Clinical status and prognostic factors in Japanese patients with uterine leiomyosarcoma

Objective Uterine leiomyosarcoma (uLMS) is a rare gynecologic malignancy for which the currently available treatments do not consistently provide long-term disease control. This study aimed to reveal the current clinical status of uLMS to support future clinical trials. Methods This study enrolled patients with uLMS treated at 53 Japanese institutions from 2000 to 2012. Central pathological review (CPR) was performed. All cases were confirmed by CPR, and epidemiological features, treatment, and prognosis were analyzed statistically. Results A total of 307 patients were enrolled. A diagnosis of uLMS was confirmed in 266 patients (86.6%) of patients after CPR, of whom data for 259 were analyzed. Of these, 186 (71.8%) patients underwent complete gross resection as primary therapy. Ninety-eight patients received no additional adjuvant therapy, while docetaxel and gemcitabine was the most frequent regimen among 155 patients treated with adjuvant chemotherapy. In all cases, the median overall survival (OS) was 44.2 months. Multivariate analyses of prognostic factors in all cases identified stage III and IV disease, high serum lactate dehydrogenase level, and menopausal status as poor prognostic factors. However, in stage I cases, high serum lactate dehydrogenase level and no adjuvant treatment were identified as poor prognostic factors. The 5-year OS of patients with stage I uLMS treated with adjuvant chemotherapy was significantly better than that of those without adjuvant treatment (67.8% vs 46.7%, P = 0.0461). Conclusions Despite complete removal of the primary lesion, the clinical course of patients with uLMS was poor due to recurrence of distant metastasis. The application of a suitable biomarker and effective adjuvant chemotherapy are required to improve the prognosis of patients with uLMS.