Yii-Her Chou

Significant predictive factors for prognosis of primary upper urinary tract cancer after radical nephroureterectomy in Taiwanese patients.

OBJECTIVES To follow up the long-term prognosis of patients who underwent nephroureterectomy for primary upper urinary tract (UUT) cancer and to evaluate the predictive factors of tumour recurrence and survival. METHODS Between January 1990 and June 2005, 260 patients with primary UUT transitional cell carcinoma (TCC) underwent radical nephroureterectomy at our institution. The medical records of these patients were retrospectively reviewed. The clinical and histopathological data were analyzed to evaluate predictive factors. RESULTS The median follow-up time was 52 mo. In total, 89 patients (34.1%) developed subsequent bladder tumours. Predictive factors of bladder tumour recurrence were being male and having renal insufficiency. Local recurrence developed in 16 patients (6.2%); only the tumour stage was significantly associated with local recurrence. Metachronous contralateral UUT tumour was diagnosed in 12 patients (4.6%), with gender being the only predictive factor. Of the 260 patients, 167 (63.9%) were disease-free and alive at a median follow-up of 56.5 mo, and 45 (17.2%) died of urothelial cancer at a median period of 20 mo. Only the tumour stage was a prognostic factor to predict cancer-specific survival. CONCLUSIONS In patients with UUT-TCC after radical nephroureterectomy, tumour stage is the only prognostic factor for both local recurrence and cancer-specific survival. Male patients with renal insufficiency should be alerted to the possibility of bladder tumour recurrence. Because female patients were more likely to develop contralateral recurrences, renal ultrasonography, intravenous pyelography, or retrograde pyelography should be performed more frequently for female patients who live in the high-prevalence area.

The Prevalence of and Risk Factors for Androgen Deficiency in Aging Taiwanese Men

INTRODUCTION Androgen deficiency in aging men has attracted much medical interest. Most studies on androgen deficiency have been conducted in Caucasian populations, and data from other ethnicities are lacking. AIM To evaluate the prevalence of and risk factors for androgen deficiency and symptomatic androgen deficiency in Taiwanese men over 40 years old. METHODS From August 2007 to April 2008, a free health screening was conducted by a medical center in Kaohsiung, Taiwan, and 819 men participated in this health screening. All participants completed a health questionnaire, received a detailed physical examination, and blood samples were drawn between 8:00 and 12:00 am. MAIN OUTCOME MEASURES Serum total testosterone (TT), albumin, and sex hormone-binding globulin levels were measured. The level of free testosterone (FT) was calculated. Clinical symptoms of androgen deficiency were assessed using the Androgen Deficiency in the Aging Male (ADAM) questionnaire. RESULTS Seven hundred thirty-four men who met the inclusion criteria (mean age 57.4 +/- 6.7 years; range: 43-87 years) were included in this study. The prevalence of androgen deficiency was 24.1% based on the criterion of TT level < 300 ng/dL, and 16.6% based on the criterion of both TT < 300 ng/dL and FT < 5 ng/dL. The prevalence of symptomatic androgen deficiency was 12.0%. Both prevalence of androgen deficiency and symptomatic androgen deficiency increased with age. Older age, obesity, and diabetes mellitus were independent risk factors for androgen deficiency and symptomatic androgen deficiency. CONCLUSIONS In a sample of aging Taiwanese men, a substantial proportion had androgen deficiency and symptomatic androgen deficiency, and the prevalence increased with age. Older age, obesity, and diabetes mellitus were independent risk factors for androgen deficiency and symptomatic androgen deficiency. Those potentially modifiable risk factors like obesity and diabetes mellitus should be prevented to maintain normal testosterone levels during aging in men.

