A study in the February 8 edition of JAMA shows that postmenopausal women who suffer from hormone receptor-positive breast cancer have a higher death risk of breast cancer as they get older.
Background information in the article states that:
"Breast cancer is the leading contributor to cancer incidence and cancer mortality in women worldwide, with 1,383,500 new cases in 2008. In the United States in 2008, 41 percent of these women were aged 65 years or older at diagnosis.
Because breast cancer incidence increases with increasing age, changing demographics and continuously increasing life expectancy will further enlarge the number of older women confronted with breast cancer. In addition to classic tumor-related prognostic factors, patient characteristics may be associated with breast cancer outcome."
To establish disease-specific death rates amongst age groups in postmenopausal patients with hormone receptor-positive breast cancer, Willemien van de Water, M.D., of the Leiden University Medical Center in Leiden, the Netherlands and her team assessed 9,766 patients who were enrolled in the TEAM (Tamoxifen Exemestane Adjuvant Multinational) randomized clinical trial from January 2001 to January 2006. The researchers split the age at diagnosis into 5,349 patients younger than 65 years, 3,060 patients who were aged between 65 to 74 years, and 1,357 patients of 75 years or older.
At the midpoint follow up of about 5.1 years, the researchers noted a total of 1,043 death, of which 391 patients (7.3%) were younger than 65 years, 341 patients (11.2%) were aged between 65 to 74 years, and 311 patients (22.9%) were 75 years or older. According to the findings, the overall death rate caused by breast cancer rose from 5.7% in patients below 65 years, to 6.3% in those aged between 65 to 74 years and to 8.3% in those aged 75 years or above.
Increasing age was associated with a lower number of deaths due to breast cancer as a proportion of all-cause mortality (less than 65 years, 77.5 percent; 65-74 years, 56.3 percent; 75 years or older, 36.3 percent). Additional analysis indicated that compared with patients younger than 65 years, disease-specific mortality increased with age for patients ages 65 to 74 years and patients 75 years or older.
In addition, the study also demonstrated that mortality from other causes increased with age, and that older age was linked to a higher risk of breast cancer relapse.
The authors believe that a possible explanation as to why older people who are otherwise relatively healthy, are at a higher risk of death may be due to the fact that older patients may be subject to being under-treated, in particular in terms of either chemotherapy or radiotherapy.
The researchers write:
"In conclusion, regardless of a higher risk of other-cause mortality and independent of tumor and treatment characteristics, disease-specific mortality increases with age among postmenopausal women with hormone receptor-positive breast cancer.
These data underline the need for age-specific breast cancer studies in order to improve breast cancer outcome in patients of all ages.
Moreover, future detailed population-based and translational studies may increase insight into causal factors of higher disease-specific mortality and breast cancer relapse with increasing age."
Written by Petra Rattue