Efficacy of Gemcitabine and Docetaxel for Treatment of Micropapillary Urothelial Carcinoma - Expert Commentary

Optimal treatment regimens for histologic variants of non-muscle invasive bladder cancer (NMIBC) are not well established. Accordingly, patients with variant cases exhibit worse clinical outcomes. Micropapillary urothelial carcinoma (MPUC) is the most common variant of urothelial carcinoma. A recent study by Abou Chakra et al. examined the efficacy of Intravesical gemcitabine/docetaxel (Gem/Doce) and intravesical valrubicin and docetaxel (Val/Doce) in patients with MPUC.

Among the 138 patients with high-risk NMIBC, 129 patients had pure UC, while 9 had MPUC. Most patients had received an adequate induction chemotherapy regimen of at least 5 instillations (96% in the pure UC group versus 100% in the MPUC group). The overall median follow-up time was 23 months. The 12-month recurrence-free survival (RFS) rates were 83% (95% CI, 75 – 89) in the pure UC group and 78% (95% CI, 36 – 94) in the MPUC group. The 24-month RFS estimates were 78% (95% CI, 69 – 85) in the pure UC group and 78% (95% CI, 36 – 94) in the MPUC group. The 12-month high-grade RFS (HG-RFS) rates were 85% (95% CI, 77 – 91) in the pure UC group and 89% (95% CI, 43 – 98) in the MPUC group. The 24-month HG-RFS estimates were 80% (95% CI, 70 – 87) in the pure UC group and 89% (95% CI, 43 – 98) in the MPUC group. The 12-month progression-free survival (PFS) rates were 98% (95% CI, 93 – 100) in the pure UC group and 100% in the MPUC group. The 24-month PFS rates were 97% (95% CI, 91 – 99) in the pure UC group and 100% in the MPUC group. For cystectomy-free survival (CFS), the 12-month estimates were 98% (95% CI, 93 − 100) in the pure UC group and 100% in the MPUC group, and 24-month estimates were 98% (95% CI, 93 − 100) in the pure UC group and 100% in the MPUC group. The 12-month overall survival (OS) estimates were 98% (95% CI, 93 − 99) in the pure UC group and 100% in the MPUC group. The 24-month OS rates were 88% (95% CI, 80 − 93) in the pure UC group and 100% in the MPUC group. There were no significant differences in survival estimates between the pure UC and MPUC groups (p > 0.1). In the MPUC group, seven out of nine patients received maintenance Gem/Doce. Four patients exhibited tumor recurrence and subsequently received Val/Doce therapy. None of these patients exhibited pathologic upstaging or disease progression at a median follow-up time of 43 months.

This important study demonstrates the efficacy of Gem/Doce for the MPUC variant. Further validation in larger and prospective cohorts is needed. This study adds to the growing body of evidence establishing effective treatment strategies for NMIBC variants.

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

References:

  1. Abou Chakra M, McElree IM, Packiam VT, Mott SL, O'Donnell MA. Early experience with sequential intravesical gemcitabine and docetaxel for micropapillary variant non-muscle invasive bladder cancer. Urol Oncol. 2024;42(9):289.e13-289.e21. doi:10.1016/j.urolonc.2024.05.006

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