A national survey of radiation oncologists and urologists on recommendations of prostate-specific antigen screening for prostate cancer

Authors


Abstract

Objective

  • To assess recommendations for prostate-specific antigen (PSA) screening in a national survey of radiation oncologists and urologists following the recent USA Preventive Services Task Force (USPSTF) grade D recommendation.

Methods

  • A random sample of 1366 radiation oncologists and urologists were identified from the American Medical Association Physician Masterfile.
  • From November 2011 to April 2012, a mail survey was sent to query PSA screening recommendations for men at average risk of prostate cancer for the following age groups: 40–49, 50–59, 60–69, 70–74, 75–79 and ≥80 years.
  • Multivariable logistic regression was used to test for differences in PSA-based screening recommendations by physician characteristics.

Results

  • Response rates were similar at 52% for radiation oncologists and urologists (P = 0.92).
  • Overall, 51.5% of respondents recommended PSA-based screening for men aged 40–49 years, while nearly all endorsed it for those aged 50–74 years (96.1% for 50–59, 97.3% for 60–69, and 87.7% for 70–74 years).
  • However, screening recommendations decreased to 43.9% and 12.8% for men aged 75–79 and ≥80 years, respectively.
  • On multivariable analysis, urologists were more likely to recommend screening for men aged 40–49 (odds ratio [OR] 3.09; P < 0.001) and 50–59 years (OR 3.81; P = 0.01), but less likely for men aged 75–79 (OR 0.66; P = 0.01) and ≥80 years (OR 0.45; P = 0.002) compared with radiation oncologists.

Conclusion

  • While radiation oncologists and urologists recommended PSA screening for men aged 50–69 years, there was less agreement about screening for younger (40–49 years old) and older (≥70 years) men at average risk for prostate cancer.

Introduction

In late 2011, the USA Preventive Services Task Force (USPSTF) issued preliminary findings that prostate cancer screening through PSA testing achieved little reduction in prostate cancer-specific or all-cause mortality, and increased the risks of harm from over diagnosis and biopsy related complications [1]. The recommendations on the merits of PSA-based screening were based on a recent systematic review of level-1 evidence from two fair and three poor quality clinical trials that randomly allocated prostate cancer screening, all of which had significant heterogeneity in screening intensity and thresholds for prostate biopsies, as well as different substantive limitations in study design [2-6]. In May 2012, the USPSTF finalised their clinical guidelines by issuing a grade D recommendation against prostate cancer screening for all men in the general USA population primarily based on the findings from the USA Prostate, Lung, Colorectal, and Ovarian (PLCO) and the European Randomized Study of Screening for Prostate Cancer (ERSPC) trials [7].

In response, the AUA and American Cancer Society of Oncologists (ASCO) put forth policy positions and provisional clinical opinions against the grade D recommendation in favour of men with a >10-year life expectancy making an informed decision on screening with their primary care providers [8, 9]. More recently, the AUA issued new clinical guidelines for the early detection of prostate cancer stating that shared decision-making about the benefits and harms of PSA testing among men between the ages 55 and 69 years [10]. To the extent radiation oncologists and urologists, who routinely diagnose and treat localised prostate cancer, agree or disagree with PSA-based screening in the wake of the USPSTF grade D recommendation bear tangibly on healthcare policy and practice variation. Moreover, expert opinion from prostate cancer specialists can influence primary care provider practice patterns regarding cancer screening. Patients, providers and key stakeholders also face conflicting clinical guidelines from the AUA, ASCO, National Comprehensive Cancer Network (NCCN), and USPSTF on whether to offer PSA screening to any man at average risk of developing prostate cancer in the USA [9, 11-13]. In this context, we sought to assess PSA-based screening recommendations across differing age groups in a national survey of radiation oncologists and urologists in the USA.

Methods

Upon study approval from the Mayo Clinic Institutional Review Board, a random sample of physicians who cited radiation oncology or urology as their primary specialty was selected from the American Medical Association (AMA) Physician Masterfile in June 2011. We further limited the survey sample to physicians who had already completed their residency training and were <65 years of age. The survey sample was also restricted to physicians who were directly involved in patient care and practiced in the USA.

