- Email: [email protected]
Digital Rectal Examination Remains an Important Screening Tool for Prostate Cancer
european urology 54 (2008) 483–484
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Editorial –
referring to the article published on pp. 581–588 of this issue
Digital Rectal Examination Remains an Important Screening Tool for Prostate Cancer Ofer Yossepowitch * Department of Urology, Rabin Medical Center, Petah-Tikva 41000, Israel
The primary objective of cancer screening is prevention of disease-specific morbidity or death. Largely based on an unproven, or yet to be proven, notion that early detection and treatment of prostate cancer improves disease-specific outcomes, annual prostate-specific antigen (PSA) tests and digital rectal examinations (DREs) are routinely offered in many countries [1]. However, given the high prevalence of clinically innocuous tumours not destined to threaten a patient’s longevity, compounded by potential treatment-related morbidity, the true value of screening for prostate cancer remains uncertain. At present, the European Association of Urology, the American Urological Association, and the American Cancer Society recommend that annual prostate cancer screening be offered to asymptomatic men 50 yr of age or older with an estimated life expectancy of greater than 10 yr [1]. In contrast, the American College of Physicians and the American College of Preventive Medicine suggest that a patient should make a decision regarding screening in consultation with his physician and only after discussing and considering the potential benefits and harms of prostate cancer screening, personal preferences, and life expectancy [1]. Hopefully, the European Randomized Study of Screening for Prostate Cancer (ERSPC) and the Prostate, Lung, Colon, and Ovary screening trial in the United States will provide meaningful data to further support or refute serum- and DRE-based screening for prostate cancer.
As the debate over the comparative merits and limitations of screening persists, the optimal screening strategy has yet to be defined. Until the advent of PSA, DRE was the most widely used screening test with 40–50% of all palpably suspicious prostates harbouring biopsy-detected cancer [2]. As a result of widespread PSA screening, the number of men diagnosed with prostate cancer due to an abnormal DRE alone has steadily declined [1,3–5]. Moreover, the ability of PSA to detect prostate cancer at an early stage, and the relative inaccuracy and subjectivity of DRE, have led some authors to question the continued use of DRE in a screening setting [5]. Although the predictive accuracy of PSA undoubtedly outperforms DRE [5,6], particularly in men with low PSA levels, if the exclusion of DRE from screening programs is to be considered, three pertinent questions should be addressed: (1) How likely is an abnormal rectal examination to prompt an unnecessary biopsy; (2) what is the incremental value of screening with DRE and PSA over PSA alone; and (3) can the inclusion of a DRE deter patients from participating in a screening program? The positive predictive value (PPV) of an abnormal DRE ranges from 6–33% and is directly associated with the PSA level, even in men with PSA 4 ng/ml [6]. In this issue of European Urology, Gosselaar et al, from the Rotterdam section of ERSPC, confirm this observation and point out that potentially aggressive cancers (Gleason score 7) are more prevalent among men who have an abnormal DRE compared
DOI of original article: 10.1016/j.eururo.2008.03.104 * Tel. +972 3 937 6553; Fax: +972 3 937 6569. E-mail address: [email protected]. 0302-2838/$ – see back matter # 2008 European Association of Urology. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.eururo.2008.03.105
484
european urology 54 (2008) 483–484
to normal DRE [7]. Although this group no longer considers an abnormal DRE to be an indication for prostate biopsy in men with PSA < 3 ng/ml [5], Okotie et al found that a substantial proportion of cancers detected by DRE alone have clinically aggressive features: 20% were non-organ confined at radical prostatectomy and nearly 20% had a Gleason score of 7 or higher [3]. Furthermore, Gosselaar et al report the PPV of an abnormal DRE in men with PSA 3 ng/ml to be 48%, approximately twice as high as the PPV for a PSA of 4–10 ng/ml. The authors rightfully conclude that although a suspicious DRE (in conjunction with an elevated PSA) does not modify the biopsy indication, the risk of harbouring high-grade disease is substantially increased and should be