Men with significant comorbidities overtreated for prostate cancer

February 1, 2012

A recent study suggests that a substantial portion of men with comorbidities serious enough to affect their lifespan are also being subjected to likely unnecessarily aggressive therapy.

Key Points

Los Angeles-Many urologists will acknowledge that a significant percentage of men with low-grade prostate cancer are being overtreated. Now comes a study from the David Geffen School of Medicine at UCLA suggesting that a substantial portion of men with comorbidities serious enough to affect their lifespan are also being subjected to likely unnecessarily aggressive therapy.

The study also compared the rates of aggressive treatment of low-risk disease in men with multiple comorbidities with those in men aged 75 years and older. The authors found that while urologists are wrestling with treatment decisions in patients with comorbidities, they are for the most part adhering to U.S. Preventive Services Task Force guidelines recommending that screening (and by extension, aggressive treatment) should end at 74 years of age.

"Men with prostate cancer who are likely to die from other causes within 10 years are unlikely to benefit from aggressive treatment. We wanted to see what impact age and comorbidity had on survival and treatment decisions," first author Timothy Daskivich, MD, chief resident in urology at UCLA, told Urology Times.

The authors sampled 509 men with low-risk prostate cancer diagnosed at the Greater Los Angeles and Long Beach Veterans Affairs Medical Centers between 1997 and 2004 for the study, which was presented at the 2011 AUA annual meeting in Washington and published in Cancer (2011; 117:2058-66).

Data on treatments were acquired and multivariate analysis was employed to determine the influence of age and Charlson comorbidity scores on treatment decisions. Cox proportional hazards analysis was used to compare other-cause mortality risks among the varied Charlson score and age groups.

"We found that men with Charlson scores of 3 or greater had a 70% chance of other-cause mortality within 10 years and yet more than half, 54%, of those with low-risk cancer were treated with surgery or radiation," said Dr. Daskivich. The study defined low-risk cancer according to the D'Amico risk assessment: a PSA of less than 10.0 ng/mL, clinical stage T2a or less, and a Gleason score of 6 or less.

Charlson score predicts mortality

"Men 75 and older can easily be triaged into treatment or surveillance. They were treated aggressively only 16% of the time. Their mortality from other causes was 24% at 10 years. But in our cohort, Charlson score was a much better predictor of mortality than age. Men with multiple significant comorbidities are at very high risk for other-cause death, and they are being overtreated for their disease," said Dr. Daskivich.

"We are hoping our work in this area will help standardize the assessment of comorbidity so that better decisions can be made."

Dr. Daskivich added that it is important for the physician community to make patients aware that low-risk prostate cancer can be managed conservatively with active surveillance or watchful waiting, although he acknowledged that convincing doctors and their patients of this may not be easy. To this end, Dr. Daskivich and his colleagues created a new, prostate cancer-specific comorbidity index whose methodology is based on the Charlson score (J Urol 2011; 186:1868-73).

"When you think about the consequences of overtreatment, of a patient spending the last years of his life unnecessarily impotent and incontinent, we need to be able to make better decisions as to whom to treat and not to treat," Dr. Daskivich said.