A 2012 collaborative reanalysis by the Collaborative Group on Hormonal Factors in Breast Cancer established a link between early menarche and increased breast cancer risk. Given changes in the average age of menarche over time, it is essential to reassess this relationship using contemporary data. This meta-analysis investigates the association between early menarche (particularly before age 13) and breast cancer risk in women, with a focus on recent observational studies across various global regions. This analysis demonstrates a 15% increased global risk of breast cancer in women who experienced menarche before age 13, while those who reached menarche at 13 or older had an 11% reduced risk. Notably, the risk associated with early menarche was particularly pronounced in women from West Asia, Europe, Oceania, and North America.

Fui-Ling Voon is a postdoctoral researcher at University of Malaysia Sarawak (UNIMAS). She obtained her PhD from The University of Western Australia. Her research focuses on cancer, inflammation, and drug development. Her academic achievements include the Best Poster Presenter Award at scientific conference and multiple publications in renowned journals.