implemented in future risk prediction models for clinically significant tumours. This recommendation is sensible inasmuch as Okotie et al’s study showed prostate cancers detected because of abnormalities in both PSA level and DRE results were associated with reduced overall and cancer-specific survival, compared to those detected by either test alone. Another relevant concern is whether the DRE is a barrier that prevents some men from being screened, either because of physicians’ reticence to perform the exam or patients simply refusing it [8]. Although the potential for patient discomfort during a DRE is indisputable, the reluctance of patients to compromise the diagnostic accuracy afforded by invasive assays for the benefit of using non-invasive assays has been documented in other areas of urologic oncology [9]. Both Borden et al [10] and Thompson et al [11] demonstrated that an abnormal DRE was an independent predictor of prostate cancer, specifically, high-grade cancer. Armed with such knowledge, we suspect patients are less likely to avoid or refuse a DRE. Our assumption is supported by a previous study indicating that 15.5% of men refused to undergo biopsy when PSA 2 ng/ml was used as the sole indication for biopsy, whereas only 4% of men refused when biopsy was indicated by an abnormal DRE [12]. It is incumbent upon urologists to provide their patients with all available data describing the purported benefits and disadvantages of prostate cancer screening with DRE and PSA over PSA alone. No data exist to support one method of screening as undeniably superior to others. A universally accepted PSA cutoff that might safely allow omission of the DRE for the individual patient has not been, and likely never will be, established. The best contemporary approach to the quandary of prostate cancer screening is based on multiple risk factors wherein the
relative value of the patient’s age and comorbidities, ethnicity, PSA and DRE, and their changes over time, are incorporated into an informed decision whether to perform or to defer a prostate biopsy [11]. Let us not discard the DRE so easily, because it may often lead us to the information we are seeking. Conflicts of interest: The author has nothing to disclose.
References [1] Lim LS, Sherin K. Screening for prostate cancer in U.S. men ACPM position statement on preventive practice. Am J Prev Med 2008;34:164–70. [2] Chodak GW, Keller P, Schoenberg HW. Assessment of screening for prostate cancer using the digital rectal examination. J Urol 1989;141:1136–8. [3] Okotie OT, Roehl KA, Han M, Loeb S, Gashti SN, Catalona WJ. Characteristics of prostate cancer detected by digital rectal examination only. Urology 2007;70:1117–20. [4] Carroll P, Coley C, McLeod D, et al. Prostate-specific antigen best practice policy—part I: early detection and diagnosis of prostate cancer. Urology 2001;57:217–24. [5] Schroder FH, van der Maas P, Beemsterboer P, et al. Evaluation of the digital rectal examination as a screening test for prostate cancer. Rotterdam section of the European Randomized Study of Screening for Prostate Cancer. J Natl Cancer Inst 1998;90:1817–23. [6] Bozeman CB, Carver BS, Caldito G, Venable DD, Eastham JA. Prostate cancer in patients with an abnormal digital rectal examination and serum prostate-specific antigen less than 4.0 ng/mL. Urology 2005;66:803–7. [7] Gosselaar C, Roobol MJ, Roemeling S, Schro¨der FH. The role of the digital rectal examination in subsequent screening visits in the European Randomized Study of Screening for Prostate Cancer (ERSPC), Rotterdam. Eur Urol 2008;54:581–8. [8] Nagler HM, Gerber EW, Homel P, et al. Digital rectal examination is barrier to population-based prostate cancer screening. Urology 2005;65:1137–40. [9] Yossepowitch O, Herr HW, Donat SM. Use of urinary biomarkers for bladder cancer surveillance: patient perspectives. J Urol 2007;177:1277–82, discussion 82. [10] Borden Jr LS, Wright JL, Kim J, Latchamsetty K, Porter CR. An abnormal digital rectal examination is an independent predictor of Gleason 7 prostate cancer in men undergoing initial prostate biopsy: a prospective study of 790 men. Br J Urol 2007;99:559–63. [11] Thompson IM, Ankerst DP, Chi C, et al. Assessing prostate cancer risk: results from the Prostate Cancer Prevention Trial. J Natl Cancer Inst 2006;98:529–34. [12] Gosselaar C, Roobol MJ, Roemeling S, van der Kwast TH, Schroder FH. Screening for prostate cancer at low PSA range: the impact of digital rectal examination on tumor incidence and tumor characteristics. Prostate 2007;67: 154–61.
