Prostate cancer test-by-request policies allow men without symptoms to get a prostate-specific antigen (PSA) test if they want one, after speaking with their doctors.
An analysis written by an international group of urologists, epidemiologists, and other experts, published Wednesday in the BMJ, argues that such shared decision policies have led to higher-than-necessary rates of PSA testing, resulting in overdiagnosis, overtreatment, and inequity.
Prostate cancer is the most common cancer in men and the third leading cause of cancer death in men. However, most high-income countries, including the U.S. and the U.K., do not have a national prostate cancer screening program, primarily due to the lack of a simple, high-quality test that can better identify the men most likely to have harmful cancers.
PSA tests cannot differentiate between low-risk cancer that may never cause any harm and aggressive disease that requires treatment. Therefore, while PSA tests save some lives, many believe it’s not accurate enough to warrant national screening recommendations, as exist for breast cancer and other diseases. Almost all high-income countries have instead opted for PSA testing based on decisions made jointly by doctors and their patients.
However, the authors contend that relying on such shared decision-making has led to excessive rates of PSA testing, particularly in older men most likely to be harmed by screening and least likely to benefit. They believe it is not clear whether the benefits of PSA screening by choice outweigh the harms of overdiagnosis and overtreatment when low-risk tumors that would never have caused symptoms or shortened life are detected and treated unnecessarily.
In addition, they say that the shared decision-making approach reflects and reproduces health inequities. For example, in Canada and the U.S., PSA testing is less common in ethnic minority groups, while in the U.K. and Switzerland, PSA testing rates are lower in economically disadvantaged areas.
“The current approach of determining testing by shared decision-making has resulted in the worst possible practical outcome of high levels of PSA testing and medical harm, with minimal benefit and inequity,” writes Dr. Andrew Vickers of New York’s Memorial Sloan Kettering Cancer Center, along with his colleagues.
Instead, the authors say implementing a comprehensive, risk-based prostate cancer early detection program that carefully manages testing, biopsies, and subsequent treatment could reduce the disadvantages accompanying PSA-based screening.
Alternatively, they suggest policies that discourage routine PSA testing and make it hard to obtain a test without specific symptoms, with exceptions for high-risk men. However, they acknowledge that such policies are untested and require further research.
“To make better use of PSA testing, policy makers should choose between a comprehensive, risk-adapted approach that is specifically designed to reduce overdiagnosis and overtreatment, or restricting PSA testing to people referred to urologists with symptoms,” the authors concluded. “That choice will need to take into account wider patient and public perspective, as well as health and economic concerns.”
