Combined drug, hormone and radiation treatment cures prostate cancer
8 July 2009
An experimental drug therapy used in combination with standardized
hormone treatment and radiation therapy has enabled two patients, whose
prostate cancer had been considered inoperable, to become cancer free.
The men were participating in a clinical trial of an
immunotherapeutic agent called MDX-010 or ipilimumab conducted by Mayo
Clinic in the US. In these two cases, physicians say the approach
initiated the death of a majority of cancer cells and caused the tumours
to shrink dramatically, allowing surgery. In both cases, the aggressive
tumours had grown well beyond the prostate into the abdominal areas.
“The goal of the study was to see if we could modestly improve upon
current treatments for advanced prostate cancer,” says Eugene Kwon, MD,
Mayo Clinic urologist and leader of the clinical trial. “The candidates
for this study were people who didn’t have a lot of other options.
However, we were startled to see responses that far exceeded any of our
The patients first received a type of hormone therapy called androgen
ablation, which removes testosterone and usually causes some initial
reduction in tumour size. Researchers then introduced a single dose of
ipilimumab, an antibody, which builds on the anti-tumour action of the
hormone and causes a much larger immune response, resulting in massive
death of the tumour cells.
Both men experienced consistent drops in their prostate specific
antigen (PSA) counts over the following weeks until both were deemed
eligible for surgery. Then, during surgery, came a greater surprise.
“The tumours had shrunk dramatically,” says Michael Blute, MD, Mayo
urologist, co-investigator and surgeon, who operated on both men. “I had
never seen anything like this before. I had a hard time finding the
cancer. At one point the pathologist (who was working during surgery)
asked if we were sending him samples from the same patient.”
One patient underwent radiation therapy after surgery; both have
resumed their regular lives. Further research is being planned to
understand more about the mechanisms of the antibody and how best to use
the approach in practice. The researchers, however, note the
significance of their findings.
“This is one of the holy grails of prostate cancer research,” says
Dr. Kwon. “We’ve been looking for this for years.”
Bookmark this page