Effect of digital rectal examination on serum concentration of prostate-specific antigen.

Prostate-specific antigen (PSA) is used for screening and follow-up of patients with prostate cancer. The effect of certain diagnostic procedures on PSA serum levels is not well defined. Therefore, the effect of digital rectal examination (DRE) on PSA serum levels was investigated. No significant difference was observed in PSA values before and after DRE when blood samples were taken 1-3 min after palpation of the prostate. Kinetic studies demonstrated a significant increase in PSA values up to the factor 3.2 in 14 of 19 patients 2-6 h after DRE. In 9 of 14 cases, PSA was within the initial range 24 h after DRE. That means that a urologist is allowed to take blood samples for the determination of PSA at least within 3 min after palpating a suspicious prostate without getting false-positive results.     

血清前列腺特异性抗原及直肠指检与前列腺癌的相关性研究

目的 分析血清PSA、直肠指检(DRE)与前列腺癌检出率、临床分期以及病理分级的相关性. 方法 回顾性分析1997年1月至2010年12月796例PSA、DRE和病理结果完整患者的前列腺穿刺活检资料,采用Spearman相关性研究分析PSA和DRE与前列腺癌相关指标间的关系,进一步将PSA及DRE分组后进行比较. 结果 PSA与前列腺癌检出率、临床分期及病理分级相关(r=0.537,P＜0.0001;r=0.365,P＜0.0001;r=0.556,P＜0.0001);DRE结果与前列腺癌诊断率及病理分级有相关性(r=0.212,P＜0.0001;r=0.126,P=0.02).分组分析显示不同PSA水平组中前列腺癌检出率、前列腺癌分期以及Gleason评分差异有统计学意义(P＜0.05).而在相同PSA水平时,只有PSA 10.0 ～ 19.9 μg/L组和20.0～99.9μg/L组中DRE阳性和阴性患者的前列腺癌检出率差异有统计学意义(P＜0.05).相同PSA组中不同DRE结果患者的前列腺癌分期以及Gleason评分差异无统计学意义(P＞0.05). 结论 PSA水平与前列腺癌的检出率、肿瘤分期及Gleason评分有显著相关性,DRE结果仅在部分PSA水平患者中影响肿瘤检出率.     

Prostate cancer screening: Role of digital rectal examination and prostate-specific antigen

Background: This study was designed to determine the efficacy of digital rectal examination (DRE) and serum prostate-specific antigen (PSA) for early detection of prostate cancer in men ≥50 years of age. Methods: A prospective single-center clinical trial was conducted to screen 644 asymptomatic men, who were elicited by newspaper and radio advertisements, with DRE and PSA. Quadrant biopsy examinations of the prostate were performed if PSA >4 ng/ml or if DRE was suspicious. Results: Thirty-seven percent of the men (n=241) had an abnormality of DRE or elevated PSA. Of the 163 patients who underwent transrectal ultrasound and quadrant biopsies of the prostate, 77% had normal biopsies, 14 (8%) had prostatic intraepithelial neoplasia, and 24 (15%) had carcinoma of the prostate. PSAs ranged from 0.3 to 65.5 ng/ml, with a mean of 2.35 and a median of 1.6. Ninety-five patients had a PSA >4 ng/ml, of whom 17 had a PSA >10 ng/ml. Sensitivity of PSA was 75% and specificity 87%; for DRE the sensitivity was 75% and the specificity 69%. Clinical stage of patients who underwent radical prostatectomy was B1 in 15 and B2 in five. Fifteen of 20 patients (75%) had organ-confined disease; the other five had specimen-confined disease. No patient was found to have nodal involvement. Conclusion: The combination of PSA and DRE seems to improve the stage of diagnosis of patients with prostate cancer. Larger, randomized studies will be necessary to evaluate the effect of screening on overall survival. The results of this study were presented at the 46th annual cancer symposium of the Society of Surgical Oncology, Los Angeles, California, March 18–20, 1993.     

Clinical implications of prostate-specific antigen (PSA)

Prostate-specific antigen(PSA) is currently the tumour marker of choice for prostatic carcinoma. This article examines the current literature on the application of PSA for cancer detection (concentrating on values of PSA in the normal and 'grey' areas of 2.5-10 ng/ml), in staging of the disease and prediction of treatment response. These areas in particular have been refined by the use of PSA indices (PSA density, velocity, age ranges) and the article focuses on the recent studies analysing their standing in clinical practice.     

