Cystectomy outcomes in patients who have failed Radiofrequency-induced Thermo-chemotherapeutic Effect Mitomycin-C (RITE-MMC) treatment for high-risk non-muscle invasive bladder cancer (HRNMIBC)-Does it complicate surgery and adversely impact oncological outcome?

Abstract

Introduction: The standard intravesical treatment for high risk non muscle invasive bladder cancer (HRNMIBC) is Bacillus Calmette-Guérin (BCG), with failure often resulting in cystectomy. Radiofrequency-Induced Thermo-chemotherapeutic Effect Mitomycin (RITE-MMC) can be an alternative in BCG failure. There has been concern that RITE-MMC may delay an inevitable cystectomy, make it more technically challenging and worsen prognosis. The aim of this study was to assess operative challenges and oncological outcome in patients undergoing cystectomy for HRNMIBC who received RITE-MMC, and contrast them with those that did not.

Patients and methods: A retrospective study of a prospective cystectomy database was conducted. Patients treated from April 2011 to June 2017 were looked at. Inclusion criteria were HRNMIBC with BCG failure undergoing cystectomy. Patient demographics and tumour characteristics were analysed. Intraoperative blood loss and length of stay were used as surrogate markers for intra-operative difficulty. Kaplan-Meier curves were constructed to analyse all-cause mortality, cancer specific mortality and time to recurrence between the RITE-MMC treatment group and those that did not receive RITE-MMC. A multivariate analysis was conducted to assess factors that may influence readmission.

Results: Thirty-six patients who received RITE-MMC underwent cystectomy, compared to 102 that did not. Median ages were comparable at 72 and 69 years, respectively. Patients were followed up for a median of 24 months across the 2 groups. The commonest histological stage in both groups was CIS. There were no significant differences in intraoperative blood loss, length of stay and 90-day readmission between the 2 groups. There were proportionally fewer recurrences in the RITE-MMC group (16% vs. 19%) and median time to recurrence was longer in the RITE-MMC group (37 months vs. 24 months). Multivariate analysis did not reveal a significant correlation between pre-op RITE-MMC and post-operative readmission (P = 0.606). Survival curves show no significant difference in time to recurrence across both groups (P = 0.513), and no overall (P = 0.069) or cancer specific mortality (P = 0.129) dis-advantage was noted in the RITE-MMC group.

Conclusion: We have found that RITE-MMC treatment does not result in a technically more challenging cystectomy and does not compromise oncological outcome compared to those patients undergoing cystectomy immediately post-BCG failure. We feel RITE-MMC remains a useful tool in a carefully selected group of patients who may not be willing to accept the morbidity of a cystectomy at the time, without significantly compromising their long-term outcome.

Keywords: CIS; Cystectomy; HRNMIBC; Hyperthermic mitomycin; RITE-mitomycin; Radiofrequency-induced hyperthermic effect.