1: Outcomes and Surveillance After Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Recurrent Uterine Leiomyosarcoma

Uterine leiomyosarcoma (uLMS) is a rare but aggressive gynecologic malignancy with high rates of peritoneal recurrence and poor overall survival. Although cytoreductive surgery (CRS) for recurrent uLMS has shown encouraging results, the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) is not well-described. In this study, we evaluate feasibility and outcomes after CRS and HIPEC for recurrent uLMS with peritoneal dissemination.


Methods:

We reviewed all patients with uLMS and peritoneal recurrence who underwent CRS-HIPEC at a single tertiary academic center between March 2021 and October 2023. HIPEC was performed for 60 minutes at 42C with either gemcitabine (1000mg/m2) for patients participating in a clinical trial, or cisplatin (75-100mg/m2) as per our institutional protocol for sarcomatosis. Following CRS-HIPEC, circulating tumor DNA (ctDNA) levels were obtained at regular intervals and compared with surveillance imaging to determine concordance in detecting disease recurrence. Demographics, operative factors including peritoneal carcinomatosis index (PCI), and recurrence data were collected.


Results:

Twenty women underwent CRS-HIPEC for recurrent uLMS at median age of 57 years. 70% had tumor disruption or morcellation at index operation. CRS-HIPEC was performed at 1^st peritoneal recurrence in 50% of patients, 2^nd peritoneal recurrence in 40%, and 3^rd peritoneal recurrence or later in 10%. Median PCI was 9 and complete cytoreduction (CC-0 or 1) was achieved in all patients. Major complications (grade 3 or higher) occurred in 15% and length of stay was 8 days. All except one patient underwent adjuvant chemotherapy after HIPEC. Half of the 20 patients developed recurrence within the peritoneal cavity at median 7 months. The remaining 50% have not developed peritoneal recurrence, with median follow up 10 months. ctDNA was trended post-HIPEC in 15 patients, all of which corresponded with imaging findings: 10 exhibited rise in ctDNA with recurrence and fall with treatment response/surgery; 5 patients had persistently negative ctDNA with no imaging evidence of recurrence. To date, 1-year survival after CRS-HIPEC in this cohort is 75%.


Conclusions:

The addition of HIPEC to CRS is feasible without increased morbidity and may have potential to improve outcomes in patients with recurrent uLMS. Given the difficulty in identifying recurrent disease on imaging, ctDNA is a promising adjunct that may detect disease earlier and allow for prompt changes in treatment.