Androgen deprivation plus radiation may become standard for PCa

Continuous androgen deprivation plus external beam radiation therapy should be the standard treatment approach for men with locally advanced prostate cancer, researchers reported at the American Society of Clinical Oncology annual meeting in Chicago.

Their conclusion was based on observation of a significant improvement in both overall and disease-specific survival compared with androgen deprivation monotherapy, reported first author Padraig R. Warde, MB, of Princess Margaret Hospital, Toronto.

In this second interim data analysis, the 7-year overall survival rate of 74% among men treated with both radiation and androgen deprivation (603 patients) was significantly superior to the rate of 66% observed for the 602 patients treated with hormone deprivation only (p=.0331; HR, 0.77). Disease-specific survival also favored dual therapy significantly, with a 7-year rate of 90% compared with 79% in the hormone deprivation arm (p=.001; HR, .57).

Three hundred twenty deaths had occurred in a total population of 1,205 patients-175 of them in the androgen deprivation therapy-only arm and 145 among men receiving the combination therapy approach. Notably, 89 of the deaths in the ADT-only group were attributed to prostate cancer, compared with 51 in the ADT/radiation group.

In this randomized international trial, radiotherapy consisted of 45 Gy in 25 fractions over 5 weeks to the pelvis plus 20 to 24 Gy in 10 to 12 fractions over 2.0 to 2.5 weeks to the prostate. Because more intensive radiation has become common, efficacy results may have favored combined therapy even more had radiation been designed by current practices, Warde said.

Anthony V. D’Amico, MD, PhD, of Harvard Medical School, Boston, who did not work on the study, recommended that standard practices for locally advanced prostate cancer take into account both the patient’s life expectancy and comorbidities. He noted that men with life expectancies of more than 5 years may be candidates for combined therapy, whereas older men and men at risk for early death may benefit from androgen deprivation without the need for radiation exposure.

However, Dr. D’Amico added that hormone therapy may be deleterious to men with cardiovascular disease, leading to myocardial infarction or congestive heart failure that may not reverse upon revascularization.