Should Patients With Primary Upper Urinary Tract Cancer Receive Prophylactic Intravesical Chemotherapy After Nephroureterectomy

PURPOSE We assessed the efficacy of prophylactic intravesical chemotherapy for primary upper urinary tract urothelial cancer after nephroureterectomy during long-term followup. MATERIALS AND METHODS From January 1985 to June 2007, 196 patients with primary upper urinary tract urothelial cancer were included in this study. Patients were divided into group 1-31 who received intravesical epirubicin instillation, group 2-27 who received intravesical mitomycin C instillation and group 3-138 who did not receive prophylactic instillation after nephroureterectomy. We compared the bladder tumor recurrence rate, number of recurrence episodes, time to first bladder tumor recurrence, tumor type, percent of patients with cystectomy and percent who died of urothelial cancer, and the recurrence-free survival rate. RESULTS Of the 196 patients 73 had subsequent bladder recurrence at a mean followup of 55.6 months. There were no significant differences in recurrence type, mean number of bladder tumor recurrences, percent of patients with cystectomy and the cancer specific survival rate. The bladder recurrence rate was lower in group 1 and 2 than in group 3. Mean time to first bladder tumor recurrence was longer in groups 1 and 2. Kaplan-Meier curves of recurrence-free survival rates were significantly increased in groups 1 and 2. CONCLUSIONS Intravesical instillation of epirubicin or mitomycin C appears to be well tolerated and effective for preventing bladder recurrence and prolonging time to first bladder recurrence. Patients should receive prophylactic intravesical chemotherapy after nephroureterectomy.

Urinary Stone Analysis of 1,000 Patients in Southern Taiwan

Urolithiasis is a common urologic disease. Stones may occur in the kidney, ureter, or urinary bladder. We collected 1,000 stone samples in the subtropical area of southern Taiwan. Stone components were analyzed by Fourier transform infrared spectroscopy. Mixed components of calcium oxalate and calcium phosphate were the most common form of stones (52.3%), followed by calcium oxalate (27.8%) and calcium phosphate (9.3%). Uric acid stones accounted for 7.6%. Magnesium ammonium phosphate stones accounted for 3.0%. Only one cystine stone was found. In the study of urinary stone formation mechanism and prevention of recurrent urolithiasis, knowing the stone composition is important.

High melamine migration in daily-use melamine-made tableware

Melamine is commonly used to manufacture tableware, and this could be one of the important exposure sources in humans. The study aims to measure melamine migrated from different material-made tableware by the most sensitive technique of liquid chromatography-tandem mass spectrometry (LC-MS/MS). The test samples were filled with pre-warmed designated-temperature (from room temperature (∼20 °C), 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, to 90 °C) simulant (either distilled water or 3% acetic acid) up to 20 ml and immersed in a water bath at that designated temperature for 15 or 30 minutes (min). High melamine migration levels, ranging from 6.97 to 19.03 μg/ml, can be measured from all melamine-made samples containing 20 ml 3% acetic acid in water bath of 90 °C for 30 min, whereas melamine cannot be detectable in all other material-made samples in the same condition. In addition, the cheaper the melamine-made tableware samples, the higher the melamine migration levels. The migration of melamine amount is dependent on different temperatures, contact times, simulant, and prices of tableware. Since tableware is used in daily life, it is prudent to cautiously select materials that contain foodstuffs.

The impact of cigarette smoking, alcohol drinking and betel quid chewing on the risk of calcium urolithiasis.

PURPOSE To evaluate the independent and combined effects of alcohol drinking, cigarette smoking and betel quid chewing on the risk of calcium urolithiasis. METHODS A total of 354 cases diagnosed with calcium urolithiasis and 354 age- and sex-matched healthy controls were recruited from Kaohsiung Medical University Hospital between June 2003 and February 2007. All subjects completed a detailed questionnaire survey and provided blood and urine samples for biochemical evaluation. RESULTS Current cigarette smoking (odds ratio [OR], 1.66; 95% confidence interval [95%CI], 1.11-2.50; p=0.014) and current betel quid chewing (OR, 1.97; 95%CI, 1.06-3.64; p=0.032), but not current alcohol drinking, were found to be independent risk factors for the development of calcium urolithiasis. The joint risk of current cigarette smoking and current betel quid chewing was increased 3.73-fold (OR, 3.73; 95%CI, 1.81-7.70, p<0.001) compared to those who had neither habit. CONCLUSIONS Both cigarette smoking and betel quid chewing are independent risk factors for the development of calcium urolithiasis. The risk effect is even strengthened when subjects have both habits. These findings suggest users can greatly reduce the risk of calcium urolithiasis if they quit these two habits.

