Combo Therapy May Help Those Whose Prostate Cancer Recurs After Gland Removed

Combo Therapy May Help Those Whose Prostate Cancer Recurs After Gland Removed

Men who show biochemical signs that their prostate cancer is recurring after removal of their prostate may live years longer from a combination of hormone and radiation therapy, a Phase 3 trial suggests.

The combination can reduce the rate of prostate cancer metastasis — or the cancer spreading to other organs — compared with radiation therapy alone, and without major side effects, the study showed.

The research, “Radiation with or without Antiandrogen Therapy in Recurrent Prostate Cancer,” was published in The New England Journal of Medicine.

Many patients with prostate cancer are treated with radical prostatectomy, or removal of the prostate. But more than 30 percent see the disease return one to four years after the surgery.

Doctors usually recommend radiation therapy for these patients, but the disease will progress in nearly half of them.

The NRG Oncology’s Radiation Therapy Oncology Group (RTOG) designed a randomized, double-blind, placebo-controlled RTOG 9601 trial (NCT00002874) of the combo treatment. The question was whether adding antiandrogen therapy for 24 months during and after radiation therapy could prolong patients’ overall survival rate, compared with radiation therapy plus placebo.

The study included 761 prostate cancer patients from 17 medical institutions in the United States and Canada. They were randomized to receive the androgen receptor blocker Casodex (bicalutamide) or a placebo every day for two years in combination with seven weeks of radiation therapy

Patients were followed every three months for two years, every six months between two and three years, and annually thereafter, until follow-up reached 12 years.

Researchers found that after 12 years, patients who received hormone treatment and radiation had a lower mortality rate than those who received a placebo and radiation — 5.4% vs. 13.4%. Patients on hormone therapy also had a lower rate of prostate cancer metastasis than the placebo group — 14.5% vs. 23%. Side effects were low and similar in both groups.

“Our study indicates that hormonal treatments should be incorporated into the management of men who need radiation therapy after surgery for prostate cancer,” Howard Sandler, MD, senior author of the study, said in a news release. He is chair of the Department of Radiation Oncology at the Samuel Oschin Comprehensive Cancer Institute at Cedar’s Sinai Medical Center in Los Angeles.

Casodex has now been replaced with the hormone therapy GnRH agonists, the researchers noted. Since both treatments suppress hormone production, they see the study as proof of the principle that combining hormone and radiation therapy can significantly reduce rates of metastasis and death in patients with signs of cancer recurrence after prostate removal.

“This important research addressed a significant question in the care of patients with prostate cancer, showing the continued advancement in extending a good quality of life to those patients,” said Steven Piantadosi, MD, PhD, director of the Samuel Oschin Comprehensive Cancer Institute.