Prediction of Survival in Resected Non–Small Cell Lung Cancer Using a Protein Expression–Based Risk Model: Implications for Personalized Chemoprevention and Therapy

Abstract

Purpose Patients with resected non-small cell lung cancer (NSCLC) are at risk for recurrence of disease but we do not have tools to predict which patients are at highest risk. We set out to create a risk model incorporating both clinical data and biomarkers. Methods We assembled a comprehensive database with archival tissues and clinical follow-up from patients with NSCLC resected between 2002-2005. Twenty-one proteins identified from our preclinical studies as related to lung carcinogenesis were investigated, including pathways related to metabolism, DNA repair, inflammation and growth factors. Expression of proteins was quantified using immunohistochemistry. Immunohistochemistry was chosen because it is widely available and can be performed on formalin-fixed paraffin-embedded specimens. Cox models were fitted to estimate effects of clinical factors and biomarkers on recurrence free survival (RFS) and overall survival (OS). Results 370 patients are included in our analysis. With median follow-up of 5.3 years, median overall survival is 6.4 years. 209 cases with recurrence or death were observed. Multicovariate risk models for RFS and OS were developed including relevant biomarkers, age and stage. Increased expression of pAMPK, pmTOR, EpCAM, and CASK were significant (p<0.05) predictors for favorable RFS; insulin receptor, CXCR2, and IGF1R predicted for unfavorable RFS. Significant (p<0.05) predictors for favorable OS include pAMPK, pmTOR, and EpCAM; CXCR2 and FEN1 predicted unfavorable OS. Conclusions We have developed a comprehensive risk model predictive for recurrence in our large retrospective database, which is one of the largest reported series of resected NSCLC.

Reaching the limits of prognostication in non-small cell lung cancer: an optimized biomarker panel fails to outperform clinical parameters

“…5,9 In contrast to gene expression signatures, [11][12][13] only a few studies in non-small cell lung cancer have combined multiple protein biomarkers into one classifier, with the aims of increasing the prognostic power and of generating a robust and reproducible assay. 14,15 In studies that have applied this strategy 14,15 the proposed biomarkers were, however, not subsequently sufficiently validated to prove their value over traditional prognostic parameters. Important limitations in these lines of work included the statistical designs not adjusting for multiple testing and cutpoint optimization without validation in independent cohorts.…”

PI3‐kinase pathway biomarkers in oral cancer and tumor immune cells

“…[13][14][15] Expression of each biomarker was jointly quantified by 2 pathologists (MN and IW) in 3 cores per sample and the average was used for downstream statistical analysis. Immunohistochemical staining was performed on deparaffinized and hydrated sections.…”

“…These antibodies had been shown to be specific by Western blot analysis using nonsmall cell lung cancer cell lines and human bronchial epithelial cell line models and had been optimized for immunohistochemistry using cell line pellets fixed in formalin and embedded in paraffin, as previously reported by our group. [13][14][15] Expression of each biomarker was jointly quantified by 2 pathologists (MN and IW) in 3 cores per sample and the average was used for downstream statistical analysis. Scoring of 3 cores allowed us to account for and potentially minimize (but not completely eliminate) interpretation bias resulting from tumor heterogeneity that certainly exists when assessing protein expression levels in different regions of the tumor.…”

Recurrence of squamous cell lung carcinoma is associated with the co-presence of reactive lesions in tumor-adjacent bronchial epithelium

“…Different factors are known to be involved in the recurrence of NSCLC [3,4]. However, highly effective personalized prognostic markers, which could predict lung cancer recurrence in individual patients, have not been identified [5].…”