Predictive value of digital rectal examination for prostate cancer detection is modified by obesity

The American Cancer Society's updated screening guidelines for prostate cancer (CaP) render digital rectal examination (DRE) optional. We investigated the impact of DRE on CaP detection among obese men. Data from 2794 men undergoing initial prostate biopsy at three centers were analyzed to assess CaP risk attributed to abnormal DRE across body mass index (BMI) categories. Predictive accuracies of a combination of PSA, age, race, center and biopsy year including or excluding DRE findings were compared by areas under the receiver-operating characteristics curves. In all cohorts, obese men were less likely to have abnormal DREs diagnosed than non-obese men. As BMI category increased, abnormal DREs became stronger predictors for overall CaP in individual (P-trends ≤ 0.05) and combined (P-trend<0.001) cohorts, and for high-grade CaP in the Italian (P-trend=0.03) and combined (P-trend=0.03) cohorts. DRE inclusion improved the predictive accuracy for overall and high-grade CaP detection among all obese men (P ≤ 0.032) but not normal-weight men (P ≥ 0.198). DRE inclusion also near-significantly improved overall CaP detection in obese men with PSA<4 ng ml(-1) (P=0.081). In conclusion, the predictive value of DRE is dependent on obesity and is significantly higher among obese men than normal-weight men.     

PCA3 sensitivity and specificity for prostate cancer detection in patients with abnormal PSA and/or suspicious digital rectal examination. First Latin American experience

IntroductionProstate Cancer Gene 3 (PCA3) is a recently described and highly specific urinary marker for prostate cancer (CaP). Its introduction in clinical practice to supplement low specificity of prostate specific antigen (PSA) can improve CaP diagnosis and follow-up. However, before its introduction, it is necessary to validate the method of PCA3 detection in distinct geographic populations.ObjectivesOur aim was to describe for the first time in Latin America, the application of the PROGENSA PCA3 assay for PCA3 detection in urine in Chilean men and its utility for CaP diagnosis in men with an indication of prostate biopsy.Materials and methodsSixty-four Chilean patients (mean age, 64 years) with indication of prostate biopsy because of elevated PSA and/or suspicious digital rectal examination (DRE) were prospectively recruited. PCA3 scores were assessed from urine samples obtained after DRE, before biopsy, and compared with PSA levels and biopsy outcome.ResultsThe median PSA value and mean PCA3 score were 5.8 ng/ml and 31.7, respectively. Using a cutoff PCA3 score of 35, the sensitivity and specificity for detecting CaP were 52% and 87%, respectively. The receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.77 for PCA3 and 0.57 for PSA, for the same group of patients. In patients with previous negative biopsy, PCA3 specificity increased by 2.2%.ConclusionsThis is the first report in Latin America on the use of PCA3 in diagnosing CaP. Our results are comparable to those reported in other populations in the literature, demonstrating the reproducibility of the test. PCA3 score was highly specific and we specially recommend its use in patients with persistent elevated PSA and prior negative biopsies.     

Finasteride improves the sensitivity of digital rectal examination for prostate cancer detection

PURPOSE: Men undergoing screening for prostate cancer are recommended to undergo digital rectal examination and prostate specific antigen measurement. We previously presented data from the Prostate Cancer Prevention Trial indicating that finasteride improves the performance characteristics of prostate specific antigen for cancer detection. In the current study we report the impact of finasteride on digital rectal examination sensitivity and specificity. MATERIALS AND METHODS: We examined the sensitivity and specificity of digital rectal examination in Prostate Cancer Prevention Trial subjects receiving finasteride or placebo who underwent prostate biopsy, had prostate specific antigen measurement and digital rectal examination within 1 year before biopsy and were on treatment at biopsy. RESULTS: Of 9,423 men in the finasteride group 4,579 and 5,112 of 9,459 in the placebo group met study evaluation requirements. Of 4,579 men in the finasteride group 695, including 264 with Gleason 7 or greater and 81 with Gleason 8 or greater, and 1,111 of 5,112 in the placebo group, including 240 with Gleason 7 or greater and 55 with Gleason 8 or greater, were diagnosed with prostate cancer. In men in the placebo and finasteride groups digital rectal examination sensitivity was greater for detecting higher grade tumors. The sensitivity of digital rectal examination was significantly greater for cancer detection in men receiving finasteride than placebo (21.3% vs 16.7%, p=0.015). Digital rectal examination sensitivity was also greater for detecting high grade (Gleason 7 or greater and 8 or greater) cancers in men receiving finasteride but this did not attain statistical significance. Digital rectal examination specificity was similar in men receiving finasteride or placebo. CONCLUSIONS: Finasteride significantly improves prostate cancer detection with digital rectal examination.     

