Women with bladder cancer have worse survival outcomes than men, but only for a short while after diagnosis, according to Anke Richters, PhD, of the Netherlands Comprehensive Cancer Organization and colleagues, who published new study findings based on national data in Urologic Oncology.
In flexible parametric survival models including 24,169 patients (24% female) with T1 or higher bladder cancer from the Netherlands, excess mortality among women was approximately 1.5-fold higher than excess mortality among men within the first 2 years of diagnosis, but it equalized thereafter. The early female survival disadvantage was apparent in analyses of patients up to age 80 years with either nonmuscle-invasive (NMIBC) or muscle-invasive (MIBC) bladder cancer.
Women more often had higher stage disease and a nonurothelial tumor histology. When the investigators adjusted for baseline differences in age, tumor, node, and metastasis-stage, and histology, it accounted for only part of the mortality gap.
The team observed no stark gender differences in treatment. Diagnostic delay was around 2 months for both men and women. In the NMIBC group, 6% of both men and women underwent a cystectomy. In the MIBC group, 39% vs 37% underwent a cystectomy, 8% vs 9% neoadjuvant chemotherapy, and 29% vs 26% radiation therapy, respectively.
“This would advocate more aggressive treatment in women, for instance considering radical cystectomies in female high-risk NMIBC patients or more frequent application of neo-adjuvant chemotherapy in female MIBC patients,” Dr Richters’ team wrote. “Additionally, the fact that women present with higher stage disease again advocates focus on efforts to increase early diagnosis in women.”
The findings support the hypothesis that women have a thinner bladder wall, according to the researchers. “This may be associated with more (micro) metastatic disease at diagnosis than men within strata of T-stage, which would assert a harmful effect especially in the first years after diagnosis.”
Richters A, Dickman, Witjes JA, et al. Bladder cancer survival: Women only fare worse in the first two years after diagnosis [published online August 31, 2019] . Urol Oncol. doi:10.1016/j.urolonc.2019.08.001