Mitomycin C allergy after passive and device-assisted hyperthermia for non-muscle invasive bladder cancer treatment: A retrospective cohort from a high-volume center

• Published in: Urologic oncology Vol. 40; no. 7; pp. 345.e19 - 345.e23
• Main Authors: González-Padilla, Daniel Antonio, Subiela, José Daniel, González-Díaz, Alejandro, Hernández-Arroyo, Mario, García-Rojo, Esther, Aumatell, Julia, Burgos Revilla, Javier, Rodríguez-Antolín, Alfredo, Guerrero-Ramos, Félix
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2022
• Subjects: Allergy; Bladder cancer; Hypersensitivity; Hyperthermia; Mitomycin c; Allergy; Mitomycin c; Bladder cancer; Hyperthermia; Hypersensitivity
• ISSN: 1078-1439; 1873-2496
• DOI: 10.1016/j.urolonc.2022.02.018

•Mitomycin C allergy has an incidence of 2.4% in passive and 6.9% in device-assisted hyperthermia.•Early postoperative instillation is the only identified risk factor for developing allergy (OR 2.47, P = 0.001).•7/18 (38%) suspected allergies were found to be negative after allergy tests, showing that confirmation is necessary before stopping treatment completely.•Patients typically present with a pruriginous rash between 1 and 24 hours after the instillation. Mitomycin C (MMC) is one of the most frequently utilized intravesical chemotherapy drugs for the management of non-muscle-invasive bladder cancer (NMIBC). Allergic reactions (Type 4 delayed hypersensitivity) are seldomly reported in the literature but not so infrequent in daily practice, its incidence has been increasing with the use of device-assisted hyperthermia. This study aims to identify the incidence, risk factors, and clinical characteristics of patients with allergic reactions to MMC. Single-center retrospective cohort from June 2014 to August 2018. Patients with intermediate or high-risk NMIBC were included. Patients received passive MMC (4 weekly and eleven monthly instillations of 40mg of MMC) or Chemohyperthermia (CHT) with MMC (6 weekly and 6-monthly instillations, heated at 43°C [+/- 0.5°C] using Combat BRS). We included 258 patients (MMC = 157, CHT = 101) and found 7 (4.4%) suspected and 4 confirmed (2.4%) allergies in the passive MMC group and 11 suspected (10.9%) and 7 confirmed (6.9%) in the CHT group. The mean number of instillations received before developing the allergy was 6 in the passive MMC and 5 in the CHT group. Seven out of 18 suspected allergy cases were pseudo-allergic reactions with negative allergy tests. Early postoperative MMC instillation was associated with an increased risk of allergy (OR 2.47 [CI 1.39–4.36], P = 0.001), while neither history of atopy nor history of other medications allergy was found to increase the risk. MMC allergy risk is increased with the use of device-assisted hyperthermia with an incidence of 2.4% for passive MMC and 6.9% for CHT. History of prior allergies does not seem to increase the risk of developing MMC allergy. In this series 38% of suspected cases were found to be pseudo-allergic reactions, highlighting the need to confirm the diagnosis before definitively stopping the treatment.