Physicians often fail to discuss risks, benefits of PCa screening

October 15, 2009

Men largely make decisions about prostate cancer screening based on conversations with their clinicians, but these discussions often do not include information about both the risks and benefits of testing, a study in Archives of Internal Medicine (2009; 169:1611-8) suggests.

Men largely make decisions about prostate cancer screening based on conversations with their clinicians, but these discussions often do not include information about both the risks and benefits of testing, a study in Archives of Internal Medicine (2009; 169:1611-8) suggests.

First author Richard M. Hoffman, MD, of the New Mexico VA Health Care System and University of New Mexico School of Medicine, Albuquerque, and colleagues conducted a telephone survey of 3,010 randomly selected English-speaking adults aged 40 years and older in 2006 and 2007. The sample included 375 men who had either undergone or discussed PSA testing with their clinicians in the previous 2 years.

Overall, nearly 70% of the men had discussed screening with their clinician before making a decision, including 14.4% who chose not to undergo testing. Most often, clinicians raised the idea of screening.

"Although respondents generally endorsed the shared decision-making process and felt informed, only 69.9% actually discussed screening before making a testing decision, few subjects reported having discussed the cons of screening, 45.2% said they were not asked for their preference about PSA testing, and performance on knowledge testing was poor," the authors wrote. "Therefore, these discussions-when held-did not meet criteria for shared decision making.

"Our findings suggest that patients need a greater level of involvement in screening discussions and to be better informed about prostate cancer screening issues."

A second report used statistical modeling to estimate the benefits and risks of PSA screening in men of various ages and risk levels.

In the study (Arch Intern Med 2009; 169:1603-10), Kirsten Howard, PhD, MPHS, of the University of Sydney, Australia, and colleagues constructed a statistical model to provide information for men aged 40 to 70 years at low, moderate, and high risk for prostate cancer based on family history. Using Australian prostate cancer incidence rates before PSA screening began in 1989 and cancer death rates in 2005, along with data from the European Randomized Study of Screening for Prostate Cancer and the Australian Bureau of Statistics, the authors examined two hypothetical cohorts of men who either participated in or declined annual PSA screening. The model predicts that benefits and harms of annual PSA screening vary with age and risk level.

"For 1,000 men screened from 40 to 69 years of age, there will be 27.9 prostate cancer deaths and 639.5 deaths overall by age 85 years compared with 29.9 prostate cancer deaths and 640.4 deaths overall in unscreened men," the authors wrote. "Higher-risk men have more prostate cancer deaths averted but also more prostate cancers diagnosed and related harms."

In the model, screened men are two to four times more likely to be diagnosed with prostate cancer than unscreened men, but death rates from prostate cancer and from all causes are not significantly different. This implies that many men whose cancer is detected by PSA screening may be undergoing treatment for clinically insignificant cancers, the authors say.