The effects of ejaculation on serum prostate-specific antigen (PSA)

To determine the effects of ejaculation on serum PSA, we measured serum levels just before masturbation and 24 hours and 5 days later in a study group (n=25) aged between 23 and 25 years. In the study group, 16 cases showed a decrease (mean 22.37%, range 10–50%) in serum PSA levels 24 hours after ejaculation, while 6 had higher levels (mean 38.33%, range 21–67%) and 3 had no changes. No relation was found between seminal plasma levels or total amounts expelled of this marker and the difference in serum levels due to ejaculation. In the control group free of ejaculation in the same period determinations of serum PSA levels revealed no significant changes between days 0, 1 and 5. As compared with the control group, the changes in the study group were found to be statistically insignificant. These results may indicate that ejaculation has an insignificant effect on serum PSA levels.     

The clinical importance of free prostate-specific antigen (PSA)

The proportion of free prostate-specific antigen (PSA) in serum relative to total PSA (F/T) is lower in patients with prostate cancer than in those with elevated levels of PSA due to benign prostatic disease. When applied to early diagnosis and screening for prostate cancer, the proportion of free PSA can be used to reduce the number of false-positive results by 20-40%. The utility of F/T is better in men with a small prostate volume, i.e. in relatively young men, who are most likely to benefit from early diagnosis and treatment of prostate cancer. The concentrations of PSA and especially free PSA are affected by considerable intra-individual variation and sample stability. Assay standardization is variable and it is therefore important to establish reference values for the methods used. Better control of these factors is likely to improve the diagnostic accuracy. The utility of determining free PSA can be improved by evaluating the combined impact of free and total PSA by logistic regression analysis or neural networks.     

直肠指检对PSA、F-PSA影响的研究

目的 :探讨直肠指检对前列腺特异抗原 (PSA)、游离前列腺特异抗原 (F PSA)的影响及其持续的时间。方法 :本组 5 1例 ,每例分别于直肠指检前、直肠指检后 1天、1周、4周抽取静脉血 2ml,采用放射免疫法测定PSA、F PSA。结果 :本组 5 1例直肠指检前血清PSA值为 0 .18～ 9.4μg/L ,平均2 .5 8± 2 .17μg/L ,F PSA值为0 .0 9～ 1.89μg/L ,平均0 .5 3± 0 .42 μg/L ,F/T比值为0 .0 6～ 0 .83,平均 0 .2 6± 0 .15 ;直肠指检后 1天、1周及 4周 ,PSA、F PSA及F/T比值虽然有所增高 ,但经统计学处理均无显著性意义。直肠指检前PSA <4.0 μg/L者 38例 ,PSA值平均为 1.5 0± 0 .92 μg/L ,PSA值≥4.0 μg/L者 13例 ,PSA值平均为5 .76± 1.5 4μg/L ;直肠指检后 1天、1周、4周 ,PSA、F PSA及F/T比值与检查前相比仍然没有统计学意义。结论 :只要检查过程中避免对前列腺作出强烈的挤压 ,常规的直肠指检对PSA、F PSA的影响极其轻微 ,且时间较短。     

Elevated prostate-specific antigen, abnormal prostate evaluation on digital rectal examination, and transrectal ultrasound and prostate biopsy

Prostate cancer screening for the early diagnosis of organ-confined, potentially curable prostate cancer has dramatically changed the practice of urology over the past 15 years. The introduction of prostate-specific antigen (PSA) testing, increased medical and public awareness for digital rectal examination (DRE), and transrectal ultrasound-assisted needle biopsy of the prostate (TRUS/PNBX) has been instrumental in these dramatic changes.     

Age-specific reference ranges for prostate-specific antigen (PSA) in Jordanian patients

In this study, the normal distribution of total prostate-specific antigen (TPSA) and free prostate-specific antigen (FPSA) values and the appropriate reference ranges for prostate-specific antigen (PSA) in Jordanian patients were established; the values were then compared to those of other studies. Serum TPSA and FPSA levels in 1852 men with no diagnostic prostate cancer, as well as in patients whose PSA value was obtained as part of the clinical work-up of symptoms relating to non-neoplastic urologic conditions, were estimated during the period 1993-2001: 1561 (84.3%) were above 40 y of age or older. We studied the data as a function of age to determine the usefulness of measuring TPSA, FPSA, and their ratio as screening tests for prostate cancer risk patients. Using the 95th percentile, the recommended age-specific reference ranges of TPSA and FPSA values were as follows: for the age group 30-34 y, 2.3 and 0.51 ng/ml, respectively; for the age group 35-39 y, 2.9 and 0.59 ng/ml, respectively; for the age group 40-44 y, 3.2 and 0.63 ng/ml, respectively; for the age group 45-49 y, 3.75 and 0.71 ng/ml, respectively; for the age group 50-54 y, 3.8 and 0.83 ng/ml, respectively; for the age group 55-59 y 3.75 and 0.96 ng/ml, respectively; for the age group >60 y old, 4.3 and 1.26 ng/ml, respectively. There was a continuous increase in TPSA and FPSA means and medians throughout the study period with a significant correlation (P<0.001, P<0.05) for TPSA and FPSA levels), respectively, and advancing age group. With regard to the ratios of FPSA-to-TPSA for each age group we found no correlation between them. As a result, the appropriate upper limit of normal 95th percentile for all ratios was 0.23 for men for all ages. The establishment of appropriate reference ranges for TPSA and FPSA as well as ratios will allow the practicing urologist to incorporate these new parameters into diagnostic evaluation of men at risk for early, potentially curable prostate cancer.     

