Age dictates risk when neoadjuvant hormone therapy is added to prostate brachytherapy

The risks associated with neoadjuvant hormonal therapy may outweigh the benefits of its use in conjunction with brachytherapy in some older men with prostate cancer, according to research from the radiation oncology program at Boston’s Harvard Medical School.

Of more than 1,700 prostate cancer patients over the age of 70 (median age 75), investigators found that all-cause mortality was 20% higher in those treated with NHT in addition to brachytherapy than in those treated with brachytherapy alone. In a cohort of more than 700 patients under the age of 70, hormone use and mortality were not significantly related, said lead investigator Amy M. Dosoretz, MD.

“In older patients, it’s very important to weigh the implications of the therapy when designing a treatment plan,” Dr. Dosoretz said. “Recent studies have alerted us to the fact that hormone therapy has more risks than was previously appreciated.”

The older cohort included 1,709 men with localized prostate cancer who were treated with brachytherapy and no supplemental external beam radiation therapy. Of those, 786 received NHT for a median duration of 3.5 months. All patients were followed for at least two years; the median follow-up time was five years (ASTRO 2008 abstract 84).

After adjusting for known prostate cancer prognostic factors and age, NHT was associated with a 20% increased risk of all-cause mortality. Older age and Gleason score of 7 or higher were also independently associated with increased mortality.

Hormone deprivation therapy has previously been associated with risk of cardiovascular disease, which can be a more significant concern in older patients who are more likely to have a history of vascular disease, diabetes, or other related comorbidities.

Risk of disease progression must also be factored into the therapeutic equation, Dr. Dosoretz emphasized. Studies that have specifically looked at high-risk prostate cancer patients, most recently a May 2007 study, reported that androgen deprivation therapy (ADT) does not significantly affect mortality. In the Harvard study, however, 61% of patients in the older cohort were at low risk for disease progression, Dr. Dosoretz said. “There is a benefit to ADT in patients with intermediate and high-risk disease. Most of our patients were low risk,” she said.