September 23, 2008 — Adding radiation to androgen deprivation therapy in older men with locally advanced prostate cancer reduces the risk of dying from the disease by half. These results, from a randomized clinical trial, suggest that men should be offered this additional option, says lead researcher Anders Widmark, MD, professor in radiation oncology at Umea University in Umea, Sweden.
Dr. Widmark presented the results at a plenary session during the American Society for Therapeutic Radiology and Oncology (ASTRO) 50th Annual Meeting in Boston, Massachusetts.
"This trial will change clinical practice," predicted Anthony Zietman from Massachusetts General Hospital in Boston, who was moderating a press briefing at which the results were highlighted. Dr. Zietman is also president-elect of the ASTRO, taking on the role of president effective September 23, 2008.
"At present, there is a bit of a fatalistic attitude towards locally advanced prostate cancer, as it generally considered to have already quietly spread elsewhere," Dr. Zietman commented. "Often the only treatment often offered to older men with this stage of disease is hormonal therapy," he continued. "This attitude is maybe more common in Europe, but it's also prevalent in the United States."
"The thinking is that the cat is already out of the bag," Dr. Zietman commented, but "the results from this trial prove that this is not the case."
"This randomised trial is the first to show that men with locally advanced prostate cancer will survive substantially longer when radiation is added to their treatment plan," Dr. Widmark told journalists.
The trial involved 880 patients, median age 67 years, the majority of whom had stage T3 disease. All of the patients underwent 3 months of intense hormone therapy to achieve total androgen blockade, followed by continuous antiandrogen therapy, but 1 group also received radiotherapy.
After a median follow-up of 7.5 years, death from prostate cancer had occurred in 79 (18%) of 437 patients in the antiandrogen group vs 37 (8.5%) of 436 patients in the combined antiandrogen and radiotherapy group. "It was rather surprising that the addition of radiation cut by half the risk of death from prostate cancer," Dr. Widmark commented. The absolute difference in cumulative incidence from prostate cancer death increased from 2.9% at 7 years to 12% at 10 years, with a relative risk of 0.44 (P = .00003).
In addition, significant reductions were seen in 2 other outcome measures. Overall mortality rate was 30% in the antiandrogen group vs 21.6% in the combination antiandrogen and radiotherapy group (P = .004). Plus, recurrence of high levels of prostate-specific antigen occurred in 65% of the antiandrogen group but in only 17.5% in the combination antiandrogen and radiotherapy group (P = .00001).
Quality of life, as reported both by patients and by clinicians, was "slightly worse" in patients who received combination antiandrogen and radiotherapy vs those in the antiandrogen group but "only marginally," Dr. Widmark commented. Adverse events included moderate to severe urinary leakage (reported by 6% of patients in the combination groups vs 3% in the hormone group 4 years after treatment) and pain on urination (reported by 2% vs 4%, respectively). Erectile dysfunction was also more common, reported by 85% of patients in the combination antiandrogen and radiotherapy group vs 72% in the antiandrogen group (P < .001).
"Considering the substantial survival benefit, the increase in symptoms seems to be acceptable and of small influence on quality of life 4 years after treatment," the researchers concluded.
The results suggest that radiotherapy should be offered in addition to antiandrogen therapy to men with locally advanced prostate cancer, Dr. Widmark commented. He said that he would encourage such men to talk to their clinicians.
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου