Prevalence and occult rates of uterine leiomyosarcoma

This study aimed to assess the prevalence and occult rates of uterine leiomyosarcoma (ULMS) in women with smooth-muscle tumors undergoing gynecological surgery. A retrospective study was performed at an academic cancer center from 2008 to 2015. Patients undergoing either hysterectomy or myomectomy via laparoscopic, abdominal, vaginal, and hysteroscopic approaches were identified with the validated pathology diagnosis of either ULMS or leiomyomas. All patients initially operated at our institute were included and reviewed. The prevalence and occult rates of ULMS were calculated and compared between different age groups. Twenty-eight patients with original ULMS were identified in 9556 gynecological surgeries. The prevalence of overall and occult ULMS in our study was 0.25% (1 in 345 patients) and 0.07% (1 in 1429 patients). The proportion of occult in all ULMSs was 25%. The prevalence rates of overall ULMS were 0.21%, 0.13%, 0.52%, 2.12%, and 6.67% in the 30 to 39, 40 to 49, 50 to 59, 60 to 69, and ≥70-year age groups, respectively. There was a significantly increased risk of ULMS after 50 years of age. The prevalence rates of occult ULMS were 0.05%, 0.08%, and 0.12% for the 30 to 39, 40 to 49, and 50 to 59 year age groups, respectively. There was no statistically significant difference among age the groups. The prevalence of ULMS was 0.41% and 0.16% for solitary and multiple tumor masses, respectively. Patients with solitary uterine tumors were at a significantly increased risk of ULMS (OR = 2.601, 95% CI = 1.108–6.141). Our retrospective data in part reflects the clinical characteristics of overall and occult ULMS and forms the basis for further prevention of occult ULMS.