Serum prostate-specific antigen as a predictor of prostate volume and lower urinary tract symptoms in acommunity-based cohort： a large-scale Korean screening study

The aim of this study is to assess the ability of serum prostate-specific antigen （PSA） to predict prostate volume （PV） and lower urinary tract symptoms （LUTS） represented by the international prostate symptom score （IPSS）. From January 2001 to December 2011, data were collected from men who first enrolled in the Korean Prostate Health Council Screening Program. Patients with a serum PSA level of 10 ng ml^-1 or age 〈40 years were excluded. Accordingly, a total of 34 857 men were included in our study, and serum PSA, PV and the IPSS were estimated in all patients. Linear and age-adjusted multivariate logistic analyses were used to assess the potential association between PSA and PV or IPSS. The predictive value of PSA for estimating PV and IPSS was assessed based on the receiver operating characteristics-derived area under the curve （AUC）. The mean PV was 29.9 ml, mean PSA level was 1.49 ng ml^-1 and mean IPSS was 15.4. A significant relationship was shown between PSA and PV, and the IPSS and PSA were also significantly correlated after adjusting by age. The AUCs of PSA for predicting PV ~20 ml, 〉25 ml and 〉35 ml were 0.722, 0.728 and 0.779, respectively. The AUCs of PSA for predicting IPSS 〉 7, 〉 13 and 〉 19 were 0. 548, 0.536 and 0. 537, respectively. Serum PSA was a strong predictor of PV in a community-based cohort in a large-scale screening study. Although PSA was also significantly correlated with IPSS, predictive values of PSA for IPSS above the cutoff levels were not excellent. Further investigations are required to elucidate the exact interactions between PSA and LUTS and between PSA and PV in prospective controlled studies. Such studies may suggest how PSA can be used to clinically predict PV and the IPSS.

The prognostic significance of percentage of tumour involvement according to disease risk group in men treated with radical prostatectomy

We investigated the prognostic significance of percentage of tumour involvement （PTI） according to the clinicopathological features of prostate cancer among patients who underwent radical prostatectomy （RP）. A retrospective study of 534 patients who underwent RP between September 2003 and March 2008 without any neoadjuvant or adjuvant therapy was performed. The associations of PTI with various clinicopathological features and biochemical recurrence-free survival were examined via uni- and multivariate analyses. The predictive accuracy of the multivariate model was assessed with a receiver operating characteristics-derived area under the curve. PTI was demonstrated to be significantly associated with preoperative prostate-specific antigen （PSA） level （P=0.001）, pathological Gleason score （P〈0.001）, extraprostatic tumour extension （P〈0.001）, seminal vesicle invasion （P〈0.001） and positive surgical margin （P〈0.001） in univariate analyses. When patients were stratified into disease risk groups, PTI was an independent predictor of biochemical recurrence-free survival in multivariate analysis only among the low-risk group （P=0.033） but not the intermediate- （P=0.287） or the high-risk groups （P=0.828）. The addition of the PTI did not significantly increase the accuracy of the multivariate model devised for the prediction of biochemical recurrence-free survival among both total patients （P=-0.459） and the low-risk group （P=0.268）, respectively. In conclusion, although PTI appeared to be a more significant prognostic factor among patients with low-risk disease than among those with higher risk diseases, overall, the PTI may not provide additional prognostic information beyond what can already be obtained via established prognostic factors.

Association of the neutrophil-to-lymphocyte ratio and prostate cancer detection rates in patients via contemporary multi-core prostate biopsy

