L1CAM expression associates with poor outcome in endometrioid, but not in clear cell ovarian carcinoma

Objective. Our aim was to study the expression of L1CAM in endometrioid and clear cell ovarian carcinomas and to evaluate its correlation with clinical parameters and patient prognosis. Methods. Tissue microarray-based immunohistochemical analysis of L1CAM expression was performed in 249 endometrioid and 140 clear cell ovarian carcinomas. Concurrent endometrial carcinoma was found in 57 of these patients. Results. L1CAM expression was found in 15% of endometrioid and 23% of clear cell ovarian carcinomas. L1CAM expression was strongly associated with poor disease-specific overall survival and poor disease-free survival in endometrioid (p < 0.0001, p = 0.0005), but not in clear cell ovarian carcinomas. Significant association of L1CAM expression with poor overall survival was observed in grade 1-2 carcinomas (p < 0.0001), but not in grade 3 tumors. In endometrioid ovarian carcinomas, L1CAM expression was associated with aggressive tumor characteristics, such as higher grade and stage, and incomplete response to primary therapy. However, L1CAM expression was not an independent prognostic factor for overall or disease-free survival. Of the 57 patients with concurrent endometrial carcinoma L1CAM positivity was found in 4 cases both in the ovarian and endometrial tumors, and in 3 cases only in the endometrial tumor. All these seven patients with L1CAM positive tumors had poor outcome. Conclusions. L1CAM expression could serve as a biomarker for predicting clinical outcome and response to therapy in patients with endometrioid ovarian carcinoma, but not in clear cell carcinomas. L1CAM positivity also predicts poor outcome in patients with concurrent endometrioid ovarian and endometrial carcinomas. (C) 2017 Elsevier Inc. All rights reserved.