Morphological Parameters of Uterine Body Leiomyosarcoma Associated with Survival Rates

Background. Uterine leiomyosarcomas are highly aggressive tumors with a poor prognosis. The main prognostic factors are the stage of the disease, the size of the primary tumor, and the grade of malignancy. It is well known that the clinical course and prognosis of uterine leiomyosarcoma do not correlate with the FNCLCC histological grade, based on assessment of the mitotic index and the presence and amount of necrosis in sarcomas. There is published data on a more unfavorable course of non-spindle cell uterine leiomyosarcomas. Aim. To evaluate the influence of pathological factors (histological subtype, mitotic index, necrosis and its type) on survival rates in uterine leiomyosarcoma. Materials and methods. The study included 58 patients who underwent radical surgery for uterine leiomyosarcoma. The following morphological parameters were evaluated on histological slides: histological subtype, mitotic index, the presence of necrosis in the tumor and its type. Further, the analysis of the influence of these morphological characteristics on the indicators of progression-free survival and overall survival was carried out. Statistical analysis was carried out using the IBM SPSS Statistics Professional 20.0 statistical software package. Long-term results are presented in the form of actuarial survival calculated by the Kaplan–Meier method. Results. Most cases of uterine leiomyosarcoma were of the spindle-cell variant (82.8 %), had a mitotic index >20 per 10 high power field (93.1 %) and large foci of necrosis (70.7 %), coagulation necrosis was more often detected (43.1 %). There was a significant difference in the median overall survival of patients with spindle-cell variant of uterine leiomyosarcoma and non-spindle-cell variants (epithelioid or myxoid): 77 months vs. 49 months (p = 0.05). There was no significant relationship between the mitotic index of the primary tumor, the size of necrosis foci in the tumor and survival rates. The presence of coagulative necrosis in the tumor was significantly associated with a deterioration in progression-free survival (9 months vs. 14 months, p = 0.05) and overall survival (51 months vs. 104 months, p = 0.05). Conclusion. The spindle-cell variant of leiomyosarcoma is associated with higher overall survival rates compared to other histological subtypes. The presence of coagulative necrosis in the tumor in comparison with other types of necrosis is an unfavorable prognostic factor associated with a decrease in both progression-free survival and overall survival.