PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement
Presenter(s)
C. P. Tello Valverde1,2, K. Pateras3, E. D. Geijsen4, T. M. de Reijke5, B. J. Slotman6, J. R. Oddens4, and H. Crezee7; 1Amsterdam University Medical Centers, Department of Radiation Oncology - Location AMC, Amsterdam, North Holland, Netherlands, 2Amsterdam University Medical Centers, Department of Radiation Oncology - Location VUmc, Amsterdam, Netherlands, 3University of Thessaly, Faculty of Public and One Health, Laboratory of Epidemiology & Artificial Intelligence, Karditsa, Greece, 4Amsterdam UMC, Amsterdam, Netherlands, 5Amsterdam University Medical Centers, Amsterdam, Netherlands, 6Cancer Center Amsterdam, Cancer Treatment and Quality of Life, Amsterdam, Noord-Holland, Netherlands, 7Amsterdam University Medical Centers, Department of Radiation Oncology - Location AMC, Amsterdam, Netherlands
Purpose/Objective(s):
We aimed to investigate the association between locoregional chemohyperthermia (CHT) and recurrence outcomes in patients with recurrent non-muscle-invasive bladder cancer (NMIBC). Materials/Methods:
In this single-arm cohort follow-up study (CHIB2; Netherlands Trial Register NL2429), patients were included between 2009-2020. Eligible patients had histologically confirmed recurrent urothelial NMIBC classified as
intermediate- or high-risk per EAU criteria. Patients were treated with 6 weekly locoregional CHT induction sessions combined with intravesical mitomycin C (MMC), followed by 4 monthly maintenance instillations; recurrence and follow-up were assessed by surveillance cystoscopy/cytology. Intravesical and perivesical temperatures (urethra, rectum, and, if applicable, vagina) were recorded, and thermal dose (TD) was expressed as cumulative equivalent minutes at 43°C (CEM43). The primary endpoint was estimated 5-year recurrence-free survival (RFS) (time from first CHT to first recurrence). The TD-effect relationship was evaluated using multivariate time-to-event modeling adjusting for recurrence rate (=1 vs >1/year), multifocality, and WHO 2004/2016 grade classification. Competing risks analysis accounted for death or radical cystectomy before recurrence. Secondary endpoints were overall survival (OS) and disease-specific survival (DSS).
Results:
Sixty patients were included; 83% were high-risk and 17% intermediate-risk. Thirty patients developed recurrence, with a median time-to-recurrence of 2.1 years (IQR 0.8-6.5 years). Median Average CEM43T50 TD was 2.5 minutes (range 0.09-15.2 minutes). Across the observed TD range, estimated 5-year RFS increased from ~37% to ~83%. A twofold increase in TD was associated with a 31% lower hazard of recurrence (95% CI 15%-45%; P < .001) and a 30% lower hazard after adjustment (95% CI 11%-46%; P = .003). Competing risks analysis confirmed a significant association between increasing TD and reduced recurrence risk (adjusted P = .007). Five-year OS and DSS were 68% and 90%, respectively.
Conclusion:
This cohort follow-up study in recurrent intermediate- and high-risk NMIBC showed that higher hyperthermia TD during locoregional CHT was independently associated with improved 5-year RFS, supporting TD as a clinically relevant treatment-quality metric, highlighting its predictive value and potential utility to inform personalization of locoregional CHT combined with MMC in NMIBC.
