Sequential Endoluminal Doxorubicin and Gemcitabine Alternating Weekly with Sequential Mitomycin and Docetaxel for Recurrent Non-Muscle Invasive Urothelial Carcinoma.

After first-line treatment failure, patients with non-muscle invasive urothelial carcinoma (NMIUC) are recommended to undergo radical cystectomy. However, those unable to pursue radical surgery or desiring bladder preservation require effective salvage therapies. Multi-agent treatment regimens are particularly useful for targeting the complex resistance mechanisms of recurrent UC. Herein, we report a regimen of sequential doxorubicin and gemcitabine alternating weekly with sequential docetaxel and mitomycin (Quad Chemo) for patients with recurrent high-risk NMIUC. We retrospectively identified all patients sequentially treated with 50 mg of doxorubicin followed by 1000 mg of gemcitabine alternating weekly with sequential 37.5 mg of docetaxel followed by 40 mg mitomycin-C between 2007-2024. Induction consisted of 8 weekly treatments, and, if disease-free, patients were initiated on monthly maintenance treatments for 2 years. In total, 29 patients (39 treated units; 26 lower urinary tract, 13 upper urinary tract) with high-grade NMIUC were included in the final analysis. The cohort had high-risk features with a median of three prior induction therapies and with 38 (97%) units presented with either biopsy-proven CIS or presumed CIS in the context of high-grade urine cytology in the absence of tumorous lesions. There were 26 recurrences during follow-up, 17 in the lower tract and 9 in the upper tract. Among all of the treated units, the complete response rate was 80%, and 1- and 2-year recurrence-free survival was 60% and 43%, respectively. In total, 10 patients experienced disease progression yielding a 5-year progression-free survival of 57%. Five patients ultimately died due to bladder cancer yielding a 5-year cancer-specific survival of 83%. A total of 19 (66%) patients reported side effects during treatment, and 7 (24%) stopped treatment secondary to side effects. In a high-risk heavily pre-treated cohort, Quad Chemo rescued a significant portion of patients with recurrent NMIUC from disease relapse. However, progression events were considerable in the long term. Further prospective evaluation of this treatment regimen is warranted.