The cutoff level of free/total prostate specific antigen (f/t PSA) ratios in the diagnosis of prostate cancer: a validation study on a Turkish patient population in different age categories.

We investigated an optimal cutoff level of free/total PSA ratios (f/t PSA) in predicting prostate cancer in different age groups, focusing on the avoidance of unnecessary prostate biopsies. A total of 4955 men were enrolled into the study. Serum tPSA, fPSA, and f/t PSA ratios were determined for the study population. All males who had suspicious digital rectal examination and tPSA > 4 ng/mL underwent transrectal ultrasonography-guided prostate biopsy. Receiver operating characteristic (ROC) curves for each group were generated by plotting the sensitivity versus 1-specificity for the f/t PSA ratio. The sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were obtained using various f/t PSA ratio cutoffs for different age groups. There were 657 patients with a PSA level of 4-10 ng/mL. According to sensitivity and specificity f/t% PSA cutoff points were determined to be 10%, 15%, 15%, and 10% in 50-59 years, 60-69 years, >70 years, and all ages categories, respectively, in patients with initial PSA level of 4-10 ng/mL. f/t PSA ratio had an area under the curve (AUC) value of 0.81 (95% confidence level: 0.80-0.82) for all age groups in detecting prostate cancer. f/t PSA ratio has an AUC value of 0.669 (0.632-0.705) in detecting prostate cancer among patients with a PSA level of 4-10 ng/mL. Ten percent of f/t PSA ratio had the highest specificity with PLR and 30% f/t PSA ratio had the highest sensitivity with lower NLR in the all-age categories. The current study shows that the use of f/t PSA ratio in patients with PSA levels of 4-10 ng/mL should enhance the specificity of PSA screening and decrease the number of unnecessary biopsies. The age-related changes warrant further investigation in a large, multicentric, and multinational population to improve the clinical use of f/t PSA cutoffs.

eNOS gene intron 4 VNTR and exon 7-G894T polymorphisms in Turkish men with erectile dysfunction: a case control study.

INTRODUCTION: The associations between the gene polymorphisms and erectile dysfunction (ED) are limited. AIM: To examine a potential association between variable number of tandem repeats (intron 4 VNTR), G894T polymorphisms, and ED in Turkish men. METHODS: Sixty-four men with ED and 82 healthy men as a control group were included in the study. The patients were evaluated by medical history, International Index of Erectile Function (IIEF), serum glucose, and lipid profiles. VNTR and G894T polymorphism were assessed by isolated DNA blood samples obtained from the patient group with ED and controls. MAIN OUTCOME MEASURES: Assesment of IIEF and VNTR and G894T polymorphism in the isolated DNA blood samples. RESULTS: Genotype distributions of endothelial nitric oxide syntase (eNOS) gene intron 4 VNTR polymorphisms in the patient group were similar to those in the healthy group (P > 0.05). The frequency of the eNOS gene intron 4 genotype was found as bb: 55 (67.1%), ab: 26 (31.7%), and aa: 1 (1.2%) in the controls and bb: 43 (67.2%), ab: 19 (29.7%), and aa: 2 (3.1%) in the patient group. The frequency of the G894T was found as gg: 61 (74.4%), gt: 21 (25.6%), and tt: 0 (0.0%) in the controls and gg: 32 (50.0%), gt: 27 (42.1%), and tt: 5 (7.8%) in the patient group (P = 0.002). The frequencies of the "t" allele were 21 (12.8%) in the control group and 37 (28.9%) in the patient group (P = 0.001). Logistic regression analysis showed that G894T polymorphism was an independent risk factor for ED. CONCLUSIONS: We found significant differences in allelic and genotypic frequencies between patients and controls for the G894T eNOS polymorphisms. The presence of 894T allele in carriers increased the risk of ED. No association was found between VNTR polymorphism and in patients with ED.

Values for free/total prostate-specific antigen ratio as a function of age: necessity of reference validation in a Turkish population.

BACKGROUND: The aim of this study was to evaluate age-related changes in free/total prostate-specific antigen (f/t PSA) ratio, focusing on the avoidance of unnecessary prostate biopsies. METHODS: A total of 898 men aged 30-88 years without a history of prostate surgery and disease were enrolled into the study. Serum tPSA, fPSA and f/t PSA ratios were determined for the study population and for different age categories. All males who had suspicious digital rectal examination and tPSA >4 ng/mL underwent transrectal ultrasonography-guided prostate biopsy. Receiver operating characteristic (ROC) curves for each group were generated by plotting the sensitivity vs. 1-specificity for the f/t PSA ratio. The sensitivity and specificity were obtained using different f/t PSA ratio cutoffs for different age groups. RESULTS: Prostate cancer was detected in 63 patients (7%). Age-specific cutoffs were determined according to likelihood ratios at the levels of 10%, 15% and 15% f/t PSA ratio for ages 50-59, 60-69 and >/=70 years, respectively. However, a single cutoff of 10% is recommended across all age ranges (positive likelihood ratio 2.36). ROC curves demonstrated that the area under the curve (AUC) was significant for all patients with initial PSA of 4-10 ng/mL (AUC 0.703-0.796), except for the >/=70-year age group (AUC 0.549). CONCLUSIONS: The current study showed that the use of f/t PSA ratio in patients with PSA levels of 4-10 ng/mL should enhance the specificity of PSA screening and decrease the number of unnecessary biopsies. f/t PSA levels may show dissimilarities according to age and ethnicity, so further studies are warranted to identify this relationship.