Biomarker quantification by multiplexed quantum dot technology for predicting lymph node metastasis and prognosis in head and neck cancer

Purpose: To predict lymph node metastasis and prognosis in head and neck squamous cell carcinoma (HNSCC). Results: The combination of membranous E-cadherin and membranous epidermal growth factor receptor (EGFR) quantified by QD technology with age, gender, and grade had greater predictive power than any of the single biomarkers or the two combined biomarkers quantified by conventional immunohistochemistry (IHC). The predictive power of this model was validated in another independent sample set; the predictive sensitivity of this model for LNM was 87.5%, with specificity up to 97.4%, and accuracy 92.9%. Furthermore, a higher membranous E-cadherin level was significantly correlated with better overall and disease-free survival (OS, DFS; P = 0.002, 0.033, respectively), while lower cytoplasmic vimentin and membranous EGFR levels were significantly correlated with better OS (P = 0.016 and 0.021, respectively). The combined biomarkers showed a stronger prognostic value for OS and DFS than any of the single biomarkers. Methods: Multiplexed quantum dots (QDs) were used to simultaneously label E-cadherin, vimentin, and EGFR with beta-actin as an internal control. Primary tissue samples from 97 HNSCC patients, 49 with and 48 without LNM were included in the training set. Levels of membranous E-cadherin, cytoplasmic vimentin, and membranous EGFR were quantified by InForm software and correlated with clinical characteristics. Conclusions: Multiplexed subcellular QD quantification of EGFR and E-cadherin is a potential strategy for the prediction of LNM, DFS, and OS of HNSCC patients.