Loss of PTEN expression is an independent predictor of favourable survival in endometrial carcinomas.

Dysregulated signalling on the phosphatidylinositol 3' (PI3)-kinase/PTEN/Akt cascade is reported to be associated with early-stage disease and favourable prognosis in some types of malignancy, including colon, breast, ovarian, and endometrial cancers. Regarding breast cancer, it has been reported that PIK3CA mutation is associated with positive oestrogen receptor status, low stage, and favourable outcome (Kalinsky et al, 2009). In colorectal cancer, Baba et al (2011) have reported that phosphorylated Akt (p-Akt) expression is associated with PIK3CA mutation, low stage, and favourable outcome. In ovarian cancer, we and others have recently reported that PIK3CA aberration is associated with favourable survival in ovarian clear cell carcinoma (Rahman et al, 2012; Abe et al, 2013). As for endometrial cancer, we and others previously reported that PTEN mutation is associated with endometrioid histology, early stage, and favourable prognosis (Risinger et al, 1998; Minaguchi et al, 2001). The current study has aimed to investigate the prognostic significance of immunohistochemical (IHC) PTEN expression in endometrial carcinoma. Here, we demonstrate that loss of PTEN expression is a significant and independent prognostic factor for favourable survival in the disease. Our observation presents additional evidence for the prognostic significance of PTEN aberration on favourable outcome in endometrial carcinoma, further providing significant implications for the management of the disease including molecular targeted therapies.