LAPTM4B overexpression is an independent prognostic marker in ovarian carcinoma

Lysosome-associated protein transmembrane 4beta (LAPTM4B) is a member of the mammalian 4-tetratransmembrane spanning protein superfamily, which is strongly expressed in some solid malignancies. The present study investigated the correlation of LAPTM4B expression with clinicopathological features and prognosis in ovarian carcinoma. Expression of LAPTM4B was evaluated semiquantitatively by immunohistochemistry in 85 cases of ovarian carcinoma. High LAPTM4B expression was found in 54 (63.5%) of these 85 carcinomas, and was positively correlated with FIGO stage, histological subtype and residual tumor after primary surgery, but not with age and tumor grade. Patients with high LAPTM4B expression had significantly poorer overall survival (OS) and progression-free survival (PFS) (P<0.001 and P<0.001, respectively) compared to patients with low expression of LAPTM4B. On multivariate analysis, LAPTM4B expression was found to be an independent prognostic factor for OS and PFS (P=0.01 and P=0.03, respectively). These results showed that high LAPTM4B expression was associated with progression of ovarian carcinoma and correlated with unfavorable clinical outcome, suggesting that LAPTM4B may be a clinically useful prognostic indicator for ovarian carcinoma.