Androgen drives many prostate cancers. But the body uses androgen for muscle growth and maintenance, among other functions. An ongoing study published in the Journal of Clinical Oncology along with the American Society for Clinical Oncology (ASCO) Annual Meeting 2017 evaluates the effects of androgen deprivation therapy not just on patients' physical function but on global geriatric health, including skills of daily living. Because the study is longitudinal, following individual patients from before treatment through the course of their care, findings can help to define not only the characteristics of men who will need supportive care, but when in treatment this care should begin.
Seventeen patients were enrolled on the study with a median age of 75 years and 14 with metastatic disease. Two tools were used to measure function and vulnerability, namely the Vulnerable Elders Survey (showing overall daily function), and the short physical performance battery (a common tool defining physical health in the context of oncology). On both scales about half of these patients were identified as vulnerable at baseline, reflecting the combined effects of age-related frailties and the influence of cancer.
Differences between these two measures emerged as early as three months after treatment. On the short performance battery, seven patients had seen declines at three months, with the most dramatic impairment being in patients' ability to stand from a chair without using hands (reflecting loss of large muscle strength with androgen deprivation therapy). However, while three patients showed decreases on the Vulnerable Elders Survey, six showed increases at three months, likely due to the effect of anti-androgen therapy against their cancer. Of the 10 patients who were followed for at least six months, five had worsening scores on the Vulnerable Elders Scale whereas only two had worsening on the short physical performance battery.
"Oncologists use measures of a patient's functional status to inform fitness for treatment, but there may be nuances you're missing," says Elizabeth Kessler, MD, oncology fellow at the University of Colorado Cancer Center and the paper's first author. "What we wanted to know is the relationship between overall geriatric health and functional status. Results of this ongoing study are beginning to show that, first, because many of these men show baseline vulnerability due to their age and cancer, androgen deprivation therapy can show almost immediate improvement in functioning. But then, second, we do see effects of androgen deprivation on things like muscle strength that could be improved with intervention."
Kessler points out that interventions already exist to support overall functioning in geriatric prostate cancer patients, often including components of cardiovascular and strength training.
"We even imply that some of these patients might benefit from pre-habilitation, starting physical interventions a few weeks before the start of anti-androgen therapy," Kessler says. She points out that both tests used in this ongoing study can be administered by clinicians in an exam room without the need for specialized gym equipment or other specific resources.
"We've known that androgen deprivation affects physical function, but we haven't known when that effect took place," Kessler says. "This can tell us when to start interventions."
The group's next step will explore the influence of supportive health interventions in this population.
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