“The findings suggest that the diagnosing urologist may influence not only the decision regarding up-front treatment, but the type of treatment the patient receives,” said Dr. Karen Hoffman, lead author of the study.
To explore care management variations for patients with low-risk prostate cancer, Hoffman and colleagues from the University of Texas MD Anderson Cancer Center in Houston analyzed data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, as well as Medicare claims for men ages 66 and older. Of more than 12,000 men diagnosed with low-risk prostate cancer by their urologist, 80% had undergone treatment within one year of diagnosis, while only 20% were simply observed, the study found. Of 7,554 men who subsequently met with a radiation oncologist following the urologist visit, 91.5% received treatment within a year, and 8.5% were observed.
Patients were more likely to undergo procedures performed by the urologists, including prostatectomy (removal of the prostate); cryotherapy (freezing the prostate to destroy cancer cells); brachytherapy (use of radioactive material inside the prostate); or external-beam radiotherapy (use of beams of radiation focused on the prostate gland from a machine outside the body).
Men with levels of the prostate-specific antigen, or PSA, that are less than 10 ng/ml are considered to be low-risk, meaning the patient's cancer is not likely to grow or spread for many years, and may not cause problems during his lifetime, according to the National Institutes of Health. In many cases, observation is recommended as a way to manage the patient's disease and avoid potential side effects.
“Our findings suggest active surveillance as a prostate cancer management strategy is underused in older men with low-risk prostate cancer,” Hoffman said. “The treatment you receive may be a consequence of the urologist who diagnoses your cancer.”
The study hypothesized that treatment variations could be due in part to financial incentives, or to urologists witnessing the effects of late-stage disease. But conclusions about either motivation could not be drawn from the analysis. The researchers also noted several study limitations.
Whether or not the choice for watchful waiting was given to the patient, or if the treatment was ultimately the most appropriate for the patient could not be determined by the research data. Also, the study analyzed patient records from 2006 and 2009, and Hoffman said treatment patterns may have shifted since that time following release of updated recommendations.
In 2010, the National Comprehensive Cancer Network updated its guidelines to establish recommended active surveillance, or watchful waiting, as the sole initial treatment for men who met certain low-risk criteria for prostate cancer.
A second study evaluated use of the widely-used androgen-deprivation therapy—or ADT—for early-stage prostate cancer and found it did not improve 15-year survival rates for localized prostate cancers. Researchers from the Rutgers Cancer Institute of New Jersey concluded that primary ADT should be used only to palliate disease symptoms or prevent imminent symptoms.
There has been disagreement among physicians over the best timing for use of ADT in men with elevated PSA levels. Some say early use of the hormone therapy before symptom onset can lead to better outcomes, while others saying early use may lead to resistance to the treatment. The researchers looked at data for more than 66,000 men ages 66 and older diagnosed with early-stage prostate cancer between 1992 and 2009. They found that 15-year survival rates were similar with either high or low use of the treatment.
“There is a limited role for ADT as primary therapy,” the study authors concluded, saying healthcare providers and older patients should carefully weigh risks and costs before initiating treatment.
In an accompanying commentary, Dr. Quoc-Dien Trinh of Dana-Farber Cancer Institute and Dr. Deborah Schrag of Brigham and Women's Hospital said “there is no compelling evidence for use of ADT alone in men with localized prostate cancer” and that use of the therapy remains “alarmingly high.”
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