A prognostic role for Nm23-H1 in laryngeal carcinoma treated with postoperative radiotherapy: an introductory investigation

Postoperative RT is generally recommended for laryngeal carcinomas (LSCCs) at high risk of recurrence after surgery. There are currently no clinicopathological parameters available to predict response to such adjuvant RT in LSCC, and only a few potentially predictive biomarkers have been investigated. Nm23-H1 protein is reportedly related to the tumor cells' metastatic potential, and low Nm23-H1 expression levels in human carcinomas often correlate with a poor prognosis. The novel aim of the present preliminary study was to investigate the prognostic value of Nm23-H1 expression and subcellular localization in a series of patients given postoperative RT for LSCC. A retrospective clinicopathological investigation was conducted at an academic tertiary referral center of 28 consecutive patients given postoperative RT for LSCC. Image analysis of immunohistochemical reactions was performed to measure Nm23-H1 total and nuclear expression levels. Disease-free survival (DFS) was significantly shorter among LSCC patients with total Nm23-H1 levels < 50.0 % (p = 0.03); the mean total Nm23-H1 expression was lower in patients with recurrent disease than in patients without it (statistical trend, p = 0.07). The disease recurrence rate was significantly higher (p = 0.021) and the DFS shorter (statistical trend, p = 0.052) among LSCC patients with nuclear Nm23-H1 levels < 5.0 %. The locoregional recurrence-risk ratio in LSCC patients with nuclear Nm23-H1 levels < 5.0 % was 9.16. Nm23-H1 warrants further investigation of its potential role as a predictive biomarker with a view to providing tailored treatments after surgery, such as combinations of chemotherapy and RT instead of RT alone, in patients whose LSCCs have low or no Nm23-H1 expression.