Management of stage I occult uterine leiomyosarcoma: effects of morcellation, second-look surgery, and adjuvant treatments on survival.

Background: This study sought to analyze the risk of morcellation in patients who underwent surgery for leiomyoma and had a final pathological diagnosis of uterine leiomyosarcoma (uLMS), and evaluate the survival benefits of second-look surgery and chemotherapy in patients with stage I occult uLMS. Methods: A retrospective analysis of the data of patients with occult stage I uLMS in the Peking Union Medical College Hospital database between 2005 and 2018 was conducted. The recurrence rate and progression-free survival (PFS) were compared between patients who underwent morcellation or not. Univariate analyses were used to evaluate the survival impact of lymphadenectomy, oophorectomy and adjuvant chemotherapy. Propensity-score matching methods were used to evaluate the effect of morcellation on recurrence while adjusting for baseline confounding factors using Poisson regression fitted by inverse probability weighting (IPW) estimation. Results: A total of 96 patients with uLMS were identified among the 31,679 surgeries performed for leiomyomas (incidence: 0.303%). Hysterectomy was performed in 60 patients, and myomectomy was performed in 36 patients (power morcellation n=20). There were 36 (37.5%) patients underwent lymphadenectomy, and 76 (79.2%) patients underwent oophorectomy. Among them, 47 (52.8%) patients received postoperative chemotherapy. The median follow-up time was 40 months (range, 12-146 months), and there were 43 cases of recurrence (44.7%). No differences in recurrence were found between the hysterectomy and myomectomy groups (hazard ratio 0.839, P=0.701). The 3-year PFS rates for patients with hysterectomy, power morcellation, and non-power morcellation were 64.3%, 53.8%, and 59.8%, respectively. No survival differences were identified between patients with/without lymphadenectomy [PFS: P=0.513; overall survival (OS): P=0.413] and oophorectomy (PFS: P=0.162; OS: P=0.815). Postoperative chemotherapy was associated with better PFS (P=0.047), but not OS (P=0.36). Conclusions: No survival differences were observed among the initial surgical procedures in stage I patients with occult uLMS. No survival benefits were observed between lymphadenectomy and oophorectomy patients. Compared to continued observation, postoperative chemotherapy was associated with improved PFS, but not OS.