Platinum-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is the gold standard treatment for muscle-invasive bladder cancer (MIBC). Although gemcitabine plus platinum-based drugs have similar efficacy and less toxicity than MVAC, the optimal dose of gemcitabine for safety and efficacy remains unclear. Therefore, we investigated an oncologic outcomes and adverse events at a dose of 800 mg/m2 and 1000 mg/m2 in NAC with gemcitabine followed by RC.

This multi-institutional retrospective study included 517 patients with MIBC who received 2–4 cycles of platinum-based NAC with gemcitabine followed by RC. Patients were divided into two groups: patients who received gemcitabine at a dose of 800 mg/m2 (800 mg/m2 group) and 1000 mg/m2 (1000 mg/m2 group). The rates of myelosuppressive hematological adverse events (AEs) were compared between the two groups. Multivariable Cox-proportional hazards regression analyses were performed to evaluate the impact of gemcitabine dose on cancer-specific survival (CSS) and overall survival (OS).

The median age and follow-up period were 70 years and 55 months, respectively. Of the 517 patients, 348 (67%) and 169 (33%) received gemcitabine at a dose of 800 mg/m2 and 1000 mg/m2, respectively. The rates of grade ≥3 neutropenia and febrile neutropenia were not significantly different between the two groups (Fig. 1 and 2, respectively), whereas the rate of grade ≥3 thrombopenia in the 800 mg/m2 group was significantly lower than that in the 1000 mg/m2 group (Fig. 3). CSS and OS in the 800 mg/m2 group were significantly shorter than those in the 1000 mg/m2 group (Fig. 4 and 5, respectively). After adjustment for confounding variables, 800 mg/m2 of gemcitabine was not significantly associated with shorter CSS and OS (Table).

The 800 mg/m2 of gemcitabine might alleviate grade ≥3 thrombopenia without sacrificing oncological outcomes. Accordingly, the 800 mg/m2 of gemcitabine might improve quality of life compared to the 1000 mg/m2 of gemcitabine.

The 800 mg/m2 of gemcitabine might alleviate grade ≥3 thrombopenia without sacrificing oncological outcomes. Accordingly, the 800 mg/m2 of gemcitabine might improve quality of life compared to the 1000 mg/m2 of gemcitabine.