CHICAGO — Combined treatment with hormone therapy and radiation significantly improved several survival end points for men with high-risk prostate cancer in a phase III trial.
Among the adults who received androgen deprivation therapy and radiation, 75% were alive at 5 years, compared with 59% of the patients who received androgen deprivation therapy alone (P = .03).
The actuarial 5-year cause-specific survival was 83% versus 70% (P = .01), respectively, Dr. Piotr Milecki and his associates reported at the annual meeting of the American Society for Radiation Oncology.
Actuarial 5-year biochemical progression-free survival was more than double at 50% with combination therapy vs. 22% with hormone therapy alone (P = .001), whereas distant metastases–free survival was also significantly improved, at 79% vs. 54% (P = .007).
The data are highly relevant because the use of hormone therapy, while still low, is increasing, said Dr. Milecki, who is head of the department of radiotherapy at the Greater Poland Cancer Centre in Poznan.
A prospective population-based study involving older American men found that widespread detection and aggressive treatment for prostate cancer in the United States has led to more androgen deprivation therapy (BJU Int. 2006;98:973-8)
In addition, many urologists do not believe that the addition of radiotherapy will change outcomes in men who are at high risk.
According to a published report, just 30% of the delegates of the European Association of Urology agreed with the EAU's recommendation to use radiotherapy in combination with adjuvant hormone therapy for men with T3-T4 prostate cancer, whereas 48% said that they would prescribe LHRH agonist monotherapy (Eur. Urol. Suppl. 2006;5:S359-96)
The current study enrolled men (aged 51-76 years) with at least one of the following high-risk factors: prostate-specific antigen levels greater than 20 ng/mL, a Gleason score greater than 7, and T3 disease.
Hormone therapy consisted of the LHRH agonist goserelin acetate (Zoladex) as a 1-month, 3.6-mg depot formulation and then a 3-month, 11.8-mg depot plus a leuprolide acetate (Lupron) depot of 7.5 mg per vial for 1 month and of 22.5 mg per vial every 3 months, Dr. Milecki said.
When combined with three-dimensional conformal radiotherapy, the same hormone regimen was started at least 2 months before radiation and then administered in an adjuvant fashion for a minimum of 24 months. The total radiation dose was 46 Gy to the whole pelvis or 70-74 Gy to the prostate and seminal vesicles.
Late toxicity from radiotherapy was moderate, with grade 3 toxicity reported in only four patients, Dr. Milecki said at the meeting.
Gastrointestinal toxicity was 45% with grade 1, 24% with grade 2, and 1% with grade 3, whereas genitourinary toxicity was 43%, 21%, and 1%, respectively. Overall quality of life was not significantly different between the two groups, although diarrhea and fatigue were more pronounced after 4 years in the combined-therapy group, he said.
Dr. Milecki reported that he had no conflicts of interest or outside study sponsorship.