(HealthDay News) – Among postmenopausal women with hormone receptor-positive breast cancer, increasing age is associated with a higher risk of death from breast cancer, according to a study published in the February 8 issue of the Journal of the American Medical Association.
Willemien van de Water, MD, of Leiden University in the Netherlands, and colleagues analyzed 9,766 patients enrolled in the TEAM (Tamoxifen Exemestane Adjuvant Multinational) randomized clinical trial. Age at diagnosis was classified as younger than 65 years (5,349 subjects), 65 to 74 years (3,060), and 75 years or older (1,357).
The researchers found that there were 1,043 deaths over a median of 5.1 years of follow-up. Disease-specific mortality, as a proportion of all-cause mortality, decreased significantly with each age group (78% [<65 years], 56% [65 to 74 years], and 36% [≥75 years]). According to multivariable analyses, compared with patients younger than 65 years, disease-specific mortality increased with age for patients aged 65 to 74 years (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.01 to 1.54) and for patients aged 75 years or older (HR, 1.63; 95% CI, 1.23 to 2.16). In a similar pattern, breast cancer relapse increased with age for patients aged 65 to 74 years (HR, 1.07; 95% CI, 0.91 to 1.25) and patients aged 75 years or older (HR, 1.29; 95% CI, 1.05 to 1.60). Other-cause mortality was associated with an increase in age in patients aged 65 to 74 years (HR, 2.66; 95% CI, 1.96 to 3.63) and patients aged 75 years or older (HR, 7.30; 95% CI, 5.29 to 10.07).
“Among postmenopausal women with hormone receptor-positive breast cancer, increasing age was associated with a higher disease-specific mortality,” the authors write.
Several authors disclosed financial relationships with pharmaceutical companies, including Pfizer, which funded the study.