Comprehensive multiregional analysis of molecular heterogeneity in bladder cancer

Genetic alterations identified in adjacent normal appearing tissue in bladder cancer patients are indicative of a field disease. Here we assessed normal urothelium transformation and intra-tumour heterogeneity (ITH) in four patients with bladder cancer. Exome sequencing identified private acquired mutations in a lymph node metastasis and local recurrences. Deep re-sequencing revealed presence of at least three and four subclones in two patients with multifocal disease, while no demarcation of subclones was identified in the two patients with unifocal disease. Analysis of adjacent normal urothelium showed low frequency mutations in patients with multifocal disease. Expression profiling showed intra-tumour and intra-patient co-existence of basal- and luminal-like tumour regions, and patients with multifocal disease had a greater degree of genomic and transcriptomic ITH, as well as transformation of adjacent normal cells, compared to patients with unifocal disease. Analysis of the adjacent urothelium may pave the way for therapies targeting the field disease.

Scientific reports. 2017 Sep 15*** epublish ***

Mathilde Borg Houlberg Thomsen, Iver Nordentoft, Philippe Lamy, Søren Vang, Line Reinert, Christophe Kamungu Mapendano, Søren Høyer, Torben F Ørntoft, Jørgen Bjerggaard Jensen, Lars Dyrskjøt

Department of Molecular Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark., Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark., Department of Pathology, Aarhus University Hospital, Ndr. Ringgade, 8000, Aarhus C, Denmark., Department of Urology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark., Department of Molecular Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark. .