Early Preterm Delivery And Breast Cancer

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Abstract Human breast tissue differentiates during pregnancy, and its regression thereafter results in anti-carcinogenic properties. Theoretically, women who delivery prematurely do not gain the anti-carcinogenic benefits of a full-term pregnancy and may be at an increased risk for breast cancer compared to women who carry to term. Limited amount of research has been conducted to determine if case studies support a positive correlation between early preterm delivery (PTD) and breast cancer in the mother. Four of five extracted articles agree that early preterm delivery (≤ 32 weeks) of a woman’s first child is associated with increased breast cancer development. This review introduces the stages of breast lobule development, theory behind…show more content…
During this time, primary and secondary ducts grow and divide, forming terminal end ducts. Alveolar buds surround terminal end ducts like a bunch of grapes, signifying the formation of type 1 lobules. Follicle stimulating hormone and Luteinizing hormone cycles during menstrual periods will increase the size and number of alveolar buds, which transforms the alveolar buds of type 1 lobules into ductules of type 2 lobules (Figure 1). Type 1 lobules have approximately 11 alveolar buds surrounding the terminal end bud, and type 2 lobules have an average of 47 ductules. This is the extent of tissue differentiation in nulliparous women (Russo, 2004). During pregnancy, especially in the last weeks, increased concentrations of estrogen and progesterone stimulate further breast tissue development and differentiation that does not occur in nulliparous women (Innes & Byers, 2004). Ductules continue to grow and proliferate around terminal end ducts, signifying the development of type 3 lobules, which have a cluster of approximately 80 ductules (Russo, 2004). Type 3 lobules transition into type 4 when ductules generate secretory capabilities and are therefore recognized as acini. Lumina of the acini become distended with colostrum in the later half of gestation (Russo, 2004). After pregnancy, type 4 lobules regress into type 3 lobules once more. Regression, also called involution, is an inflammatory response that clears secretory epithelial cells from the
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