Differential response of low- and high-grade intermediate-risk non-muscle-invasive bladder cancer to bacillus Calmette-Guérin and gemcitabine-docetaxel therapy.

BACKGROUND AND

OBJECTIVE

Sequential intravesical gemcitabine/docetaxel (Gem/Doce) is a potential alternative to bacillus Calmette-Guérin (BCG) for treating non-muscle-invasive bladder cancer (NMIBC). Intermediate-risk NMIBC group (IR-NMIBC) includes both low-grade (LG) and high-grade tumors (HG). This study investigates the response of HG and LG IR-NMIBC to Gem/Doce compared to BCG therapy.

METHODS

We included patients with IR-NMIBC who received either BCG or Gem/Doce between 2013 and 2023. Maintenance regimens were administered to patients without recurrence after induction for 1 year. Follow-up cystoscopies were performed per American Urological Association (AUA) guidelines. Kaplan-Meier and Cox regression analyses were performed to evaluate recurrence-free survival (RFS) and progression-free survival (PFS).

RESULTS

Among 505 NMIBC patients, 150 were IR-NMIBC: 115 with HG tumors (69 received BCG, 46 received Gem/Doce) and 35 with LG tumors (14 received BCG, 21 received Gem/Doce).With a median follow-up time of 31 months (Interquartile Range [IQR] 13-54), The overall 2-year any-grade RFS was 55%. For HG and LG groups, the 2-year any-grade RFS was 58% and 35% (P = 0.009), respectively. High-grade RFS at 2 years was 75% for HG and 94% for LG (P = 0.065). The 2-year PFS was similar between groups, at 96% for both HG and LG (P = 0.39). In HG patients, 2-year high-grade RFS was higher with BCG than Gem/Doce (81% vs. 59%, P = 0.008). In LG patients, 2-year any-grade and high-grade RFS were comparable between BCG and Gem/Doce (P = 0.067 and P = 0.37, respectively).

CONCLUSIONS

Our findings suggest that BCG may offer a superior benefit in terms of high-grade RFS for HG IR-NMIBC compared to Gem/Doce, while LG tumors respond similarly to both treatments. This emphasizes the role of risk stratification in treatment selection. Prospective studies are needed to validate these findings and refine treatment strategies.