PROSTATE-SPECIFIC ANTIGEN IN MASS SCREENING FOR CARCINOMA OF THE PROSTATE

Background:
Prostate-specific antigen (PSA) has various advantages over prostatic acid phosphatase (PAP) as a marker for prostate cancer, but its role in prostate cancer mass screening remains controversial. We measured serum PSA in addition to serum PAP determination and digital rectal examination (DRE) in our mass screening program to assess the usefulness of PSA for prostate cancer mass screening.
Methods:
Serum PSA and PAP measurements and DRE were performed in 1249 patients in mass screening for carcinoma of the prostate in 1989 and 1990. Thirteen cancers were diagnosed. We calculated the mean plus standard deviations (2SD) of the PSA and PAP values of men without cancer, and assessed the usefulness of PSA for prostate cancer screening by using these figures as the upper limit of normal.
Results:
The number positive for PSA, PAP and DRE were 39, 36 and 48, respectively. If our screening had been performed without DRE, three cancers would have remained undetected, and the number would have been the same if performed without PSA. If the screening had been performed without PAP, on the other hand, no cancers would have remained undetected. The sensitivities of PSA and PAP were 54% and 23%, respectively. The screening detection rate with DRE and PSA was 0.88%, and with DRE and PAP was 0.64%.
Conclusions:
Measurement of serum PSA values with adjustment of the cut-off value was considered more useful than PAP in mass screening for prostate cancer.     

Prostate-Specific Antigen Levels from a Mass Screening Program Using Highly Sensitive RIA Kits

Background This study was designed to evaluate the distribution of prostate-specific antigen (PSA) levels of men in a mass screening program for prostatic disease.
Methods A total of 763 men over 40 years of age underwent mass screening for prostatic disease in a Japanese prefecture using the highly sensitive Eiken kit and the Hybritech (Tandem-R) kit. The screening tests consisted of serum PSA determination, digital rectal examination, a questionnaire on symptoms, evaluation of prostate volume, and determination of the obesity rate.
Results Serum PSA levels of all subjects were measured with both kits. The correlation between the values obtained by the Eiken kit and those of the Tandem-R kit was high (r = 0.990), but the values of the former were slightly higher than those of the latter. Serum PSA weakly correlated with age, however, when estimated within decade age brackets, the levels of PSA showed significant differences among only 1 pair of groups stratified by age. In contrast, the levels of PSA showed significant differences among 9 pairs of groups stratified by prostate volume.
Conclusion A highly sensitive assay kit is useful to evaluate both the distribution of PSA levels and the relationship of PSA values to age and prostate volume of men in mass screening programs for prostatic disease, since approximately 40% of the subjects who underwent the present mass screening showed PSA values under 1 .Ong/mL, which have been the the lower limit of detection of many PSA kits.     

前列腺癌筛查患者的临床病理特点及其意义

目的 通过分析集团筛查和临床诊断发现的前列腺癌,探讨前列腺癌筛查的临床价值.方法 2000年1月至2008年1月共收治441例前列腺癌患者,分为两组,临床组为门诊收治的前列腺癌患者122例;筛查组为同期23 183名50岁以上男性人群筛查发现的前列腺癌患者319例(均住院治疗);对两组患者年龄、直肠指检阳性率、血清前列腺特异性抗原(PSA)、病理Gleason评分、分型及临床分期和治疗方法等进行比较.结果 筛查组直肠指检阳性率为42.0%,低于临床组的79.5%.筛查组中PSA>20.0 μg/L的比例低于临床组.筛查组的中度分化腺癌占61.8%,高于临床组的29.5%,而低分化腺癌则相反.筛查组低于T2的患者比例为56.1%,T3以上患者比例为43.9%;临床组低于T2的患者比例为25.4%,T3以上患者比例为74.6%.发生局部及远处转移患者,筛查组26.0%,临床组46.0%.临床组根治性前列腺切除术占9.8%;筛查组根治手术占18.2%.结论 人群中筛查前列腺癌可以发现早期局限无症状的前列腺癌.     

