Breast cancer risk is associated with a number of factors. As with all types of cancer there are some risk-factors over which a person has no control. However, there are also behavioural factors that are within an individual’s control and can contribute to the reduction of risk despite other predisposing risks.
Factors that are outside a woman’s control as it relates to breast cancer are being born female, advancing age, breast density, inherited genetic mutations such as the BRCA1, BRCA2, ATM and CHEK2 genes, family medical history and factors related to oestrogen exposure such as when the woman began having her monthly periods and when she experiences menopause.
The common themes in the research on the impact of lifestyle on reducing the risk of breast cancer are the importance of controlling weight gain and avoiding obesity, the importance of a healthy diet and physical activity, reducing the amount of alcohol consumed and limiting the use of hormone replacement therapy
Last year in a United Kingdom study it was reported that a tenth of all breast cancer cases in that country could be prevented by 2024 if women made simple lifestyle changes.
In a study published in the American Journal of Epidemiology earlier this year it was reported that approximately 40 per cent of breast cancers among postmenopausal women may be prevented through lifestyle change. This is a significant result as the majority of all breast cancer incidences occur in women who are postmenopausal.
Being overweight increases the risk of breast cancer. According to an American Cancer Society study, women who gain more than 30 pounds after the age of 18 are 40 per cent more likely to develop breast cancer than women who had gain five pounds or less. Women who gain 70 pounds as adults doubled their risk of breast cancer.
Being overweight or obese is also a concern for postmenopausal women because most of a woman’s oestrogen will be produced by fat cells as opposed to the ovaries. The more fat cells a woman has, the more oestrogen is likely to be circulating in her blood and this will in turn increase her risk of developing breast cancer.
The reports are controversial as to whether there is a ‘breast cancer prevention diet’, but in general a diet low in total fat especially polyunsaturated and saturated fats is recommended and this will also help with weight control.
A study reported in Cancer Detection and Prevention in 2008 concluded that a lower-fat, plant-based diet contributed to lower risk for breast cancer and that a diet high in meat and saturated fat intake contributed to higher risk.
Physical activity influences breast cancer risk reduction by acting on circulating hormones and also helping to control weight.
Research published this year in the Journal of the National Cancer Institute reported that physical activity reduces the risk of breast cancer in premenopausal women. Earlier studies have reported a 10 to 25 per cent reduction in risk among women who are physically active.
It is recommended that all women should be moderately to vigorously active for at least 45 minutes for at least five days a week.
Regular alcohol consumption of more than one drink per day increases risk regardless of the type of alcohol consumed, particularly if women are lacking folate in their diet. The risk is greater the more alcohol you consume. Women who limit their alcohol consumption will therefore lower their risk of breast cancer.
The use of hormone replacement therapy is a risk factor for breast cancer and limiting its use has been cited as one of the ways a woman can reduce her risk.
According to the American Cancer Society there appears to be few strong reasons for a woman to use combined HRT. However the decision to use or not use HRT should be made by a woman and her doctor after considering the risks and benefits associated with its use.
For more information contact the Cayman Islands Cancer Society at 949-7618 or email [email protected].