Clinical significance of pmTOR expression in endometrioid endometrial carcinoma

Objective: Endometrial adenocarcinoma has been proposed, due to frequent activation of the PI3K/AKT pathway, as a candidate neoplasm for treatment with mTOR inhibitors. However, data on the expression of mTOR in endometrial cancer are lacking. Study design: We used immunohistochemistry to evaluate the expression of pmTOR in 62 endometrial cancer surgical specimens. Results: The pmTOR protein was diffusely expressed in the cytoplasm of neoplastic epithelial cells, showing variable intensity. According to the chosen cutoff value, 34 (54.8%) out of 62 patients were scored as pmTOR-positive. pmTOR expression was significantly decreased in carcinomas with deep infiltration into the myometrium (P = .009), though it was not correlated with disease stage or lymph node metastasis. Univariate analysis showed that increased expression of pmTOR was significantly associated with better disease-free survival (P = .021). Conclusions: We show for the first time an association between pmTOR and better survival in patients with endometrial cancer. Future studies to stratify endometrial tumors by pmTOR status are needed.