The result of mass screening of 1997 for prostatic cancer in Isesaki City

PURPOSE: Screening by only prostate specific antigen (PSA) for prostate cancer was started since PSA had been added to mass screening as one of check lists in 1997 in Isesaki city, Gunma pref. We expected PSA screening to be introduced into other areas. We therefore studied how to perform a screening procedure for prostate cancer as well as discussed our result of the screening conducted lately. MATERIALS AND METHODS: 1,382 out of 1,423 Isesaki citizens who took mass screening aged 40 to 64 were chosen. Regardless of age, men with a serum PSA level equal or larger than 4.1 ng/ml (Tandem R) were selected for second screening since we determined it was a cut-off level for further check-up. Of those men, 38 were requested for second screening and actually only 24 took it. All these men took PSA check-up again, furthermore 23 took transrectal examination (TRE) and/or transrectal ultra sonography (TRUS) except for one of them. The next screening was requested for sixteen of them. Prostate biopsy was conducted for all of them. RESULTS: More old men took screening and were diagnosed prostate cancer. The findings derived from such diagnosis showed one of them aged 50 to 59 and six of them aged 60 to 64 had the cancer. Moreover, four out of twenty with PSA level ranging 4.1 to 10.0 ng/ml and all of three with PSA level over 20.0 ng/ml had the cancer. Five out of sixteen with a positive sign for further PSA check-ups had the cancer. All the three suspect of the cancer by TURS and DRE had prostate cancer. Two of seven with PSA negative showed suspicion of prostate cancer and had the cancer. No neo-adjuvant and total prostatectomy was conducted for four with 4.0 to 10.0ng/ml diagnosed T2N0 M0. One of them with PSA equal or over 20.0 ng/ml was diagnosed T3N0M0. After hormone therapy its PSA decreased to that equal or under 0.5 ng/ml. Total prostatectomy was conducted for it. CONCLUSION: It is not proved that only PSA mass screening for prostatic cancer contributes to detect early cancer and better prognosis cure case. For the proof, it will be nessary that PSA mass screening is examined more people in the wide area. We conclude men aged 65 to 69 also should take PSA check-up based on epidemiological feature of prostatic cancer.     

Decreasing trend in prostate cancer with high serum prostate-specific antigen levels detected at first prostate-specific antigen-based population screening in Japan

To clarify the recent trends in prostate-specific antigen （PSA） distribution in men in Japan, we analyzed the PSA distributions of men undergoing PSA-based population screening. We summarized the annual individual data of PSA-based population screening in Kanazawa, Japan, from 2000 to 2011, and analyzed baseline serum PSA values of the participants at the first population screening. Serum PSA distributions were estimated in all participants and those excluding prostate cancer patients according to age. From 2000 to 2011, 19 620 men participated aged 54-69 years old in this screening program. Mean baseline serum PSA level of all participants at the first screening was 2.64 ng m1-1 in 2000, and gradually decreased to approximately 1.30 ng ml-I in 2006. That of participants excluding prostate cancer patients was 1.46 ng m1-1 in 2000, and there was no remarkable change during the study period. The 95t＂ percentiles in the participants excluding prostate cancer patients detected at the first population screening of men aged 54-59, 60-64, and 65-69 years old were 2.90, 3.60, and 4.50 ng m1-1, respectively. After the commencement of population screening, the proportion of prostate cancer patients with high serum PSA levels decreased. However, there were no changes in serum PSA levels in men without prostate cancer. Age-specific PSA reference level of men without prostate cancer in Japan was similar to that in China and Korea.     

