Michael Williams, MD
Study results presented at the 2017 American Urological Association Annual Meeting demonstrated that split-doses of gemcitabine and cisplatin as neoadjuvant chemotherapy for treating muscle-invasive bladder cancer (MIBC) has a good pathologic response with a high safety profile.1
“Our aim was to evaluate our experience with respect to gemcitabine and split-dose cisplatin in terms of safety and efficacy, as well as pathologic downstaging and survival,” said Michael Williams, MD, a practicing urologist at Urology of Virginia and assistant professor in the Department of Urology at Eastern Virginia Medical School. This is especially significant for patients who are unable to tolerate standard treatment with the combination of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC).
A previous randomized phase III study investigated the combination of gemcitabine and cisplatin compared with treatment with MVAC in advanced or metastatic bladder cancer. This trial found that gemcitabine and cisplatin provided a similar survival advantage to MVAC, but with a better safety profile and tolerability. The investigators even concluded that the standard of care for this patient population should change from MVAC to gemcitabine and cisplatin.2
In the large, randomized, multicenter trial, 405 patients were randomized to either receive gemcitabine and cisplatin (n = 203) or MVAC (n = 202). Overall survival (OS) was similar in both arms, as was time to disease progression, time to treatment failure, and response rate. More patients completed 6 cycles of gemcitabine and cisplatin therapy, with fewer dose adjustments. The toxic death rate was 1% in the gemcitabine and cisplatin arm and 3% in the MVAC arm.
In terms of adverse events, more patients in the gemcitabine and cisplatin arm experienced grade 3/4 anemia (27% vs 18% in the MVAC arm) and thrombocytopenia (57% vs 21%). These patients, however, had better improvement in terms of their weight, performance status, and fatigue. More patients in the MVAC arm had grade 3/4 neutropenia (82% vs 71% in the gemcitabine and cisplatin arm), neutropenic fever (14% vs 2%), neutropenic sepsis (12% vs 1%), grade 3/4 mucositis (22% vs 1%) and alopecia (55% vs 11%).
A retrospective study investigating the role for neoadjuvant gemcitabine and cisplatin in MIBC similarly concluded that the combination is feasible and allows for timely drug delivery. Further, the proportion of patients who were treated, whose primary tumors were downstaged and who had prolonged disease-free survival with minimal or no residual disease, was similar to patients treated with MVAC.3
With 4 cycles planned in the study, 39 of 42 patients received all cycles, with complete responses achieved in 28%. Notably, all 15 patients receiving gemcitabine and cisplatin who achieved downstaging of their tumors below pathological stage T2 remained disease-free at a median follow-up of 30 months.
Williams presented a study that included patients who received gemcitabine and cisplatin split-doses followed by treatment with open radical cystectomy for T2 to T4 bladder cancer between 2004 and 2015. The median age was 67.2 years, and the majority of patients had ECOG performance statuses of 1 or 2. The study included 82 patients, 47 (57.3%) of whom were clinical stage T2, 20 (24.3%) were T3, and 14 (17.1%) were T4. Of the patients with clinical stage T3 and T4 disease, 6 had hydronephrosis and 18 had a 3-D mass.
Patients were given 1000 mg/m2 of gemcitabine and 35 mg/m2 of cisplatin administered on days 1 and 8 of a 21-day cycle, for a total of 4 cycles. Twenty-six were deceased at the time of the final evaluation, and 10 patients (12%) were unable to complete all 4 cycles of treatment due to complications. Patients with unavailable follow-up data were excluded from the study.
The majority of patients were able to receive more than 2 cycles of therapy on this split-dose regimen. “If you look at the number of cycles, 78% of patients received 4 cycles,” Williams commented. Twelve patients (14.6%) were treated with 3 cycles, and 2 patients (2.4%) received 2 cycles or fewer. The median time for the chemotherapy was a total of 12 weeks, “which is what you would expect for 4 cycles at 3 weeks apiece,” he said. The median time from the end of chemotherapy to the patient progressing to surgery was 7 weeks.
In terms of pathologic response, the pathologic T0 downstaging rate was 31.7%, and when incorporating T1, Ta, and carcinoma in situ, the downstaging rate increased to 46.3%. At the end of the study, 72% of the patients achieved pathologic N stage 0; 14.6%, N1; and 11%, N2. “There is a rare cohort of patients who are pathologic T0 remaining node-positive, and of those patients, the majority have a very small number of lymph nodes that are actually positive,” Williams said.