New Study on Genetic Aspects of Rapid Involution and Aggressive Breast Cancer

Infant feeding and lactation specialists often provide patient and client teaching on the many health aspects of breastfeeding and human milk.  One of these aspects is the lesser incidence of inflammatory and triple-negative breast cancers among women who breastfeed their children with greater frequency and longer duration.  This new peer-reviewed, open access study from the University of Texas looked at the genetic changes in rapid "forced" weaning and breast involution, finding an association between these genetic changes and aggressive breast cancers.   

Study title:  Gene set analysis of post-lactational mammary gland involution gene signatures in inflammatory and triple-negative breast cancer

Study authors: Arvind Bambhroliya, Renae D. Van Wyhe, Swaminathan Kumar, Bisrat G. Debeb, Jay P. Reddy, Steve Van Laere, Randa El-Zein, Arvind Rao, Wendy A. Woodward

From the abstract:

Background: Epidemiological studies have found that triple-negative breast cancer (TNBC) and TN inflammatory breast cancer (IBC) are associated with lower frequency and duration of breast-feeding compared to non-TNBC and non-TN IBC, respectively. Limited breast-feeding could reflect abrupt or premature involution and contribute to a “primed” stroma that is permissive to the migration of cancer cells typical of IBC. We hypothesized that gene expression related to abrupt mammary gland involution after forced weaning may be enriched in the tissues of IBC patients and, if so, provide a potential correlation between limited breast-feeding and the development of aggressive breast cancer.

Results: Examining the combined data, we identified 10 involution gene clusters (Inv1-10) that share time-dependent regulation after forced weaning. Inv5 was the only cluster significantly enriched in IBC in the training and validation set (nominal p-values <0.05) and only by unadjusted p-values (FDR q-values 0.26 and 0.46 respectively). Eight genes in Inv5 are upregulated in both the training and validation sets in IBC. Combining the training and validation sets, both Inv5 and Inv6 have nominal p-values <0.05 and q-values 0.39 and 0.20, respectively. The time course for both clusters includes genes that change within 12 hours after forced weaning.