Genomic characterization of high-risk non-muscle invasive bladder cancer

Autor: Francis J. Giles, Joshua J. Meeks, Nike Beaubier, Daniel T. Oberlin, Alfred Rademaker, Sachin Gopalkrishna Pai, Julia A. Elvin, Kyle Fedorchak, Sohail Balasubramanian, Benedito A. Carneiro
Rok vydání: 2016
Předmět:
Zdroj: Oncotarget
ISSN: 1949-2553
Popis: // Joshua J. Meeks 1, * , Benedito A. Carneiro 2, * , Sachin G. Pai 2 , Daniel T. Oberlin 1 , Alfred Rademaker 4 , Kyle Fedorchak 5 , Sohail Balasubramanian 5 , Julia Elvin 5 , Nike Beaubier 3 , Francis J. Giles 2 1 Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA 2 Developmental Therapeutics Program, Division of Hematology/Oncology, Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL, USA 3 Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA 4 Northwestern University Department of Preventive Medicine, Chicago, IL, USA 5 Foundation Medicine Inc, Cambridge, MA, USA * These authors contributed equally to this work Correspondence to: Joshua J. Meeks, email: joshua.meeks@northwestern.edu Benedito A. Carneiro, email: benedito.carneiro@northwestern.edu Keywords: bladder cancer, mutation burden, progression, invasion Received: August 29, 2016 Accepted: October 05, 2016 Published: October 14, 2016 ABSTRACT The genetic mechanisms associated with progression of high-risk non-muscle-invasive bladder cancer (HR-NMIBC) have not been described. We conducted selective next-generation sequencing (NGS) of HR-NMIBC and compared the genomic profiles of cancers that responded to intravesical therapy and those that progressed to muscle-invasive or advanced disease. DNA was extracted from paraffin-embedded sections from 25 HR-NMIBCs (22 with T1HG; 3 with TaHG with or without carcinoma in situ ). Ten patients with HR-NMIBC developed progression (pT2+ or N+) (“progressors”). Fifteen patients had no progression (“non-progressors”). Tissue from 11 patients with metastatic bladder cancer (BC) were analyzed for comparison. We found no difference in frequency of mutations of TP53 , PIK3CA , or KMT2D between the primary tumors of progressors compared to non-progressors and metastatic tumors. An increased frequency of deletions of CDKN2A/B was identified in tumors at progression (37%) compared to non-progressors (6%) ( p = 0.10). We found a significant decrease in total mutational burden (TMB) that has been associated with immunotherapy response comparing non-progressors, progressors and metastatic tumors at 15, 10.1 and 5.1 mutations/MB respectively ( p = 0.02). This association suggests more advanced tumors have decreased neoantigen burden and may explain the mechanism of BCG response in non-progressors. We found no novel genetic drivers in progressors and HR-NMIBC had many genetic features similar to metastatic BC. Loss of CDKN2A/B may occur late during invasion of BC and may represent an important step in progression. Further research is necessary to evaluate TMB and loss of CDKN2A/B locus as a biomarker for progression of NMIBC.
Databáze: OpenAIRE