Planting the Seeds of Prevention - Siteman Cancer Center

Initially due to share results in 2013, PLCO investigators led by
Andriole issued an early report in March 2009 stating that annual
screening doesn’t appear to reduce deaths from prostate cancer among
those with a limited life expectancy. “For men with a life expectancy
of seven to 10 years or less, it’s probably not necessary to be screened
for the disease,” Andriole says. But it’s too soon, he adds, to make
broad recommendations for all men based on the study’s initial
findings. “We don’t have enough data yet about the youngest men
in the study — those in their 50s — and it may be that over time,
we will in fact see a benefit from screening.”
Another big issue: “We can’t tell the difference between killer
prostate cancer and slow-growing, nonkiller prostate cancer,”
Andriole says. That uncertainty confounds treatment planning.
To make the distinction, molecular studies by Adam Kibel, MD,
professor of surgery and assistant professor of genetics, look for
signatures in DNA that separate dangerous, fast-growing cancers
Senior research technician Bill Wu prepares prostate cancer samples for from less threatening cases.
high-throughput analysis as Adam Kibel, MD, looks on. In his research, Kibel, who also serves as director of urologic oncology, has
Kibel is looking for genetic markers that could help distinguish
identified a number of small changes in DNA, called polymorphisms,
more deadly forms of prostate cancer from less aggressive ones.
that might be reliable markers for prostate cancer. He is examining
three cohorts of patients for the presence of those polymorphisms: 3,000 men in the PLCO
trial, to see if there is a concordance between prostate cancer and any of the DNA changes;
800 to 1,000 men in a Johns Hopkins University study of metastatic disease, to see if any of the
polymorphisms are associated with aggressive prostate cancer; and all newly diagnosed cases
at Siteman. From these patients, Kibel also collects dietary and environmental information to
find any differences among them that ameliorate the disease. “The goal is not only to tell men if
they are at high risk for prostate cancer but also to tell them how to decrease that risk,” he says.
12 The Alvin J. Siteman Cancer Center
On the prevention front, it was thought that vitamin E and selenium might have a
suppressive effect on prostate cancer development. But surprisingly, the SELECT clinical trial,
in which Andriole was involved, recently closed with the finding that neither supplement reduces
a man’s chance of getting the disease. Another study directed by Andriole — the REDUCE trial
— evaluated the preventive power of dutasteride, a drug widely prescribed to shrink enlarged
prostates. Worldwide, 8,200 men at high risk for prostate cancer took part. The study, funded
by dutasteride manufacturer GlaxoSmithKline, showed the drug lowered prostate cancer risk
by 23 percent, an encouraging result, says Andriole, a consultant for the company.
Andriole still recommends screening, even though the odds of dying from the disease are
slim. “It’s better to know what’s going on in your prostate,” he says. “I’d rather know and make
an informed decision about what course to take, whether that’s watchful waiting or aggressive
treatment, than stick my head in the sand and hope everything turns out all right.”