Combination therapy improves survival in some PCa patients

Men with localized prostate cancer who are treated with androgen suppression therapy and radiation therapy have longer survival, but those with moderate to high levels of concomitant illness do not experience this effect, according to a study in last week’s JAMA (2008; 299:289-95).

Anthony V. D’Amico, MD, PhD, of Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, and colleagues performed an analysis of overall survival of 206 men with localized but unfavorable-risk prostate cancer in subgroups defined by their level of comorbidity at the time of randomization. Patients received a combination of androgen suppression and radiation therapy or radiation therapy alone. During a median follow-up of 7.6 years, 74 deaths occurred.

Estimates of overall survival were significantly higher for men randomized to the combination therapy than to radiation therapy alone. Cumulative incidence estimates of prostate cancer-specific mortality significantly favored the combination therapy group, with an increased risk of prostate cancer-specific mortality (14 vs. 4 deaths). This translated to increased risk of all-cause mortality (44 vs. 30 deaths) in men randomized to radiation compared with the combination therapy.

For the 157 men with no or minimal comorbidity scores, combination treatment was associated with a significantly higher survival (31 vs. 11 deaths) than radiation was. Among the 49 men with moderate or severe comorbidity, those randomized to radiation alone versus combination therapy did not have increased risk of all-cause mortality (13 vs. 19 deaths).

“The clinical significance of this finding is that pre-existing comorbid illnesses may increase the negative effects of specific anti-cancer treatments, such as androgen suppression,” the authors wrote. “In conclusion, the addition of 6 months of androgen suppression to RT resulted in increased overall survival in men with localized but unfavorable-risk prostate cancer.”