The revised breast screening recommendations by the US Preventive Services Task Force (USPSTF) advise that women should be screened for breast cancer from age 40 and in alternate years until the age of 74. This article discusses the potential drawbacks of screening women for breast cancer at 40.

The US Preventive Services Task Force (USPSTF) has revised breast cancer screening guidelines to recommend women begin breast cancer screening from age 40.[1]

The recommendations advise that women be screened for breast cancer in alternate years until the age of 74.

“More women in their 40s have been getting breast cancer, with rates increasing about 2 per cent each year, so this recommendation will make a big difference for people across the country,” Dr Wanda Nicholson, Chair of the Task Force, said in a press statement.

“By starting to screen all women at age 40, we can save nearly 20 per cent more lives from breast cancer overall. This new approach has even greater potential benefit for women, who are much more likely to die of breast cancer.”

Breast cancer is the second most common cancer in women in the United States, second only to some kinds of skin cancer.[2] Overall, 13 per cent of the female population in the US will develop breast cancer in their lifetime.[3] That’s one in eight women. African women are 40% more likely to die from breast cancer, and they often get breast cancer at a younger age.[3]

For this reason, the Task Force says screening from age 40 is important for this group. But they note this is only the beginning of addressing the inequity between rates of breast cancer and breast cancer–related deaths in women of different ethnicities.

“We need to know how best to address the health disparities related to breast cancer so all women can live longer and healthier lives,” 

-Dr. John Wong, Task Force vice chair.

“Clinicians must help reduce any barriers to patients getting the recommended screening, timely, equitable, and appropriate follow-up, and effective treatment of breast cancer,” he added.

Previously, the USPSTF recommendations allowed women aged between 40 and 50 to make their own decisions regarding screening, guided by their health history and their individual preferences.

However, experts say lowering the age to begin screening is a good decision.

“We know that regular screening leads to diagnosis at an earlier stage and that this is associated with better survival. I am thrilled that younger women now have recommended access to earlier screening,” said Dr Daphne Stewart, breast oncologist with USC Norris Comprehensive Cancer Center.

“Just 9% of newly diagnosed breast cancer patients are 45 years or younger,” she said. “However,” she explained,  “younger women tend to present with more aggressive breast cancer and are at higher risk for developing recurrence. The incidence of breast cancer in women 40-49 has gradually increased every year since 2000.”

Potential drawbacks

The new recommendations from the Task Force apply to women with an average risk of breast cancer, those with a family history of breast cancer, and those with dense breasts.[4]

“If you think about dense breasts,” she said, “at least in the United States, about 40% of women are classified as having dense breasts. So they're almost half the population. Dense breasts do make the mammogram not work as well. Also, we know that having dense breasts is a risk factor for getting breast cancer. So we need new research to help us know what we should do for women with dense breasts.”

She cautioned, though, that “With the state of the science right now, we couldn't recommend specific increased testing frequency or use of other tests for those women.”

One possible downside of screening earlier, experts say, is the risk of false positives. Dr Stewart addressed this.

“The most commonly reported harm to screening women 40-49 is a higher rate of false-positive findings compared to women 50-74. This means a more common abnormal result on screening mammograms that requires additional testing with ultrasound or MRI and potential biopsy, that does not lead to benefit. The additional evaluation of a false-positive result means the cancer is excluded, but this leads to more frequent follow-up and causes a great deal of anxiety that can lead to a lack of trust in the screening process,” Dr Stewart said.

 Although the guidelines recommend screening every second year, not all experts agree. Dr Steward is one of them, as she explained:

“I believe that data show regular, scheduled screening improves survival, and I prefer annual screening. I find that a gap in screening actually leads to less compliance, and screening is often spaced out because patients are not consistently being evaluated,” she said.

Both experts note that there is no modern trial that compares the benefits of screening annually vs every second year. However, they agree that beginning screening at age 40 is important.

 As Dr. Mangione said, “Starting at 40 is going to save lives. We know from the current science that we looked at that starting at 40, instead of 50, could potentially save as many as one out of five women who were diagnosed with breast cancer. So this is a huge benefit. And we hope that our clinical practice community embraces this and encourages women to start at that age.” 

Disclaimer: This story is contributed by  Elizabeth Pratt and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.