Genetics, it is thought, plays a big role in determining who might be more susceptible to developing cancer, but not a great deal is yet known about how this works.
There is no straight path to prevention or cure - and the sad outcome of Kirstie Allsopp's mother, Lady Fiona Hindlip, who recently passed away at the age of 66, following a 26-year battle with breast cancer that included a double mastectomy to lower her risk, is proof of this.
One thing that we do know is that while breast cancer affects every race, across a broad range of ages, there are some steps to make sure you lower your risk as much as possible.
Dr Anne Rigg, consultant medical oncologist at the London Bridge Hospital had the following advice:
Regular exercise can play a part in the prevention of breast cancer
There is no doubt the lifestyle of the modern woman has changed dramatically since the time of our grandmothers. Domestic appliances have made housework less physically strenuous and less time-consuming. Access to cars and good public transport means that there is less need to walk than for previous generations.
There is also the fact that employment opportunities have improved significantly for women in the last century so more women than ever are working. Whilst all of these factors have helped women they have come at a cost. The reality is that most British women are far less physically active than they used to be.
Body weight matters
There has been a steady rise in the incidence of breast cancer in the UK (the number of women diagnosed with the condition each year) and this correlates with the rise in body weight. No one can yet claim to fully understand why an individual woman develops breast cancer but there is plenty of evidence already that being overweight is a significant risk factor for breast cancer.
Therefore, keeping body weight within normal limits is beneficial. The most important way to do this is through regular exercise. As well as reducing the risk of breast and other cancers, it is also beneficial for the heart and prevents osteoporosis. I advise my patients once they have completed treatment for breast cancer to keep their weight in check through regular exercise and healthy eating.
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The link between excess body fats and breast cancer
Two-thirds of breast cancers occurring in British women are sensitive to the female hormone oestrogen (termed oestrogen-receptor positive cancer).
These breast cancer cells are stimulated by oestrogen and this promotes their growth. Oestrogen is produced by the ovaries if a woman is pre-menopausal but also by adipose tissue (fat). Hence, the more body fat a woman has the more oestrogen she will be producing. This accounts for the link between being overweight and the increased risk of breast cancer.
Steps people can take to reduce their risk of breast cancer
Women should be aware of a family history of breast cancer or ovarian cancer. Having a first degree relative (mother, sister) who has had breast or ovarian cancer can lead to an increased risk for the future and these women should start having screening mammograms at 40 rather than 47-50 as for the rest of the population.
Maintaining weight within normal limits through exercise and healthy eating is a sensible approach especially if there is already a family history. Avoiding or limiting alcohol intake is also advocated. Unfortunately, young women are drinking far more alcohol than previous generations and there is concern this is likely to be reflected in a further rise in breast cancer in the future for this age group.
Oral contraception and hormonal replacement therapy have revolutionised women’s lives for the better. However, the exposure to these drugs has led some women to have an increased risk of developing breast cancer. Women should talk to their GP when making decisions to use these treatments and be aware of the potential risks as well as the benefits.
What exercise should you do?
In terms of breast cancer prevention, the predominant reason for recommending exercise is to keep weight within normal limits (body mass index 20-25). Therefore, the most useful exercise is aerobic exercise such as cycling, swimming and running/jogging which will increase the heart rate and help to burn fat.
The exercise should be at an intensity that causes the woman to perspire and breathe faster. These signs indicate that the heart rate is elevated. The other key factor is that exercise should take place several times a week so maintaining the routine is just as important as the intensity. The current NHS recommendations for women are a minimum of 30 minutes of exercise 5 times per week.
Tips and advice to maintain a healthy lifestyle
There are no quick fixes to prevent breast cancer. It is all about making long-term commitments to patterns of exercise, eating and alcohol intake. I would recommend that a woman tries to take strenuous exercise for 30 minutes at least 5 times a week. In addition, she should keep her alcohol consumption to 7 units per week.
The NHS change4life website has an easy to use alcohol unit calculator. With the rising percentage alcohol content in many drinks you can underestimate the amount of alcohol you are drinking unless you check. Alcohol also has a high sugar content and can contribute to weight gain.
I would also advocate a diet that tries to limit high calorie and high saturated fat products as both lead to weight gain. There is evidence from other cultures with diets lower in animal fat and sugar content that the incidence of breast cancer is correspondingly lower.