Abstract
ObjectiveSodium bicarbonate has been reported to maximize the efficacy of intravesical instillation of mitomycin-C (IVI-MMC) therapy by urine alkalinization in non-muscle-invasive bladder cancer (NMIBC). This study aimed to analyze the changes in MMC concentration according to urinary pH and evaluate the efficacy of sodium bicarbonate to maintain the concentration of active form of MMC during IVI-MMC.MethodsWe prospectively enrolled 26 patients with NMIBC after transurethral resection of bladder tumor. Patients with very high-risk and low-risk NMIBC were excluded. Urinary creatinine, volume, pH, and concentrations of MMC and its degraded form were measured immediately before and after IVI-MMC. The patients were administered 1.5 g of oral sodium bicarbonate during the preceding evening, in the morning, and immediately before the fourth cycle of the six-cycle IVI-MMC. The correlation between MMC concentration and urinary pH changes was explored with or without oral bicarbonate therapy.ResultsRecurrence without progression to muscle-invasive disease was noted in 4 of 26 patients in a 23.7-month follow-up. The mean urinary pH before and after the therapy increased from 6.03 to 6.50, and 6.46 to 7.24, without or with oral SB therapy, respectively. Despite this increase, the concentration of active form of MMC did not change significantly. No correlation was found between urinary pH and MMC concentration. Urine alkalinization by SB administration did not maintain the high concentration of urinary MMC.ConclusionsUrine alkalinization by sodium bicarbonate administration for IVI-MMC did not maintain the high concentration of active urinary MMC in NMIBC.
Highlights
70–80% of bladder cancer (BC) initially present with non-muscle-invasive bladder cancer (NMIBC) confined to the mucosa (Ta, Tis) and submucosa (T1) [1, 2]
No correlation was found between urinary pH and mitomycin-C BC (MMC) concentration
Urine alkalinization by sodium bicarbonate (SB) administration did not maintain the high concentration of urinary MMC
Summary
70–80% of bladder cancer (BC) initially present with non-muscle-invasive bladder cancer (NMIBC) confined to the mucosa (Ta, Tis) and submucosa (T1) [1, 2]. The shortage of BCG worldwide and its associated local and systemic adverse effects eventually result in withdrawal of treatment in approximately 30–50% patients in real clinical settings [8, 9]. IVI-mitomycin-C (IVI-MMC) is another most commonly used alternative cytotoxic agent for NMIBC. This treatment has lesser local and systemic adverse effects than IVI-BCG; it shows lower efficacy [10]. The lower efficacy of IVI-MMC can be explained by primary MMC resistance and inadequate drug delivery to tumor cells [11,12,13]. Several studies suggested IVI-MMC with oral intake of sodium bicarbonate (SB) for urine alkalinization [11, 13]. Our findings may have potential implications in the management of patients with NMIBC
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
