A new study examines time trends, separately at premenopausal and at postmenopausal ages, in the incidence rates of breast cancer, i.e. the number of new breast cancer diagnoses per year for a standard population size. The study was led by researchers at Alberta Health Services, Canada, in conjunction with the International Agency for Research on Cancer (IARC) and partners, and was published in The Lancet Global Health.
The researchers examined data from 44 populations in 41 countries in 1998–2012. They found that during this period, breast cancer incidence rates at premenopausal ages increased in higher-income countries, whereas the rates at postmenopausal ages increased more rapidly in lower-income countries. Breast cancer incidence rates at premenopausal ages increased significantly in 20 of the 44 populations, and the rates at postmenopausal ages increased significantly in 24 of the 44 populations.
The risk of developing cancer increases as a woman ages. Risk factors for postmenopausal breast cancer, such as obesity, having fewer children, low levels of physical activity, lack of breastfeeding, and having children later in life, are well studied, but risk factors for developing breast cancer at younger ages are not as well known. Given the substantial burden of disability and premature mortality due to breast cancer in younger women, research to understand the etiology of these cancers is urgently needed. The findings from this study emphasize the need for continued prevention initiatives and for the introduction and/or expansion of early diagnosis programmes in lower-income countries faced with an increasing number of patients with breast cancer every year.
Heer E, Harper A, Escandor N, Sung H, McCormack V, Fidler-Benaoudia MM
Global burden and trends in premenopausal and postmenopausal breast cancer: a population-based study
Lancet Glob Health, Published online 22 July 2020;