Perioperative outcomes and platinum resistant recurrence in patients undergoing systematic, protocol-based, total parietal peritonectomy during interval cytoreductive surgery for advanced ovarian cancer: results of the TORPEDO study.

Objective: The TORPEDO (CTRI/2018/12/016789) is the single-arm, prospective, interventional study evaluating the role of a total parietal peritonectomy (TPP) in patients undergoing interval cytoreductive surgery (iCRS). In this manuscript, we report the perioperative outcomes and platinum resistant recurrence (PRR) in 218 patients enrolled in the study.

Methods: A TPP was performed in all patients undergoing iCRS irrespective of the residual disease extent. hyperthermic intraperitoneal chemotherapy (HIPEC) was performed as per the clinician's discretion with 75 mg/m² of cisplatin. Maintenance therapy was also used at the discretion of the treating clinicians.

Results: From 9th December 2018 to 31st July 2022 (recruitment complete), 218 patients were enrolled at 4 medical centers in India. The median surgical peritoneal cancer index was 14 and a complete gross resection was achieved in 95.8%. HIPEC was performed in 130 (59.6%) patients. The 90-day major morbidity was 17.4% and 2.7% patients died within 90 days of surgery. Adjuvant chemotherapy was delayed beyond 6 weeks in 7.3%. At a median follow-up of 19 months (95% confidence interval [CI]=15.9-35 months), 101 (46.3%) recurrences and 19 (8.7%) deaths had occurred. The median progression-free survival was 22 months (95% CI=17-35 months) and the median overall survival (OS) not reached. Platinum resistant recurrence was observed in 6.4%. The projected 3-year OS was 81.5% and in 80 patients treated before may 2020, it was 77.5%.

Conclusion: The morbidity and mortality of TPP with or without HIPEC performed during iCRS is acceptable. The incidence was of PRR is low. Early survival results are encouraging and warrant conduction of a randomized controlled trial comparing TPP with conventional surgery.