Michael Abrahams | Reduce your breast cancer risk
Despite impressive developments of diagnostic methods, surgical techniques, drug regimens and radiation treatments, breast cancer continues to plague us.
Worldwide, it is the most common invasive cancer in women, comprising 16 per cent of all female cancers. Its incidence is actually increasing in the developing world as a result of increased life expectancy and urbanisation, as well as the adoption of Western lifestyles, many of which are unhealthy. There is no cure for the disease, but early detection significantly decreases morbidity and mortality.
As a cure continues to evade us, it is imperative that risk factors for the disease are identified, and appropriate steps taken to reduce them. Unfortunately, the majority of women who develop breast cancer have no identifiable risk factors, apart from their gender, as although the disease afflicts men as well, its occurrence in women is far greater.
One of the best known risk factors is family history. Having a first-degree relative (mother, sister, or daughter) with breast cancer almost doubles a woman's chance of developing the disease. Some gene mutations significantly increase risk, but are found in only a small percentage of cases.
Prolonged exposure to endogenous (originating in the body) oestrogen, a steroid hormone that promotes the development and maintenance of anatomical female characteristics, is known to increase the risk of developing breast cancer.
So early onset of menstruation and late menopause increase risk, as these women have longer periods of uninterrupted menstrual cycles.
Other risk factors are age (the older a woman becomes, the greater the likelihood), ethnicity (increased incidence in white women), certain benign breast conditions, dense breast tissue and a previous history of breast cancer, which increases the chance of the disease appearing in the other breast (if the initial presentation was unilateral}.
All of the above-mentioned factors are fixed and beyond our control. Fortunately, there are other factors that are modifiable. For example, late age at first childbirth, like early onset of periods and late menopause, is associated with increased oestrogen exposure and breast cancer risk. Breastfeeding, on the other hand, is protective.
The bad news for female alcohol drinkers is that consumption increases the risk of developing breast cancer, the likelihood increasing with the quantity of alcohol ingested. Women who have three alcoholic drinks per week have a 15 per cent higher risk than those who abstain, and it has been estimated that the risk increases by another 10 per cent for each additional drink women regularly have each day. Alcohol exerts its effect by elevating levels of oestrogen and other hormones associated with hormone-receptor-positive breast cancer, and it can also damage DNA in cells.
The risk of developing breast cancer is also increased by physical inactivity, which can lead to being overweight and obese, which are also independent risk factors, especially after the menopause.
Before menopause, oestrogen is manufactured mainly by the ovaries. But after the transition, oestrogen production from these organs ceases, and the hormone is produced in fat cells. So having more fat in the body after menopause can raise oestrogen levels and increase the probability of developing breast cancer.
In addition, women who are overweight tend to have higher blood-insulin levels, and this has been linked to breast and other cancers. The adverse effects appear to be greater in women who gained weight in adulthood, and in those who gain weight in the waist area, as opposed to the hips and thighs. A high-fat diet is also associated with increased risk.
Exogenous hormone use, such as some forms of hormonal contraception and hormone replacement therapy, may also increase risk, but this is not necessarily a reason to avoid or discontinue these forms of therapy, as their benefits may outweigh their risks. Radiation to the chest before the age of 40 is also a risk factor. Luckily, mammograms, which are not recommended before the age 40, have not been shown to increase cancer risk.
Smoking tobacco, a substance that is loaded with carcinogens, is associated with an increased risk of developing many cancers, and breast cancer appears to be no exception.
Research also suggests a correlation between second-hand smoke exposure and breast cancer risk in postmenopausal women.
It is, therefore, obvious that a healthy lifestyle decreases breast cancer risk. Indeed, one study concluded that 21 per cent of all breast cancer deaths worldwide are attributable to alcohol use, overweight and obesity, and physical inactivity. So it would be in women’s best interests to limit alcohol use to less than one drink per day, avoid tobacco, eat healthily and control their weight. Appropriate levels of physical activity are to be encouraged.
The American Cancer Society recommends that adults get at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week (or a combination of these).
Physical activity may decrease risk by decreasing fat levels, reducing inflammation, and optimally altering the levels of sex and other hormones and chemical mediators in the body.
Women who have children should breastfeed, and women should also discuss contraception, hormone replacement and radiological investigation options with their physicians.
In extreme cases, where there is a very strong family history and genetic testing suggests a very high risk, prophylactic mastectomy may be an appropriate option. The thought of a woman having both of her breasts lopped off is unpalatable for many of us, but the procedure saves lives.
According to the National Cancer Institute, prophylactic mastectomy in women who carry certain gene mutations may be able to reduce the risk of developing breast cancer by 95 per cent. And the procedure is not as morbid as it sounds, as it is usually accompanied by breast reconstruction surgery, often giving good results.
Cancer is not always avoidable, but it is our responsibility to control the factors that we can to decrease our risk.