Rare Disease Day: Standing together for people affected by rare bladder cancers

Rare Disease Day, held each year on the last day of February, is a global reminder that people living with rare conditions often face additional barriers to diagnosis, treatment and support. For those affected, rarity can mean uncertainty, limited information and fewer options.

While bladder cancer is one of the most common cancers worldwide, around 3–5% of cases are rare subtypes. These include urachal cancer, small cell carcinoma, plasmacytoid carcinoma and other uncommon forms. Because they are diagnosed less frequently, these cancers are often:

• Identified later or misdiagnosed
• Under-researched compared to more common forms
• Associated with fewer dedicated treatment guidelines
• Linked to limited access to clinical trials

Urachal cancer illustrates both the challenges and the progress being made. It develops from the urachus, a structure present before birth that usually disappears. This cancer behaves differently from typical bladder cancer, and until recently, very little was known about its biology.

A study published in Nature analysed the largest collection of urachal tumour samples to date. Researchers identified important genetic changes, including mutations in TP53, KRAS, BRAF and PIK3CA. The findings show that urachal cancer has distinct molecular features and may require tailored treatment strategies. Some tumours share characteristics with colorectal cancers, suggesting that certain existing therapies could be relevant. The study also highlights the potential of targeted treatments and immunotherapy for selected patients.

Despite these advances, people living with rare bladder cancers often report:

• Difficulty finding clear and reliable information
• Limited access to specialised expertise
•  Feeling isolated due to the rarity of their diagnosis

Rare Disease Day is an opportunity to reaffirm that no patient should be left behind. Greater investment in research, improved access to innovative treatments and stronger collaboration across the bladder cancer community are essential.

We encourage patients, families, healthcare professionals and advocates to use this day to raise awareness of rare bladder cancers, share trusted information and amplify patient voices. Together, we can help ensure that rarity does not mean invisibility.

Learn more about Rare Disease Day and discover how you can get involved. 

Reference: Grose, D., Dadhania, V., Kerr, R., & Black, P. C. (2024). Comprehensive molecular analysis of urachal carcinoma reveals distinct genetic profiles and potential therapeutic targets. npj Precision Oncology, 8, Article 12. Available at: https://www.nature.com/articles/s41698-024-00795-4