Prognostic Significance of p53 and X-ray Repair Cross-complementing Group 1 Polymorphisms on Prostate-Specific Antigen Recurrence in Prostate Cancer Post–Radical Prostatectomy

Purpose: The tumor suppressor p53 and DNA repair gene X-ray repair cross-complementing group 1 (XRCC1) are thought to play important roles on prostate cancer susceptibility and tumor development. We investigated the potential prognostic roles of p53 (codon 72) and XRCC1 (codons 194, 280, and 399) polymorphisms in clinical localized prostate cancer after radical prostatectomy. Experimental Design: A total of 126 clinical localized prostate cancer patients undergoing curative radical prostatectomy at the Kaohsiung Medical University Hospital and Kaohsiung Veterans General Hospital were included in this study. The p53 codon 72 and XRCC1 codons 194, 280 and 399 polymorphisms were determined by the PCR-RFLP method. Their prognostic significance on prostate-specific antigen (PSA) recurrence were assessed using the Kaplan-Meier analysis and Cox regression model. Results: The p53 codon 72 Arg/Arg genotype was associated with increased PSA recurrence risk compared with the Arg/Pro and Pro/Pro genotypes, although the difference did not reach significance (30.3% versus 20.4%, P = 0.247). Of these three XRCC1 polymorphisms, the codon 399 Arg/Gln + Gln/Gn genotypes were significantly associated with higher risk of PSA recurrence after radical prostatectomy compared with the Arg/Arg genotype (34.0% versus 15.1%, P = 0.013) and poorer PSA-free survival (log-rank test, P = 0.0056). After considering for other covariates in a Cox proportional hazard model, the XRCC1 Arg/Gln and Gln/Gln genotypes (hazard ratio, 4.73; 95% confidence interval, 1.61-13.92; P = 0.005) and high Gleason score (Gleason score, 8-10; hazard ratio, 5.58; 95% confidence interval, 1.58-19.71; P = 0.008) were still independent predictors of poor PSA-free survival after radical prostatectomy. The similar significant results were not found in XRCC1 codons 194 and 280. Conclusions: Our results suggest that the XRCC1 codon 399 polymorphism may be a prognostic factor for PSA recurrence after radical prostatectomy.

Low exposure to melamine increases the risk of urolithiasis in adults

Melamine, a widely used chemical found in many products in daily use, became a public health concern due to melamine-associated urinary stone formation in children. In adults, it is still unknown whether low-dose melamine exposure may also cause urolithiasis. To address this question, we studied 211 Taiwanese patients diagnosed with calcium urolithiasis and 211 age- and gender-matched controls. All patients completed a detailed questionnaire and provided blood and urine samples for biochemical analysis. Urinary melamine concentrations were measured by triple-quadrupole liquid chromatography tandem mass spectrometry. Compared with those whose urinary melamine levels were below the detection limit of the method, patients with urinary melamine levels of up to 3.11  ng/ml and those with levels of ≥3.12  ng/ml had 3.01- and 7.64-fold increased risk, respectively, of calcium urolithiasis after adjusting for educational level, fluid intake, cigarette smoking, betel quid chewing, alcohol drinking, urinary uric acid, calcium, creatinine, and estimated creatinine clearance rate. The population attributable risk of calcium urolithiasis averaged 50% when melamine was detected in the urine, after considering other covariates. MALDI-TOF mass spectrometry detected melamine in the stones of nine representative patients who had measurable urinary melamine levels. Thus, low-dose melamine exposure can play an important role in calcium urolithiasis in Taiwanese adults.

