LRIG2 in contrast to LRIG1 predicts poor survival in early-stage squamous cell carcinoma of the uterine cervix

Background. The human leucine-rich repeats and immunoglobulin-like domains (LRIG) protein family comprises LRIG1, 2, and 3. LRIG1 negatively regulates growth factor signaling and is a proposed tumor suppressor. In early stage uterine cervical carcinoma, expression of LRIG1 is associated with good survival. Less is known about the function and expression of LRIG2; it has not been studied in cervical carcinoma, previously. Materials and methods. LRIG2 expression was studied by immunohistochemistry in 129 uterine cervical squamous cell carcinomas and 36 uterine cervical adenocarcinomas. Possible associations between LRIG2 immunoreactivity and patient survival were evaluated. Results. In early-stage squamous cell carcinoma (stages IB-IIB), high expression of LRIG2 was associated with poor survival (Kaplan-Meier, log-rank, p=0.02). The 10-year survival rate for patients with high expression of LRIG2 was 60%, compared to 87% in patients with low expression (odds ratio 0.22, 95% CI 0.07-0.64). In multivariate analysis including the previously studied tumor suppressor LRIG1 and clinical stage, LRIG2 emerged as an independent prognostic factor (odds ratio 0.22, 95% CI 0.09-0.50). For patients with both high expression of LRIG2 and low expression of LRIG1, the 10-year survival rate was only 26% compared to 66% for the remaining study population. There was no correlation between LRIG2 expression and prognosis in the limited adenocarcinoma series. Discussion and conclusion. LRIG2 appears to be a significant predictor of poor prognosis in early-stage squamous cell carcinoma of the uterine cervix. A combination of high LRIG2 expression and low LRIG1 expression identified women with a very poor prognosis.