There is no single cause of breast cancer, however there are are a number of risk factors that can increase your chance of developing breast cancer including genetic, lifestyle and environmental factors.

These can include:

• Gender – being female increases your risk
• Having a family history of, or close relative who has had, breast cancer
• Aging – women who are 50-years-old are 10 times more at risk to develop breast cancer than women who are 30-years-old ¹¹
• Drinking alcohol ¹¹
• Being overweight

There is convincing evidence that combined (oestrogen-progesterone) replacement therapy increases the risk of breast cancer.¹¹

Risk increases the longer that HRT is used, and is higher in women who start replacement therapy close to menopause.¹¹

There are several lifestyle factors you can control to help reduce your risk of developing breast cancer, including:

• Getting regular exercise – At least 30 minutes of moderate-intensity exercise each day¹²
• Eating a healthy, balanced diet – Eat a fibre-rich diet from grain and legume sources, as well as enjoy a variety of fruit (2 serves) and vegetables (5 serves) per day, limit your intake of salt, saturated fats, and avoid all processed meat¹³
• Reducing alcohol intake – If you choose to drink, limit your alcohol intake to no more than two standard drinks a day. ¹¹
• Maintaining a healthy weight – Maintain a healthy weight within the normal BMI (Body Mass Index)^* range of 18.5 – 24.9kg/m².¹⁴

*To calculate your BMI = (weight (kg))/(height(m))²

Breast cancer in men is rare and only makes up approximately 1% of all breast cancer cases.

Like women, there are a number of factors that can increase male breast cancer risk. These include: ²⁰

• Age – the average age of breast cancer diagnosis is 69 years
• Family history of breast cancer, or a known BRCA gene mutation
• Hormonal imbalances – such as increased levels of oestrogens
• Previous radiotherapy treatment

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3. Stages, types and treatment of breast cancer. (n.d). National Breast Cancer Foundation. Retrieved on 18 December 2018 from https://nbcf.org.au/about-national-breast-cancer-foundation/about-breast-cancer/stages-types-treatment-breast-cancer/
4. Breast Cancer Stages. (2017). American Cancer Society. Retrieved on 19 December 2018 from https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/stages-of-breast-cancer.html
5. What are the symptoms of breast cancer. (2018). Centre for Disease Control and Prevention (CDC). Retrieved on 18 December 2018 from https://www.cdc.gov/cancer/breast/basic_info/symptoms.htm
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10. Hormone therapy for breast cancer. (2017). American Cancer Society. Retrieved on 18 December 2018 from https://www.cancer.org/cancer/breast-cancer/treatment/hormone-therapy-for-breast-cancer.html
11. Risk factors for breast cancer: A review of the Evidence. (2018). Cancer Australia. Retrieved on 18 December 2018 from https://canceraustralia.gov.au/system/tdf/publications/risk-factors-breast-cancer-review-evidence-2018/pdf/rfbcr_risk_factors_for_breast_cancer_a_review_of_the_evidence_2018_report.pdf?file=1&type=node&id=6421
12. Physical Activity and sedentary behaviour. (n.d). Cancer Australia. Australian Government. Retrieved on 18 December 2018 from https://canceraustralia.gov.au/publications-and-resources/position-statements/lifestyle-risk-factors-and-primary-prevention-cancer/lifestyle-risk-factors/physical-activity-and-sedentary-behaviour
13. (n.d) Cancer Australia. Australian Government. Retrieved on 18 December 2018 from https://canceraustralia.gov.au/publications-and-resources/position-statements/lifestyle-risk-factors-and-primary-prevention-cancer/lifestyle-risk-factors/diet
14. Overweight and obesity. (n.d). Cancer Australia. Australian Government. Retrieved on 18 December 2018 from https://canceraustralia.gov.au/publications-and-resources/position-statements/lifestyle-risk-factors-and-primary-prevention-cancer/lifestyle-risk-factors/overweight-and-obesity
15. Stage 0 – pre-breast cancer. (n.d) National Breast Cancer Foundation. Retrieved on 13 January 2019 from https://nbcf.org.au/18/stage0-pre-breast-cancer
16. Stage 1 or 2 – Early breast cancer. (n.d). National Breast Cancer Foundation. Retrieved on 13 January 2019 from https://nbcf.org.au/about-national-breast-cancer-foundation/about-breast-cancer/stages-types-treatment-breast-cancer/stage-1-2-early-breast-cancer/
17. Stage 2 or 3 – Locally advanced breast cancer. (n.d). National Breast Cancer Foundation. Retrieved on 13 January 2019 from https://nbcf.org.au/about-national-breast-cancer-foundation/about-breast-cancer/stages-types-treatment-breast-cancer/stage-2-3-locally-advanced-breast-cancer/
18. Stage 4 – Metastatic breast cancer. (n.d). National Breast Cancer Foundation. Retrieved on 13 January 2019 from https://nbcf.org.au/about-national-breast-cancer-foundation/about-breast-cancer/stages-types-treatment-breast-cancer/stage-4-metastatic-breast-cancer/
19. Targeted Therapies. (n.d). ICON Cancer Centre. Retrieved on 13 January 2019 from https://iconcancercentre.cn/treatment/targeted-therapies/
20. Men get breast cancer too. (2016). Breast Cancer Network Australia (BCNA). Retrieved on 14 January 2019 from https://www.bcna.org.au/media/6467/men-get-breast-cancer-too-booklet-web.pdf?_ga=2.267601998.1909084069.1547442095-719496387.1547442095