Antiperspirants, deodorants and underwire bras are among the everyday items or habits that have been blamed over the years for causing breast cancer.
The sad fact, though, is that while internet rumours about unsubstantiated links between these items and breast cancer cause some women to worry needlessly, there are other, proven breast cancer risk factors that many others are overlooking.
Last year alone it was estimated that more than 18,000 Australian women would be diagnosed with breast cancer, and statistics show that around three quarters of those women will be aged 50-plus, because getting older is the single biggest risk factor for women developing breast cancer.
There are other factors that are also known to increase a woman’s risk of developing breast cancer, and there are plenty of random myths about the causes of breast cancer too, so we asked Dr Jane Brazier, the Director of BreastScreen Queensland Brisbane Northside Service, to help us sort the fact from the fiction.
This myth started in 1995 when the authors of a book called Dressed to Kill claimed that tight bras, including those with underwiring, restricted the functioning of the lymphatic system, leading to a build-up of toxins in the breast tissue, that went on to cause cancer.
There is no evidence to support this and the best available evidence shows that, in fact, wearing a bra doesn’t increase your risk of breast cancer.
The Cancer Council says this particular myth started as an email hoax that claimed women who used deodorant or antiperspirant were preventing their bodies from ‘sweating out toxins’, that were then absorbed by the lymph glands and caused cancer.
Again, there is no conclusive evidence to support this. While deodorants and antiperspirants may contain chemicals such as parabens and aluminium compounds and are applied close to where breast cancer develops, studies haven’t found an association between those chemicals and breast cancer risk.
As the Cancer Council points out, breast cancer actually starts in the breast and spreads to the lymph glands, not the other way around. And toxins aren’t released from the body through sweat but mainly through the liver and kidneys, which aren’t connected to the lymph glands.
“Sometimes women have a fall or they get a kick from their grandchild or a toddler or something and they become aware of a lump in their breast,” Dr Brazier explains.
“The breast cancer that is subsequently detected is not caused by the trauma or the bruise or the bump they’ve received, it just happened to help them find what was going on that they were previously unaware of.”
There is no conclusive evidence that trauma or injury causes breast cancer or evidence that it could increase the spread of breast cancer cells.
Plenty of ‘cancer truth’ sites claim the radiation used in the mammogram, or breast-screening, process is a cancer risk itself, which can make some women worry about the risk of being exposed to radiation when having a screening mammogram.
The truth is that each time you have a screening mammogram your breast is exposed to the smallest amount of radiation possible to gain a high-quality x-ray image. This is about the same as 18 weeks of exposure to natural radiation in the environment.
The potential benefits for women aged 50-74 years of having regular breast screens are considered to outweigh the potential risks. These benefits include detecting breast cancer early when women have more treatment choices that are usually less invasive and the chance of surviving the disease is better. More information about the potential benefits and harms of breast screening is available here.
“A lot of women are lulled into a false sense of security, thinking it’s not in their family so they don’t have to think about it,” Dr Brazier says.
“However, out of women who are diagnosed with breast cancer, only one in 10 actually have a family history and nine out of 10 women who get a diagnosis of breast cancer have no one at all in the family who’s had breast cancer so far.”
Women who do have a known family history of breast cancer have a higher risk of developing breast cancer, with the risk increasing with the number of family members affected and the younger their ages at diagnosis. You can learn more about the degrees of risk associated with family history here.
“We find things with mammograms long before women are even aware that there’s a change in their breast,” Dr Brazier points out.
A breast screen, which effectively involves taking an x-ray of the breast tissue, picks up changes in the tissue that are far too small to be felt by a woman or even her doctor during a breast examination.
That said, Dr Brazier encourages women to know what their breasts normally look and feel like and if they detect a lump or nipple discharge or any changes that are of concern, to make an appointment with their doctor to have it investigated immediately.
So, if many of the common worries about breast cancer risks are misplaced, what factors are proven to increase the risk of developing the disease?
The evidence tells us that there doesn’t appear to be a ‘safe’ level of regular alcohol consumption, with even one standard alcoholic drink each day increasing a woman’s risk of developing breast cancer.
Research by the World Cancer Research Fund and the American Institute for Cancer Research found women who drink one standard glass of alcohol each day had a 7 percent higher risk of breast cancer than women who never drank alcohol. This risk was also found to have increased as the number of drinks regularly consumed increased.
The research concluded that alcohol may increase risk for breast cancer in a number of ways, including by helping cancer-causing molecules to enter cells or damaging cell DNA. Alcohol is also thought to increase levels of the hormone oestrogen, which can influence breast cancer risk.
There is evidence to show that post-menopausal women who are overweight or obese are at an increased risk of developing breast cancer.
“Maintaining a healthy weight and exercising regularly are good things to do as part of a healthy lifestyle and can help reduce things like breast cancer risk,” Dr Brazier says.
Aim for at least 30 minutes of physical activity most days of the week and try and incorporate activity into your day for example try riding to work, going for a brisk walk with friends, gardening or even cleaning the house.
There is convincing evidence that using menopausal hormone therapy (MHT) that contains combined oestrogen-progestogen is associated with an increased risk of breast cancer. The risk increases the longer you use combined MHT and decreases after you stop using it.
As such, it’s important for women to discuss these therapies with their health professional to ensure they’re comfortable with the benefits and risks of the treatment.
“There are alternate providers of non-proven tests that, unfortunately, women seem to think is going to be something they can do instead of a mammogram,” Dr Brazier says. “A mammogram is the gold standard for finding breast cancer early and if we can find breast cancer in an early stage, it’s much easier to treat. With early detection, the breast cancer survival rate has increased to 90 percent.”
A breast screen with BreastScreen Queensland is free, simple and doesn’t require a GP referral. There are more than 260 BreastScreen Queensland locations around the state, offering convenient appointments and screening sessions that take just 30 minutes or less, with friendly female staff on hand to make women comfortable with the process.
For more information and to book your breast screen, visit breastscreen.qld.gov.au or call 13 20 50.
IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.
A breast screen only takes 30 minutes and is a must every two years for women aged between 50 and 74.