A new study shows that androgen deprivation therapy does not improve survival from prostate cancer among elderly men with localized disease. Given the costs and side effects of this approach, physicians need to consider carefully before offering it, given this new evidence.

 Summary

Depriving the prostate gland of male hormones called androgens is one approach to treating prostate cancer. But a new trial suggests this is not as good as conservative management when the cancer remains localized. There was just a small benefit in one sub-group, with poorly differentiated cancer, when it came to prostate cancer specific survival. So men and their doctors should now think twice about opting for hormone deprivation therapy where disease is still localized.

Introduction

After skin cancer, prostate cancer is the most common form of the disease and is the second leading cause of cancer death among men. Most men with prostate cancer, 85 percent, still have local disease. They can opt for radiotherapy, surgery or "watchful waiting" where their condition is closely monitored to see if it progresses or not. However, there is an increasing trend toward treating men in this group with primary androgen deprivation therapy (PADT), the rationale being that androgens, a group of male sex hormones, stimulate the growth of prostate cancer. There's some evidence this may be so in most advanced disease. But we do not really know if PADT is beneficial in earlier, localized, prostate cancer.

And messing with hormone levels can be detrimental to the patient. Chronic PADT is linked to increased risk of fractures, heart disease, diabetes and poorer quality of life. If it is life-saving, then clearly PADT could be worth these risks. But localized prostate cancer often progresses slowly, if at all, and many men may die of some other cause entirely.

What was done

Researchers at the Cancer Institute of New Jersey and elsewhere recruited a group of nearly 20,000 men aged 66 or older diagnosed with localized prostate cancer. Of these, 41 percent were assigned to watchful waiting, while the rest were treated with PADT. Diagnosis was between 1996 and 2002 and follow up for prostate cancer specific mortality was to end 2004 and for all cause mortality to end 2006.

What was found

Use of PADT was associated with lower prostate cancer specific mortality at ten years than watching waiting - 80.1 percent versus 82.6 percent. There was no difference between the two groups in ten year overall survival - at about 30 percent each. It was only in men who had a poorly differentiated cancer that PADT seemed to offer some prostate cancer specific survival benefit - at 59.8 percent versus 54.3 percent. But there was still no overall survival benefit with PADT, even in this group.

What this study means

PADT does not offer a survival benefit in older men with localized prostate cancer. It even seems to increase mortality from the disease. The researchers wonder if androgen deprivation therapy kills off less aggressive cancer cells, leaving the more aggressive ones to flourish and so progress the disease. The conclusion seems to be that in these cases it may be better to leave well alone.

Source

Survival following primary androgen deprivation therapy among men with localized prostate cancer G. Lu-Yao, P. Albertsen, Journal of the American Medical Association, July 9 2008, vol. 300, pp. 173--181