Age, prostate-specific antigen, and digital rectal examination as determinants of the probability of having prostate cancer

Objectives. The decision to perform prostate biopsy has traditionally been based on an abnormal prostate-specific antigen (PSA) level or abnormal digital rectal examination (DRE) findings. For example, a 60-year-old man with a benign DRE and PSA level of 4.1 ng/mL would be counseled for biopsy, and the same man with a PSA level of 3.9 ng/mL might be counseled against biopsy. However, the difference in these PSA levels and in the likelihood of these two men having prostate cancer is not significant. We constructed a probability nomogram for the likelihood of detecting prostate cancer, thus aiding in the decision of whether to perform a prostate biopsy.Methods. Using multivariate logistic regression analysis and data from 2054 men (mean age 64 years) participating in the Tyrol Screening Project between January 9, 1993 and January 9, 1997, patient age, PSA level, and DRE findings were analyzed for their ability to determine the likelihood of finding prostate cancer on transrectal ultrasound-guided biopsy.Results. DRE was suspicious in 278 men (13.5%). Overall, 498 (24.5%) of 2054 men biopsied had prostate cancer. The probability of discovering cancer on biopsy was calculated using patient age, DRE findings, and PSA level.Conclusions. DRE status had a large influence on the likelihood of positive biopsy across all PSA and age ranges. A combination of PSA, DRE result, and age better defined the probability of a positive biopsy than any factor alone. Using this nomogram, the decision to proceed with or defer prostate biopsy can be based on an actual probability of discovering prostate cancer rather than a single PSA-based cutpoint. These data may aid physicians and patients in decision-making.     

Serum prostate-specific antigen and digital rectal examination for early detection of prostate cancer in a national community-based program

Objectives

This study analyzed methods of prostate cancer early detection in community settings throughout the United States against standards and findings of earlier studies conducted at academic medical centers.

Methods

The study was conducted at 148 clinical centers during Prostate Cancer Awareness Week in September 1993 and continued through June 1994. A total of 31,953 eligible subjects were tested by both digital rectal examination (DRE) and prostate-specific antigen (PSA). PSA was tested with the Abbott IMx PSA assay and reported by Roche Biomedical, Inc.

Results

The study confirmed that elevated PSA levels (greater than 4.0 ng/mL) aid in the detection of organconfined prostate cancer when used in conjunction with the DRE. Reflecting more conservative biopsy decision-making practices, study results nonetheless are comparable to earlier reports. Among 1307 subjects who underwent biopsy, 322 cancers were detected. The cancer detection rate was 3.6% for PSA, 3.0% for DRE, and 4.7% if either test result was positive. The positive predictive value (PPV) for elevated PSA levels (greater than 4.0 ng/mL) was 31.6%, significantly better (P <0.0001) than the PPV for abnormal DRE results (25.5%). Nearly 90% (88.9%) of staged cancers were diagnosed as localized. Elevated PSA levels detected more localized cancers (76 of 105 [72.4%]) than the DRE (72 of 105 [68.6%]). Of localized tumors, 33 (31.4%) were missed by DRE and detected solely by PSA, and 29 (27.6%) were missed by PSA and detected solely by DRE. The combined use of the two methods detected 33 additional localized tumors.

Conclusions

Community practice throughout the United States demonstrates that PSA and DRE are consistently effective and efficient in the early detection of prostate cancer.     

