Immediate post-operative intravesical instillation of a single dose chemotherapy is not superior to continuous saline irrigation

INTRODUCTION AND OBJECTIVESTo evaluate whether there is any difference between immediate postoperative instillation of intravesical chemotherapy (IPOIC) and continuous saline bladder irrigation (CSBI) in terms of bladder cancer (BC) recurrence in patients with primary low- or intermediate-risk non-muscle-invasive BC (NMIBC). MATERIALS AND METHODSMedical records of 1482 patients who underwent transurethral resection of bladder tumor between March 1994 and August 2020 were reviewed retrospectively. Patients were divided into two groups according to IPOIC and/or CSBI administration status [Group-1 = CSBI alone; Group-2 = CSBI following IPOIC]. Low- and intermediate-risk NMIBC patients were also divided into subgroups according to IPOIC and/or CSBI administration status. RESULTSA total of 594 patients with primary NMIBC were included. Of the patients, 86 (14.5%) were female and 508 (85.5%) were male with a median age of 69 (60-78) years. The frequency of patients in Group-1 and Group-2 were 361 (60.8%) and 233 (39.2%), respectively. Recurrent disease was observed in 213 (35.9%) patients. There was no difference between the groups when they were compared for recurrent disease frequency, median time to first recurrence and frequency of recurrence within first 12 months (P = .064, P = .671, and P = .145, respectively). Disease recurrence rates in low-risk NMIBC patients was lower when they were treated with "CSBI following IPOIC" when compared to "CSBI alone" (P = .042). However, no difference was observed in low-risk NMIBC subgroups when they were compared for pathological features of recurrent tumors such as number, size, grade, stage, and presence of carcinoma in situ (P > .05, for each). CONCLUSIONS"CSBI following IPOIC" combination was not superior to "CSBI alone" for preventing adverse pathological outcomes in recurrent low- and intermediate-risk NMIBC.