A new study has found that women with dense breasts and no lobular involution are at a higher risk for developing breast cancer than those with non-dense breasts and complete involution.
Apart from age, family history, and age at menarche, two additional factors associated with breast cancer risk include mammographic breast density and extent of lobular involution.
To determine whether these two factors are independently associated with breast cancer risk, Karthik Ghosh, of the Mayo Clinic, and colleagues investigated the factors' association with breast cancer risk in a cohort of 2666 women with benign breast disease.
The researchers found that breast density and extent of lobular involution were independent risk factors for breast cancer, and that combined, they pose an even greater risk.
"Our findings also reveal that having a combination of dense breasts and no lobular involution was associated with higher breast cancer risk than having non-dense or fatty breasts and complete involution," said the authors.
Future studies, they write, should include larger numbers of patients from diverse racial and ethnic backgrounds and aim to understand the relationship between involution and epidemiological risk factors such as body mass index.
The study is published online in Journal of the National Cancer Institute.