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Editorial –
referring to the article published on pp. 581–588 of this issue
Digital Rectal Examination Remains an Important Screening Tool for Prostate Cancer Ofer Yossepowitch * Department of Urology, Rabin Medical Center, Petah-Tikva 41000, Israel
The primary objective of cancer screening is prevention of disease-specific morbidity or death. Largely based on an unproven, or yet to be proven, notion that early detection and treatment of prostate cancer improves disease-specific outcomes, annual prostate-specific antigen (PSA) tests and digital rectal examinations (DREs) are routinely offered in many countries [1]. However, given the high prevalence of clinically innocuous tumours not destined to threaten a patient’s longevity, compounded by potential treatment-related morbidity, the true value of screening for prostate cancer remains uncertain. At present, the European Association of Urology, the American Urological Association, and the American Cancer Society recommend that annual prostate cancer screening be offered to asymptomatic men 50 yr of age or older with an estimated life expectancy of greater than 10 yr [1]. In contrast, the American College of Physicians and the American College of Preventive Medicine suggest that a patient should make a decision regarding screening in consultation with his physician and only after discussing and considering the potential benefits and harms of prostate cancer screening, personal preferences, and life expectancy [1]. Hopefully, the European Randomized Study of Screening for Prostate Cancer (ERSPC) and the Prostate, Lung, Colon, and Ovary screening trial in the United States will provide meaningful data to further support or refute serum- and DRE-based screening for prostate cancer.
As the debate over the comparative merits and limitations of screening persists, the optimal screening strategy has yet to be defined. Until the advent of PSA, DRE was the most widely used screening test with 40–50% of all palpably suspicious prostates harbouring biopsy-detected cancer [2]. As a result of widespread PSA screening, the number of men diagnosed with prostate cancer due to an abnormal DRE alone has steadily declined [1,3–5]. Moreover, the ability of PSA to detect prostate cancer at an early stage, and the relative inaccuracy and subjectivity of DRE, have led some authors to question the continued use of DRE in a screening setting [5]. Although the predictive accuracy of PSA undoubtedly outperforms DRE [5,6], particularly in men with low PSA levels, if the exclusion of DRE from screening programs is to be considered, three pertinent questions should be addressed: (1) How likely is an abnormal rectal examination to prompt an unnecessary biopsy; (2) what is the incremental value of screening with DRE and PSA over PSA alone; and (3) can the inclusion of a DRE deter patients from participating in a screening program? The positive predictive value (PPV) of an abnormal DRE ranges from 6–33% and is directly associated with the PSA level, even in men with PSA 4 ng/ml [6]. In this issue of European Urology, Gosselaar et al, from the Rotterdam section of ERSPC, confirm this observation and point out that potentially aggressive cancers (Gleason score 7) are more prevalent among men who have an abnormal DRE compared
DOI of original article: 10.1016/j.eururo.2008.03.104 * Tel. +972 3 937 6553; Fax: +972 3 937 6569. E-mail address: [email protected]. 0302-2838/$ – see back matter # 2008 European Association of Urology. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.eururo.2008.03.105
484
european urology 54 (2008) 483–484
to normal DRE [7]. Although this group no longer considers an abnormal DRE to be an indication for prostate biopsy in men with PSA < 3 ng/ml [5], Okotie et al found that a substantial proportion of cancers detected by DRE alone have clinically aggressive features: 20% were non-organ confined at radical prostatectomy and nearly 20% had a Gleason score of 7 or higher [3]. Furthermore, Gosselaar et al report the PPV of an abnormal DRE in men with PSA 3 ng/ml to be 48%, approximately twice as high as the PPV for a PSA of 4–10 ng/ml. The authors rightfully conclude that although a suspicious DRE (in conjunction with an elevated PSA) does not modify the biopsy indication, the risk of harbouring high-grade disease is substantially increased and should be implemented in future risk prediction models for clinically significant