We developed a pilot survey questionnaire aimed at assessing perceptions and beliefs of radiation oncologists and urologists on emerging issues in the screening and treatment of localised prostate cancer. The pilot survey was initially tested in a random sample of 50 radiation oncologists and 50 urologists from a single mailing in July 2011. Items were then revised according to the responses in the pilot survey.

Among items included in the final survey for both specialties, respondents were asked whether they would recommend primary care providers perform PSA-based screening as part of the routine physical examination for men at average risk of developing prostate cancer for the following age groups: 40–49, 50–59, 60–69, 70–74, 75–79 and ≥80 years. Framing variables obtained from the survey and AMA Masterfile included physician demographics, practice setting (academic or community), compensation structure (billing or salary with/without bonus), number of physicians in practice, average time spent counselling newly diagnosed patients about treatment decisions, and geographic region (Northeast, Midwest, South, or West).

From November 2011 to April 2012, the revised survey was mailed to a national sample of 1366 physicians (686 for radiation oncology and 680 for urology). Each eligible respondent was mailed a cover letter, survey and a token cash incentive. Non-responders were mailed a reminder letter and another copy of the survey questionnaire for three successive waves approximately every 6 weeks for a total of four waves.

The primary outcome of this study was PSA-based screening recommendations from specialists to primary care providers concerning men at average risk of developing prostate cancer across different age groups. We used Pearson's chi-square and multivariate logistic regression to test for differences in PSA screening recommendations by physician characteristics, compensation structure, practice setting and geographic region. A two-sided P ≤ 0.05 was considered to indicate statistical significance.

Results

Among the 1366 respondents eligible to participate, 717 physicians completed the survey for an overall response rate of 52.5%. Response rates for radiation oncologists and urologists were similar at 52.6% (361) and 52.3% (356), respectively (P = 0.92). In comparison to radiation oncologists, urologists were more likely to be older, male, and have a billing compensation structure and in solo practice (Table 1). However, there were minimal differences in race and geographic region by physician specialty.

Table 1. Physician characteristics (N = 717)
VariableRadiation oncologists (N = 361), %Urologists (N = 356), %P
Age, years:  0.006
<4023.014.3 
40–5446.848.0 
≥5530.237.7 
Race:  0.74
Non-white14.715.4 
White85.384.6 
Gender:  <0.001
Female18.65.6 
Male81.494.4 
Practice setting:  <0.001
Academic23.512.1 
Community76.587.9 
Compensation structure:  0.001
Billing32.644.4 
Salary ± bonus67.455.6 
No. of physicians in group:  0.009
Solo11.419.6 
2–932.828.1 
≥ 1055.852.3 
Region:  0.82
Northeast24.322.5 
Midwest22.122.5 
South36.235.4 
West17.119.6 

Overall, physicians in our survey sample continued to overwhelmingly recommend screening at high rates for the age groups of 50–59 (96.1%), 60–69 (97.3%), and 70–74 years (87.7%). However, half of all respondents recommended that primary care providers continue to screen for average risk men between the ages of 40 and 49 years (51.2%). Support for PSA-based screening as part of a routine physical examination also continued to some degree for men between aged 75–79 years (43.9%), but decreased to only 12.8% for men aged ≥ 80 years.

Figure 1 presents the differences in PSA screening recommendations across age groups by physician specialty. Radiation oncologists and urologists both endorsed PSA screening at similarly high percentages for the age groups of 50–59, 60–69 and 70–74 years. However, compared with urologists, radiation oncologists had higher percentages of recommending PSA screening for the older age groups of 75–79 (47.59% vs 40.18%; P = 0.05) and ≥80 years (16.33% vs 9.12%; P < 0.001). Yet, nearly two thirds of urologists preferred screening for men in the 40–49 year age group compared with just one third of radiation oncologists (P < 0.001).

Figure 1.

Proportion of respondents recommending PSA testing as part of the routine physical examination for men who are of average risk for developing prostate cancer across age groups by specialty.

On multivariable analysis, physician specialty and practice setting were associated with PSA-based screening recommendations across different age groups (Table 2). After adjusting for other physician characteristics, urologists were significantly more likely than radiation oncologists to recommend PSA screening for men aged 40–49 (odds ratio [OR] 3.09; P < 0.001) and 50–59 years (OR 3.81; P = 0.01). However, urologists were far less likely to recommend screening for older age groups between 75 and 79 (OR 0.66; P = 0.01) and ≥80 years (OR 0.45; P = 0.002) relative to radiation oncologists. Interestingly, physicians practicing in academic medical centres were associated with lower odds of endorsing PSA screening for younger age groups compared with physicians in community practice. The remaining physician characteristics including physician age, gender and compensation structure were not associated with statistically significant differences in PSA screening recommendations.

