In a recent issue of Cancer Letters Gouveia and colleagues  studied a series of 40 Angolan patients diagnosed with Urogenital Schistosomiasis (UGS). They reported that 45% of them presented UGS-associated Squamous Cell Carcinoma (SCC) and/or urothelial cell carcinoma . In addition these authors performed Liquid Chromatography-Mass Spectrometry and this analysis revealed numerous estrogens like metabolites. These schistosome infection-associated metabolites included Catechol Estrogen Quinones (CEQ) and CEQ-DNA-adducts, two of which had been identified previously in S. haematobium [1-3]. They conclude suggesting that these metabolites can be expected to provide deeper insights into the carcinogenesis UGS-induced bladder cancer, and as biomarkers for diagnosis and/or prognosis of this neglected tropical disease-linked cancer.
The results we have recently obtained partly confirm and partly diverge from the results reported by Gouveia and colleagues . We have studied 300 individuals from the North of Angola . Prevalence of S. haematobium infection was 71.7% (215/300). Ultrasound and cystoscopy examinations revealed pathological conditions at the urinary tract in all examined in a sub-sample of 29 (13.5%) of the patients diagnosed with UGS. One case (0.3%) presented with a vesical tumor. This tumor was classified as Squamous Cell Carcinoma (SCC) . The low frequency of tumors found in our series in comparison to the high frequencies of tumors in the series of Gouveia, et al.  suggests that bladder cancer associated to UGS might have an increased burden than already described previously. In fact other authors reported that the incidence of SCC is 3-4/100000 cases  which are more in agreement with our study.
In keeping with the results of Gouveia and colleagues  we have previously described estrogen metabolites to be associated with schistosomiasis infected persons [6-8]. Our group has been working on the identification of parasite derived compounds that might be implicated in the carcinogenesis of S. haematobium. The majority of these compounds are catechol estrogens. The carcinogenic effect of this estrogen–DNA adduct mediated pathway could explain the link between chronic schistosomiasis haematobia and SCC of the bladder [6-8]. The association found by Gouveia and colleagues  and our selves between estrogen metabolites and schistosomiasis associated bladder cancer remains to be clarified.
Citation: Botelho MC, Alves H and Richter J. Estrogen Metabolites for the Diagnosis of Schistosomiasis Associated Urinary Bladder Cancer. SM Trop Med J. 2016; 1(1): 1004.