tumours. This recommendation is sensible inasmuch as Okotie et al’s study showed prostate cancers detected because of abnormalities in both PSA level and DRE results were associated with reduced overall and cancer-specific survival, compared to those detected by either test alone. Another relevant concern is whether the DRE is a barrier that prevents some men from being screened, either because of physicians’ reticence to perform the exam or patients simply refusing it [8]. Although the potential for patient discomfort during a DRE is indisputable, the reluctance of patients to compromise the diagnostic accuracy afforded by invasive assays for the benefit of using non-invasive assays has been documented in other areas of urologic oncology [9]. Both Borden et al [10] and Thompson et al [11] demonstrated that an abnormal DRE was an independent predictor of prostate cancer, specifically, high-grade cancer. Armed with such knowledge, we suspect patients are less likely to avoid or refuse a DRE. Our assumption is supported by a previous study indicating that 15.5% of men refused to undergo biopsy when PSA 2 ng/ml was used as the sole indication for biopsy, whereas only 4% of men refused when biopsy was indicated by an abnormal DRE [12]. It is incumbent upon urologists to provide their patients with all available data describing the purported benefits and disadvantages of prostate cancer screening with DRE and PSA over PSA alone. No data exist to support one method of screening as undeniably superior to others. A universally accepted PSA cutoff that might safely allow omission of the DRE for the individual patient has not been, and likely never will be, established. The best contemporary approach to the quandary of prostate cancer screening is based on multiple risk factors wherein the
relative value of the patient’s age and comorbidities, ethnicity, PSA and DRE, and their changes over time, are incorporated into an informed decision whether to perform or to defer a prostate biopsy [11]. Let us not discard the DRE so easily, because it may often lead us to the information we are seeking. Conflicts of interest: The author has nothing to disclose.
References [1] Lim LS, Sherin K. Screening for prostate cancer in U.S. men ACPM position statement on preventive practice. Am J Prev Med 2008;34:164–70. [2] Chodak GW, Keller P, Schoenberg HW. Assessment of screening for prostate cancer using the digital rectal examination. J Urol 1989;141:1136–8. [3] Okotie OT, Roehl KA, Han M, Loeb S, Gashti SN, Catalona WJ. Characteristics of prostate cancer detected by digital rectal examination only. Urology 2007;70:1117–20. [4] Carroll P, Coley C, McLeod D, et al. Prostate-specific antigen best practice policy—part I: early detection and diagnosis of prostate cancer. Urology 2001;57:217–24. [5] Schroder FH, van der Maas P, Beemsterboer P, et al. Evaluation of the digital rectal examination as a screening test for prostate cancer. Rotterdam section of the European Randomized Study of Screening for Prostate Cancer. J Natl Cancer Inst 1998;90:1817–23. [6] Bozeman CB, Carver BS, Caldito G, Venable DD, Eastham JA. Prostate cancer in patients with an abnormal digital rectal examination and serum prostate-specific antigen less than 4.0 ng/mL. Urology 2005;66:803–7. [7] Gosselaar C, Roobol MJ, Roemeling S, Schro¨der FH. The role of the digital rectal examination in subsequent screening visits in the European Randomized Study of Screening for Prostate Cancer (ERSPC), Rotterdam. Eur Urol 2008;54:581–8. [8] Nagler HM, Gerber EW, Homel P, et al. Digital rectal examination is barrier to population-based prostate cancer screening. Urology 2005;65:1137–40. [9] Yossepowitch O, Herr HW, Donat SM. Use of urinary biomarkers for bladder cancer surveillance: patient perspectives. J Urol 2007;177:1277–82, discussion 82. [10] Borden Jr LS, Wright JL, Kim J, Latchamsetty K, Porter CR. An abnormal digital rectal examination is an independent predictor of Gleason 7 prostate cancer in men undergoing initial prostate biopsy: a prospective study of 790 men. Br J Urol 2007;99:559–63. [11] Thompson IM, Ankerst DP, Chi C, et al. Assessing prostate cancer risk: results from the Prostate Cancer Prevention Trial. J Natl Cancer Inst 2006;98:529–34. [12] Gosselaar C, Roobol MJ, Roemeling S, van der Kwast TH, Schroder FH. Screening for prostate cancer at low PSA range: the impact of digital rectal examination on tumor incidence and tumor characteristics. Prostate 2007;67: 154–61.