Breast cancer prevention should start early in life

So many of my breast cancer patients ask me,“When should my daughter begin screening for breast cancer?” They also ask, “What can I do now to prevent myself from getting another breast cancer?” But so few ever ask, “What can my daughter or granddaughter do to reduce her risk of ever developing breast cancer?” I’m assuming my patients never ask because they don’t realize that breast cancer prevention begins during childhood and continues during teenage years and into young adulthood. Almost 25 percent of breast cancers are diagnosed in women under 50, and many of these cancers are more aggressive than those diagnosed in postmenopausal women. Lifestyle choices that begin early in life can reduce this risk, especially when started at a young age.

The breast tissue goes through a change at the time of a first full-term pregnancy. Prior to this change, the breast tissue is more sensitive to environmental factors. (The breasts do not fully mature until they have gone through a full term pregnancy.) Therefore, preventative efforts should begin early in a girl’s life. The glandular tissue of the breast is going through its very highest rate of growth during puberty; therefore, this is the time that the breast tissue is very sensitive to environmental factors. Those factors include diet, smoking and alcohol use.

So what steps can women take at a young age?

1. Never start smoking, or quit early! Smoking, especially when combined with alcohol consumption, can increase the risk of breast cancer. Tobacco smoke contains polycyclic aromatic hydrocarbons (PAHs) as well as several other chemical which have been shown to cause breast cancer in animals. These could explain a potential link between increased breast cancer risk and both active and passive smoking. Several studies have shown that there is an increased risk of breast cancer among women who began smoking as teenagers.
2. Avoid heavy alcohol consumption, and especially binge drinking as teenagers and young adults. Youth alcohol consumption is common in the US, and nearly 70 percent of youth alcohol consumption is in the form of binge drinking (four or more drinks in one sitting.) Two prospective studies in particular showed an increased risk in nurses who reported binge drinking compared to women with the same amount of intake spread over the week. The higher levels of blood alcohol achieved with multiple drinks at one time may contribute to the suspected increased risk. Alcohol also aggravates and increases the risk of benign breast disease in young women, such as cysts and fibrocystic changes.
3. Maintain a diet high in fruits and vegetables, low in animal fat. There is evidence that diet during childhood may affect the risk of breast cancer, but there are no perfect studies or recommendations as of yet. There are several historic studies that suggest dietary influences are important:  A large population study looked at Asian women’s diet and risk of breast cancer and compared them to US women. They found there was a lower rate of breast cancer in women who were raised in Asia. Immigrants to the US had breast cancer rates that were similar to US white women after the second or third generation, suggesting that exposure during childhood is important in breast cancer risk. Another study based in Norway looked at adolescent women during World War II, when the average calorie and animal protein was restricted by more than 20 percent. These women showed a significantly reduced risk of breast cancer. Another study in particular in China looked at women with and without breast cancer and evaluated their intake of soy products during childhood. It showed that the women with higher amounts of soy intake as children had significantly lower rates of breast cancer as adults. A recent study followed young girls through adolescence and compared their diet with their breast density as young adults. They found that girls consuming a diet lower in animal fats eventually had less dense breasts on mammogram as adults later in life. We have evidence that the more dense a woman’s breast is on a mammogram, the higher her risk of breast cancer. There are no perfect studies yet showing that girls who consume a diet higher in animal fat or higher in overall calories have a higher risk of breast cancer later in life, but these and many more studies are pointing in this direction.
4. Get regular exercise and maintain a healthy body weight. There is more and more evidence suggesting a protective effect of exercise in many different types of cancer formation. Maintaining a BMI of under 26, especially in post-menopausal women, has been shown to reduce the risk of breast cancer. Now more studies are showing consistent risk reduction of life-time breast cancer with exercise during adolescence. Encouraging girls and young women to exercise regularly will not only promote other health benefits, but will help women to maintain a healthy routine throughout adulthood.

We know that many habits, both good and bad, form early in life and are continued into adulthood. I encourage my patients to teach their daughters about the importance of taking care of their bodies at an early age by eating a healthy diet, exercising regularly, quitting smoking and minimizing alcoholic drinks. All of these healthy lifestyle choices combined can have a positive effect on breast cancer risk and are good for overall health maintenance!