The Most Important Cause Of Breast Cancer All Women Ignore
Although breast cancer can arise in both sexes, women are particularly susceptable because of an often overlooked risk factor: estrogen exposure. There is a strong body of evidence demonstrating a correlation between lifetime cumulative estrogen exposure and breast cancer risk.
Natural estrogen exposure
An increased cummulative exposure to estrogens contributes, in part, to the increased risk of breast cancer associated with increased age. While women of any age can develop breast cancer, those younger than 45 are highly unlikely to develop breast cancer without a family history or positive BRCA1/BRCA2 genetic profile.
A more important risk factor than age is the age of first menstruation, known as menarche, and the age of last menstruation or menopause. Menarche before age 12 or menopause after age 55 put women at an increased risk of developing breast cancer. Similarly, childbirth effects lifetime hormonal exposure. Times of pregnancy and breastfeeding alter the hormonal milleu in such a way as to be protective. Therefore, women who have never given birth are at greater risk of developing breast cancer than women who have and women who had their first child after the age of 35 are at a greater risk for breast cancer than women who bear children at an earlier age. The protective action of childbirth is additive, with a woman’s risk of breast cancer decreases with each child she has.
Synthetic hormone exposure
With an understanding of the risk for breast cancer development created by estrogen exposure, much concern has arisen around the use of estrogen hormone replacement therapy (HRT) and oral contraceptives containing synthetic estrogen. Interestingly, these two types of treatment do not confer the same risk despite being comprised of essentially the same ingredients. HRT has been shown to increase the risk of breast cancer development but only in women who do not begin using it during the earliest portion of menopause and who continue to use it for longer than five years. In contrast, oral contraceptives used during child-bearing years have not been shown to increase the risk for breast cancer development.
Risk assessment and screening
As is true of all health conditions, prevention is the best medicine for breast cancer. All women should be having regular mammographic screening from the age of 45. This is based on the likelihood of having developed cancer by that age and detecting it in the earlier stages. Women with increased risk factors should consult their healthcare providers about starting screening ealier. While self-exams were once thought to be an important screening tool, they have been shown to confer no additional benefit over mammography alone.