Risk Factors

Given all that, it’s small wonder that an increasing amount of research and resources are being directed at two very basic questions: what causes breast cancer and what can women do to lessen their risk of contracting the disease?

The answers to those questions are nuanced. After all, there are several risk factors, including gender and age, over which women have no control. On the other hand, research is revealing lifestyle choices that can make a difference. 

Gender and Age

Breast cancer is overwhelmingly a female challenge; men can develop the disease but rarely do. At the same time, a woman’s chances of being diagnosed changes dramatically with age. A 40 year-old woman has a 1.4 per cent risk of facing breast cancer over the next 10 years. For a 50 year-old woman, the rate of risk is 2.6 per cent, or nearly double. Overall, 80 per cent of breast cancer diagnoses occur in women 50 years or older.

Hormones

Reproductive cycles and choices also play a role. Women who start menstruating at an early age or who go through menopause at a later age face a higher risk of breast cancer. The same is also true for post-menopausal women who opt to undergo hormone replacement therapy—one reason why the practice, once widespread, is on the decline.

Childbirth


On the other hand, women who have children at a young age, or who have several children, lessen their risk of breast cancer. But, as expert Heather Bryant notes, “It’s unlikely a woman would make fundamental child-rearing decisions based on a theoretical cancer risk.”

Family History


Family history is also a risk factor, though not as prevalent a one as many might believe. Over 80per cent of women diagnosed with breast cancer have no family history of the disease, and less than 10% are genetically pre-disposed to the disease.

That said, women who have a “first-degree” relative—defined as a mother, sister or daughter—who have breast cancer are at higher risk. And while these women may be referred for prevention counselling, some of their options—such as a pre-emptive mastectomy or removal of the ovaries—are so serious that a lot of thought and care must be taken before they make any final decisions.

Geography

Breast cancer rates also vary geographically. Women who live in North America, Western Europe and Australia are at higher risk. That  has led to speculation over whether something in the environment of those countries, or in their cultural practices, might explain the higher incidence. Research in this area continues. But already, some theories have been discounted while others have gained credence.

Urban Myths

Use of hair dyes, underarm deodorant and even underwire bras have, over the years, been rumored to lead to higher rates of breast cancer. Studies have rejected the alleged connection in each case.

More plausibly, perhaps, the use of birth control pills has been cited as a potential culprit; after all, the pills do affect estrogen levels, which are linked to breast cancer. But after extensive research, says Bryant, the conclusion is that birth control pills do not represent a significant breast cancer risk. The same is true, she says, of therapeutic abortions, another practice that has sometimes been wrongly associated with the disease.

What Can You Do?

So what are the risk factors women can do something about? Two of the biggest, says Bryant, are obesity and lack of physical exercise—both common in the countries where breast cancer rates are high.

Lose Weight & Exercise More


Obesity is a factor for post-menopausal women; in their case, estrogen is formed in the fatty tissues of the body rather than the ovaries. There is also mounting evidence that physical activity can help stave off breast cancer. Better yet, it is never too late to start: even if exercise is only adopted later in life, its effects have been proven beneficial.

While there has been no strong link drawn between smoking and breast cancer, moderate alcohol consumption is advised.  Most studies suggest that more than one drink a day may put an individual at a slightly increased risk.

Mammograms & Screening

One of the most significant developments in the battle against breast cancer is the increased use of mammography, particularly by women in high-risk age groups. While such screening won’t prevent the onset of breast cancer, it can—and does—provide early detection, which is critical to effectively treat the disease and reduce mortality rates.

In Alberta, an Alberta Cancer Board initiative known as Screen Test  was launched in 1990. It has been bringing mammography across the province  with the help of mobile vans, and has encouraged women between the ages of 50 and 69 to have a mammogram once every two years. The results are impressive. Prior to Screen Test, only 17 per cent of Alberta women in their sixties and 27 per cent of women in their fifties were getting screened. Now, about 60 per cent of  all women are being screened.

We have also recently launched the Alberta Breast Cancer Screening Program, which aims to significantly increase the number of women at risk who receive mammograms with the ultimate goal of reducing deaths of Alberta women from breast cancer by at least 30 per cent.

The Alberta Breast Cancer Screening Program will bring all screening, whether conducted through the Alberta Cancer Board or by private radiologists, under one umbrella and collect and share data to ensure that no woman falls through the cracks.

Together with public education programs aimed at informing women how they can lessen their personal breast cancer risk, this new Alberta Cancer Board initiative has a very simple but vital goal—to save lives.

 Learn more about breast cancer
 Read about one patient's experience with breast cancer: Susan Leach's story
 More about Alberta's cancer screening programs