For these factors, the overall scientific evidence suggests they aren’t linked to the disease. In some cases there simply isn’t any evidence of a link; in others, research has shown there’s no link.
Despite the lack of evidence, these factors can still receive a lot of media attention, which can cause confusion about what has or hasn’t been shown to be linked to breast cancer.
Deodorants, antiperspirants and shaving
Using deodorants or antiperspirants does not increase your risk of breast cancer.
Claims that deodorant or antiperspirant use increases the risk of breast cancer have been circulating since 1999. More recently, there have been claims that aluminium in antiperspirants can cause breast cancer. Aluminium salts are commonly used as an ingredient in antiperspirants as they block the sweat ducts and stop sweating. There is no good evidence to support these claims.
Women are advised to avoid using a deodorant, antiperspirant or talc containing aluminium when they go for a mammogram only because the aluminium might show up on the x-ray image and give an inaccurate reading.
Wearing underwired bras does not increase your risk of breast cancer, despite some claims. Women need not be concerned about wearing any type of bra.
A good-fitting bra provides support. Women should be properly measured for their bras, which should be tried on to ensure a good fit. Bras that do not fit properly can cause discomfort and breast or back pain.
Bumping or bruising your breast
There is no good evidence that a bump or injury to the breast, including through sport, increases your risk of breast cancer. Sometimes a woman might just check her breasts more carefully after bumping or injuring her breast, and so may notice an unusual change in her breast, such as a lump.
Breast implants (silicone, saline or PIP) do not increase your risk of breast cancer.
Women with implants should let their screening service know they have implants before attending breast screening appointments. Implants make it harder for the radiographer to see breast tissue during breast screening, so they may wish to take additional x-ray images from different angles to be sure that all of your breast tissue is completely examined. They may also want to check the images straight away to make sure they are suitable, which means your screening needs to take place at a unit with digital technology.
All women, whether or not they have implants, should be breast aware. If you notice any unusual changes to your breast, check this with your doctor.
It is unlikely that having an induced abortion (a planned termination out of choice or medical necessity) affects your risk of developing breast cancer.
Some people claim that having an abortion increases the risk of breast cancer because it disrupts the natural development of breast cells during pregnancy, making them susceptible to changing into cancerous cells. This claim is not supported by scientific or clinical evidence.
Some early, less well-designed studies suggested that abortion might increase the risk of breast cancer; however, over the past 20 years, several well-designed studies have shown this is not the case.
Culled from breastcancerawarenow.org