Prostate cancer screening with prostate specific antigen in spinal cord injured men

PURPOSE: As the spinal cord injured population ages, prostate cancer becomes a more significant cause of potential mortality. Consequently due to various bladder management techniques the validity of standard prostate specific antigen (PSA) screening values in this population must be evaluated. We compared screening PSA values in a large population of spinal cord injured patients with those in age matched, nonspinal cord injured men. MATERIALS AND METHODS: Screening PSA values were obtained using the AxSYM assay (Abbott Laboratories, Abbott Park, Illinois) in 366 spinal cord injured men 40 to 79 years old. In those with PSA elevated to greater than 4 ng./ml. who consented to further evaluation standard sextant needle biopsy of the prostate were performed under transrectal ultrasound guidance. Data were compared with data on 371 randomly selected, age matched controls from the Baylor College of Medicine community screening program database of more than 19,000 patient-tests. Analysis was performed with the unpaired Student t test. RESULTS: When we divided patients 40 to 80 years old into 4 age groups by decade and compared them with normal controls by decade, there was no statistically significant difference in mean PSA in the 2 groups. Of 18 spinal cord injured patients with PSA greater than 4 ng./ml. 12 underwent transrectal ultrasound guided needle biopsy of the prostate and 6 refused further evaluation. Five of these biopsies (1.3% overall) were positive and 7 were negative for adenocarcinoma. CONCLUSIONS: As in healthy men, PSA and digital rectal examination can be performed in spinal cord injured men to screen for prostate cancer. None of the various bladder management techniques in these cases seemed to affect screening results.     

Screening for prostate cancer using prostate-specific antigen testing in Japanese men on hemodialysis

Objectives The objectives of this study were to evaluate the usefulness of serum prostate-specific antigen (PSA) screening in detecting prostate cancer in Japanese men on hemodialysis, and to analyze features of prostate cancer detected in these patients. Materials and methods This study included 115 male hemodialysis patients aged >55 years who agreed to the measurement of serum PSA value (group A) and 7529 men aged >55 years participating in a PSA mass screening test in Kobe City (group B) between April 2005 and March 2006. Prostate biopsy was recommended in men with serum PSA > 4.0 ng/ml in both groups. Seventy-eight patients with normal renal function aged >55 years diagnosed as having prostate cancer during the same time period as groups A and B were also included as a comparison group (group C). Results There was no significant difference in the distribution of serum PSA values between groups A and B. Prostate biopsy was performed in 8 and 205 men in groups A and B, respectively, and prostate cancer was detected in 5 and 68 in groups A and B, respectively; that is, there was no significant difference in the rate of positive prostate biopsy between these two groups (group A, 62.5%; group B, 33.2%), while the cancer detection rate in group A (4.3%) was significantly greater than that in group B (0.90%). In addition, there was no evident metastasis in five patients on hemodialysis who were diagnosed as having prostate cancer, and their serum PSA, clinical T stage and biopsy Gleason score were similar to those in group C. However, the percent of positive biopsy cores in these five was significantly greater than that in group C. All five were treated by maximal androgen blockade therapy, and all are currently alive without emergence of hormone-refractory diseases. Conclusions These findings indicate that hemodialysis patients may have an increased risk of prostate cancer, and that prostate cancer detected in such patients tends to be relatively advanced. Therefore, it would be recommended for hemodialysis patients to undergo PSA testing to screen for prostate cancer.     

Lower urinary tract symptoms and risk of prostate cancer in Japanese men

Our aim was to investigate whether or not men with lower urinary tract symptoms are at increased risk of prostate cancer. A total of 3511 men aged 50-79 years who underwent mass screening for prostate cancer between 2002 and 2004 for the first time, and completed the International Prostate Symptom Score (IPSS) questionnaire at the time of the prostate specific antigen (PSA) test, were enrolled in the present study. All men with PSA values greater than 4.0 ng/mL were advised and encouraged to undergo transrectal systematic sextant biopsy. The number of cancers subsequently detected was compared between men with IPSS scores of 0-7 and 8-35. Of the 3511 men, 219 (6.2%) had PSA values greater than 4 ng/mL, 178 (5.1%) underwent biopsy, and 51 (1.5%) were found to have prostate cancer. Although the PSA positivity rate for men with IPSS scores of 8-35 was significantly higher than that in the 0-7 group, there were no significant intergroup differences in the cancer detection rates for biopsied men and for total screened subjects. Multivariate logistic regression analysis revealed that prostate volume was the dominant predictor for the detection of prostate cancer, followed by PSA level, but the IPSS made no significant contribution. No significant difference was noted in the IPSS scores between men with cancer and the others of the same age group. Symptomatic Japanese men are not at higher risk of prostate cancer despite their higher PSA values compared with asymptomatic men of the same age group.     

