A multi-institutional retrospective study of hyperthermic plus intravesical chemotherapy versus intravesical chemotherapy treatment alone in intermediate and high risk nonmuscle-invasive bladder cancer

To compare the efficacy and safety of hyperthermic intravesical chemotherapy (HIVEC) and intravesical chemotherapy (IVEC) in patients with intermediate and high risk nonmuscle-invasive bladder cancer (NMIBC) after transurethral resection. We included 560 patients diagnosed with primary or recurrent NMIBC between April 2009 and December 2015 at 1 of 6 tertiary centers. We matched 364 intermediate or high risk cases and divided them into 2 groups: the HIVEC+IVEC group [chemohyperthermia (CHT) composed of 3 consecutive sessions followed by intravesical instillation without hyperthermia] and the IVEC group (intravesical instillation without hyperthermia). The data were recorded in the database. The primary endpoint was 2-year recurrence-free survival (RFS) in all NMIBC patients ( = 364), whereas the secondary endpoints were the assessment of radical cystectomy (RC) and 5-year overall survival (OS). There was a significant difference in the 2-year RFS between the two groups in all patients ( = 364; HIVEC+IVEC: 82.42% IVEC: 74.18%, = 0.038). Compared with the IVEC group, the HIVEC+IVEC group had a lower incidence of RC ( = 0.0274). However, the 5-year OS was the same between the 2 groups ( = 0.1434). Adverse events (AEs) occurred in 32.7% of all patients, but none of the events was serious (grades 3-4). No difference in the incidence or severity of AEs between each treatment modality was observed. This retrospective study showed that HIVEC+IVEC had a higher 2-year RFS and a lower incidence of RC than IVEC therapy in intermediate and high risk NMIBC patients. Both treatments were well-tolerated in a similar manner.