Youth matters: a systematic review of the molecular and clinical landscape of bladder cancer in young adults.

Abstract

Background: Bladder cancer is uncommon in individuals under the age of 45, and its clinical and molecular characteristics in this population differ significantly from those observed in older patients. This systematic review aims to evaluate recurrence, progression, survival outcomes, and molecular profiles of bladder cancer in young adults.

Methods: A systematic search was conducted in MEDLINE, Embase, Scopus, and CENTRAL databases for studies published between 1998 and 2024. Eligible studies included patients aged ≤ 40 years and reported outcomes such as recurrence-free survival (RFS), progression, and overall survival (OS). A total of 18 studies were included. Risk of bias was assessed using the ROBINS-I tool, and pooled estimates were calculated using random-effects meta-analysis models.

Results: Bladder cancer in young adults is predominantly non-muscle-invasive and low-grade, with high survival rates. Recurrence rates varied across studies, ranging from 0 to 35.9%, while disease progression was rare. Several studies reported 100% RFS and OS in pediatric and young adult populations. The molecular profile of tumors in younger patients differed from that of older adults, with lower rates of TP53 and FGFR3 mutations. Meta-analysis revealed favorable long-term outcomes, particularly in patients diagnosed at early stages.

Conclusion: Bladder cancer in young adults presents a distinct clinical and molecular entity with excellent prognosis, minimal progression, and high survival. Despite this, recurrence remains a concern, highlighting the need for age-specific surveillance strategies and further research into molecular drivers of the disease in this age group.