of postoperative adverse events of any grade was similar between the two groups. CONCLUSION The addition of HIPEC to complete or nearly complete primary SCS did not confer a benefit in terms of PFS in patients with platinum-sensitive peritoneal recurrence.