Incidence, mortality, and five-year survival of bladder cancer in six population-based cancer registries in Colombia, 2003–2018

Background
Bladder cancer is a neoplasm with a higher prevalence in men and older adults. In Colombia, it accounts for approximately 1% of all cancer cases, with a marked difference between sexes (1.6% in men vs. 0.5% in women).
Objective
To determine the incidence, mortality, and 5-year relative survival (RS5) of bladder cancer in six population-based cancer registries (PBCRs) in Colombia, 2003–2018.
Methods
This retrospective observational study employed data from six population-based cancer registries (Barranquilla, Bucaramanga, Cali, Manizales, Medellín, Pasto). Crude and age-standardized incidence and mortality rates were calculated by the direct method using the Segi world standard population. Trends were evaluated using Joinpoint regression (Annual Percent Change, APC). RS5 was estimated using the Pohar-Perme method. Analyses were stratified by sex, age, PBCR, and histological subtype.
Results
During the study period, 3019 cases were registered (69.9% male, 30.1% female). The incidence was 2.3 times higher in men compared to women, with age-standardized rates ranging from 4.3 to 6.8 per 100,000, increasing sharply after the age of 55. Urothelial carcinoma of the bladder (UCB) was the most frequent subtype (77.9%), followed by the unspecified category (16.7%), adenocarcinoma (2.2%), and squamous cell carcinoma (1.9%). For the survival analysis (n = 2066, excluding Cali), RS5 varied significantly across registries, ranging from 42.6% (Pasto) to 83.7% (Medellín). In all registries, NS5 was consistently higher in men than in women.
Conclusion
Bladder cancer in Colombia showed a marked male predominance, with incidence increasing sharply after the sixth decade of life. The urothelial subtype was the most frequent and exhibited the most prognosis among the reported cases.