Suspected Causes

RISK FACTORS — WHAT ARE THE ODDS THAT YOU MIGHT GET BREAST CANCER?
by Ken L. Smith, Breast Health Facilitator for ACS

SEX (GENDER)
This is the largest risk factor of them all. Each year, about 193,000 women in the U.S. discover that they have breast cancer. About 1,500 men will get breast cancer. Those numbers tell us that the gender of a person makes a major difference in the probability of that person developing breast cancer.

What can a woman do to help avoid this risk? Nothing, unless we can identify something that a woman does that a man usually will not do. This fuels thoughts about clothing, make-up, general activity levels, hormones, etc. Gender re-assignment (sex change) does not seem to make a difference, although no studies seem to have been done in that area.

AGE
The longer a woman (or man) lives, the greater chance the person has of developing breast cancer. There is nothing that we can do about that, unless we can prevent the actual "cause" of the cancer. Many malfunctions of the body systems eventually gain enough control to cause death, if the problem (disease, etc.) can last longer than the body's ability to fight off the problem. The tough part is determining what that "cause" is. If a woman in the U.S. lives to be older and older, her "odds" of getting breast cancer get much greater, up until the risk is one woman out of eight, if she lives to the age of 95 years.

Keeping herself healthy by doing proper amounts and types of exercise, and eating proper foods (and proper amounts of food), will undoubtedly assist the body in its defense against all diseases. Cancer could very well be included.

FAMILY HISTORY
If you have a grandmother, mother, aunt or sister that had breast cancer, there is a chance that the genes that MIGHT cause breast cancer have passed to you too. If two of them have gotten breast cancer, there is a little better chance that you got that same gene.

What can a woman do to help avoid this risk? While there is nothing that we can do about which genes are passed to us, some women have taken tests (thousands of dollars) to find out if the BRCA1 or BRCA2 genes are in their genetic makeup. BRCA, by the way, stands for nothing more sinister than BR (breast) CA (cancer), and as we find more of them, the numbers continue to climb. There are exciting times ahead of us. Research is continuing to find answers that will help us.

One solution that some high-risk women have chosen is a prophylactic bilateral mastectomy, which means that they have both breasts removed before they have a chance to develop breast cancer. That is a very controversial decision, and is still being studied.

PERSONAL HISTORY
Any woman that has had previous breast cancer, in either breast, has a higher risk of breast cancer. Not only because it may not have been completely removed the first time, but, we suspect, it could also be because the condition that caused the cancer the first time continues to create a problem. The big question: What is the source of the breast cancer? Can it be controlled? Or eliminated?

What can a woman do to help avoid this risk? There is nothing that we can do to change history, but a woman with a history of breast cancer has an added impetus to do very careful monthly breast self examinations, have a doctor do an annual clinical breast examination (CBE), and have a mammogram done every year. Some doctors may recommend the CBE and/or the mammogram at earlier intervals than a year, at least for the first few years after the first incidence of breast cancer. None of this will prevent the cancer from returning, but the earlier any cancer is detected and dealt with, the greater a woman's chances are of surviving the cancer.

NATURAL HORMONES
Hormones, such as estrogen, affect our body in a direct manner. It is estrogen (or the absence of it) that plays a predominant roll in breast development (or lack of it) during puberty. Other factors affect breast development too, of course, and some of them may be heavily influenced by estrogen. At several times in a woman's life her body affects the amount of estrogen that is available. These are:

Early Menarche
Menarche (men - are - key) is the term for the first menstrual flow, which is one of several possible indications of the beginning of puberty. The start of menstruation means that the ovaries are releasing ova (eggs) and are sending a larger amount of estrogen into a woman's blood stream. If a woman starts estrogen production earlier than usual (average age of menarche' is between 11.5 and 12.3 years old), she will produce it for more years of her life. Estrogen is considered the "fuel" to breast cancer, and the longer it is allowed to flow freely in the blood stream, the greater risk a woman has of developing breast cancer.

