Study: Prostate Cancer Overtreated
Many men undergo radical surgery or radiotherapy despite life expectancies of less than 10 years
Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, Timothy J. Daskivich, MD, of the University of California Los Angeles (UCLA), and colleagues sampled 96,032 men aged 66 years or older with early-stage PCa and Gleason scores of 7 or less. A total of 50,048 men (52%) had life expectancies of less than 10 years, as determined using patient age and comorbidities at PCa diagnosis. In this group, 68% of men aged 66 to 69 years, 69% of those aged 70 to 74 years, 57% of those aged 75 to 79 years, and 24% of those aged 80 years and older received aggressive treatment (radical prostatectomy, external beam radiotherapy, or brachytherapy), Dr. Daskivich's group reported online ahead of print in Cancer.
Even men with the heaviest comorbid disease burdens were frequently treated aggressively, the researchers noted. For example, among men aged 66 to 69 and 70 to 74 years with a Charlson score of 3 or higher, 60% and 50%, respectively, received aggressive treatment, despite other-cause mortality rates of 81% and 86%, respectively, at 10 years after diagnosis.
The authors said they hope study findings “will promote greater awareness of the role of life expectancy in treatment decision-making for men with low- and intermediate-risk prostate cancer.”
In a press release issued by UCLA, Dr. Daskivich observed, “Life expectancy is poorly integrated into treatment decision-making for prostate cancer, yet it is one of the primary determinants of whether a patient will benefit from treatment with surgery or radiation.”
Guidelines from the American Urological Association, National Comprehensive Cancer Network, and the European Association of Urology recommend conservative management of early-stage disease in patients with life expectancies of less than 10 years.
Among men aged 66 to 69, 70 to 74, 75 to 79, and 80 years or older with life expectancies less than 10 years, 50%, 53%, 63%, and 69% received radiation treatment and 30%, 25%, 13%, and 9% underwent surgery. “The disparity in receipt of radiation over surgery increased with both advancing age and increasing comorbidity,” the authors wrote in their report. “The finding that surgery was less common that radiation therapy in older and sicker men is not surprising because these men are often poor surgical candidates; the lack of a similar inherent check on treatment with radiation therapy may be enabling the overtreatment of older and sicker men with radiation.”
In an accompanying editorial, Matthew R. Danzig, a medical student, and James M. McKiernan, MD, both of Columbia University in New York, commended the work by Dr. Daskivich and colleagues “for its thoughtfully articulated design and rigorous statistical methodology.” For example, the editorial writers pointed out, the investigators calculated non-cancer-specific mortality using competing-risks regression analysis, which is superior to an alternative method of calculating cause-specific mortality commonly used in the clinical literature.
“A novel element of the study is that inferred life-expectancy values, vis-à-vis rates of other-cause mortality, are calculated from the actual outcomes of the sample population.”
Danzig and Dr. McKiernan noted that an inherent limitation of the data presented by Dr. Daskivich's group “is that no insight is available into the clinical decision-making process.” Many factors may result in overtreatment, they noted. For example, clinicians may understand the limited benefit of treatment but fail to inform patients properly about current literature findings and society guidelines and to explain their implications properly. “Conversely, patients may understand these points but choose to pursue aggressive treatment regardless.”