BY MARK SCHOLZ, MD
Dr.Kevin Nead authored an article published in the Journal of Clinical Oncology this month. It created a media
sensation and generated multiple calls to the PCRI Helpline. Last week, three separate articles about this
topic were posted on the Yahoo home page at the same time.
no surprise that an article on this topic generates wide-spread interest. About
500,000 thousand men in the United States are undergoing prostate cancer
treatment with androgen deprivation therapy (ADT). This treatment works by blocking
the male hormone levels delivering notable anticancer efficacy and also proven
to prolong life in men with prostate cancer. Despite it’s known effectiveness, a
variety of side effects can occur, including memory problems. The previously reported studies evaluating this
phenomenon seem to indicate that when memory deficits occur, they usually
reverse after ADT is stopped.
research published in the Journal of Clinical Oncology, relied on a new method
of searching through patient’s medical charts with computers. No human review
of these medical charts were performed. The computer software searched the medical
records in an attempt to determine if men on ADT had a higher incidence of
Alzheimer’s. The authors report that this new computer searching methodology in detecting a specific medical diagnosis is 74% accurate.
of all the charts at Stanford and Mount Sinai hospital unearthed 16,888 prostate
cancer patients of which 2,397 were treated with ADT. After the fancy computer analysis, designed to
compensate for multiple factors such as patient age and underlying heart disease
(both of which lead to Alzheimer’s more frequently), the conclusion was that
the ADT-treated men were twice as likely to have developed Alzheimer’s. A total
of about 9 cases would have been expected from normal causes, but 18 were
actually detected. If these conclusions
are accepted as gospel truth, an additional 9 out of 2,397 men treated with ADT
would equate to an increased risk of less than half of 1%.
conclusion that there is tiny increase risk of Alzheimer’s with ADT, needs to
be put in context based on what we already know about prostate cancer. First,
is it possible that these men have reversible
memory problems while still taking ADT? There was no attempt in the study made
to determine if the “Alzheimer’s” patients were still on ADT when the diagnosis
of Alzheimer’s was made. Second, men treated with ADT are substantially sicker
than men who don’t need ADT. There is no
way for the computer analysis to compensate for how this may have impacted mental
performance. Third, patients getting ADT receive closer medical surveillance
and visit physicians more frequently than men who are not receiving ADT. As such, memory problems are more likely to
come to medical attention and be diagnosed when men are on ADT. Fourth, general
anesthesia (from surgery) is known to cause long-term memory problems. This study did not perform any analysis to
determine if surgery was performed with equal frequency in both groups.
summary, it is not clear from this JCO article whether the men labeled having Alzheimer’s
disease had memory problems while still receiving ADT or whether they had true
Alzheimer’s, i.e., long-term irreversible memory problems continuing after the
ADT was stopped. There is one thing, however, this study does show: At worst,
memory problems serious enough to be labeled as “Alzheimer’s” occur in in less
than one out of every 200 men treated with ADT.