Volume 200 - Issue 7
The utility of genetics in inherited cancer
Author: Rosalie Schultz
Med J Aust 2014; 200 (7): 388-389. || doi: 10.5694/mja13.00187
Published online: 21 April 2014
Published online: 21 April 2014
Population-based strategies are needed to prevent breast cancer and to complement identification and treatment
To the Editor: In their perspective article, Winship and Tucker highlight the possibility of preventing genetic breast cancer, a triumph of modern medicine.1 However less than 5% of breast cancer is caused by genetic mutation.2 The vast majority of breast cancers are not genetic.
Compared with cases of breast cancer with genetic causes, many more cases have environmental causes, including lack of physical activity, overweight and obesity, and alcohol consumption. These are powerful effects: for example, cohort and case–control studies suggest that walking 3–4 hours per week may reduce the risk of breast cancer by around 30%.3 Smoking is also an important cause of breast cancer, particularly smoking before a woman's first birth.4
Effective implementation of established health promotion strategies will prevent breast cancer.3 Changes in behavioural risk factors are effective in preventing both pre- and postmenopausal breast cancer, including in women at high genetic risk.3 These strategies complement screening mammography and targeted strategies for the 1% of women at high risk.3 Women should be informed that these common behavioural risk factors increase risk of breast cancer, in addition to their effects on other chronic diseases.5 Population-based health promotion strategies should highlight reduction in breast cancer risk from healthy lifestyles.
Competing interests
No relevant disclosures.
References
- Winship IM, Tucker K. The utility of genetics in inherited cancer. Med J Aust 2013; 199: 644. 1
- Cancer Australia. Clinical best practice. Breast cancer. Familial risk assessment FRA-BOC. http://canceraustralia.gov.au/clinical-best-practice/gynaecological-cancers/familial-risk-assessment-fra-boc (accessed Nov 2013).
- Coyle YM. Lifestyle, genes, and cancer. In: Verma M, editor. Cancer epidemiology. Vol. 2: modifiable factors. Toolwa, NJ: Humana Press, 2009: 25-56. 3
- Gaudet MM, Gapstur SM, Sun J, et al. Active smoking and breast cancer risk: original cohort data and meta-analysis. J Natl Cancer Inst 2013; 105: 515-525. lefthere
- Royal Australian College of General Practitioners. Breast cancer. In: Guidelines for preventive activities in general practice. 8th ed. http://www.racgp.org.au/your-practice/guidelines/redbook/early-detection-of-cancers/breast-cancer (accessed Nov 2013).