Positive expression of pro-opiomelanocortin (POMC) is a novel independent poor prognostic marker in surgically resected non-small cell lung cancer

This study aims to investigate the expression level of pro-opiomelanocortin (POMC) and its prognostic value in non-small cell lung cancer (NSCLC). Immunohistochemical staining was used to detect the expression level of POMC. Correlations between POMC expression and clinical and pathological characteristics were evaluated with the chi-square test, and the prognostic value was determined with the Kaplan-Meier method and COX proportional hazards model, alpha < 0.05. Of the samples, 48.0 % had positive POMC expression. POMC expression was significantly related to poorly differentiated tumors, N-stage, p-stage, postoperative failure pattern, expression of vimentin, and expression of E-cadherin (P < 0.05). Multivariate analysis revealed that POMC-positive expression was an independent risk factor for disease-free survival (hazard ratio (HR) 1.988, 95 % confidence interval (CI) 1.094-3.910, P = 0.024) and overall survival (HR 1.892, 95 % CI 1.726-3.709, P = 0.036). The addition of POMC protein expression to the prognostic model using pathological stage markedly improved the prognostic potential, and the area under the ROC increased from 0.691 to 0.775. Further study revealed that patients with POMC-negative expression can benefit more from a regimen of paclitaxel and carboplatin chemotherapy than a regimen of vinorelbine and carboplatin compared to patients with POMC-positive expression. We found that POMC-positive expression is a novel, independent poor prognostic marker in patients with NSCLC. Prospective studies are needed to validate the potential prognostic value of POMC in combination with the current staging system and in consideration of adjuvant chemotherapy.