Transurethral resection of bladder tumours is an established operation but is a flawed operation. Recurrence rates for superficial bladder cancer are astronomically high at up to 64% at 5 years. In other tumour types this rate of recurrence would be unacceptable and the question inevitably arises as to why recurrence is so common .
Recurrence could in theory be due to
- Implantation of tumour cells shed from the original tumour
- Tumour was simply missed at the original surgery
- A field effect where the whole bladder lining becomes unstable.
Studies from Germany suggest that ‘ missed tumour’ is a very significant factor: if patients return to theatre for a re-look operation at 2 weeks then in 25% of patients tumour is identified which was presumably missed at the time of the original surgery!
How can we be certain that all the tumour is removed at the first operation ?
Photodynamic diagnosis aims to improve the visualization of bladder tumours allowing more complete removal by the surgeon. A photosensitive compound is introduced into the bladder for one hour via a catheter before a cystoscopy is performed under ultraviolet light. The tumour tissue fluoresces bright red under ultraviolet light whereas the normal tissue is yellow/grey. The technique is straightforward and safe and does appear to allow better visualization of tumour.
In patients operated on by the LBU surgeons since 2005 , extra tumours ( not seen under conventional white light ) have been found in around 30%. Over 200 ‘blue light’ cystoscopies have been performed and there have been no side effects or reactions to the photosensitiser used , HEXVIX.
The technique can potentially benefit most patients with non-muscle invasive (superficial) bladder cancer but is particularly helpful in patients with tumours that seem to be recurring rapidly, or those in whom a diagnosis of carcinoma in situ is suspected . The technique is of much less help in patients with muscle invasive bladder tumours.
Blue-light cystoscopy is then an exciting new tool in the quest to improve bladder cancer treatment.