ORLANDO – The clinical outcomes when using neoadjuvant chemotherapy for muscle-invasive bladder cancer vary by molecular subtype, according to a study presented at the 2017 Genitourinary Cancers Symposium.1
For this study, researchers conducted a transcriptome-wide microarray analysis to evaluate the impact of different subtyping methods on clinical responses to neoadjuvant cisplatin-based chemotherapy.
Lead author Roland Seiler, MD, of the University of British Columbia in Vancouver, Canada, explained that he and his colleague analyzed data from transurethral resection specimens of 223 patients with muscle-invasive bladder cancer taken prior to receipt of neoadjuvant chemotherapy and cystectomy. They classified the specimens according to 4 published methods for molecular subtype: University of North Carolina (UNC) dataset, MD Anderson (MDA) dataset, The Cancer Genome Atlas (TCGA) dataset, and the Lund dataset.
The investigators then compared overall survival for each subtype between patients who received neoadjuvant chemotherapy and those who did not have neoadjuvant chemotherapy from the provisional TCGA.
Patients with luminal tumors had the best overall survival irrespective of receipt of neoadjuvant chemotherapy, while patients with tumors classified as UNC basal, MDA basal, and TCGA cluster III had the greatest improvement in overall survival following neoadjuvant chemotherapy compared with cystectomy alone.
Patients with tumors designated as UNC claudin-low had the worst overall survival of the different bladder cancer subtypes regardless of neoadjuvant chemotherapy receipt (P = .005)
Dr Seiler and colleagues also developed a genomic classifier that could accurately predict 4 classes (luminal, luminal-infiltrated, basal, claudin-low) and the impact of a basal subtype on overall survival among patients who received neoadjuvant chemotherapy vs those who did not.
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“Further validation of the genomic classifier is needed,” said Dr Seiler. “But this study suggests that basal tumors should be prioritized for neoadjuvant chemotherapy, while novel therapies are needed for other subtypes.”
- Seiler R, Winters B, Douglas J, et al. Muscle-invasive bladder cancer: Molecular subtypes and response to neoadjuvant chemotherapy. Paper presented at: 2017 Genitourinary Cancers Symposium; February 16-18, 2017; Orlando, FL.