Breast Cancer Awareness Month: How Hormonal Changes During Pregnancy Impact Cancer Risk

Pregnancy is a time of huge change in hormones in a woman's body. These hormonal fluctuations, particularly those concerning estrogen and progesterone, have complex relations with breast tissue and therefore dictate the risk of breast cancer. Therefore, analyzing the impact that this fluctuation has on the risk of breast cancer at the time of pregnancy enlightens a person about the impact of pregnancy on breast cancer.

The levels of estrogen and progesterone status jump sharply in a woman's pregnancy. This evokes huge alterations within the breast tissue. These hormones will, thus stimulate the development of breast ducts and lobules to prepare the breasts for the production of milk. Such sudden development creates more differentiated breast tissue that can be less susceptible to cancer.

It has also been found out that with a pregnancy occurring before the age of 30, the risk of one contracting breast cancer later in life reduces. This is because at the end of the pregnancy, tissue that constitutes the breast is fully developed, therefore resulting in a protection effect. The differential production and maturation of cells may reduce chances of mutation leading to cancer growth.

More pregnancies may affect the risk of developing breast cancer. There is some evidence that the woman who has had two or more full-term pregnancies is at a lower risk of having breast cancer than women who have never been pregnant. The protection will increase with each additional pregnancy, although the relationship seems to be modified by age, family history, and possibly other factors.

However, most such studies show that while pregnancy is thought to cut down the long-term risk of breast cancer, a pregnancy does not always protect from breast cancer. In fact, some studies suggest that there is a temporary increase in risk in the years following a pregnancy. Such increased risk has been ascribed to involutional changes in the tissue of the breast, by which the tissues might become sensitized to carcinogens after a pregnancy. Again, however, this risk often returns to a more minimal level after a few years.

Pregnancy hormonal profile also affects the kind of breast cancer that may be developed. Some studies point out that pregnancies reduce the risk for hormone receptor positive breast cancers or estrogen dependence, whereas hormone receptor negative breast cancers may not be at the same risk, complicating the association between pregnancy and risk for breast cancer.

The other important factor that influences pregnancy and its impact on the risk of breast cancer is genetic factors made by the woman. Women with a family history of breast cancer or genetic alterations, such as BRCA1 and BRCA2, may even face varied risks associated with hormonal alteration due to pregnancy. It is vital that such women should discuss their personal situation with the health care providers so that they become more conscious of their risk.

The incidence of breast cancer can be further modified by breastfeeding. Women who have such an experience may have fewer opportunities to develop breast cancer simply because hormonal changes and reduced exposure to estrogen take place over time.

Additionally, breastfeeding could further differentiate the cells of the breasts, thereby strengthening mechanisms that would otherwise suppress cancer.