Qualitative Interferon-γ Release Assay for Predicting Response to BCG instillations in Bladder Cancer

Abstract Background This study aims to fill the void in predictive markers for BCG instillation responsiveness in high-risk non-muscle invasive bladder cancer. Focusing on elevated progression risk, it explores the potential of the qualitative interferon-γ release assay T-spot, emphasizing CFP-10 positivity as a marker for BCG efficacy anticipation. Objective This study aims to investigate the potential of qualitative interferon-γ release assay T-spot testing, specifically focusing on CFP-10 positivity, in predicting the response to intracavitary BCG instillations among patients with high-risk non-muscle invasive bladder cancer. Materials and Methods Patients with NMIBC were recruited from the database retrospectively and tested with T-spot prospectively. Following sufficient BCG instillations, patients demonstrating unresponsiveness to BCG were designated as the study group, while those with at least one year of recurrence-free status were assigned to the control group. ResultsIn this cohort of 42 high-risk NMIBC patients, with a median age of 67, 40% displayed BCG unresponsiveness. The distribution included 50% pTa and 81% high-grade cases. Over a median follow-up of 18 months, the positive BCG response varied between pTa (81%) and pT1 (38%) (p=0.005). T-spot testing revealed positivity in 75% of the control group and a higher 92% in BCG unresponsive patients (p=0.235). Significantly, CFP-10 positivity was more pronounced in the BCG unresponsive group at 91.7%, in contrast to 35.7% in the control group (p=0.004). Conclusions CFP-10 positivity T-spot test may be a marker for predicting the response to BCG instillations.