Non-invasive methods to detect schistosome-based bladder cancer: is the association sufficient for epidemiological use?

The association between chronic infection with Schistosoma haematobium and squamous cell carcinoma of the bladder is well known but there are few epidemiological data available to assess the extent of this cancer in schistosome-endemic areas. Invasive surgical procedures are not practical for epidemiological appraisal, therefore this important health matter is unresolved. This review examines recent work done to identify and detect biomarkers that can be found in voided urine and therefore obtained without invasive procedures. A variety of products of cell cycle kinetics, nuclear activity enzymes and even nuclear morphometry have been studied in urine specimens and these in concert may be sufficient to indicate the likelihood of the presence of bladder cancer or some predictive pre-cancerous state. Although these techniques require a sophisticated central laboratory for analysis, specimens can easily be collected in the field and brought to the centre, which could serve regional programmes. We suggest that early diagnosis of pre-cancerous conditions associated with urinary schistosomiasis, if appropriately treated, could save countless lives.