Vancouver Prostate Centre researchers led a national study supporting ctDNA testing for FGFR-targeted therapy in metastatic bladder cancer

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Researchers at the Vancouver Prostate Centre led a national multicentre study demonstrating that circulating tumour DNA (ctDNA) testing can help identify patients with metastatic urothelial carcinoma who may benefit from FGFR-targeted therapies.

The study, Prospective multicenter study of ctDNA versus tumor tissue guiding FGFR-targeted therapy in metastatic urothelial cancer, was published in Nature Communications and evaluated whether plasma ctDNA analysis could complement conventional tumour tissue testing used to determine eligibility for FGFR inhibitors such as erdafitinib.The research involved a collaborative team including Vancouver Prostate Centre investigators David C. Müller, Andrew J. Murtha, Gillian Vandekerkhove, Alexander W. Wyatt, and Bernhard J. Eigl, alongside collaborators across 12 Canadian cancer centres.

FGFR alterations represent an important actionable genomic driver in metastatic urothelial carcinoma. However, traditional tumour tissue testing can be limited by sample availability and tumour heterogeneity, meaning archival samples may not fully reflect the biology of metastatic disease.

To address this challenge, investigators prospectively analyzed plasma samples from 208 patients undergoing standard-of-care FGFR tissue testing. The study demonstrated that ctDNA testing achieved 90% concordance with tissue testing among evaluable samples and 84% sensitivity for detecting tissue-identified FGFR alterations. Importantly, plasma analysis also identified seven additional patients with actionable FGFR alterations that were not detected through tissue testing alone.

One patient identified solely through ctDNA testing received the FGFR inhibitor erdafitinib and experienced a durable response lasting 33 months, highlighting the potential clinical value of integrating blood-based genomic testing into routine diagnostic workflows. Serial plasma sampling also enabled investigators to monitor tumour evolution and detect emerging resistance mechanisms during therapy, demonstrating the dynamic advantages of ctDNA-based testing.

Together, the findings support the clinical integration of ctDNA FGFR testing as a complementary approach alongside tissue-based diagnostics in metastatic urothelial carcinoma.