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-specific antigen coordinated with digital rectal examination and transrectal ultrasonography in the detection of prostate cancer

Summary In a aptient population, coordinated use of digital rectal examination and prostate-specific antigen can alert the physician as to the possible existence of prostate cancer. If both are used as first-line studies, abnormality of either can then direct the need for further study by transrectal ultrasonography and, in selected instances, prostatic biopsy. Such sequential use of these tests in a programmed manner results in an increased level of cancer detection as compated with use of the digital rectal examination alone.     

Comparison of the diagnostic value of sonography and rectal examination in cancer of the prostate

The value of endorectal sonography for the diagnosis of prostatic cancer was established after retrospective interpretation of sonographic findings in 213 patients, without prior knowledge of either the clinical or pathological data. Endorectal sonography was performed by the authors with a mechanical sectorial high frequency (7.5 MHz) probe. A pathology report (73 biopsies, 52 TUR, 7 suprapubic adenomectomy specimens) was available from 132 patients: 25 pathological examinations were interpreted as normal; 41 adenomas; 24 prostatitis or fibrosis, and 42 cancers (5 clinical stage T0, 22 T1, 2 T2 and 13 T3). Specificity for the diagnosis of cancer was 65 or 81%, respectively, according to the normality reference considered, i.e. either the group of patients having a normal pathological control (90 patients) or the same group plus another group of patients with a normal rectal examination (171 patients). The sensitivity for the diagnosis of cancer was only 48%. 43% of cancers were falsely interpreted as prostatitis or adenomas and 9% as normal (2 T0 and 2 T1). The large proportion of local stages without capsular involvement (29 of 42) is partly responsible for this lack of sensitivity. Rectal examination and sonography are complementary techniques. In the same study, rectal examination had a 48% specificity and a 92% sensitivity.     

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.     

结肠镜结合肛门指检诊断低位直肠息肉的价值探讨

目的分析肛门指检及结肠镜检中低位直肠息肉的漏诊率及漏诊息肉特征,探讨结肠镜检结合肛门指检的重要性。方法收集2012年9月至2013年5月在体检中心先后接受肛门指检及结肠镜检的244例受检者,分别对两种方法检查低位直肠息肉的漏诊情况进行分析。结果89例发现直肠息肉并切除息肉143个。65例在距离肛门〈7 cm肠段发现息肉94个,其中15例肛门指检漏诊息肉23个,29例结肠镜检漏诊息肉38个,结肠镜检的漏诊率高于肛门指检（24.5%vs 40.4%,χ2=5.460,P=0.019）。小息肉、平坦型息肉容易被漏诊;多发性息肉患者漏诊率较高;初级医师的息肉漏诊率明显高于有经验医师;肛门指检时间〈2 min者的漏诊率高于≥2 min者;结肠镜检操作时间〈35 min者的漏诊率高于≥35 min者;结肠镜检距离肛门≤3 cm的息肉的漏诊率明显高于肛门指检,差异均有统计学意义（P〈0.05）。结论结肠镜检和肛门指检均存在漏诊息肉的可能,息肉漏诊与息肉大小、形态、数目、病理以及操作医师、检查时间密切相关。结肠镜检查结合肛门指检,能降低低位直肠息肉的漏诊率。     

血清PSA联合直肠指诊诊断前列腺癌的价值

目的 探讨前列腺特异性抗原(PSA)及直肠指诊(DRE)在前列腺癌诊断中的作用。方法 回顾性分析268例前列腺疾病患者的临床资料及PSA、DRE的结果。结果 经病理学确诊14例为前列腺癌,其中PSA值为4.0～9.9μg/L时有5例前列腺癌(5/13),PSA值≥10μg/L有5例前列腺癌(5/7);而DRE可疑者有6例前列腺癌(6/41)。如果单独用PSA或DRE对前列腺癌进行筛选,对前列腺癌诊断的漏诊率分别为28.6％(4/14)、57.1％(8/14),联合使用这两种方法仅有2例漏诊。结论 PSA联合DRE是临床上筛选前列腺癌的可靠方法。     

Predictive value of prostate specific antigen density in the detection of prostate cancer in patients with elevated prostate specific antigen levels and normal digital rectal findings or stage A prostate cancer