Table 2. Adjusted OR of recommending PSA screening as part of a routine physical examination for men who are of average risk of prostate cancer across age groups by practice setting and physician specialty.*
Feature (reference)Adjusted OR (95% CI)P
  1. *ORs adjusted for physician age, race, gender, practice setting, compensation structure, number of physicians in group practice, geographic region, and geographic region.
40–49 years  
Academic (community)0.59 (0.37–0.93)0.03
Urologists (radiation oncologists)3.09 (2.23–4.28)<0.001
50–59 years  
Academic (community)0.15 (0.05–0.41)<0.001
Urologists (radiation oncologists)3.81 (1.37–10.56)0.01
60–69 years  
Academic (community)0.13 (0.04–0.44)0.001
Urologists (radiation oncologists)1.98 (0.71–5.58)0.19
70–74 years  
Academic (community)0.49 (0.27–0.92)0.03
Urologists (radiation oncologists)0.99 (0.62–1.62)0.99
75–79 years  
Academic (community)0.67 (0.43–1.06)0.08
Urologists (radiation oncologists)0.66 (0.48–0.91)0.01
>80 years  
Academic (community)1.38 (0.71–2.72)0.34
Urologists (radiation oncologists)0.45 (0.27–0.75)0.002

Discussion

In this national survey of radiation oncologists and urologists, we sought to ascertain specialist recommendations to primary care providers on PSA-based screening across different age groups among men at average risk of prostate cancer. To our knowledge, the present study is the first to gauge the professional recommendations from physicians who commonly diagnose or treat this prevalent malignancy in the wake of the current controversy and now conflicting guidelines from the ASCO, AUA, NCCN, and USPSTF [7, 9, 11-13]. The results of the present study have several important findings that help inform the debate to the degree to which radiation oncologists and urologists endorse age-based PSA screening, especially in light of the recent changes from the AUA guidelines recommending shared decision-making for men aged 55–69 years [10].

The present study shows that there continues to be overwhelming support for PSA-based screening from radiation oncologists and urologists for men aged 50–69 years and at average risk of developing prostate cancer. In the present study, > 90% of radiation oncologists and urologists endorse primary care provider PSA-based screening as part of routine examination for these age groups. Responses from radiation oncologists and urologists in the present survey are consistent with the ASCO and ACS clinical guidelines about initiating an informed discussion about the risks and benefits of PSA testing men beginning at 50 years of age [9, 12]. Interestingly, despite the publication of several large randomised trials on prostate cancer screening [1-3, 5, 6, 14], opinions on routine PSA screening for men between the ages of 50 and 69 years remain essentially unchanged since Fowler et al. [15] last evaluated this very issue in 2000. For example, > 95% of both radiation oncologists and urologists recommended routine PSA screening for men between the ages of 60 and 69 years at that time. The present results argue that despite the conflicting level-1 evidence and grade D recommendation from the USPSTF, the attitudes of urologists and radiation oncologists have remained unchanged since being assessed more than a decade ago.

Support for prostate cancer screening decreased for men at the extremes of age. About half of all respondents recommended PSA testing for men aged between 40 and 49 years, while only 10% agreed with such screening for those aged ≥ 80 years. However, urologists had a higher rate of endorsing PSA-based screening in the youngest age group (40–49 years) compared with radiation oncologists, which is consistent with the AUA and NCCN best practice guidelines [11, 13]. More recently, a recent survey asked whether a 55-year-old man should receive an annual DRE and PSA for prostate cancer screening [16]. After an interactive presentation from two experts reviewing the pros and cons of screening [17], 55% of all respondents stated that they would recommend PSA testing and DREs for this case presentation. Moreover, 71% of physicians made comments in favour of prostate cancer screening, while a large proportion supported shared decision-making and discussed personal experiences where screening resulted in ‘lifesaving treatment’.