Trials are being done to see if we can get young women to reach menarche at later ages. That will mean less years of high estrogen production. The concept is: Less estrogen = less breast cancer. These trials consist of a modification of the young girls' physical training. Eight year old girls are given a more strenuous exercise training routine (during the Physical Education & Sports period at school) than is usual for the other girls their age (at that school). Body fat helps the body's hormones develop, so the theory is that if there is less body fat, there will be less estrogen production (less fat = less estrogen produced = less number of years to develop breast cancer). This is similar to why many serious, professional women athletes may have a later menarche, or why they may even stop menstruating while they are competing.

What can a woman do to help avoid this risk? Start her exercise program early (before puberty), and make sure that she gets plenty of physical exercise every day,

Late Menopause
Just like an early menarche, a late menopause will mean more years during which a woman's ovaries produce the high levels of estrogen. That translates to a longer duration of time over which a woman might develop breast cancer. Be aware that ERT, which is Estrogen Replacement Therapy is used by women to offset (or postpone) some of the symptoms of menopause, but it is not recommended for women that have had breast cancer, because of the influence of estrogen on breast cancer cells.

There is nothing that a woman can do to hurry the start of menopause. Most women would prefer it took longer to come around. ERT is usually used for the SYMPTOMS, and does not alter the timetable of menopause. Please do not forget that women that are post menopausal are still subject to breast cancer.

Childbirth After Thirty (or bearing no children)
This is another situation that is related to a woman's hormones. It has been determined that if a woman does not bear her first child before she is 30 years old (or she bears no children) she will have a greater risk of developing breast cancer during her lifetime. Early terminated pregnancies are suspected to have a causative effect on breast cancer.

What can a woman do to help avoid this risk? Obviously, bearing children will make a difference, but that is certainly no reason to bring a child into this world.

PREMATURE BIRTH
A report of a study in Sweden supports "the hypothesis of a relationship between the perinatal hormonal environment and the risk for breast cancer." (1) Reuters Medical News reported this study, which showed that "The breast cancer risk in women born before 31 weeks' gestation was 6.7 times that of the general population."

Other than doing everything possible to carry a child full term, there is very little that a woman could do to influence this risk factor.

BREASTFEEDING
Two interesting references from our friends at www.bosombuddies.com have suggested that there are some beneficial attributes to breastfeeding (for both the breastfeeding mother and the female infant) that might help prevent breast cancer.

1. P. A. Newcomb referred to a 1994 study that was published in The New England Journal of Medicine, where the breast cancer rates of women that had never lactated were compared to the breast cancer rates of women that lactated for varying lengths of time. The findings were described in this way: "If you set the frequency of premenopausal breast cancer among the women who never lactated at 1.00, then the relative risk of breast cancer for women who had lactated was:

Lactated 3 months or less = .85
Lactated 4-12 months = .78
Lactated 13-24 months = .66
Lactated 24 + months = .78

Ref: Newcomb, P.A. et al. 1994. "Lactation and a reduced risk of premenopausal breast cancer." The New England Journal of Medicine 330(2):81-87

2. In another 1994 study that was published in Epidemiology, J Freudenheim found that for both the premenopausal and the postmenopausal women that suffered from breast cancer, women that were breastfed, "even if only for a short time, had a 25% lower risk of developing breast cancer than women who were bottle-fed as an infant."

Ref: Freudenheim, J. et al. 1994. "Exposure to breast milk in infancy and the risk of breast cancer." Epidemiology 5:324-331.

EXERCISE
A 14 year Norwegian study of 25,000 women was mentioned by the good people at www.intelihealth.com. They said it showed that "women who exercised at least four hours a week were 37 percent less likely to develop breast cancer than less active women". They mention a California study that said "women younger than 40 who exercised 3.8 or more hours per week had half the rate of premenopausal breast cancer as inactive women".

When we talked about Early menarche earlier in this article, it was mentioned that there is a connection between body fat and the production of estrogen. We can easily see how a woman might reduce her body fat by exercising, and that would possibly reduce the risk of developing breast cancer. More Exercise = Loss of Body Fat = Lower Cancer Risk.

