For women who have finished treatment for early stage breast cancer, taking a preventive drug such as tamoxifen or letrozole every day offers hope and a way to dramatically improve the chances of staying cancer-free.
Among men treated for early prostate cancer, though, one out of every four patients is considered at high risk for relapse - and physicians have no standard treatment that has been proven through studies to help men stave off recurrence.
“There are little data to indicate whether adjuvant therapy helps after surgery,” said City of Hope medical oncologist Przemyslaw Twardowski, M.D., but answers are coming.
Twardowski is principal investigator at City of Hope for a trial comparing two treatment strategies for these men: One offers hormone therapy and chemotherapy, while the other offers hormone therapy alone.
The trial is run through the Southwest Oncology Group, and with about 32 patients enrolled so far, City of Hope is one of the cooperative group’s biggest study sites. Many of the men are drawn to City of Hope because of the prostate cancer surgery team’s treatment expertise and robotic laparoscopic surgery, he noted.
Unfortunately, while surgery may be successful, certain characteristics of the cancer itself may mean that the men are at high risk for relapse. A high Gleason score - a way to measure cancer’s aggressiveness by looking at it under a microscope - is one characteristic. Risk also rises if surgeons find that cancer has spread to the seminal vesicles, or if the surgical margins around the tumor (the outer edge of tissue removed in surgery) show signs of cancerous cells. High prostate-specific antigen levels, too, can hint at increased risk that the cancer will come back.
Twardowski and fellow physicians across the nation want to determine solid, proven steps they can take to help these patients drop their risk. A growing number of trials of various regimens have started nationwide to try to find answers. Some are combining radiation therapy, hormone therapy and chemotherapy after surgery, for example; others are investigating giving chemotherapy and hormone therapy before surgery.
At City of Hope, patients in the high-risk trial may either receive hormone therapy alone or hormone therapy combined with a four-month course of the drugs mitoxantrone and prednisone.
Through hormone therapy, patients receive a drug that suppresses the body’s levels of androgens - male hormones such as testosterone - because androgens drive the growth of most prostate cancers. Patients receive hormone therapy (an injection given once every 12 weeks) for two years.
Researchers will compare patient outcomes from both arms of the trial to see how well the strategies work. “We expect the earliest answers from this to come in about four or five years,” Twardowski said. “We need to have a standard of care for these patients.”
More information on the trial is available at http://clinicaltrials.coh.org