Differences in specialty recommendations for prostate cancer screening remain poorly described. In a random sample of 1063 specialists from the state of Florida in 1998, radiation oncologists were more likely to recommend screening for men aged 75–79 years than urologists (92% vs 84%; P = 0.001). Likewise, the present study also shows that urologists were less likely to recommend screening among men aged 75–79 and ≥80 years compared with radiation oncologists on multivariable analysis. A plausible explanation in the differences for age-based screening recommendations may reflect the patient characteristics commonly seen at the time of treatment. For example, several population-based studies from Surveillance, Epidemiology and End Results (SEER)-Medicare and Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) suggest that older patients (aged > 70 years) are more likely to be treated with radiation therapy, while younger patients more typically receive surgery [18, 19]. Consequently, differences in the patient case mix at the time of treatment for newly diagnosed localised prostate cancer may contribute to these differences in opinion on optimal prostate cancer screening across age groups by specialty.

The present data suggesting that physicians practicing in academic settings compared with those in community hospital settings were less likely to recommend PSA testing for most age groups (40–49, 50–59, or 60–69 years) are intriguing but not conclusive. The present study is the first to report this type of association where physicians in academic medical centres appear to disagree with prostate cancer screening among patients who may derive a benefit in a modest reduction in prostate cancer-specific mortality and endorsement by most clinical guidelines. Whether social norms at academic centres about how particular types of guidelines influence screening specialist recommendations to primary care provides on prostate cancer screening behaviour is unknown.

While the present study highlights the current recommendations of radiation oncologists and urologists on the existing controversy for prostate cancer screening, there are several limitations that warrant discussion. First, we administered our survey after the release of the USPSTF preliminary recommendations on prostate cancer screening. It is possible that the timing of the survey administration may have influenced the responses from the radiation oncologists and urologists. However, there were no trends in differences in responses to screening recommendations to primary care providers from the four waves of mail survey. Second, our response rate may have biased the findings, although the response rates overall and by specialty are similar to other large national survey of physicians (52–54% on average) [20, 21]. Furthermore, our response rate was relatively robust for a physician survey. Third, our survey sought the opinions of specialists, who are involved the downstream consequences (i.e. diagnosis and treatment) of prostate cancer screening, rather than from primary care providers who routinely confront this issue in clinical practice. Indeed, survey studies assessing the opinions of primary care providers about the clinical value of prostate cancer screening and which clinical guidelines from different organisations would be more informative.

Nonetheless, our national survey of radiation oncologists and urologists on PSA-based screening of men at average risk in developing prostate cancer has important policy implications. The present study found that urologists and radiation oncologists to a large degree continue to recommend prostate cancer screening of men who may benefit from early diagnosis and treatment (i.e. those patients screened between the ages of 50 and 70 years). While the USPSTF grade D recommendations against offering PSA-based screening to any male patient has provoked significant public controversy, it remains to be seen to what degree it will change clinical practice in the USA. Previous studies suggest that changes to clinical guidelines have had little impact on changing PSA-based screening rates [22-24]. For example, two studies using the National Health Interview Survey (NHIS) reported that the USPSTF 2008 recommendations against offering screening to men aged ≥ 75 years did little to change the PSA screening rates for these patients by primary care providers [22, 23]. However, more recently, a survey of primary care providers from a large community based practice affiliated with an academic medical centre reported that about half of the providers agreed with the USPSTF recommendation and that 41% of those agreeing would likely discontinue offering PSA testing [25].

The USPSTF has been recently criticised for the grade D recommendation and the methodological limitations of its systematic review [1, 26-29]. Other leading societies recommend a more targeted approach with patients and primary care providers making informed decisions. Before the present study, it was unknown to what degree physicians who routinely treat patients with prostate cancer support screening. The present study clearly shows that radiation oncologists and urologists continue to see clinical efficacy in recommending PSA-based screening in an age-based targeted approach for men who are at average risk of prostate cancer in the USA, which is consistent with clinical guidelines from the AUA, ACS, ASCO, and NCCN. However, there were differences between radiation oncologists and urologists in screening recommendation for men aged 50–59 and ≥75 years.

Conflict of Interest

None declared.

Abbreviations
ACS

American Cancer Society

ASCO

American Society of Clinical Oncology

AMA

American Medical Association

ERSPC

European Randomized Study of Screening for Prostate Cancer

NCCN

National Comprehensive Cancer Network

OR

odds ratio

PLCO

Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial

USPSTF

USA Preventive Services Task Force

Ancillary