Population-based cohort study of hormonal contraceptive formulations and breast cancer risk in adolescents and premenopausal women

A population-based cohort study in Sweden was conducted to investigate the association of different hormonal contraceptive formulations among girls and women aged 13 to 49 years with risk of breast cancer. In this study of more than 2 million girls and premenopausal women, breast cancer risk varied by hormone formulation in hormonal contraceptives. Oral formulations containing desogestrel were associated with a higher number of additional cases per 100,000 person-years compared to those containing levonorgestrel. The authors conclude that these findings suggest that individuals at risk of breast cancer may benefit from avoiding desogestrel-containing hormonal contraceptives, particularly in progestogin-only formulations.