Does Lactation Mitigate Triple Negative/Basal Breast Cancer Progression.

摘要

Young Black women develop and die more from aggressive forms of breast cancer compared to young White women. Recent data show increased risk of basal-like breast cancer with increased childbearing in Black women. Breast cancers associated with a recent pregnancy are more likely to be metastatic. We predict that aggressive breast cancers are promoted by a recent pregnancy. We developed a murine mammary intraductal model to examine effects of host reproductive status on the tumor suppressive myoepithelial cell layer with respect to tumor progression. Our data, demonstrating that DCIS lesions with an intact myoepithelial cell layer display progressive loss of specific myoepithelial cell markers, suggest that the myoepithelium is compromised prior to DCIS progression to invasive disease. The loss of p63 was identified as an early indicator of compromised myoepithelium. Further, our data suggests that this protective layer may be maintained by tumors formed during pregnancy lactation cycle, but may be preferentially compromised by tumors formed in postpartum involuting mammary glands.Our preclinical model of human breast cancer provides a rigorous approach to study effects of reproductive state on DCIS progression. Our model could aid research of early disease progression, a requisite for research focused on breast cancer prevention and inhibition of local invasion. Further, this model may provide a unique opportunity to address and study tumor growth disparities among ethnically diverse women.