Clinical usefulness of serum prostate specific antigen for the detection of prostate cancer is preserved in men receiving the dual 5alpha-reductase inhibitor dutasteride

PURPOSE: We determined whether the decrease in serum PSA seen with 5alpha-reductase inhibitors affects the clinical usefulness of PSA for prostate cancer screening using data from 2 dutasteride benign prostatic hyperplasia studies. MATERIALS AND METHODS: A total of 2,802 men 50 years or older with a clinical diagnosis of benign prostatic hyperplasia, no history of prostate cancer, PSA 1.5 to 10 ng/ml, prostate volume 30 cc or greater, an American Urological Association symptom score of 12 or greater and peak urinary flow rate 15 ml per second or less were randomized to 0.5 mg dutasteride daily or matching placebo for 24 months. Increases in PSA from baseline and the maximum increase from nadir to month 24 were compared between the groups and analyzed by prostate cancer status, as determined by PSA driven biopsy and an advised cutoff of more than 4 ng/ml after doubling to correct for dutasteride treatment with sensitivity and specificity calculated for each. RESULTS: In placebo treated men without prostate cancer there was an 8.3% median increase in PSA at month 24 compared with -59.5% in those who received dutasteride, using doubled values to correct for dutasteride treatment. In those with prostate cancer these changes were 23.8% and -37.2%, respectively. Using the upper PSA limit of 4 ng/ml sensitivity for prostate cancer in men receiving dutasteride vs placebo was 0.737 vs 0.804, while specificity was 0.671 vs 0.578. Using a PSA increase from nadir of 0.8 ng/ml the sensitivity of dutasteride was 0.548 and its specificity was 0.795. CONCLUSIONS: A doubling factor is effective for maintaining the sensitivity and specificity of PSA for prostate cancer detection in men on dutasteride. Increases in serum PSA in men receiving dutasteride should be considered suspicious and serial PSA measurements should be used to evaluate changes from nadir.     

Ten year trend in prostate cancer screening with high prostate-specific antigen exposure rate in Japan

Background:   The tendency of the results and quality control of prostate cancer screening serially performed for 10 years in an area of Japan were evaluated.
Methods:   A total of 39 213 men over 55 years of age have participated in the mass screening of prostate cancer in the Otokuni District, since 1995. Men whose prostate-specific antigen (PSA) levels were more than 4.1 ng/mL were indicated for the second screening. In the second screening, prostate-specific antigen density (PSAD) was calculated in men whose PSA levels ranged from 4.1 to 10.0 ng/mL.
Results:   Secondary screening was indicated in a total of 2428 subjects, of whom 1633 underwent it. Prostate cancer was diagnosed in 267 men. As a result of the evaluation of the indication of prostate biopsy according to the PSAD in 894 who underwent secondary screening for the first time, the procedure was judged to be unnecessary in 269 (35%) of 765 cases. Of these 269 subjects, 23 (8.5%) were found to have cancer. Clinically localized prostate cancer increased by 17%, and locally advanced and metastatic cancers decreased by 12% in the second compared with the first five years of the ten-year period. The exposure rate of PSA screening in the Otokuni District was 65% with the application for the rate of screenees whose PSA level was 4.1 ng/mL or above.
Conclusions:   The Japanese basic health screening system allows the determination of high-PSA exposure areas. Serial prostate cancer screening showed a tendency of stage migration in the screened cancer patients. The use of PSAD in secondary screening substantially reduces the necessity of prostate biopsy; however, the encouragement of PSA-positive individuals to periodically receive prostate cancer screening is essential to maintain the quality of the screening system.     

