TABLE 3.

Summary of direction of associations between established breast cancer risk factors with microcalcification cluster risk, mammographic density and breast cancer risk

Established risk factors for breast cancer	Suspicious microcalcification clusters	Mammographic density	Breast cancer risk
High age	Higher	Lower	Higher
High MD	Higher	—	Higher
High PRS	Higher	Higher	Higher
Family history of breast cancer	Higher	Higher	Higher
More children	Higher	Lower	Lower
Longer period of breast feeding	Higher	Higher	Lower
High BMI a	Lower	Lower	Higher
Current smoking	Lower	Lower	Higher
Alcohol consumption	Lower	Higher	Higher
Physical activity	Lower	Lower	Lower
Late menarche	Lower	Higher	Higher
High age at first birth	Lower	Higher	Higher
Oral contraceptive use b	Lower	Lower	Lower
MHT use	Lower	Higher	Higher

Notes: The summary direction of associations are based on the previous studies using KARMA cohort ²⁰ , ³⁴ , ³⁵ and a most up‐to‐date and comprehensive breast cancer polygenic risk score. ³² A detailed description of this table with point estimates is presented in Supplementary Table 2.

Abbreviations: BMI, body mass index; MD, mammographic density; MHT, menopausal hormone therapy; PRS, polygenic risk score.

^aIncreased risk for breast cancer only seen among postmenopausal women.

^bWe found an opposite direction of association between oral contraceptive use with the risk of breast cancer compared to previous evidence, ³⁶ however, the result was not statistically significant.