Variation in percentage-free prostate-specific antigen (PSA) with prostate volume, age and total PSA level

OBJECTIVE: To examine the correlation between prostate volume, patient age and total prostate-specific antigen (tPSA) with the percentage-free PSA (f/tPSA) in a population-based cohort of men with no prostate cancer and with a tPSA of < 10.0 ng/mL. SUBJECTS AND METHODS: Men who in 1988-1989, after randomized selection in the general population, participated in a population-based screening study for prostate cancer, were investigated. In all, 1622 of the men (aged 55-70 years) were considered free from prostate cancer and had a tPSA level of < 10.0 ng/mL. The f/tPSA and tPSA were determined in frozen sera from each individual, and related to prostate volume and age measured at the time of the study. The entire population was investigated, as were four subpopulations based on tPSA levels (< 2.0, 2.0-3.9, 4.0-6.9 and 7.0-9.9 ng/mL). Statistical calculations included multiple regression and correlation analysis. RESULTS: The f/tPSA level varied with prostate volume and age, but the decisive factor for this variation was the tPSA level. The closest correlation was in the tPSA interval 7.0-9.9 ng/mL, where volume and age together explained 47% of the variation in f/tPSA. Also, for men with tPSA levels in each of the intervals 2.0-3.9, 4.0-6.9 and 7.0-9.9 ng/mL, the f/tPSA increased with higher prostate volumes and age. In men with tPSA levels of < 2.0 ng/mL the f/tPSA was not affected by variations in prostate volume or age. CONCLUSION: The variation in f/tPSA with prostate volume, age and tPSA is highly dependent on the tPSA level. Volume and age in the tPSA interval 7.0-9.9 ng/mL can explain almost half the variation in f/tPSA, whereas this influence is insignificant in men with a tPSA of < 2.0 ng/mL.     

Estimation of prostate cancer risk on the basis of total and free prostate-specific antigen,prostate volume and digital rectal examination

Background and Objective: Approximately 70% of the men with an elevated serum prostate-specific antigen (PSA) identified in prostate cancer screening do not have prostate cancer. Other available diagnostic variables may be utilized to reduce the number of false positive PSA results, but few algorithms for calculation of the combined impact of multiple variables are available. The objective of this study was to establish nomograms showing the probability of detecting prostate cancer at biopsy on the basis of total PSA, and the percentage of free PSA in serum, prostate volume and digital rectal examination (DRE) findings.Methods: In a randomized, population-based prostate cancer screening trial 10 284 men aged 55–67 years were screened during 1996 and 1997 in two metropolitan areas in Finland. Results for men (n=758) with a serum PSA of 4–20 μg/l were used to establish the risk nomograms. Of these 200 (26%) had prostate cancer at biopsy.Results: Prostate cancer probability depended most strongly on the percentage of free PSA. Total PSA, prostate volume, and DRE also contributed to prostate cancer probability, whereas age and family history of prostate cancer did not. More false positive PSA results could be eliminated by using the multivariate risk model rather than the percentage of free PSA (p<0.001) or PSA density (p=0.003) alone.Conclusions: Wide variation in probability of detecting prostate cancer among screened men with a serum PSA of 4–20 μg/l was observed. The nomograms established can be used to avoid or defer biopsy in men with a low prostate cancer probability in spite of a serum PSA level exceeding 4 μg/l.     

Prostate cancer detection with digital rectal examination, prostate-specific antigen, transrectal ultrasonography and biopsy in clinical urological practice

OBJECTIVE: To evaluate the utility of digital rectal examination (DRE), prostate specific antigen (PSA) and transrectal ultrasonography and biopsy (TRUSB) in detecting prostate cancer in one teaching-hospital urological practice. PATIENTS AND METHODS: In all, 2800 consecutive patients had TRUSB as outpatients by one urologist, the indications for which were a raised or rising PSA level or an abnormal DRE. In addition, the indications for repeat TRUSB included previous abnormal histology, e.g. suspicious areas or atypia or high-grade prostatic intraepithelial neoplasia. All data were collected prospectively. RESULTS: Of 2800 TRUSB, 223 were known cases of prostate cancer (previously diagnosed from transurethral prostatectomy chips or after radical prostatectomy) and were excluded from the analysis. There were 2194 initial and 383 repeat TRUSB; of the former patients, 1129 were found to have prostate cancer, giving a cancer-detection rate of 52%. The positive predictive values (PPVs) for patients with a normal DRE and PSA of < 4, 4-10 and > 10 ng/mL were 9%, 31% and 48%, respectively; the corresponding PPVs for patients with an abnormal DRE and the same PSA levels were 27%, 67% and 85%, respectively. Of the 383 repeat TRUSB, the cancer-detection rate was 31% for the first repeat and 28% for the second. CONCLUSIONS: The present values are higher than those reported previously, because these patients were within a clinical urological practice, and the indications for and methods of TRUSB have changed in recent years, such that more lateral areas were biopsied. These values are useful in helping clinicians to counsel patients about the probability of detecting cancer.