Efficacy and safety of anthracycline combined with alkylating agent for treatment of advanced leiomyosarcoma.

Abstract

e23558 Background: Leiomyosarcoma(LMS) accounts for 12-14% of all soft tissue sarcomas(STSs) and this STS subtype has high metastatic potential. We evaluated the efficacy and safety of epirubicin combined with temozolomide(EPI-TMZ) for treatment of advanced LMS. Methods: Oral TMZ(200 or 300 mg) was administered each day on days 1-5, and intravenous EPI(60 mg/m2) was administered on days 1-4, with even distribution over these 96h within a 21‐day cycle. After 8 cycles of intensive chemotherapy, monodrug maintenance therapy consisted of TMZ alone(dosing as in the primary therapy, most choices, stop taking medication after 1 year control), and two-drug maintenance therapy consisted of TMZ with thalidomide(only 3 patients). All patients-initiated EPI-TMZ treatment between January 2018 and January 2024. Results: We examined 31 patients who received EPI-TMZ. There were 25 females and 6 males, with average age 50.5 years old. All were unresectable patients derived from abdominal retroperitoneum, uterus, inferior vena cava, mesentery, small intestine, stomach, thighs, elbows, wrists, pancreas, nasal cavity, meantime with distant metastasis. Average Ki67 is above 40%. This was a first-line treatment in 16 patients, a second- or third-line in 13, and a fourth-line in 2. At the time of data cutoff (January 31, 2024), the median PFS was 12.6 months, 1 patient had cCR, 9 PR and 20 SD. The ORR was 32.3%(10/31) and DCR was 96.8%(30/31). The only patient who progressed after two cycles of medication had PMS2 deficiency, and studies have reported that it may have a primary resistance mechanism. Even the shortest disease control period is also 5 months, indicating this regime has significant clinical benefit. Some patients have undergone tumor reduction surgery to improve quality of life after achieving significant tumor relief. The current longest PFS is 42 months up to now and under continuous tumor control. Previous retrospective studies indicated the best mPFS was 9.2 months and the best ORR was 30.9%. 2023 ESMO declared prospective doxorubicin with trabectedin obtained mPFS of 12.19 months. The most common treatment-related adverse effects were leukopenia, neutropenia, thrombocytopenia, anemia, nausea, vomiting, fatigue, and oral mucositis. Two patients had severe febrile neutropenia, but there were no treatment-related deaths, survival data follow-up. Conclusions: EPI-TMZ is potentially effective for treatment of advanced LMS, and the adverse effects appear tolerable. EPI-TMZ may provide better outcomes than reported in previous studies of other treatments for advanced LMS, worth further prospective research.