Evaluation of the effect of spinal cord injury on serum PSA levels

OBJECTIVES: Prostatic structure and secretory activity are thought to be influenced by autonomic innervation of the prostate. Prostatic denervation is especially likely in patients with spinal cord injury (SCI) at the level of the cauda equina or the conus medullaris, where the peripheral nerve supply to the prostate may be specifically damaged. This may result in changes in serum prostate-specific antigen (PSA) levels, either directly or indirectly. Therefore, we measured serum PSA levels and also studied the influence of factors such as age, catheterization, duration of SCI, urinary tract infection, and history of cystitis on serum PSA values in men with SCI. METHODS: Serum PSA levels were determined in 79 men with SCI (age older than 40 years) using banked sera by the Abbott MEIA PSA assay. Variables such as age, catheterization, duration of SCI, urine culture results, and history of cystitis were obtained from a review of patient records. Comparisons were made with a randomly selected, non-SCI control population of 501 men, 40 to 89 years old, who underwent serum PSA determination at our institution. Statistical comparisons were performed using the Mann-Whitney U test (nonparametric), since the populations were not normally distributed. Multivariate logistic regression analysis was used to assess the correlation between the various factors and the serum PSA levels in men with SCI. RESULTS: No statistically significant differences were found in the median serum PSA values between the SCI group and the non-SCI control population. The age-specific PSA values obtained in the SCI group were also comparable to those reported for the general population at large. Age (P <0.03) and the presence of a catheter (P <0.0002) were the only two factors that were correlated with higher serum PSA values in the SCI group by regression analysis. CONCLUSIONS: Men with SCI tended to have serum PSA value distributions that were similar to those of the general population. However, those in the SCI group who had indwelling catheters were more likely to have higher PSA values at baseline, as were older men with SCI.     

Mass screening of prostate cancer in a Chinese population：the relationship between pathological features of prostate cancer and serum prostate specific antigen

Aim: To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA). Methods: A total of 12027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen tPSA test (by Elisa assay). Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was > 4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subsequent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS. Inc., Chicago. USA). Results: Of the 12027 cases, 158 (including 137 patients whose serum tPSA values were 4.0 ng/mL and 21 patients [serum tPSA < 4.0 ng/mL] who had obstructive symptoms) undertook prostate biopsy. Of the 158 biopsies, 41 cases of prostatic carcinoma were found (25.9 %, 41/158). The moderately differentiated carcinoma and poorly differentiated carcinoma accounted for 61% and 34%, respectively. A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r = 0.312, P < 0.01) was established. A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r = 0.406, P < 0.01), indicating a significant linear relationship between serum tPSA and the size of tumor. Conclusion: This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men. Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer. This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.     

Prostate specific antigen based biennial screening is sufficient to detect almost all prostate cancers while still curable

PURPOSE: We evaluated whether biennial screening with prostate specific antigen (PSA) only is sufficient to detect prostate cancer while still curable. MATERIALS AND METHODS: In G?teborg, Sweden 9,972 men 50 to 65 years old were randomized to PSA screening. During 1995 and 1996 these men were invited for a first PSA screening and invited during 1997 and 1998 for a second screening. The screening procedure included PSA measurement in all men and in those with a PSA of 3 ng./ml. or greater also it included digital rectal examination, transrectal ultrasound and sextant biopsies. RESULTS: In the first screening 5,854 men participated and 145 cancers were detected. In the second screening 5,267 men participated and 111 cancers were detected. Only 9 interval cancers were diagnosed. In the second screening 102 cancers (92%) were associated with PSA less than 10 ng./ml. Of 465 men with increased PSA and who underwent biopsy with a benign outcome in the first screening 50 had cancer at the second screening. Of 241 men in whom PSA increased between screenings 1 and 2 cancer was detected in 46. None of the 2,950 men with an initial PSA of less than 1 ng./ml. had a PSA of greater than 3 ng./ml. or interval cancer. CONCLUSIONS: In men with a PSA of less than 2 ng./ml. it seems safe to offer repeat screening after 2 years with PSA only. Men with a PSA of 2 to 3 ng./ml. or a value of greater than 3 ng./ml. with negative biopsy may be better served by a shorter screening interval. Thus, different screening intervals are implied depending on baseline PSA.     

