Breast health aware
How cancer starts
Our bodies are made up of billions of cells. Each of our cells contain genes, which act like a set of instructions for our cells. Genes give our cells messages to tell them how to behave. Normally, genes ensure our cells grow and divide properly. But sometimes genes make mistakes. These mistakes can happen by chance but can also be caused by things like chemicals in tobacco smoke or alcohol. If a gene makes too many mistakes, it can start giving cells the wrong message, which might make cells grow more quickly, or divide too much. Over time, this activity can lead to cancer.
A hormone called oestrogen plays an important role in triggering breast cancer. Normally, oestrogen works with the genes in breast cells to control how often they divide. But if a woman has too much oestrogen, her breast cells can receive too many messages to divide and start to grow out of control. This explains why things that reduce a woman’s exposure to oestrogen – like having children – decrease breast cancer risk, but things that raise oestrogen levels – like alcohol and excess weight – increase risk.
Myths and misconceptions
There are many myths and rumours about the causes of breast cancer
- Plastic bottles: There’s no convincing evidence to show using plastic bottles or plastic containers increases the risk of cancer.
- Bras: Despite internet rumours, wearing a bra or keeping a mobile phone in your bra hasn’t been shown to cause cancer.
- Deodorants: Concerns about deodorants causing breast cancer started as an email hoax. There isn’t good evidence that deodorants cause breast cancer.
- Cosmetics: People sometimes worry about whether chemicals in common products such as moisturisers or make-up cause cancer, but there’s no good scientific evidence to show that these products affect the risk of cancer.
- Family history: For some people with a strong family history of breast, ovarian or prostate cancer, their risk can be higher because they inherit a faulty gene. The most well-known of these genes are the BRCA genes. But the total number of breast cancer cases caused by inherited faulty genes is small – it’s fewer than 3 in 100 cases .

Take action to lower the risk
Understanding Breast Cancer screening and early detection


It's good to talk
Advice for friends and family on how to tackle conversations around cancer.
These educational materials were developed in partnership with Cancer Research UK with funding provided by the Avon Foundation for Women.
The information is intended to help you understand some of the risk factors for breast cancer, as well as actions you can take. It is provided for educational purposes only and should not be interpreted as medical advice. Be sure to consult your doctor or medical provider to develop the best personal care plan for you. Cancer Research UK has provided all statistics.