July 2, 2004

Reducing side effects in prostate cancer patients

An alternative way of blocking hormone activity in prostate cancer patients produces fewer side effects and may be a better choice than standard therapy for some patients. In the July Journal of Clinical Oncology, MGH researchers describe how patients taking bicalutamide, which blocks receptors for testosterone and other hormones, had improved bone density and reported fewer side effects than did those taking leuprolide, a traditional form of hormone therapy that lowers hormone production.

"The differences between the two groups were dramatic; bone mineral density increased among men taking bicalutamide while men in the leuprolide group lost bone," says Matthew Smith, MD, PhD, of the MGH Cancer Center, who led the study. Since male hormones can accelerate the development of prostate cancer, reducing their activity is a standard treatment. Most commonly this is done with drugs like leuprolide that stop the body's production of all sex hormones, but totally blocking hormone activity can lead to potentially serious side effects such as loss of bone density, weight gain and increased body fat. Because bicalutamide blocks testosterone activity without reducing hormone levels in the blood, the researchers wanted to see if it might avoid or reduce side effects.

The investigators enrolled 51 men with nonmetastatic prostate cancer who received either bicalutamide or leuprolide treatment for one year. At the end of the study period, blood levels of testosterone and the female hormone estradiol had risen significantly in the bicalutamide group but fallen in those receiving leuprolide. Bone mineral density, which decreased in the leuprolide group, had increased in participants receiving bicalutamide, who also reported unpleasant side effects — such as hot flashes, fatigue and sexual effects — much less frequently. The study's co-authors are Melissa Goode, Anthony Zietman, MD, Francis McGovern, MD, Hang Lee, PhD, and Joel Finkelstein, MD, all of the MGH.