Urinary melamine and adult urolithiasis in Taiwan

BACKGROUND This study aims to investigate the association between urinary melamine concentration and the risk of urolithiasis in adult. METHODS From 2003 to 2007, 11 and 22 patients diagnosed with upper urinary tract uric acid urolithiasis and calcium urolithiasis, respectively, were recruited from Kaohsiung Medical University Hospital. For comparison, we randomly collected 22 sex- and age-matched subjects who come to the same hospital for regular health check-up at the same period of time. Urinary melamine concentration was measured by the method of triple-quadrupole liquid chromatography tandem mass spectrometry (LC-MS/MS). Wilcoxon rank sum test was used to compare the urinary melamine concentrations in uric acid urolithiasis patients with controls as well as in calcium urolithiasis patients with controls. FDR (false discovery rate) was used to correct the p-values for two comparisons. RESULTS Subjects with uric acid urolithiasis (median: 0.50 vs 0.06microg/mmol creatinine, Wilcoxon test: FDR_p=0.024) and with calcium urolithiasis (median: 0.14 vs 0.06, FDR_p=0.024) had significantly higher urinary melamine concentration than controls. Based on the ROC curves, subjects whose melamine levels were over 0.262 and 0.037microg/mmol creatinine, respectively, might have significant risks to have uric acid and calcium urolithiasis. CONCLUSION This preliminary study suggests that exposure to even low-dose melamine-related products still have the potential to develop both uric acid and calcium urolithiasis in adults.

Androgen receptor gene polymorphism and prostate cancer in Taiwan

BACKGROUND AND PURPOSE The length of polymorphic CAG trinucleotide repeats in the polyglutamine region of the androgen receptor (AR) gene has been suggested to be inversely correlated with the transactivation function of the AR. An increase in androgen activity may be associated with prostate cancer, and ethnic variations in CAG repeat length may contribute to varying prostate cancer risks in different populations. This case-control study investigated the potential role of AR polymorphism in prostate cancer risk in Taiwanese. METHODS Sixty six pathologically-confirmed prostate cancer patients and 104 controls were studied. CAG repeat polymorphism was genotyped by a polymerase chain reaction (PCR)-based direct sequencing method. Logistic regression was used to determine the relative risk of AR gene CAG number on prostate cancer risk. The associations of AR-CAG polymorphism with disease stage, pathologic grade, and age at diagnosis were assessed. AR-CAG repeat number was first treated as a continuous variable, then was divided into short and long groups (n < 23 vs n > or = 23) for categorical analysis. The extreme groups of AR-CAG distribution were also analyzed for these associations (n < or = 20 vs n > or = 26 and n = 21-25 vs n > or = 26). RESULTS The mean number of CAG repeats in patients and controls was similar: 23.2 +/- 3.0 (range, 15 to 31) and 22.9 +/- 3.1 (range, 15 to 31), respectively. No association was found between AR-CAG repeat polymorphism and disease stage (p = 0.30), histological grade (p = 0.49), or age at diagnosis (p = 0.51). After adjusting for other covariates (age, body mass index, education level, smoking, and alcohol status), the number of AR-CAG repeats was not significantly associated with prostate cancer risk [odds ratio (OR) = 0.97, 95% confidence interval (95% CI) = 0.72 to 1.31; p = 0.84]. In categorical analysis, men with short CAG repeats (n < 23) did not have increased risk for prostate cancer (OR = 0.45, 95% CI = 0.29 to 1.05) compared to those with long CAG repeats (n > or = 23). Non-significant differences in prostate cancer risk were also found when comparing the extreme short group (n < or = 20) and the intermediate group (n = 21-25) to the extreme long group (n > or = 26) [n < or = 20 vs n > or = 26: OR = 1.00, 95% CI = 0.34 to 3.00; n = 21-25 vs n > or = 26: OR = 0.82, 95% CI = 0.37 to 1.81]. CONCLUSIONS The results of this study do not support an important effect of AR-CAG repeat polymorphism on prostate cancer risk. A large-scale study is needed to clarify genetic components of prostate cancer risk in the Taiwanese population.