Downstaging of Muscle-Invasive Bladder Cancer Using Neoadjuvant Gemcitabine and Cisplatin or Dose-Dense Methotrexate, Vinblastine, Doxorubicin, and Cisplatin as Single Regimens or as Switch Therapy Modalities

Abstract

Background: Consensus guidelines recommend gemcitabine and cisplatin (GC) or dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (ddMVAC) as equally preferable neoadjuvant chemotherapy before cystectomy for muscle-invasive bladder cancer. This study sought to compare the ability of GC and ddMVAC to achieve pathologic response; and to evaluate the benefit of switching regimens after 1 or 2 cycles of the other.

Patients and methods: Patients aged ≥ 18 with muscle-invasive bladder cancer (≥ cT2) and who had received either GC or ddMVAC as neoadjuvant chemotherapy followed by cystectomy were retrospectively evaluated using the electronic medical record. Patients who received 1 or 2 cycles of one regimen followed by several cycles of the other regimen before cystectomy were classified as switch therapy patients. This study assessed the rates of pathologic complete response (pCR) and any degree of downstaging.

Results: Among 109 patients who received GC or ddMVAC, 7 (21%) of 33 ddMVAC patients demonstrated pCR, and 19 (25%) of 76 GC patients demonstrated pCR (odds ratio, 1.24; 95% confidence interval, 0.46-3.31; P = .67). Downstaging rates were 39% for ddMVAC and 50% for GC (P = .31). Thirty-three of 36 patients aged ≥ 70 years received GC (P < .001). Four of 7 patients treated with switch therapy showed downstaging, and 2 of 7 experienced pCR.

Conclusion: There was no difference in pCR rates between GC and ddMVAC, and patients were most often able to receive 3 or 4 cycles of treatment. Switch therapy may be of benefit in patients whose disease has a poor initial response.

Keywords: Cystectomy; GC; MIBC; MVAC; Urothelial carcinoma.