Relationship between early age at menarche, older age at menopause and subtypes of breast cancer: a scoping review.

Objective: To determine the relationship between early age at menarche, late age at menopause with specific subtypes of breast cancer (BC).

Methods: A literature search was conducted in Embase, Lilacs, PubMed, Scopus, and Scielo databases, following the Joanna Briggs Institute scoping review protocol and answering the question "How early age at menarche or late age at menopause are related to different breast cancer subtypes?".

Results: A number of 4,003 studies were identified, of which 17 were selected. Most of the included articles found a clear relationship between early menarche, late menopause and some subtypes of BC, mainly, PR+, ER+, luminal, and HER-2 tumors. However, some studies have found a contradictory relationship and one study didn't find any relationship between them.

Conclusion: A relationship between early age at menarche and advanced age at menopause was observed with some subtypes of breast cancer, since other factors must be considered in its understanding.