Non-invasive Methods To Detect Schistosome-based Bladder Cancer: Is The Association Sufficient For Epidemiological Use?

Main Category: Urology / Nephrology
Also Included In: Cancer / Oncology
Article Date: 16 Nov 2009 - 4:00 PST

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UroToday.com - Urinary schistosomiasis caused by the trematode parasite Schistosoma haematobium is endemic in most of Africa. This infection is one of the world's great neglected diseases and it is a known carcinogen. The parasite is long lived, and causes sustained inflammation in the vesicular veins where the adults live for as long a 10 or 12 years. From the urological viewpoint, this prolonged inflammation as well as products of the parasite itself lead over time to the development of squamous cell carcinoma of the bladder.

In Africa, where the parasite occurs, bladder cancer is the most common form of cancer seen in populations, and the majority of these cancers are squamous cell carcinoma. The association is clear; we do not know much about the epidemiology and actual mortality of this condition because the only definitive diagnostic procedure is cystoscopy and biopsy. This cannot be done on a population wide study.

The paper we wrote is a review of some noninvasive techniques that can be applied on a population level in endemic areas. We propose that a battery of non-invasive tests, both cytological and biochemical should be sufficient to predict the serious nature of this infection. In Egypt it has been shown that reduction of this infection to very low levels and almost eliminated squamous cell carcinoma of the bladder. We feel that a sophisticated diagnostic center should be set up in Ghana from which a service could be provided to regional countries and societies where this parasite abounds. Prior studies in Ghana have demonstrated that:

1. A high incidence of abnormal bladder pathology (~40%) demonstrated in the four Ghanaian villages surveyed as assessed by portable ultrasound studies.
2. Digital image analysis (DIA) using Feulgen-stained urine cytology preparations could predict abnormal pathology by ultrasound.
3. About 60% of cases studies by DIA also had abnormal BlCa4 tumor-associated antigen present in their urine.
4. The application of DIA on captured transitional and squamous urine cytology preparations proved that both cell types could predict abnormal pathology but that squamous-type cells did so with greater accuracy.
5. In the future such non-invasive biomarker technology applied to an at-risk population should improve early detection and result in early intervention.

References:

Shiff C, Veltri R, Naples J, Quartey J, Otchere J, Anyan W, Marlow C, Wiredu E, Adjei A, Brakohiapa E, Bosompem K. Ultrasound verification of bladder damage is associated with known biomarkers of bladder cancer in adults chronically infected with Schistosoma haematobium infection in Ghana. Trans. R. Soc. Trop. Med. Hyg. 2006; 100: 847-854.

Naples J, Isharwal S, Shiff C, Bosompem KM, and Veltri RW. Clinical Utility of Squamous and Transitional Nuclear Structure Alterations induced by Schistosoma haematobium in chronically infected adults with bladder damage verified by Ultrasound in Ghana. Anal Quant Cytol Histol 2009; 31:143-152.

Written by Clive Shiff, MD and Robert W. Veltri, MD as part of Beyond the Abstract on UroToday.com

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