Adverse effects of ADT in men with non-metastatic prostate cancer
Posted Nov 03 2010 12:00am
Two new studies just posted on line in the Journal of Clinical Oncology specifically address some of the adverse effects associated with 12 months of continuous androgen deprivation therapy in men with non-metastatic prostate cancer. It is unclear whether these studies are based on the same groups of patients, but it does seem highly likely.
In the first study, Alibhai et al. examined the impact of ADT on physical functioning in a total of 259 men in three groups: 87 patients on ADT (Group A), 86 other prostate cancer patients (group B), and 86 healthy controls (Group C). The groups were all similar in age (mean, 69.1 years; range, 50 to 87 years) and physical function at study initiation.
They report the following results:
Distance walked during a 6-minute walk test was stable over time in Group A (the ADT group) but improved significantly in Groups B and C.
Grip strength declined in Group A, but remained stable in Group B, and improved significantly in Group C.
TUG scores (“timed up-and-go” scores) were stable over time across all three groups.
SF-36 physical function summary score declined significantly in Group A, but increased significantly in Groups B and C.
Negative effects on outcomes were observed within 3 months of starting ADT and were generally independent of age.
In their second study, Alibhai et al. examined the impact of ADT for up to 12 months on cognitive function on a total of 241 men in three groups: 77 patients on ADT (Group D), 82 other prostate cancer patients (group E), and 82 healthy controls (Group F). The groups were all similar in education (mean 15.4 years; range, 8 to 24 years) and age (mean, 68.9 years; range, 50 to 87 years) at study initiation. All patients received a predetermined set of 14 neuropsychological tests, examining eight cognitive domains, at baseline, 6 months, and 12 months.
Here are the results of this second study:
After adjustment for age and education level, all three patient groups had similar cognitive scores at baseline (with the exception of one test of working memory).
There was no apparent association of use of ADT with significant changes in attention/processing speed, verbal fluency, verbal memory, visual memory, or cognitive flexibility at 6 or 12 months after the start of treatment in for patients in Group D compared to those in Groups E and F.
For patients in Group D, one test each of immediate memory, working memory, and visuospatial ability demonstrated significantly poorer results at 12 months that for patients in Groups E and F, but these findings were not confirmed by other testing techniques.
For the first of these two studies, the authors conclude that, ”Endurance, upper extremity strength, and physical components of [quality of life] are affected within 3 months of starting ADT.” They go on to suggest that exercise interventions to counteract these losses may be warranted. For the second study, they conclude only that, “There is no consistent evidence that 12 months of ADT use has an adverse effect on cognitive function in elderly men with [prostate cancer].”
The “New” Prostate Cancer InfoLink suggests that the first conclusion is what might be expected and the second is accurate but based on a flawed study. Basically, we suspect that neither study population was really either large enough or continued for long enough. Although some men do report relatively rapid changes in cognitive function when treated with ADT, this adverse effect appears to be much more likely in men treated for significantly longer than 12 months. It would be helpful to know if this was a continuing study that might report additional data after 2 years of follow-up, when we might expect to see some more significant impact on cognitive function among a subset of the patients in Group D.