We compared the usefulness of PSA and PSA density (PSAD) in diagnosing prostate cancer in 102 men who had a PSA value higher than 4.0 ng/ml and normal digital rectal examination and who had undergone transrectal ultrasonography-guided systematic sextant biopsies of the prostate between August 1996 and October 1999. In addition, for a group of 53 patients who underwent retropubic simple prostatectomy, PSA, PSAD and PSA transition zone (PSA-TZ) examination results for those with stage A prostate cancer were compared with the results for those with benign prostatic hyperplasia (BPH). Of the former 102 men, 20 (19.6%) had prostate cancer. There was no significant difference in mean PSA level between patients with negative and those with positive biopsy results (mean 9.3 and 11.8, respectively, p = 0.295), but the mean PSAD of patients with positive biopsy results was significantly higher than that of those with negative results (mean 0.55 and 0.29, respectively, p = 0.0007). Of the 53 men who underwent retropubic simple prostatectomy, 10 (18.9%) were diagnosed with stage A prostate cancer. There was no significant difference in mean PSA, PSAD and PSA-TZ examination results between patients with BPH and those with stage A prostate cancer. For all 102 patients and for 71 patients with PSA levels of 4.1-10.0 ng/ml, a PSAD cutoff value of 0.1 reduced the number of biopsies 15.7% (16 of 102 cases), and 22.5% (16 of 71 cases), respectively. These results suggest that by measurement of PSAD some patients with benign disease could be spared a biopsy which would have been performed based on PSA results alone.     

Prostate cancer detection in a clinical urological practice by ultrasonography, digital rectal examination and prostate specific antigen.

The prostate cancer detection rate from screening by digital rectal examination and tactilely guided prostate biopsy is approximately 1.7%. Among 1,807 men a detection rate of 14.6% was achieved in a clinical urological practice by physician-conducted prostate ultrasonography, digital rectal examination and determination of serum prostate specific antigen. Results are presented in 5-year increments as well as for the group as a whole. The possible benefit to be derived from an improved detection rate is undetermined. Recommendations are made regarding the clinical use of these diagnostic modalities.     

Biopsy-based diagnosis of prostate cancer in 1290 patients referred for prostate examination: results according to the PSA level, digital rectal examination and ultrasonography

Authors present their retrospective study of 1290 patients referred for prostate evaluation. The risk of cancer was analysed according to PSA, rectal palpation and ultrasound examination. Among the 1290 patients, 54.8% had cancer. The risk of cancer was multiplied by 2.8 when the PSA was between the normal limit and 10 ng/ml, by 7.5 when it exceeded 10 ng/ml, by 4.0 when rectal palpation was abnormal and by 1.6 when a hypoechogenic zone was present. Although a hypoechogenic zone does not improve the detection of cancer compared to PSA and rectal palpation, an increased PSA level even lower than 10 ng/ml indicates biopsies.     

Early detection of prostate cancer in Germany: a study using digital rectal examination and 4.0 ng/ml prostate-specific antigen as cutoff

OBJECTIVE: While international screening studies for prostate cancer are by now almost reaching the estimated number of recruitments mandatory for the necessary power to investigate an effect on mortality of prostate cancer, no statistical figures on the detection of prostate cancer in Germany - apart from historical data before the use of prostate-specific antigen (PSA) are available. In order to generate a database and to investigate the diagnostic efficacy of the primarily practice-based urological care system, a case finding study designed as a nationwide longitudinal early detection trial was initiated. METHODS: In one week in November 1997, 963 urologists prospectively examined 11,644 men between 45 and 75 years of age by digital rectal examination (DRE) and PSA with 4.0 ng/ml as cutoff. Data of family history and physical examination were collected by questionnaire. At this time participants were not aware of their PSA value. PSA was determined in the study center. Indication for sextant biopsy was a PSA value above 4.0 ng/ml or a suspicious lesion on DRE. Any indicated biopsy not performed had to be clarified. In a second questionnaire results of prostate biopsy, treatment and tumor status were documented. RESULTS: The mean age of the study population was 62 years (median 62). The PSA median was 1.4 ng/ml with 82.8% presenting with < 4.0 ng/ml, 12.8% with 4-10 ng/ml and 4.4% with >10 ng/ml. From 1,115 men (47.7%) biopsied, 262 cancers were detected resulting in a detection rate of 23.5%. While 399 men refused biopsy, further investigation was not recommended in 387 men by their urologist, because prostatitis or benign hyperplasia was thought to be the cause for elevated PSA. From the 143 patients undergoing radical prostatectomy, 93 (65%) cancers were organ confined. T(1c) cancers with elevated PSA > 10 ng/ml could be treated with curative intent in 44% only. The positive predictive value (PPV) was estimated to be 16% for DRE alone (14/90), 17% for PSA alone (143/819) and 51% for the combination of both (105/206). In that cohort, use of age-adjusted PSA values and PSA density increased the PPV of PSA testing nonsignificantly. CONCLUSIONS: Significant higher PPV indicated that utilizing a combination of both DRE and PSA is most effective in the early detection of prostate cancer. Unnecessary biopsies can be avoided using either age-adjusted PSA value or PSA density, but the PPV is not significantly changed and potentially curable cancer is missed in up to 25%. Given the substantial variability of the diagnostic approach despite the study design, uniform guidelines are necessary to ensure countrywide sufficient screening.     