Prostate specific antigen isoforms and human glandular kallikrein 2--which offers the best screening performance in a predominantly black population?

PURPOSE: Free prostate specific antigen, complexed PSA and human glandular kallikrein 2 have independently been tested against the gold standard of total PSA for prostate cancer screening in largely white populations. With the incidence of prostate cancer much higher in black men, we sought to evaluate these markers simultaneously in a predominantly black population. MATERIALS AND METHODS: A total of 138 men, of whom 108 were black, underwent ultrasound guided biopsy of the prostate for tPSA levels greater than 2.5 ng/ml or an abnormal digital rectal examination. Sera were drawn before biopsy and analyzed for tPSA, fPSA, cPSA and hK2 concentrations using standard methods (hK2 assay is for research use only, not for use in diagnostic procedures). The areas under the receiver operator characteristic curves were determined for each marker as well as biomarker combinations. Additionally, each parameter's specificity, positive and negative predictive values, and theoretical screening efficiency were assessed at or above the 95% sensitivity level. RESULTS: A total of 43 (31.1%) men had prostate cancer by biopsy. While the AUC for %fPSA was statistically the highest (0.822, p <0.001), cPSA offered the highest specificity (31.6%) and positive predictive power (31.7%) of any of the tested biomarkers at comparable sensitivity (greater than 95%). The calculated efficiency of cPSA (51.4%) was also higher than the other markers. Nearly 20% of biopsies would be avoided using cPSA vs standard tPSA screening methods. CONCLUSIONS: Comparing the major PSA isoforms and hK2, cPSA alone appears to offer superior diagnostic discrimination for cancer detection in a predominantly black population.     

Relationship between prostate‐specific antigen and obesity in prostate cancer screening: Analysis of a large cohort in Japan

Previous studies have shown that lower prostate‐specific antigen (PSA) levels in obese men might decrease the sensitivity of prostate cancer screening, leading to delayed diagnosis and unfavorable prognosis. We examined whether the effect of obesity is important in prostate cancer screening of Japanese men, who have a low prevalence of obesity. We analyzed 19 294 male subjects from a large cohort of Toyota Motor Corporation (TMC) employees (aged >50 years, serum PSA level ≤4.0 ng/mL) who underwent physical examinations from August 2006 to December 2009. The relationship between PSA level and obesity‐related factors was analyzed by simple and multiple regression analysis. The relationships between six body mass index (BMI) categories, and PSA level and PSA mass (PSA concentration × plasma volume) were analyzed. PSA level decreased significantly with increasing BMI, but the coefficient of determination was very low. Mean PSA values decreased from 1.02 to 0.85 ng/mL as BMI increased from underweight (BMI <18.5) to morbidly obese (BMI >35). However, PSA mass peaked in the overweight category and was slightly reduced with increasing BMI. On multiple regression analysis, PSA level was influenced by age, diastolic blood pressure and high‐density lipoprotein as well as BMI. We found an inverse but weak relationship between PSA level and BMI. Obesity seems to have very limited influence on prostate cancer screening in this population. Nonetheless, when considering indications for prostatic biopsy in obese men, we should be aware that the hemodilution effect might reduce PSA levels.     

