My sister passed away last year after a short battle with bladder cancer. What I noticed when researching the disease, is that the most prominent symptom in the early stages is haematuria. Maybe my sister was a rarity, but she never had haematuria but she presented to her GP with high urination frequency.
This led her down the path of being tested for diabetes and it was another month before an ultrasound showed a large bladder tumour that had started to infiltrate the bladder wall. I wonder if high urination frequency should be included in the early symptoms of bladder cancer in your literature.