DEAR DOCTOR K:
My doctor has proposed androgen deprivation therapy to treat my prostate cancer. Can you tell me about this treatment?
Androgens are the family of male sex hormones that includes testosterone. When prostate cancer develops, testosterone contributes to the growth and spread of the tumor. Androgen deprivation therapy deprives cancer cells of this stimulation. Also known as hormonal therapy, it can be a powerful weapon in the fight against prostate cancer.
Hormonal therapy was once reserved for prostate cancer that had spread beyond the prostate. These days, doctors also combine it with radiation to treat locally advanced tumors. Hormonal therapy reduces the chance that a tumor will progress or return. And it makes radiation therapy more effective at controlling prostate cancer.
The downsides? Some types of hormonal therapy have known cardiovascular risks. The treatment also causes weight gain and bone loss.
Still, studies have consistently shown that the longer a man receives hormonal therapy, the better his chances for extended survival. Results from a recent clinical trial add to this evidence. They show that the survival benefits of long-term hormonal therapy outweigh the risks.
The study was launched in 1992. It enrolled about 1,500 men with cancer confined to the prostate, or cancer that had spread into nearby tissues, such as the bladder. From the appearance of prostate cancers under the microscope, doctors can estimate which cancers are likely to behave aggressively. The patients in this study had cancers that ranged from just slightly aggressive to highly aggressive.
During the study, half the men got only four months of hormonal therapy. It started before and continued during radiation treatment. The other half got that treatment plus two additional years of hormonal therapy.
The results were presented last November. They showed that after following the men for an average of 20 years, men who got the long-term treatment had a 40 percent lower risk of the cancer spreading. They also had a 33 percent lower risk of dying from prostate cancer. This was compared to men who were given hormonal therapy for just four months. In men with the highest-risk prostate cancer, long-term hormonal therapy dropped the odds of cancer spreading and death even further.
These results seem to weigh the scale heavily in favor of long-term hormonal therapy. But because of the side effects, the optimal duration of treatment remains an open question.
It’s obviously very important to know the best treatment to prevent a cancer from spreading and causing death. Every patient with cancer wants their doctor to know the answer.
This study demonstrates how tough it can be to get answers. Nearly 1,500 people needed to agree to participate in the study, and they needed to continue participating for nearly a quarter century. A research team needed to remain intact for that same quarter century. Research requires time and money. It’s the only way to get answers, and we need more answers.