Disparities in male versus female oncologic outcomes following bladder preservation: A population-based cohort study

In surgical series of muscle-invasive bladder cancer (MIBC), women have higher recurrence rates, disease progression, and mortality following radical cystectomy than men. Similar reports of oncologic differences between men and women following trimodality therapy (TMT) are rare. Our hypothesis was that there would be no difference in overall survival (OS) between sexes receiving TMT.

We queried the National Cancer Database (NCDB) for patients diagnosed with clinical stage T2-T4aN0 M0 MIBC between 2004-2016. We considered patients to have received TMT if they received 55 Gy in 20 fractions or 59.4-70.2 Gy of radiotherapy with concurrent chemotherapy following a transurethral resection of bladder tumor (TURBT). We used multivariable Cox proportional hazard models to determine whether sex was associated with risk of mortality. In addition to OS, we calculated relative survival (RS) to adjust for the fact that females generally survive longer than males.

Of the patients, 1960 underwent TMT and had survival data. Less than one quarter were female. In the first year following treatment, women had worse OS and RS than men (p = 0.093 and p = 0.030, respectively). However, overall and relative survival differences between sexes were not statistically significantly different in Years 2 and later. Unlike with OS, the RS between sexes remained significant at 9 years; in multivariable analysis based on RS, women were 43% more likely to die than men (p < 0.001).

Women had a higher initial risk of death than men in the first year following TMT. However, long-term survival between sexes was similar. TMT is an important treatment option in both men and women seeking bladder preservation.