Gender-specific Differences in Recurrence of Non-muscle-invasive Bladder Cancer: A Systematic Review and Meta-analysis

The incidence of urothelial carcinoma of the bladder (UCB) is lower in women; however, women tend to present with more advanced disease. To date, there is no quantitative synthesis of studies reporting gender-specific outcomes in non-muscle-invasive UCB.

To conduct a meta-analysis evaluating gender-specific differences in recurrence of non-muscle-invasive urinary bladder cancer (NMIBC).

An unrestricted systematic literature search of the MEDLINE, EMBASE, and Cochrane libraries was conducted. Studies evaluating the impact of gender on disease recurrence after local treatment of NMIBC using multivariable Cox proportional hazard models were included. Random effect meta-analysis, subgroup analyses, meta-influence, and cumulative meta-analyses were conducted. Publication bias was assessed via a funnel plot and Eggeŕs test.

Of 609 studies screened, 27 comprising 23 754 patients were included. Random effect meta-analyses indicated women at increased risk for UCB recurrence compared with men (hazard ratio [HR]=1.11, 95% confidence interval [CI]: 1.01-1.23, p=0.03). Subgroup analyses yielded estimates between HR=0.99 and HR=1.68. Gender-specific differences in UCB recurrence were most pronounced in studies administering exclusively bacillus Calmette-Guerin (BCG; HR=1.64, 95% CI: 1.13-2.39, p=0.01), especially in a long-term treatment regimen (HR=1.68, 95% CI: 1.32-2.15, p<0.001). Sensitivity analyses confirmed female patients at increased risk for UCB recurrence.

Women are at increased risk for disease recurrence after local treatment of NMIBC compared with male patients. Reduced effectiveness of BCG treatment might underlie this observation. Gender-specific differences were evident across various subgroups and proved robust upon sensitivity analyses.

In this report, we combined several studies on gender-specific differences in relapse of superficial bladder cancer. Women were more likely to experience cancer relapse than men.

European urology focus. 2017 Sep 06 [Epub ahead of print]

Annemarie Uhlig, Arne Strauss, Ali Seif Amir Hosseini, Joachim Lotz, Lutz Trojan, Marianne Schmid, Johannes Uhlig

Department of Urology, University Medical Center Goettingen, Goettingen, Germany. Electronic address: ., Department of Urology, University Medical Center Goettingen, Goettingen, Germany., Department of Radiology, University Medical Center Goettingen, Goettingen, Germany., Department of Radiology, University Medical Center Goettingen, Goettingen, Germany; Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.