Some experts are convinced that the movement of the body helps to move the lymphatic fluids that are between the body cells. Lymphatic fluids carry away toxins and cellular waste products that are suspected to be a cause of breast cancer. Without exercise, some body parts get no movement, which means the lymphatic flow is compromised. In the specific example of the breasts, when do they move? We lock them down with a bra and prevent them from moving, so the circulation of the lymphatic fluids in the breasts is limited. Consider the relationship that the bra has with the breasts, in that the bra restricts breast movement anytime it is worn. That is a major reason for some to wear a bra. Is wearing a bra going to help the circulation of the lymphatic system or hinder it?

This risk factor can certainly be reduced, by a woman that wants to improve her chances of avoiding breast cancer, by starting and maintaining an effective exercise program. She should get a medical practitioner to work with her before she starts any exercize program.

BODY WEIGHT
If body fat encourages excess estrogen production, less body fat would be better. We know that a lack of exercise causes a woman to have a higher risk for breast cancer. While some people are larger because they do not get enough exercise for their body, most people that are heavier (for whatever reason) are less active than they should be, due to their size.

This is another risk factor that can be reduced, if a woman can find a way to reduce her body weight.

DIET
Some foods contain natural plant chemicals that may "fool" the body into producing less estrogen. Some others tend to impede the formation of tumors. Just eating foods that are healthy for us makes a lot of sense too. A lot of research is being done in this area. Highly processed and refined foods like sugar, grains and flour are suspect. Many products are on the "questionable foods" list, so you may want to learn a little more about nutrition and alter your diet.

BIRTH CONTROL PILLS
Birth control pills usually cause a woman's ovaries to function differently that they do naturally. This is done by modifying the hormones in the body. Breast cancer risks are increased as much as 50% for a woman that is taking birth control pills. Once she stops taking them, and her body hormones get back "on track", there is no increased risk.

ALCOHOL
Women that drink three ounces of alcohol (three beers) a day have twice the usual risk of developing breast cancer. Alcohol will travel in a woman's blood to every part of her body. Alcohol will get into the breast milk, which will then go into the infant. If alcohol gets into the milk, it certainly gets into the breast cells. The question that needs to be answered is: Does the alcohol modify the breast cells and cause them to become malignant?

SMOKING
It has been shown that tobacco smoke does increase a woman's risk to develop breast cancer. Studies continue to follow up on this.

ENVIRONMENTAL FACTORS
These refer to the many chemicals and toxins that we come into contact with during our lives. They are in our foods, including the growth hormones that are used by beef and poultry producers that find their way into our body. They are applied to the plant before harvest time to keep the insects and birds from eating the farmer's already depleted profit margin. They are in our clothes from the dry-cleaning and the dyes, stiffeners, and manufacturing compounds used to manufacture the clothing. Exhaust gasses from our vehicles, gasses that escape from manufacturing processes, and even simple degassing of chemicals from vinyl upholstery and carpets contribute to the pool of toxins.

We do not know whether there is a direct cause/effect relationship between these chemicals and breast cancer, but research continues to search for the truth.

If these toxins get into our body, and if they are capable of causing breast cancer, how can we prevent them from doing their damage? We discuss the Lymphatic System elsewhere on this site, where we discuss how that system removes these toxins from our body. The toxins that stay in the body must be destroyed or controlled with our immune system. We must do whatever we can to enable these two systems to perform at their peak levels. Anything that impedes the lymphatic system (tight clothes or a bra?) or the immune system (illnesses, drugs!!) will enable toxins to build to dangerous levels in our bodies.

Please remember that Risk Factors are just that: Risk Factors. If you have a risk factor, that does not mean that you will get cancer. It is only an indicator that you have a higher risk (higher odds) of developing breast cancer.

There is a possibility that research will find yet other risk factors in the future. We are blessed by living during a very exciting time; a time when new medical discoveries are being unearthed almost daily. For any new information that may come in about Risk Factors of Breast Cancer, look under Topics Of Interest.

(1) Journal of the National Cancer Institute 2000;92:840-841