Population-based screening for prostate cancer by measuring total serum prostate-specific antigen in Iran

OBJECTIVE: To report the results from an Iranian large population-based randomized study of screening using prostate-specific antigen (PSA) to detect prostate cancer. MATERIALS AND METHODS: A total of 3758 Iranian men older than 40 years were mass checked by PSA-based screening. Men with an abnormal digital rectal examination (DRE) and serum total PSA level of greater than 4 ng/mL, underwent transrectal ultrasonography (TRUS)-guided extended prostate biopsy. RESULTS: The PSA value (mean +/- standard deviation, SD) in all men without prostate cancer was 1.6 +/- 1.1 ng/mL and in those with cancer 18 +/- 44.8 ng/mL (P = 0.001). PSA values increased with age. In those aged 40-49, 50-59, 60-69 and > or = 70 years, the mean +/- SD PSA values were 1.3 +/- 0.7, 1.4 +/- 0.8, 1.8 +/- 1 and 2.2 +/- 1.6 ng/mL, respectively. Among the screened men, 323 (8.6%) had a serum PSA concentration greater than 4 ng/mL. Of patients who underwent prostate biopsy (230, 71.2%), 129 (positive predictive value, 56.1%) had prostate cancer. Additionally, nine cancers were detected among 16 patients with PSA of less than 4 ng/mL who had a doubtful DRE finding. The overall cancer detection rate was 3.6%; 1.4% at 40-49, 1.6% at 50-59, 4.2% at 60-69 and 12.9% at >/=70 years. Conventional systematic sextant biopsies, which accounted for six of the 10 cores in our biopsy scheme, detected 98 (71%) of the cancers. CONCLUSIONS: The Iranian male population develops prostate cancer quite commonly if their serum PSA levels are greater than 4.0 ng/mL. In this study, 65.9% of the detected cancers were clinically significant. The conventional systematic sextant technique may be inappropriate for detection of all prostate cancers. The results need to be confirmed in other randomized trials.     

Retrospective evaluation of PSA density for selection of biopsy candidates with prostate specific antigen in the gray zone

PURPOSE: We examined the usefulness of prostate specific antigen density (PSAD) for selection of biopsy candidate with prostate specific antigen levels between 4.1 and 10.0 ng./ml. in prostate cancer screening retrospectively. MATERIALS AND METHODS: The screening was conducted on male candidates in Natori city, aged 55 years or older, for 6 years from 1994 through 1999. We could analyze serum PSA levels and PSA density in 118 men with PSA levels between 4.1 and 10.0 ng./ml. All of 118 men underwent ultrasound guided systematic prostate biopsy regardless of findings of digital rectal examination and transrectal ultrasound. Prostate volume was estimated by transrectal ultrasound measurements using the prolate ellipse formula (pi/6 x length x width x height). PSAD was calculated by dividing serum PSA level by prostate volume. Serum PSA levels were determined by Tandem-R assay. RESULTS: In 118 men, twenty-five men had prostate cancer. There was no significant difference in mean PSA between those with prostate cancer and those without prostate cancer, but the difference was significant in the mean PSA density (mean 0.26 and 0.16, respectively, p < 0.0001). Receiver operating characteristic curves for PSA and PSAD demonstrated superior benefit for PSAD in 118 men. A sensitivity, a specificity, a positive predictive value and a negative predictive value of PSAD cut-off of 0.15 were 88%, 52.7%, 33.3% and 94.2%. PSAD cut-off of 0.18 showed the highest sum of sensitivity and specificity, which gave a sensitivity of 80%, a specificity of 72%, a positive predictive value of 43.5% and a negative predictive value of 93.1%. PSAD cut-off of 0.15 would seem to be preferable to cut-off of 0.18 because of less cancer missing. CONCLUSIONS: Although further studies are needed to determine optimal cut-off value to be used in clinical practice, PASD seems to be useful for the selection of biopsy candidates with PSA levels of 4.1 to 10.0 ng./ml. in the prostate cancer screening.     

