We asked specialist oncologic breast and general surgeon Nicola Davis about the best ways to reduce the risk of breast cancer. Learn more about Dr. Nicola Davis.
There are many risk factors for breast cancer, many of which we have no control over, such as being female, increasing age, breast density, our family history and genetics. These non-modifiable risk factors have the most impact on the likelihood of developing breast cancer.
Women often worry that they caused their breast cancer. This is never true and, overall, the impact of lifestyle factors is small, however, it is an area where you can take control to actively decrease your risk.
Studies show that, compared to other lifestyle factors, maintaining a healthy weight has the most benefit.
This is most important after menopause when estrogen in your body comes from fat cells rather than ovaries.
Moderate exercise of at least 2 1⁄2 hours per week also decreases risk. We also know that for women who have had breast cancer, regular exercise decreases the chance of cancer recurring.
Drinking alcohol has been shown to increase risk and should be minimised. There is no known safe level of consumption with even one drink a day increasing risk.
Finally, smoking increases the chance of breast cancer, especially in younger, pre-menopausal women, and cessation is advised.
BE BREAST AWARE – EARLY DETECTION COUNTS:
- Breast cancer is the most common cancer affecting New Zealand women with more than 3,300 cases diagnosed each year.
- Screening mammograms are important because early detection can result in more positive outcomes.
- Women aged between 45-69 are encouraged to get a mammogram every two years. Screening is free through BreastScreen Aotearoa.
- Self-awareness is also important. From age 25, all women are encouraged to examine their breasts to learn what is normal for them and recognise changes.
- If you notice any changes, such as a lump or thickened area, nipple inversion or discharge, persisting redness, unusual pain, breast distortion, or dimpling or puckering, see your GP for an assessment. While many breast changes are due to non-cancerous conditions, it is important to get it checked.

2mm – size of the smallest cancer found by a regular mammogram
14.5mm – average size of lump found during regular mammogram
22mm – average size of a lump found by self-examination
