Radiotherapy plus hormone therapy improves PFS after radical prostatectomy
CHICAGO — The addition of short hormone therapy to radiation therapy improved 5-year PFS in a cohort of patients with prostate cancer who had a biological relapse after radical prostatectomy, according to findings presented at the ASCO Annual Meeting.
Christian Carrie, MD, of the department of radiation oncology at the Centre Léon Bérard in Lyon, France, and colleagues, sought to evaluate the efficacy of radiation therapy alone — the standard salvage treatment after radical prostatectomy — vs. radiation plus short hormone therapy in a randomized, multicenter, open-label phase 3 study. OS, toxicity and QOL served as secondary endpoints.
“About one-third of patients with prostate cancer will relapse after radical prostatectomy with rising PSA without clinical progressive disease,” Carrie said.
The analysis included 743 patients (median age, 67 years) who underwent radical prostatectomy and experienced biological relapse. The PSA doubling time to relapse was more than 6 months for 74% of patients.
Researchers stratified patients by risk factors at radical prostatectomy and randomly assigned 374 patients to radiotherapy alone and 369 patients to radiotherapy and hormone therapy. Patients assigned hormone therapy received 6 months of goserelin (Zoladex, AstraZeneca). The median radiation dose was 66 Gy over 7 weeks, according to Carrie.
The median follow-up duration was 63.1 months.
Results of the intent-to-treat analysis indicated 62.1% (95% CI, 57-67) of patients who received radiation alone achieved 5-year PFS compared with 79.6% (95% CI, 75-84) of patients on the combination arm (P < .0001).
The 5-y OS rates were 94.8% for radiotherapy alone and 96.2% for radiotherapy and hormone therapy.
Eleven patients died due to progressive disease. Eight of those occurred in the radiotherapy alone arm (2.1%) and three occurred in the combination arm (0.8%).
Carrie reported that toxicities were low in both arms. “Most of them were grade 2,” he said. “Late toxicities were also relatively mild and well balanced between the two arms.”
A comparable proportion of patients in the radiation alone arm and combination arm experienced grade 3 acute toxicities (1.9% vs 2.2%) and late toxicities (18.8% vs 21.9%).
Researchers reported no differences between the two groups in terms of quality of life. Two-thirds of the overall cohort reported improvement after treatment, according to Carrie.
“Salvage radiotherapy combined with limited hormone therapy improves 5-year PFS compared radiotherapy alone,” Carrie said. “The effect was seen in all subgroups.” – by Rob Volanksy
For more information:
Carrie C, et al. Abstract 5006. Presented at: ASCO Annual Meeting; May 29-June 2, 2015; Chicago.
Disclosure: Carrie reports receiving accommodations and travel expenses from AstraZeneca. Please see the abstract for a complete list of all other researchers’ relevant financial disclosures.