Author: Joanna    LaFrance

Major: Biology

Graduation Year: 2021

Thesis Advisor: Lynn Atkins

Description of Publication: This thesis examines the negative correlation between breastfeeding duration and breast cancer rates and how they may intersect with race and socioeconomic status for Black women in the United States. There is well documented evidence that exclusive breastfeeding for at least six months, as recommended by the American Pediatric Association, has numerous benefits to both mother and baby, specifically in decreasing the mother’s lifetime risk of developing breast cancer (1). Similarly, many resources state a negative correlation between number of offspring and breast cancer risk. However, after a systematic analysis of 91 articles was conducted, it appears that statements like these can be deceiving. High rates of parity, the number of times a woman has been pregnant and carried the pregnancies to a viable gestational age (offspring), only decreases the risk of hormone receptor positive cancers and may increase the risk of the more aggressive estrogen receptor negative and triple-negative breast cancers unless it is paired with the recommended duration of breastfeeding where the risk is then reduced. TNBC cells do not contain either hormone receptors and does not over-express the HER2 gene, making it triple-negative. Of the groups studied, Black women are more likely to be diagnosed with this aggressive breast cancer type, triple-negative breast cancer (TNBC). On average, Black women have lower rates of breastfeeding (17.2% breastfeed at 6 months compared to 29.5% whites) and have higher rates of parity (2.1 for Blacks vs 1.8 births for whites) (2), (3). This could explain the observed higher rates of triple-negative breast cancer (TNBC) in Black women (4) because TNBC was shown to be increased when parity is high and breastfeeding rate is low. The results from this study also supported the hypothesis that one of the contributing factors as to why Black women breastfeed less which contributes to their cancer rate, is stress caused by low socioeconomic status. Low socioeconomic status has a significant negative impact on the duration of breastfeeding for Black mothers which may contribute to their inflated rates of triple-negative breast cancer.

Location of Publication:

URL to Thesis: https://digitalcommons.library.umaine.edu/honors/682/