Ki-67 and vascular endothelial growth factor expression in uterine leiomyosarcoma

Uterine leiomyosarcomas (LMS) are rare female neoplasms of high malignant potential. The importance of different prognostic parameters in these malignancies remains controversial. The aim of the present study was to evaluate the prognostic value of Ki-67 and vascular endothelial growth factor (VEGF) in uterine LMS.

Ki-67 and VEGF expression was assessed using immunohistochemistry from paraffin-embedded tissue in 20 patients with uterine LMS.

Ki-67 was expressed in 10 of 20 cases (50%) of uterine LMS. A statistically significant positive correlation was observed between vascular space involvement and Ki-67 expression (P = 0.05). There was no statistically significant relationship between Ki-67 expression and clinical stage (P = 0.38), recurrent disease (P = 0.86), and age (P = 1.0). An expression of VEGF could be observed in 1 of 20 (5%) cases. The median disease-free survival was 13 months (range: 3-23 months). Eleven (55%) patients died of the disease with a median overall survival of 47.4 months (range: 1-227 months), resulting in a 5-year-overall survival rate of 45%. In a univariate analysis a statistically significant shortened disease-free survival in patients with Ki-67 positive tumors could be observed (P = 0.01).

Our results suggest that the significant expression of Ki-67 in uterine LMS, correlating with vascular space involvement and being associated with a shortened disease-free survival, may be an indicator of the biological aggressiveness of these rare tumors.