Research studies around the world have shown a link between weight and the risk for breast cancer after menopause. Maintaining a healthy weight throughout your life will help reduce your risk.

The research:

Fat cells produce estrogen and other hormones that cause your cells to divide. If you are overweight or obese, you will produce more of these hormones than your body needs. This increases the chance that cells in your breasts will become cancer cells.

Your risk of breast cancer rises if you are moderately to significantly overweight. Factors that increase your risk include:

• a Body Mass Index (BMI) of 25 or more
• a high percentage of body fat
• extra weight around your waist and abdomen, rather than on your hips and thighs
• weight gain later in life.
  

The research shows quite clearly that after menopause, overweight women have a higher risk of breast cancer. It is true that before menopause, excess weight appears to protect against breast cancer. However, because extra weight increases your risk of many other diseases, it's always better to maintain a healthy weight throughout your life.

What you can do:

You can use a Body Mass Index (BMI) calculator to find out whether your weight falls within the healthy range for your height. A BMI of between 18.5 and 24.9 is generally considered normal.

Eating a healthy diet and getting regular exercise are the best ways to manage your weight. There are many resources available online that offer information and support to help you achieve and maintain a healthy body weight. You can also ask for advice from your doctor.

Learn more:

BC Ministry of Health – Healthy Families BC

Canadian Cancer Society

Physical fitness is good for your entire body, including your breasts. Physical activity protects you against developing breast cancer, no matter how old you are. Even if you have never exercised before, it's never too late to start.

The research:

Regular physical activity helps to keep hormones in your body at healthy levels. This is important because when you produce high levels of hormones such as estrogen, your risk of breast cancer can increase.

Research has shown that regular exercise reduces the risk of breast cancer. This is especially true during adolescence, as well as after menopause. It's estimated that if women in BC who don't currently exercise became physically active, we could reduce the province's breast cancer rate by 11%.

When it comes to reducing your risk of breast cancer through physical activity, studies suggest some may benefit more, including those who:

• have previously given birth
• have a healthy body weight
• have no family history of breast cancer.
  

What you can do:

It is important to maintain regular physical activity throughout your life. Most experts agree that to effectively reduce your risk of breast cancer, you need to engage in moderate activity most days of the week. Vigorous activity is even better for your breast health.

Learn more:

BC Ministry of Health – Healthy Families BC

Canadian Cancer Society 

Canadian Breast Cancer Foundation

When it comes to reducing your risk of breast cancer, less alcohol is better, and no alcohol is best. Drinking alcohol increases your risk of developing breast cancer. The less you drink, the better, and no alcohol is best.

The research:

Drinking too much alcohol is a risk factor for many diseases, including breast cancer. While we still don't know exactly how alcohol leads to cancer, it is thought that alcohol damages DNA in cells. DNA damage increases the risk of cancer.

There is a large amount of research showing that alcohol increases risk for breast cancer before and after menopause. Studies also suggest that the more you drink, the greater your risk. Those who are heavy drinkers and who take hormone therapy for menopause symptoms are especially at risk for breast cancer.

It's true that research has shown that drinking small amounts of alcohol every day may benefit your heart health. However, it's important to recognize that when it comes to breast cancer, no amount of alcohol has been found to be "risk-free."

What you can do:

If you don't drink alcohol, don't start.

If you do drink alcohol, consider reducing the amount you drink. Canada's Low-Risk Alcohol Drinking Guidelines recommend that to reduce your risk for several long-term health problems, you should limit your drinking to no more than 10 drinks a week, and no more than 2 drinks a day most days. Breast cancer experts recommend even less alcohol – less than one drink per day.

Learn more:

Canadian Centre on Substance Use & Addiction – Canada's Low-Risk Drinking Guidelines

Several months of breastfeeding can reduce your risk of breast cancer. Although not everyone has the opportunity to breastfeed, it is important to know that breastfeeding is not just best for a baby's health — it can also reduce a mother's risk of developing breast cancer.

The research:

Breastfeeding causes changes in the body's chemical balance, which may provide protection from breast cancer. It lowers pH levels and reduces the production of estrogen, which are both linked to lower breast cancer risk. Milk production may also help to "flush out" cancer-causing substances in breast tissue.

