Outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal dissemination from ovarian carcinosarcoma.

Background: Ovarian carcinosarcoma (OCS) is an uncommon and aggressive malignancy, with poor response to current treatment approaches and no clear guidelines. Our aim is to evaluate the outcomes of an OCS cohort after cytoreduction with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC).

Methods: A descriptive cohort study was performed. Patients who underwent CRS/HIPEC for peritoneal dissemination from tubo-ovarian malignancies (1999-2021) were retrospectively reviewed. Patients with confirmed histopathologic diagnosis of FIGO stage III/IV OCS were included. Overall (OS) and progression-free survival (PFS) were determined with the Kaplan-Meier method.

Results: Of 267 patients with tubo-ovarian malignancies reviewed, 7.5% (20/267) had OCS. Of these, 16 underwent CRS/HIPEC, including 9 for a new diagnosis and 7 for disease recurrence. Median age at surgery was 66.5 (IQR: 54.5-74.5) years. Nine (56.2%) patients were FIGO stage IV. Median peritoneal cancer index was 22 (IQR: 14-28). Complete cytoreduction was achieved in 15/16 (93.7%) cases. HIPEC agents included carboplatin (n = 7), cisplatin+doxorubicin (n = 4), and melphalan (n = 5). Major complications occurred in 4/16 (25%), with no 90-day mortality. Median follow-up was 41.8 months. Median PFS was 11.7 (95%CI: 10.5-17.1) months. Malignant bowel obstruction occurred in 3/16 (18.7%). Median OS from CRS/HIPEC was 21.3 (95%CI: 16.3-31.6) months, not reached for newly diagnosed vs 19.7 months for recurrent patients (p = 0.23).

Conclusions: CRS/HIPEC showed promising survival and abdominal disease control with low rates of malignant obstruction in patients with advanced stage OCS. Collaborative studies with larger cohorts and longer follow-up may further elucidate the role of CRS/HIPEC in OCS.