Bladder cancer is among the most common cancers worldwide (4th in men). It is responsible for high patient morbidity
and displays rapid recurrence and progression. Lack of sensitivity of gold standard techniques (white light cystoscopy,
voided urine cytology) means many early treatable cases are missed. The result is a large number of advanced cases of
bladder cancer which require extensive treatment and monitoring. For this reason, bladder cancer is the single most
expensive cancer to treat on a per patient basis. In recent years, autofluorescence spectroscopy has begun to shed light
into disease research. Of particular interest in cancer research are the fluorescent metabolic cofactors NADH and FAD.
Early in tumour development, cancer cells often undergo a metabolic shift (the Warburg effect) resulting in increased
NADH. The ratio of NADH to FAD (“redox ratio”) can therefore be used as an indicator of the metabolic status of cells.
Redox ratio measurements have been used to differentiate between healthy and cancer breast cells and to monitor cellular
responses to therapies. Here, we have demonstrated, using healthy and bladder cancer cell lines, a statistically significant
difference in the redox ratio of bladder cancer cells, indicative of a metabolic shift. To do this we customised a standard
flow cytometer to excite and record fluorescence specifically from NADH and FAD, along with a method for
automatically calculating the redox ratio of individual cells within large populations. These results could inform the
design of novel probes and screening systems for the early detection of bladder cancer.