L1CAM is an independent predictor of poor survival in endometrial cancer - An analysis of The Cancer Genome Atlas (TCGA)

BACKGROUND

L1-cell adhesion molecule (L1CAM) was previously reported to carry a poor prognosis in Stage I, low-risk endometrial cancer (EC). We evaluated the role of L1CAM among all stages and histologies in ECs in The Cancer Genome Atlas (TCGA).

METHODS

Clinical information and RNA-Seq expression data were derived from TCGA uterine cancer cohort. Associations between L1CAM expression and clinical factors were tested with linear and logistic regression. Differences in survival between "high" and "low" expression groups (defined by median expression) of L1CAM were compared using Cox regression analysis, with p-values calculated via log-rank test. Kaplan-Meier curves were tested with the log-rank test.

RESULTS

Patient characteristics of 545 primary tumors with RNA-Seq gene expression data were analyzed. Median age was 64years (range 31-90). Stage I, II, III, and IV comprised 62%, 10%, 23%, and 5%, respectively. 75% were endometrioid; 21% serous. Grade 1, 2, and 3 comprised 18%, 22%, and 60%, respectively. Median follow-up was 23.0months. High L1CAM expression was associated with advanced stage (OR 3.2), high grade (OR=6.8), serous histology (OR=16.3), positive cytology (OR=3.5), positive pelvic (OR=21.8) and para-aortic lymph nodes (OR=10.3) (all p≤0.001). High L1CAM was associated with a median overall survival (OS) of 107months, versus not reached for low L1-expressing ECs (HR=3.46, CI 1.97-6.07, p<0.001). On multivariate analysis, L1CAM expression remained an independent prognostic variable in predicting OS in EC.

CONCLUSIONS

L1CAM expression is an independent predictor of poor survival in endometrial cancer, and is associated with advanced stage, high-risk endometrial cancer.