The Incidence of Breast Cancer in American Women is on the Rise
- The incidence of breast cancer in women in the US has been slowly, but steadily rising — by about .5% each year
- Experts suggest that the rising rates could have something to do with an increasing rate of obesity and a decreasing rate of fertility
- Excess weight can lead to inflammation, which increases the risk of breast cancer
- Giving birth at a young age, as well as giving birth to multiple children, have both been associated with lower breast cancer risk
A recent study published by the organization predicts that there will be nearly 340,000 new cases of breast cancer diagnosed in the US in 2022, and more than 43,000 women are expected to die from the disease. Study authors suggested that the slow, but steady rise in breast cancer cases could be due in part to slowing fertility rates as well as a rise in obesity rates.
Excess Weight & Breast Cancer RiskRead More
Dr. Elizabeth Comen, a breast oncologist at Memorial Sloan Kettering Cancer Center, explained that exercise can reduce the risk breast cancer because when women are carrying around excess weight, it can lead to inflammation in the body.
Dr. Elizabeth Comen explains how exercise can reduce a woman’s breast cancer risk.
“We know that when women are overweight, they can have a state of inflammation in their bodies,” she said. “Some of those fat cells can make estrogen. And we know that being exposed to too much estrogen over a woman’s lifetime can significantly increase her risk of breast cancer.”
Dr. Comen also noted that exercise can be really helpful for women going through breast cancer treatment as well.
“We know that women who exercise do better during treatment,” she explained. “Their hearts do better in the long run if they take the time to exercise, and there are, again, lots of different ways that you can do it … Even just something more than what you did yesterday is better than nothing. Exercise doesn’t have to mean all of a sudden you’re running a triathlon or you’re doing something that you’ve never done before.”
Fertility & Breast Cancer Risk
Fertility rates have been steadily going down in the US over recent years. In 2020, the total fertility rate (the average number of children women have in their lifetime) dropped to 1.64, the lowest ever recorded. Rates of teen pregnancy have also dropped significantly, more than 75% over the past three decades. While women having access to contraceptives to be able to plan when and if they want to have children is obviously a positive, having children younger is actually linked to a lower risk of breast cancer.
According to the National Cancer Institute, women who have a full-term pregnancy at a young age as well as women who have more children may have a decreased risk of developing breast cancer.
Women who have their first full-term pregnancy before age 20 have about half the risk of developing the disease than women whose first full-term pregnancy occurs after age 30, according to the organization. However, it’s important to note that this risk reduction is limited to hormone receptor-positive breast cancer.
The risk of breast cancer also appears to decline with the number of children a woman has. Women who give birth to five or more children have about half the breast cancer risk of women who have not given birth at all, according to the organization. Breastfeeding for a year or more also appears to be associated with a decreased risk of both hormone receptor-positive and hormone receptor-negative breast cancers.