Research Supports Value of Screening Mammograms Starting at 40
Two new studies underscore the value of annual screening mammograms starting at age 40.
In November 2009, the U.S. Preventive Services Task Force (USPSTF) recommended that routine screening mammograms for women with an average risk of breast cancer should start at age 50, instead of age 40. These recommended changes were very controversial and were not adopted. U.S. guidelines call for all women age 40 and older to have screening mammograms every year. While not ideal, some women may choose to have a screening mammogram every other year.
Results from two studies presented at the 2011 Annual Meeting of the American Society of Breast Surgeons strongly support the value of regular mammogram screenings starting at age 40.
The first study found that breast cancers diagnosed in women between the ages of 40 and 49 were at a more advanced stage when they were found by something other than a mammogram (a breast self-exam, for example) compared to cancers found by mammogram.
The second study found that very early-stage breast cancer (DCIS or stage I) diagnosed in women between the ages of 40 and 49 is more likely to be an aggressive type -- HER2-positive or triple-negative -- compared to women 50 and older who were diagnosed with breast cancer.
In the first study, the researchers looked at the medical records of 311 women younger than 50 diagnosed with breast cancer:
- 145 women had breast cancer detected by a mammogram
- 166 women had breast cancer detected another way -- breast self-exam or doctor's exam
The researchers compared the cancers and the outcomes of the cancers detected by mammogram to the cancers not detected by mammogram. Compared to mammographically detected breast cancers, non-mammographically detected breast cancers were:
- 50% larger
- more than twice as likely to have spread to lymph nodes
- nearly 5 times more likely to come back (recur)
Survival also was worse for women with non-mammographically detected breast cancer.
Disease-free survival (being alive with no cancer recurrence) over 5 years was:
- 71% in women with non-mammographically detected breast cancer
- 94% in women with mammographically detected breast cancer
Overall survival (being alive whether or not the cancer comes back) over 5 years was:
- 78% in women with non-mammographically detected breast cancer
- 97% in women with mammographically detected breast cancer
In the second study, the characteristics of breast cancers diagnosed in 46,700 women were analyzed. About 23% (10,566) of the women were between the ages of 40 and 49. The researchers compared the characteristics of cancers diagnosed in the younger women to characteristics of cancers diagnosed in the older women.
Compared to breast cancers diagnosed in the women age 50 and older, breast cancers diagnosed in the younger women were:
- 46% more likely to be HER2-positive
- 67% more likely to be triple-negative
HER2-positive breast cancers make too much of the HER2 protein. The HER2 protein sits on the surface of cancer cells and receives signals that tell the cancer to grow and spread. About 1 out of every 4 breast cancers is HER2-positive.
Triple-negative breast cancer is breast cancer that is estrogen-receptor-negative, progesterone-receptor-negative, and HER2-negative.
Both HER2-positive and triple-negative breast cancers are usually more aggressive, harder to treat, and more likely to come back than cancers that aren't HER2-positive or triple-negative.
Breast cancer also was more likely to be diagnosed younger than 50 in minority racial/ethnic women.
These two studies strongly suggest that breast cancers diagnosed in women between the ages of 40 and 49 will be:
- more aggressive than cancers diagnosed in older women
- more advanced and/or more aggressive when diagnosed if detected by something other than a mammogram
Women between the ages of 40 and 49 could have a worse prognosis after diagnosis if they don't get regular screening mammograms. Other studies have shown that regular screening mammograms starting at age 40 save lives. Despite that evidence and current guidelines, many women between the ages of 40 and 50 don't get regular screening mammograms.
If you're 40 or older and have an average risk of breast cancer, yearly screening mammograms should be part of your healthcare. If your breast cancer risk is higher than average, you may want to talk to your doctor about a more aggressive breast cancer screening plan that makes the most sense for your particular situation.
There's only one of you and you deserve the best care possible. Don't let any obstacles get in the way of regular screening mammograms.
If you're worried about cost, talk to your doctor, a local hospital social worker, or staff members at a mammogram center. Ask about free programs in your area.
If you're having problems scheduling a mammogram, call the National Cancer Institute (800-4-CANCER) or the American College of Radiology (800-227-5463) to find certified mammogram providers near you.
If you find mammograms painful, ask the mammography center staff members how the experience can be as easy and as comfortable as possible for you.
For more information on mammograms and other tests to detect breast cancer, visit the Breastcancer.org Screening and Testing section.
— Last updated on February 22, 2022, 9:53 PM
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