April 1, 2020
The appropriateness of prostate cancer screening with the prostate-specific antigen (PSA) blood test remains one of the most controversial topics in medicine. The clinical dilemma is that many men with prostate cancer will never experience symptoms or die from the disease and, therefore, would be unaware that they have the disease unless it is detected through other means, such as screening.
Screening carries risks, including false-positive results and psychological harms, and the downstream consequences of diagnosing and treating a condition that could otherwise have had no effect on the individual. This concept is easiest to comprehend in men with limited life expectancy because of a comorbidity and who will die from competing risks as opposed to their screen-detected cancer.1
These risks apply to all cancer screening, including breast, cervical, colorectal, and lung cancers, as well; however, screening also carries benefits, such as a reduced chance of death from prostate cancer in some otherwise healthy men. Society has struggled to balance the risks and benefits of prostate cancer screening, and despite the reporting of three large randomized trials—including more than 600,000 patients, and with more than 10 years of follow-up—screening recommendations remain equivocal.2-4
In 2018, the U.S. Preventive Services Task Force updated its prostate cancer screening recommendations. The panel recommends that “for men aged 55 to 69 years, the decision to undergo periodic PSA-based screening for prostate cancer should be an individual one and should include discussion of the potential benefits and harms of screening with their clinician.”5 Given the complexity of balancing the risks and benefits of prostate cancer screening for an individual patient, patient decision aids have been developed to facilitate the patient-clinician shared decision-making process.6
Similar to the controversy regarding prostate cancer screening, there also is controversy surrounding prostate cancer treatment. Again, the clinical dilemma is that many men will never be affected by their prostate cancer and ultimately will die from other causes. Treatment itself carries its own risks, such as sexual dysfunction, urinary incontinence, and bowel symptoms. The benefits of treating prostate cancer are the same as those for screening—reducing the chance of death from prostate cancer in otherwise healthy men.
Standardized shared decision-making tools have the potential to mitigate cultural and social differences and better ascertain patient preferences.
Further complicating the decision to pursue treatment for prostate cancer is that several competing treatment modalities are available that are thought to be equally efficacious in men with early-stage prostate cancer. In the Prostate Testing for Cancer and Treatment (ProtecT) trial, men diagnosed with prostate cancer were randomized to external beam radiotherapy, radical prostatectomy, or active monitoring (involving regular monitoring instead of immediate treatment). More than 1,600 men were randomized, and with 10 years of median follow-up, no difference was detected in prostate cancer-specific mortality between arms.7 However, the toxicity profiles and quality of life outcomes between the different treatment approaches varied dramatically.8
Minority patients are frequently underrepresented in most of these trials (for example, less than 1 percent of patients in ProtecT were of African descent),9 despite prostate cancer disproportionately affecting men of African descent and concern that they have an underlying aggressive disease.10 Standardized shared decision-making tools have the potential to mitigate cultural and social differences and better ascertain patient preferences. It is plausible that decision aids facilitate meaningful progress in addressing disparities in prostate cancer treatment.11
These aforementioned issues have motivated the Alliance for Clinical Trials in Oncology (Alliance) to initiate a trial that aims to study the use of decision aids in men choosing treatment for localized prostate cancer, with a goal of oversampling minority populations.
Alliance A191402CD (Testing Decision Aids to Improve Prostate Cancer Decisions for Minority Men) aims to compare the effectiveness of two decision aids—Knowing Your Options and Prostate Choice—in diverse populations with early-stage prostate cancer.11 It is a cluster-randomized controlled trial in the National Cancer Institute (NCI) Community Oncology Research Program (NCORP). This four-arm trial tests each decision aid alone and in combination versus usual care (that is, without a decision aid) as seen in Figure 1. Eligible patients are men with a new diagnosis of localized prostate cancer who are enrolled before their first urology consultation to discuss treatment options. Patients seeking second opinions are ineligible. Importantly, the trial oversamples underrepresented populations to determine whether decision aids mitigate disparities in prostate cancer awareness and treatment. At least 50 percent of the study’s enrollees will be African Americans, Native Americans, and Hispanic men. As a clustered trial, the randomization is by participating site, which means entire urology practices will be randomized to one of the study arms. Participation will be limited to NCORP sites within the NCI’s National Clinical Trials Network.
Figure 1. Alliance A191402CD study schema
The exposure is the use of a decision aid, which conveys information about prostate cancer and its treatment to assist patients in making informed treatment decisions. Knowing Your Options was developed by the Agency for Healthcare Research and Quality. Prostate Choice was developed by the study investigators. Both resources use clinical information to assess for prostate cancer risk and for quality-of-life priorities as they relate to treatment options.
The primary outcome is patient knowledge about prostate cancer treatments, which will be assessed with a 12-item knowledge measure called the Prostate Cancer Treatment Questionnaire designed by the study team and administered immediately after initial clinical consultation. A secondary outcome will be decisional conflict and regret, as measured by validated scales. Regret will be assessed 12 months after treatment. Target accrual is 100 patients among 20 sites for five patients per site.
It is anticipated that this study will provide data showing the impact of decision aids on patient knowledge among a population with a new diagnosis of prostate cancer, while accounting for underrepresented minorities. This study may advance the implementation of shared decision making for patients with prostate cancer facing challenging and complex treatment decisions. By enriching the study population with underrepresented men, this investigation also may make progress in mitigating the known racial disparities in prostate cancer treatment and outcomes.