Comparison of endorectal magnetic resonance imaging, guided prostate biopsy and digital rectal examination in the preoperative anatomical localization of prostate cancer

PURPOSE: We compared the accuracy of endorectal magnetic resonance imaging (erMRI), transrectal ultrasound (TRUS) guided biopsy and digital rectal examination (DRE) for detecting the location of cancer in the prostate gland and seminal vesicles. MATERIALS AND METHODS: This is a retrospective study of 106 consecutive patients with prostate cancer who were referred for erMRI before radical prostatectomy. Step-section pathological data and erMRI were available in 90 patients, DRE data were available on 86 and individually labeled sextant core biopsies were available in 45. T1 and T2-weighted erMRI was interpreted by a single reader, who scored the likelihood of tumor on a 5-point scale in each seminal vesicle and in 12 locations in the prostate gland. MR spectroscopy data were not used for erMRI interpretation. One pathologist reviewed whole mount serial sections of radical prostatectomy specimens. The area under ROC curves was used to evaluate accuracy. RESULTS: The area under ROC curves for tumor localization was higher for erMRI than for DRE at the prostatic apex (0.72 vs 0.66), mid gland (0.80 vs 0.69) and base (0.83 vs 0.69). It was likewise higher for erMRI than for TRUS biopsy in the mid gland (0.75 vs 0.68) and base (0.81 vs 0.61) but not in the apex (0.67 vs 0.70). On mixed model analysis erMRI significantly increased the accuracy of prostate cancer localization by DRE or TRUS biopsy (each p <0.0001). CONCLUSIONS: For prostate cancer localization erMRI contributes significant incremental value to DRE or TRUS biopsy findings (each p <0.0001).     

Prediction of prostate cancer risk: the role of prostate volume and digital rectal examination in the ERSPC risk calculators

Background

The European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculators (RCs) are validated tools for prostate cancer (PCa) risk assessment and include prostate volume (PV) data from transrectal ultrasound (TRUS).

Objective

Develop and validate an RC based on digital rectal examination (DRE) that circumvents the need for TRUS but still includes information on PV.

Design, setting, and participants

For development of the DRE-based RC, we studied the original ERSPC Rotterdam RC population including 3624 men (885 PCa cases) and 2896 men (547 PCa cases) detected at first and repeat screening 4 yr later, respectively. A validation cohort consisted of 322 men, screened in 2010-2011 as participants in ERSPC Rotterdam.

Measurements

Data on TRUS-assessed PV in the development cohorts were re-coded into three categories (25, 40, and 60 cm³) to assess the loss of information by categorization of volume information. New RCs including PSA, DRE, and PV categories (DRE-based RC) were developed for men with and without a previous negative biopsy to predict overall and clinically significant PCa (high-grade [HG] PCa) defined as T stage >T2b and/or Gleason score ≥7. Predictive accuracy was quantified by the area under the receiver operating curve. We compared performance with the Prostate Cancer Prevention Trial (PCPT) RC in the validation study.

Results and limitations

Areas under the curve (AUC) of prostate-specific antigen (PSA) alone, PSA and DRE, the DRE-based RC, and the original ERSPC RC to predict PCa at initial biopsy were 0.69, 0.73, 0.77, and 0.79, respectively. The corresponding AUCs for predicting HG PCa were higher (0.74, 0.82, 0.85, and 0.86). Similar results were seen in men previously biopsied and in the validation cohort. The DRE-based RC outperformed the PCPT RC (AUC 0.69 vs 0.59; p = 0.0001) and a model based on PSA and DRE only (AUC 0.69 vs 0.63; p = 0.0075) in the relatively small validation cohort. Further validation is required.

Conclusions

An RC should contain volume estimates based either on TRUS or DRE. Replacing TRUS measurements by DRE estimates may enhance implementation in the daily practice of urologists and general practitioners.