Impact of age on the effectiveness of intravesical Bacillus Calmette‑Guérin and gemcitabine/docetaxel in treatment-naïve high-risk non‑muscle‑invasive bladder cancer

Background: Intravesical Bacillus Calmette‑Guérin (BCG) has long been the standard therapy for high‑risk non‑muscle‑invasive bladder cancer (HR‑NMIBC), yet treatment response may vary with age. Sequential intravesical gemcitabine/docetaxel (Gem/Doce) has emerged as a well‑tolerated and effective alternative, particularly during periods of BCG shortage, contributing to its increasing global adoption. However, the influence of age on oncologic outcomes with either regimen remains unclear, with prior studies reporting heterogeneous results, especially within BCG‑treated cohorts. This study evaluated the impact of age on the effectiveness of intravesical BCG and Gem/Doce in treatment‑naïve patients with HR‑NMIBC. Methods: We retrospectively reviewed data on treatment naïve HR-NMIBC patients treated with BCG or sequential Gem/Doce from 2011-2024. The BCG cohort received a 6‑week induction course followed by maintenance at 3, 9, and 15 months. Gem/Doce consisted of six weekly induction instillations, followed by monthly maintenance for up to 24 months in patients who responded to induction. Age groups were defined as