Prostate-specific antigen-based screening for prostate cancer: Evidence, controversies and future perspectives

The most recent epidemiological survey revealed that the mortality rate for prostate cancer in Japan has increased and has been getting very close to that in the USA, where it has decreased since 1992. The low exposure rate of prostate-specific antigen (PSA) screening in Japan and the high exposure rate of PSA screening in the USA may result in completely deferent trends in the mortality rate of prostate cancer between the two countries. The Japanese Urological Association recommends PSA-based screening for men at risk of prostate cancer at age 50 years or older in general and 45 years or older in men with a family history of prostate cancer within first generation relatives. The fact sheet on screening for prostate cancer should indicate the most recent reliable clinical research on screening for prostate cancer and its demerits including false-negative and false-positive PSA test results and prostate biopsy, overdetection and overtreatment. However, it should be explained to the public that the demerits for PSA screening will be clarified step by step during screening, and in general, men having more information on screening results (PSA level, pathological findings of biopsy specimens, clinical stage, etc.) can understand their current situation better than those having no information on screening results, including PSA levels.     

Pitfalls in Interpreting Prostate Specific Antigen Velocity

Purpose

The concept of prostate specific antigen (PSA) velocity as an improved marker for prostate cancer detection is intriguing. However, before this concept is applied to individual patients several confounding parameters must be addressed. We determined the variability of serum PSA levels in men without prostate cancer.

Materials and Methods

We reviewed data from a prostate cancer screening program, and determined inter-assay and individual variability of the serum PSA values for a 2-year followup period in 265 men clinically free of prostate cancer.

Results

Our average inter-assay coefficient of variation was 7.5 percent. Therefore, we considered only PSA changes exceeding plus/minus 15 percent as significant. Fluctuations in serum PSA occurred in 78 percent of the men during the observation period, and 12.5 percent had at least a single PSA increase exceeding 0.75 ng./ml. per year. Fluctuations were noted throughout the entire range of serum PSA levels but became progressively larger with an increasing mean PSA.

Conclusions

The inter-assay variability must be considered when interpreting PSA velocity. Individual fluctuations in serum PSA dictate an observation period of at least 2 years before PSA velocity is considered abnormal.     

The effect of obesity and lower serum prostate‐specific antigen levels on prostate‐cancer screening results in American men

OBJECTIVE

To determine if lower serum total prostate specific antigen (PSA) levels in obese American men affect prostate‐cancer screening results, as an increased body mass index (BMI) is inversely associated with PSA level, but the effect of this association on PSA screening results for prostate cancer is unknown.

SUBJECTS AND METHODS

We analysed the most recent National Health and Nutrition Examination Surveys (NHANES 2001–2002, 2003–2004, and 2005–2006), a nationally representative cross‐sectional sample of non‐institutionalized adults aged ≥20 years. Logistic regression was used to estimate the odds of an ‘abnormal’ PSA level (4.0 or 2.5 ng/mL) based on BMI categories of normal (18.5–24.9 kg/m²), overweight (25–29.9) and obese (30–39.9) in men who were eligible for prostate‐cancer screening with serum total PSA tests (age 40–75 years, BMI 18.5–39.9 kg/m², PSA <20 ng/mL).

RESULTS

In all, 3152 participants with no known prostate cancer, representing 46 million American men, were eligible for prostate‐cancer screening. After controlling for age and race, there was a statistically significant trend of a lower likelihood of having a serum total PSA level of ≥4.0 ng/mL with increased BMI. When men were stratified by race, this effect was apparent only in white non‐Hispanic men, with obese men in this group having a 46% lower likelihood of having an ‘abnormal’ PSA level (odds ratio 0.54, 95% confidence interval 0.31–0.91; P = 0.024) than those with a normal BMI. There was no observable trend in either African‐American or Hispanic men. In addition, there was no observable trend with a serum total PSA threshold of 2.5 ng/mL, regardless of race.

CONCLUSIONS

Obese white non‐Hispanic men are about half as likely as those with a normal BMI to have a PSA level of ≥4.0 ng/mL. These results might affect prostate‐cancer screening with serum total PSA. Further studies are needed to better define the association of BMI and PSA in racial minority subgroups.