Abstract
ObjectivesSurgery with curative intent is the standard treatment for stage I lung adenocarcinoma. However, disease recurrence occurs in a third of patients. Prognostic biomarkers are needed to improve postoperative management. Here, we evaluate the utility of Homeobox A9 (HOXA9) promoter methylation, alone or in combination with Blood Vessel Invasion (BVI) assessment, for prognostic stratification of stage I lung adenocarcinoma patients. Materials and methodsWe developed a Droplet Digital PCR (ddPCR) assay to measure HOXA9 promoter methylation in formalin-fixed paraffin-embedded (FFPE) biospecimens generated during routine pathology. The prognostic value of HOXA9 promoter methylation and BVI, alone and in combination, was evaluated by Kaplan-Meier survival and Cox regression analyses in a cohort of 177 stage I lung adenocarcinoma patients from the NCI-MD study. ResultsThe ddPCR assay showed linearity, sensitivity and specificity for measuring HOXA9 promoter methylation down to 0.1% methylated DNA input. The HOXA9 promoter was methylated de novo in FFPE tumors (P < 0.0001). High methylation was independently associated with worse cancer-specific survival (Hazard Ratio [HR], 3.37; P = 0.0002) and identified high-risk stage IA and IB patients. Addition of this molecular marker improved a risk model comprised of clinical and pathologic parameters (age, gender, race, stage, and smoking history; nested likelihood ratio test; P = 0.0004) and increased the C-index from 0.60 (95% CI 0.51–0.69) to 0.68 (0.60–0.76). High methylation tumors displayed high frequency of TP53 mutations and other molecular characteristics associated with aggressiveness. BVI was independently associated with poor outcome (HR, 2.62; P = 0.054). A score that combined BVI with HOXA9 promoter methylation further stratified high-risk patients (trend P = 0.0001 comparing 0, 1 or 2 positive markers). ConclusionsddPCR can be used to quantify HOXA9 promoter methylation in FFPE samples. Alone or combined with BVI in a prognostic classifier, HOXA9 promoter methylation could potentially inform the clinical management of patients with early-stage lung adenocarcinoma.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.