The aim of this study was to determine whether the neutrophil-to-lymphocyte ratio （NLR）, a measure of the systemic inflammatory response is associated with the overall prostate cancer detection rate in men who underwent contemporary multi （〉12）-core transrectal ultrasound （TRUS） biopsy. We reviewed the records of 3913 patients with initial prostate-specific antigen （PSA） levels ranging from 4 to 10 ng ml^-1 who underwent TRUS-guided prostate biopsy between April 2006 and May 2014. NLR was calculated by prebiopsy neutrophil and lymphocyte counts. We excluded patients who had evidence of acute prostatitis, a history of prostate surgery, and any systemic inflammatory disease. A multivariate logistic regression model was used to analyze prostate cancer detection. After adjusting for confounding factors, predictive values were determined according to the receiver operating characteristic-derived area under the curve, both including and excluding the NLR variable. In univariate analyses, NLR was a significant predictor of prostate cancer detection （P 〈 0.001）. In multivariate analyses, a higher NLR was significantly associated with prostate cancer detection after adjusting for other factors （OR = 1.372, P = 0.038）. The addition of NLR increased the accuracy from 0.712 to 0,725 （P = 0.005） in the multivariate model for prostate cancer detection. NLR may be a potentially useful clinical marker in the detection of prostate cancer among men with a PSA level in the 4-10 ng ml^-1 range. These findings are derived from a retrospective analysis and should be validated in larger populations through prospective studies.

Development and validation of a clinical nomogram predicting bladder outlet obstruction via routine clinical parameters in men with refractory nonneurogenic lower urinary tract symptoms

We aimed to develop and validate a clinical nomogram predicting bladder outlet obstruction(BOO)solely using routine clinical parameters in men with refractory nonneurogenic lower urinary tract symptoms(LUTS).A total of 750 eligible patient ≥50 years of age who had previously not responded(International Prostate Symptom Score[IPSS]improvement<4 points)to at least three different kinds of LUTS medications(including a-blocker)for the last 6 months were evaluated as subcohorts for nomogram development(n=570)and for split-sample validation(n=180).BOO was defined as Abrams-Griffiths number^40,or 20-39.9 with a slope of linear passive urethral resistance ratio>2 cmH20 ml^-1 s^-1.A stepwise multivariable logistic regression analysis was conducted to determine the predictors of BOO,and^-coefficients of the final model were selected to create a clinical nomogram.The final multivariable logistic regression model showed that age,IPSS,maximum urinary flow rate,postvoid residual volume,total prostate volume,and transitional zone index were significant for predicting BOO;these candidates were used to develop the final nomogram.The discrimination performance of the nomogram was 88.3%(95%Cl:82.7%-93.0%,P<0.001),and the nomogram was reasonably we 11-fitted to the ideal line of the calibration plot.Independe nt split-sample validation revealed 80.9%(95%Cl:75.5%-84.4%,P<0.001)accuracy.The proposed BOO nomogram based solely on routine clinical parameters was accurate and validated properly.This nomogram may be useful in determining further treatment,primarily focused on prostatic surgery for BOO,without impeding the detection of possible BOO in men with LUTS that is refractory to empirical medications.

Does prostate-specific antigen (PSA)mass or free PSA mass improve the accuracy of predicting total prostate volume in relation to obesity in men with biopsy-proven benign prostatic hyperplasia?

We evaluated whether the prostate-specific antigen (PSA)mass or free PSA (fPSA)mass (i.e.,absolute amount of total circulating PSA or fPSA protein,respectively),versus serum PSA or fPSA concentration,improves the accuracy of predicting the total prostate volume (TPV)in relation to obesity.Among men whose multicore (≥12)transrectal prostate biopsy was negative,586 who had a PSA of <10 ng ml^-1 and underwent the fPSA test prior to biopsy were enrolled.The PSA mass or fPSA mass (pg)was calculated by multiplying the serum level by plasma volume.At each TPV cut-off point (30 ml,40 ml,and 50 ml),the areas under the receiver operating characteristics curve (AUCs)of each variable were compared in obesity-based subgroups.AUCs of fPSA and fPSA mass for predicting TPV were significantly larger than those for PSA and PSA mass by 8.7%-12.1%at all cut-off points. Subgroup analyses based on obesity showed that,although PSA mass and fPSA mass enhanced accuracy by 4%(P =0.031)and 1.8%(P =0.003),respectively,for determining TPVs of ≥30 ml and ≥50 ml in obese and overweight men,they did not improve the accuracy in most other combinations of the degrees of obesity with TPV cut-off points.Thus,compared with serum PSA or fPSA,the absolute amount of PSA or fPSA protein mass improved the accuracy of predicting TPV in obese men very minimally and only for certain TPV cut-off points.Hence,these indicators may not provide clinically meaningful improvement in predicting TPV in obese men.