Breast Cancer Screening: Personalizing Starting Age Based on Reproductive Factors
Posted: Monday, February 10, 2020
Reproductive factors—such as parity and age at first birth—appear to affect the age when breast cancer screening should begin for women with no personal or family history of the disease, according to a study published in the European Journal of Cancer. The researchers found that women with a reproductive history attain risk levels associated with recommended screening ages at different ages than the general population—between 9 years later and 3 years younger.
“Our study provides evidence-based practical and clinically relevant information for risk of breast cancer based on [an] individual’s reproductive profile that can be used to find the personalized starting age of breast cancer screening,” stated Elham Kharazmi, MD, PhD, of the German Cancer Research Center and National Center for Tumor Diseases, Heidelberg, Germany, and colleagues.
The study included 5,099,172 Swedish women, born after 1931, from a nationwide cohort. The researchers calculated the 10-year cumulative risk of breast cancer at age 40, 45, and 50 years in the general population.
In women with no family history of breast cancer, nulliparous women attained the same level of risk as 50-year-old women at age 48 years—2 years earlier. Among women with their first birth at a maternal age younger than 25 years, those who had one child (parity 1) reached the same level of risk as 50-year-old women in the general population (2.2%) at age 51, those with parity 2 at age 53, and those with parity 4 or higher at age 59. However, this protective effect was not observed in women with an age at first birth of 30 years or older; in this population, women with parity 1 or 2 reached a similar 2.2% risk at age 47 and parity 3 at age 49.
Disclosure: The study authors reported no conflicts of interest.