The more times you can breastfeed in your lifetime, the less your risk of breast cancer. Studies have shown that compared to those who have never breastfed, those who breastfeed for a total of three years have a 10-20% reduction in breast cancer risk. If you breastfeed for less time, you won't get as much benefit, but your risk will still be lower compared to those who have never breastfed. The research also suggests that breastfeeding is especially protective for those who have a family history of breast cancer.

What you can do:

If you are planning to have a family, educate yourself about the many health benefits of breastfeeding for baby and mother. Look into the resources that are available to help you breastfeed successfully. If you are currently breastfeeding your baby, try to continue for as long as possible – ideally for at least several months.

Learn more:

Breastfeeding and Breast Cancer

Susan G. Komen for the Cure

Breastfeeding Information and Support

BC Ministry of Health

BC Women's Hospital & Health Centre

Tobacco use is strongly linked with many cancers. While there are mixed research findings about the link between smoking and overall breast cancer risk, what has clearly emerged in recent years is the importance of avoiding tobacco smoke. Higher rates of premenopausal breast cancer are linked with tobacco smoke exposure during adolescence and young adulthood – either from direct smoking or exposure to environmental smoke. There are positive general health benefits of not smoking, and not being around tobacco smoke also extends to breast cancer prevention. ‎

In the last 10 years, greater attention has been focused on identifying links between toxic chemicals and pollutants in the environment and cancer. Some recent studies by Canadian researchers have found evidence of an association between the development of breast cancer and work in several industries including agriculture.¹ These results need to be confirmed and replicated by other researchers before firm conclusions or recommendations can be drawn. While this issue understandably invokes a great deal of public concern, at this time research does not show a clear link between breast cancer risk and exposure to these substances.

¹ Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case–control study, Environmental Health November 2012 Brophy et al.

Most studies have shown no significant increase in risk of breast cancer for those who take oral contraceptives when compared to those who do not. Some studies have suggested a small increase in risk in those who mainly used older types of oral contraceptives, which contained more estrogen than those commonly used today. Also, studies have shown that the risk goes down after a woman stops taking oral contraceptives.

Other types of contraceptives that are estrogen/progesterone based (topical, injectable, patches, implants, etc.) have been less well-studied. The risk may be similar to oral contraceptives but this has not been proven.

There is growing evidence that vitamin D may reduce the risk of some types of cancer, particularly colorectal and breast cancers. You can get vitamin D from exposure to sunlight, in your diet (especially if you eat foods fortified with vitamin D), or by taking vitamin supplements. For more information, talk to your health care provider.

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Breast implants do not increase the risk of breast cancer, but they can make early detection more difficult. Before getting implants, you are strongly advised to have a mammogram. These baseline images can be used to compare against future mammograms with your implants.

If you have implants, talk to your health care provider about your options around screening for breast cancer. While screening mammography recommendations are the same for those with breast implants, you won't be able to make an appointment directly with the Breast Screening program. Those with breast implants require special positioning and additional images. Contact your health care provider to refer you for a screening mammogram at a diagnostic imaging office.

Further tests may include:

• Diagnostic mammograms: further x-rays of the area of concern.
• Ultrasound: uses sound waves to produce an image of the area of concern. It does not use radiation
• Biopsy: a sample of tissue from the area of concern.

Friends and family play an important role in supporting women to take steps that can reduce their risk of developing breast cancer.

Important facts about breast health & breast cancer

• Risk of getting breast cancer nearly triples between the ages of 40 and 70. About one in eight women in BC will develop breast cancer in her lifetime.
• Most who develop breast cancer don't have a family history of the disease. Only 5-10% of all breast cancers have a genetic cause; up to 42% are linked to lifestyle factors.
• Only 54% of BC women aged 50-69 currently go for a mammogram every two years as recommended.
• Advances in early detection have increased survival rates. Today, 89% of women are alive five years after a breast cancer diagnosis.
• Women in BC have one of the lowest breast cancer rates in the country and the highest survival rates in the country.

We all have a role to play:

Women value the support and encouragement of the people who love them. In fact, in a survey we conducted, women listed family and friends as one of the top factors that would motivate them to take steps to reduce their risk of breast cancer.

• If you're a woman, make a personal commitment to look after your breast health. Remember that by taking care of yourself, you are in a better position to take care of the people you love.
• Encourage the women in your life to reduce their risk through prevention and screening. Be there to support her health decisions.