Personalized Medicine and Imaging An Aggressive Subtype of Stage I Lung Adenocarcinoma with Molecular and Prognostic Characteristics Typical of Advanced Lung Cancers Elisa Dama 1,2 , Valentina Melocchi 1 , Fabio Dezi 1 , Stefania Pirroni 1 , Rose Mary Carletti 1,2 , Daniela Brambilla 3 , Giovanni Bertalot 1 , Monica Casiraghi 3 , Patrick Maisonneuve 4 , Massimo Barberis 5 , Giuseppe Viale 5,6 , Manuela Vecchi 1,2 , Lorenzo Spaggiari 3,6 , Fabrizio Bianchi 1,7 , and Pier Paolo Di Fiore 1,2,6 Abstract Purpose: The National Lung Cancer Screening Trial has con- firmed that lung cancer mortality can be reduced if tumors are diagnosed early, that is, at stage I. However, a substantial fraction of stage I lung cancer patients still develop metastatic disease within 5 years from surgery. Prognostic biomarkers are therefore needed to identify patients at risk of an adverse outcome, who might benefit from multimodality treatment. Experimental Design: We extensively validated a 10-gene prognostic signature in a cohort of 507 lung adenocarcinoma patients using formalin-fixed paraffin-embedded samples. Fur- thermore, we performed an integrated analysis of gene expression, methylation, somatic mutations, copy number variations, and proteomic profiles on an independent cohort of 468 patients from The Cancer Genome Atlas (TCGA). Results: Stage I lung cancer patients (N ¼ 351) identified as high- risk by the 10-gene signature displayed a 4-fold increased risk of death [HR ¼ 3.98; 95% confidence interval (CI), 1.73–9.14], with a 3-year overall survival of 84.2% (95% CI, 78.7–89.7) compared with 95.6% (92.4–98.8) in low-risk patients. The analysis of TCGA cohort revealed that the 10-gene signature identifies a subgroup of stage I lung adenocarcinomas displaying distinct molecular characteristics and associated with aggressive behavior and poor outcome. Conclusions: We validated a 10-gene prognostic signature capable of identifying a molecular subtype of stage I lung ade- nocarcinoma with characteristics remarkably similar to those of advanced lung cancer. We propose that our signature might aid the identification of stage I patients who would benefit from multimodality treatment. Clin Cancer Res; 23(1); 62–72. Ó2016 AACR. Introduction Lung cancer is the primary cause of cancer-related death world- wide (1). Survival of patients with non–small cell lung cancer (NSCLC), the predominant type of lung cancer, accounting for approximately 85% of all lung cancer cases, largely depends on tumor stage at diagnosis; only approximately 15% of all patients with advanced disease (stage III–IV) are alive after 5 years, while survival increases to approximately 60% in patients diagnosed with stage I disease (1). Thus, efforts have been devoted to the development of strategies for early lung cancer detection. In particular, annual low-dose CT (LDCT) screening in high-risk individuals (>55 years and smokers, >30 pack/year) was shown to be effective in diagnostic anticipation, resulting in a reduction in mortality (2–5). As our ability to detect NSCLC in its early stage improves, the issue of the clinical management of stage I patients is becoming increasingly relevant. As of today, a sizable fraction of stage I NSCLC patients (up to 40%) develops disease recurrence within 5 years from surgery. Stage I NSCLC is treated preferentially by surgery, as the benefit of adjuvant chemotherapy in these patients remains controversial (6–9). However, prognostic biomarkers could change this scenario by allowing the stratification of stage I patients according to risk of disease recurrence and the selection of those patients who might benefit from multimodality treatment. We previously described a 10-gene signature able to predict prognosis of patients with stage I lung adenocarcinoma, the major subtype of NSCLC (10). Subsequently, other prognostic gene 1 Molecular Medicine Program, European Institute of Oncology, Milan, Italy. 2 IFOM, The FIRC Institute for Molecular Oncology Foundation, Milan, Italy. 3 Division of Thoracic Surgery, European Institute of Oncology, Milan, Italy. 4 Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy. 5 Division of Pathology, European Institute of Oncology, Milan, Italy. 6 DIPO, Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy. 7 Institute for Stem-cell Biology, Regenerative Medicine and Inno- vative Therapies (ISBReMIT), Casa Sollievo della Sofferenza - IRCCS, San Giovanni Rotondo, Italy. Note: Supplementary data for this article are available at Clinical Cancer Research Online (http://clincancerres.aacrjournals.org/). E. Dama and V. Melocchi contributed equally to this article. L. Spaggiari, F. Bianchi, and P.P. Di Fiore share last authorship. Corresponding Authors: Fabrizio Bianchi, IRCCS Casa Sollievo della Sofferenza, Via Cappuccini 1, San Giovanni Rotondo 71013, Italy. Phone: 3908-8241-0954; Fax: 3908-8220-4004; E-mail: f.bianchi@operapadrepio.it; and Pier Paolo Di Fiore, European Institute of Oncology, Via Ripamonti 435, Milan 20141, Italy. Phone: 3902-9437-5198; Fax: 3902-9437-5991; E-mail: pierpaolo.difiore@ieo.eu doi: 10.1158/1078-0432.CCR-15-3005 Ó2016 American Association for Cancer Research. Clinical Cancer Research Clin Cancer Res; 23(1) January 1, 2017 62 on May 22, 2020. © 2017 American Association for Cancer Research. clincancerres.aacrjournals.org Downloaded from Published OnlineFirst June 29, 2016; DOI: 10.1158/1078-0432.CCR-15-3005