Patients diagnosed with nonmuscle-invasive bladder cancer (NMIBC) before the age of 50 years have a lower risk of dying from their cancer than older patients aged 50 to 70 years, according to new study findings presented at the 36th annual European Association of Urology virtual congress.
Using the Swedish national bladder cancer registry (BladderBaSE), investigators examined data from 15,452 patients younger than 70 years newly diagnosed with bladder cancer during 1997-2014. Of the 12,100 patients with NMIBC, 1019 (8.4%) were younger than 50 years and 11,081 (91.6%) were aged 50 to 70 years, the age group with the highest prevalence of bladder cancer.
Among patients with NMIBC, the younger group had a significant 57% lower risk of dying from bladder cancer compared with the older group, Mieke Van Hemelrijck, PhD, of King’s College London in the United Kingdom reported for her team.
A higher proportion of patients younger than 50 years than aged 50-70 years had clinical Ta and low grade tumors, she pointed out. The younger NMIBC group also had fewer comorbidities. Lower urinary tract infections in the 24 months prior to NMIBC diagnosis, however, occurred in comparable proportions of both groups: 5% of the younger group vs 6% of the older group. The older NMIBC group had a higher proportion of male patients. Smoking history was not captured in the registry precluding analysis, which is a study limitation.
Differences in survival may in part be explained by the distribution of NMIBC stage and grade among younger patients, Dr Van Hemelrijck said. Other possible factors include differences between groups in tumor biology, diagnostic delay, and clinical decision-making for treatments.
Among patients with NMIBC, 8% of the younger group and 13% of the older group received intravesical treatment. Among those with high-risk NMIBC, 13% of the younger group and 10% of the older group underwent radical cystectomy.
The investigators also examined bladder cancer survival among 3352 patients with muscle-invasive bladder cancer (MIBC) but found no significant differences by age group.
Russell B, Leidberg F, Hagberg O, et al. Risk of bladder cancer death in patients younger than 50 with non-muscle-invasive and muscle-invasive bladder cancer. Presented at the EAU 2021 virtual conference, July 8-12, 2021. Abstract P0738.