Effect of green tea catechins in patients with high-grade prostatic intraepithelial neoplasia: Results of a short-term double-blind placebo controlled phase II clinical trial.

BACKGROUND AND STUDY OBJECTIVE: Several studies suggest a protective role of green tea catechins against prostate cancer (PCa). In order to evaluate the efficacy of green tea catechins for chemoprevention of PCa in patients with high-grade prostate intraepithelial neoplasia (HG-PIN) we performed a phase II clinical trial. METHODS: Sixty volunteers with HG-PIN were enrolled to carry out a double-blind randomized placebo-controlled phase II clinical trial. Treated group took daily 600 mg of green tea catechins (Categ Plus®) for 1 year. Patients were screened at 6 and 12 months through prostatic biopsy and measurements of prostate-specific antigen (PSA). RESULTS: Despite the statistically significant reduction of PSA observed in subjects who received green tea catechins for 6 and 12 months, we did not find any statistical difference in PCa incidence between the experimental groups neither after 6 nor after 12 months. However, throughout the one-year follow- up we observed very limited adverse effects induced by green tea catechins and a not significant improvement in lower urinary tract symptoms and quality of life. CONCLUSIONS: Although the small number of patients enrolled in our study and the relatively short duration of intervention, our findings seems to deny the efficacy of green tea catechins. However, results of our clinical study, mainly for its low statistical strength, suggest that the effectiveness of green tea catechins should be evaluated in both a larger cohort of men and longer trial.

Chemical and Mineralogical Analysis of Ureteral Stent Encrustation and Associated Risk Factors.

OBJECTIVE: To assess the burden and chemical and mineralogical composition of stent coating at both stent ends, with evaluation of associated risk factors. MATERIALS AND METHODS: A total of 40 consecutive patients submitted to ureteral-stent removal were considered. Stents were previously positioned for both urolithiasis and during the management of other urologic diseases and/or procedures. Mean indwelling time was 59.2 ± 7.5 days. ANALYTICAL PROCEDURES: Encrustations were submitted to chemical-mineralogical analysis as well as to their quantification. Quantification was achieved by measuring the weight of stent fragments before and after oxidative acid treatment to dissolve the deposited (both organic and inorganic) material. The analytical solution obtained by acid attack was used to acquire information on calcium and magnesium content with atomic-absorption spectroscopy. X-ray diffraction was used to determine the mineralogy of encrustations for a group of stent samples characterized by relatively high amounts of deposited material. RESULTS: The composition of encrustations at the proximal coil reflected the composition of stones in patients with urolithiasis. Whewellite was the more common encrustant. In a regression model, the variable mostly related to the burden of proximal encrustation was urolithiasis (P = .04), especially in frequent stone formers. At the distal coil, higher degrees of encrustation were related to urinary tract infection (P = .012) and patient's aging (P = .05), thus suggesting a possible association with a bladder outlet dysfunction. CONCLUSION: The present study highlighted some variables related to stent encrustation and seems to be the first one analyzing separately the two coils. Our outcomes suggest that the so-obtained risk factors have to be considered when positioning a ureteral stent.