Dr. Michael Lisanti and colleagues at Thomas Jefferson University found that extended lactation protects against mammary tumor development. These findings are presented in The American Journal of Pathology.

Women who breastfeed for greater than two years have a significantly reduced risk of developing breast cancer later in life. It has been difficult to determine the cause of this benefit, however, due to the lack of a suitable animal model of extended lactation.

In this study, Sotgia et al demonstrated that mice deficient in caveolin 3, which is expressed in some mammary cells, had a constitutive lactation phenotype. Notably, caveolin 3-deficient mice were also protected against mammary tumor formation and lung metastases. These mice, therefore, provide a model of constitutive lactation that may be used to study the prevention or treatment of human breast cancers.

Lisanti's group suggest that "a lactation-based therapeutic strategy would provide a more natural and non-toxic approach to the development of novel anti-cancer therapies. In this regard, targeted reduction of Cav-3 levels in the mammary gland may represent a new therapeutic strategy for preventing the onset of human breast cancers."

SOURCE:
The American Journal of Pathology, February 2009