Identification of an immunotherapy-responsive molecular subtype of bladder cancer.

Although various molecular subtypes of bladder cancer (BC) have been investigated, most of these studies have focused on muscle-invasive BC (MIBC). A few studies have investigated non-muscle-invasive BC (NMIBC) or NMIBC and MIBC together, but none has classified progressive NMIBC or immune checkpoint inhibitor (ICI)-based therapeutic responses in early-stage BC patients.

A total of 1,934 samples from seven patient cohorts were used. We performed unsupervised hierarchical clustering to stratify patients into distinct subgroups and constructed a classifier by applying SAM/PAM algorithms. We then investigated the association between molecular subtypes and immunotherapy responsiveness using various statistical methods.

We explored large-scale genomic datasets encompassing NMIBC and MIBC, redefining four distinct molecular subtypes, including a subgroup containing progressive NMIBC and MIBC with poor prognosis that would benefit from ICI treatment. This subgroup showed poor progression-free survival with the distinct features of high mutation load, activated cell cycle, and inhibited TGFβ signalling. Importantly, we verified that BC patients with this subtype were significantly responsive to an anti-PD-L1 agent in the IMvigor210 cohort.

Our results reveal an immunotherapeutic option for ICI treatment of highly progressive NMIBC and MIBC with poor prognosis.

This research was supported by the National Research Foundation of Korea grant funded by the Korean government, a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health and Welfare, Republic of Korea, and a grant from the KRIBB Research Initiative Program.

EBioMedicine. 2019 Nov 15 [Epub ahead of print]

Bic-Na Song, Seon-Kyu Kim, Jeong-Yeon Mun, Young-Deuk Choi, Sun-Hee Leem, In-Sun Chu

Genome Editing Research Centre, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea; Department of Bioinformatics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, Korea., Personalized Genomic Medicine Research Centre, KRIBB, Daejeon, Korea., Department of Biological Science, Dong-A University, Busan, Korea., Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea., Department of Biological Science, Dong-A University, Busan, Korea. Electronic address: ., Genome Editing Research Centre, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea; Department of Bioinformatics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, Korea. Electronic address: .