Prostate Cancer Treatment Informed with New Findings
A new report in the medical journal The Lancet Oncology brings good news to men with advanced prostate cancer confined to the prostate.
The study found that in men with advanced prostate cancer that is confined to the prostate, radiation treatment along with a six-month program of androgen (male hormone) deprivation therapy can improve survival by as much as 50 percent.
Androgen deprivation therapy lowers concentrations of testosterone, which experts have long recognized as a powerful stimulator of prostate cancer cell growth.
Although hormone therapy is now standard treatment for metastatic (spread to other parts of the body) prostate cancer, whether it is beneficial in treating prostate cancer still confined to the organ has been less clear.
Also unclear was whether short-term hormone therapy might be effective - most patients now receive the treatment over a period of at least three years.
"Finding that we can stop cancerous progression in 40 percent of men by just six months of testosterone suppression treatment with minimal side effects is enormously important," says study author Dr. Jim Denham, from the University of Newcastle, New South Wales, Australia.
One expert says these findings support a shorter course of hormone therapy.
"This is an important study, validating a [previous] study we published in 2004 that showed that six months of hormonal therapy and radiation improves cancer-specific survival compared with no hormonal therapy," remarks Dr. Anthony D'Amico, a Harvard researcher and chief of radiation oncology at Brigham and Women's Hospital in Boston.
Overall survival has not been affected, but this may be due to other causes of death among men in the study, he adds.
"Whether three years of hormonal therapy should still be standard is questioned by the current study and ours, and will be answered definitively by the large randomized study of three years versus six months of hormonal therapy, the results of which are soon to be released," Dr. D'Amico says.
In the study, Dr. Denham's team randomly assigned 818 men with locally advanced prostate cancer to radiation treatment with no testosterone suppression, or three months or six months of testosterone suppression.
The Australian team found that men treated with three months of hormone therapy before and during radiation were at a 35 percent lower risk of relapse compared to men receiving radiation alone.
For men treated with six months of hormone therapy before and during radiation, that risk of relapse was reduced by 44 percent.
In addition, survival among men receiving both radiation and hormone treatment was 54 percent better compared with men who received radiation alone, according to the report.
Radiation therapy has also changed for the better since this study was conducted, Dr. Denham notes.
"Technical improvements in radiotherapy equipment in the last 10 years will also improve treatment results," he notes.
"Our new trial, which is known as the RADAR trial, is testing the new radiotherapy equipment, as well as determining whether an additional year of testosterone suppression can produce further benefits in those men at greatest risk," comments Dr. Denham.
However, another expert questions whether the findings apply to the radiation therapy patients typically receive today.
"It's an interesting result," says Dr. Stephen J. Freedland, an assistant professor of urology at Duke University School of Medicine. "The question is how applicable is it to your average patient today with prostate cancer?"
"I'm not sure it applies to most men today," he says.
For one thing, the dose of radiation used in the study is lower than what patients currently receive, Dr. Freedland notes.
Androgen deprivation therapy may be making up for less-than-optimal radiation therapy, Dr. Freedland explains. "If we give higher-dose radiation, do we need to do androgen deprivation therapy?"
Furthermore, Dr. Freedland believes the patients in the study had more advanced cancers than are commonly seen in prostate cancer patients today.
"So if you take men who have low-risk disease, do these studies, observations, really apply?" he asks. "We don't know the answer to that."
Patients who consult a radiation therapist regarding treatment for prostate cancer should ask about hormone therapy, Dr. Freedland advises. "The question to ask your radiation oncologist is: Am I one of those people who stand to benefit from hormone therapy?"
Always consult your physician for more information.
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Prostate Cancer Facts
Online Resources
Prostate cancer is the most common cancer among men, excluding skin cancer.
American Cancer Society (ACS) estimates for 2005 include 232,090 new cases of prostate cancer in the US.
And for 2005, estimates include 30,350 deaths occurring from prostate cancer in the US alone, making it the second leading cause of cancer death in men.
All men are at risk for prostate cancer. The risk increases with age, and family history also increases the risk.
African-American men have about a 60 percent higher incidence rate of prostate cancer than Caucasian men, and nearly a two-fold higher mortality rate than Caucasian men.
According to the National Cancer Institute (NCI), this year in the US, almost 180,000 men will be told that they have prostate cancer.
After a diagnosis of prostate cancer, a man and his family face several choices regarding treatment. Decisions involve many factors, personal as well as medical.
Before making these decisions, the NCI states, it is very important that he learns about all the options available. With this knowledge, a newly diagnosed prostate cancer patient can participate more confidently with his doctor in planning his individual treatment.
According to the NCI, by age 50, about one-third of American men have microscopic signs of prostate cancer. By age 75, half to three-quarters of men will have some cancerous changes in their prostate glands.
Most of these cancers remain latent, producing no signs of symptoms, or are so indolent, or slow-growing, that they never become a serious threat to health.
A much smaller number of men will actually be treated for prostate cancer. About 16 percent of American men will be diagnosed with prostate cancer during their lives; 8 percent will develop significant symptoms; and 3 percent will die of the disease.
Until the last several years, prostate cancer death rates had been rising steadily.
For example, this cancer in 1932 killed 17 of every 100,000 American men. By 1991, this number had reached 25 in 100,000. Since then, however, the death rates have been declining.
The reasons for both the earlier increase and the recent decline in the prostate cancer death rates are unclear.
Always consult your physician for more information.
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