Insulin‐like growth factor II messenger RNA ‐binding protein‐3 is an independent prognostic factor in uterine leiomyosarcoma

Aims The aim of this study was to identify the prognostic factors of uterine leiomyosarcoma ( ULMS ). Methods and results We reviewed 60 cases of surgically resected ULMS s and investigated conventional clinicopathological factors, together with the expression of insulin‐like growth factor II messenger RNA ‐binding protein‐3 ( IMP 3), hormone receptors and cell cycle regulatory markers by immunohistochemistry. Mediator complex subunit 12 ( MED 12 ) mutation analysis was also performed. Univariate analyses revealed that advanced stage ( P < 0.0001), older age ( P = 0.0244) and IMP 3 expression ( P = 0.0011) were significant predictors of a poor outcome. Multivariate analysis revealed advanced stage ( P < 0.0001) and IMP 3 ( P = 0.0373) as independent predictors of a poor prognosis. Expressions of cell cycle markers and hormone receptors, and MED 12 mutations (12% in ULMS s) were not identified as prognostic markers in this study. Conclusions IMP 3 expression in ULMS could be a marker of a poor prognosis.