Mammary glands are called branched tubulo-alveolar glands and primarily function for milk production. They are collected in clusters that branch out from the areola, the colored part of the nipple. The starting point of the gland is the lactiferous sinus.
Mammary glands are believed to be modified sweat glands, and they are present in all mammals, females and males. Hormones present in the female body, progesterone and estrogen, initiate the growth and branching of the gland. To date, these are the only two hormones proven to promote the growth of breast cancer cells.
What is Progesterone?
Progesterone is a precursor hormone that initiates the production of other subsequent sex hormones. Both estrogen and testosterone are among the sex hormones that are affected by this initiation.
Studies show that naturally occurring progesterone does not increase your risk for breast cancer; however, synthetic progestins are thought to increase the risk for cancer. Synthetic progestins are included in products like birth control pills, which combine them with estrogen hormones.
What is Estrogen?
Estrogen actually refers to a class of hormones. The key estrogen compounds are estradiol, estrone and estriol. The majority of estrogen compounds are produced mainly within the ovaries, though small quantities are secreted from the adrenal glands. The placenta and fat cells are created during pregnancy due to the influx of the estrogen hormone.
Growth of Mammary Glands
Men and women are both born with mammary glands. However, mammary glands never start to form and branch in males due to the presence of testosterone. Estrogen, on the other hand, promotes the mammary cells to grow and develop into full functioning glands.
Progesterone and estrogen are female sex hormones that regulate the the growth of mammary glands. Progesterone initiates the production of four hormones in the estrogen class. Estrogen initiates the growth, division and branching of mammary gland cells.
Hormones Regulate the Body’s Development
Starting around 8 years old, the female body goes through natural hormonal changes that initiate the breast tissue to form and grow. During puberty, the ovaries expand causing progesterone and estrogen production to increase. The estrogen present in the body causes the cells that make up the breast to grow; therefore, the breasts develop into fully functioning mammary glands by the end of puberty.
During pregnancy mammary glands go through changes initiated by the additional hormones. In the first trimester, the areola darkens causing an increased production of progesterone and estrogen stimulating growth. The darkening and thickening of the areola also provides protection against infection, lessens pain from breastfeeding, and makes it easier for the child to see the nipple and latch on. During the second and third trimesters, the breasts are actually producing milk, which increases the size of the breast.
The natural response of the mammary glands to progesterone and estrogen is to initiate immediate cell growth. When cancerous cells are multiplying both progesterone and estrogen promote the growth of the malignant cells as well as healthy ones. Thusly, the presence of progesterone and estrogen inadvertantly helps the cancer to grow.