Prognostic signature of protocadherin 10 methylation in curatively resected pathological stage I non-small-cell lung cancer

Although curative resection is the current treatment of choice for localized non-small-cell lung cancer (NSCLC), patients show a wide spectrum of survival even after complete resection of pathological stage I NSCLC. Thus, identifying molecular biomarkers that help to accurately select patients at high risk of relapse is an important key to improving the treatment strategy. The purpose of this study was to evaluate the prognostic signature of protocadherin 10 (PCDH10) promoter methylation in curatively resected pathological stage I NSCLC. Using methylation-specific polymerase chain reaction assays, methylation of PCDH10 promoter was assessed in cancer tissues of 109 patients who underwent curative resection of pathological stage I NSCLC. Associations between PCDH10 methylation status and disease outcome was analyzed. PCDH10 promoter methylation was detected in 46/109 patients (42.2%). Patients with methylated PCDH10 showed significantly worse recurrence-free, overall, and disease-specific survival compared with those without methylation (P < 0.0001, P = 0.0004, P = 0.0002, respectively). Multivariate Cox proportional hazard regression analysis revealed that adjusted hazard ratios of methylated PCDH10 were 5.159 for recurrence-free, 1.817 for overall, and 5.478 for disease-specific survival (P = 0.0005, P = 0.1475, P = 0.0109, respectively). The pattern of recurrence was not significantly different between patients with and without PCDH10 methylation (P = 0.5074). PCDH10 methylation is a potential biomarker that predicts a poor prognosis after curative resection of pathological stage I NSCLC. Assessment of PCDH10 methylation status might assist in patient stratification for determining an appropriate adjuvant treatment and follow-up strategy.