Several large studies, including a review by the U.S. Preventive Services Task Force in 2009 and a study on the causes of death in the United Kingdom in 2013, have questioned the value of screening mammograms.
Doctors who question the value of mammograms say that while mammograms do save lives, for each breast cancer death prevented, three to four women are overdiagnosed. Overdiagnosis means either:
- a screening mammogram finds a suspicious area that would have been eventually diagnosed as cancer by other means, without any effect on prognosis
- a screening mammogram finds a suspicious area that never would have affected a woman’s health if it hadn’t been found or treated
False positive results from screening mammograms also have helped fuel the debate about the value of breast cancer screening. When a mammogram shows an abnormal area that looks like a cancer but turns out to be normal, it’s called a false positive. Ultimately the news is good: no breast cancer. But the suspicious area usually requires follow-up with more than one doctor, extra tests, and extra procedures, including a possible biopsy. There are psychological, physical, and economic costs that come with a false positive.
These studies and the resulting stories in the media have fueled an ongoing debate about the value of screening mammograms.
Since that time, the American Medical Association, the American Congress of Obstetricians and Gynecologists, the American College of Radiology, the National Cancer Institute, and the National Comprehensive Cancer Network all have issued guidelines saying that all women should be eligible for annual screening mammograms starting at age 40. In 2015, the American Cancer Society recommended that annual screening mammograms start at age 45 and then change to having mammograms every 2 years starting at age 55.
A small study suggests that women prefer to have mammograms every year instead of every 2 years because the benefits of annual screening outweigh any potential risks.
The study was presented on Nov. 27, 2017 at the Radiological Society of North American annual meeting. Read the abstract of “Biennial versus Annual Screening Mammography: What Do Women Prefer?” (PDF)
"Women understand that yearly mammograms have been shown to save lives and do not consider previously reported 'harms' to be as important as getting screened," said study author Ghizlane Bouzghar, M.D., chief radiology resident at Einstein Medical Center in Philadelphia.
For the study, the researchers surveyed 731 women with an average age of 59 who were having both screening and diagnostic mammograms at Einstein Medical Center from December 2016 to February 2017.
The women were asked a number of questions about mammogram screening, including:
- Does an abnormal mammogram or breast biopsy cause emotional harm?
- Is screening every 2 years associated with more or less anxiety?
- Do you prefer to have a screening mammogram every other year or every year?
The researchers also recorded the women’s:
- family and personal history of breast cancer
- any previous breast biopsies
- any previous abnormal mammograms
- any underlying anxiety disorders
The results showed that 71% of the women preferred having a mammogram every year.
"Only 17% of the participants felt having biennial screening would cause less anxiety," the researchers said. "Of the patients who reported a previous abnormal mammogram, 13% believe biennial screening would cause less anxiety."
"Many women are much better educated about the value of screening mammography than they are given credit for," Bouzghar said. "I also think that some of the U.S. Preventive Services Task Force's concerns about the 'harms' were somewhat paternalistic, and in 2017 women are more empowered about many things, including their healthcare."
At Breastcancer.org, we believe that a woman’s best chance for early detection requires coordination of our current screening tools:
- high-quality mammography
- clinical breast exam
- breast self-exam
To not use all three tools are missed opportunities for early detection.
The reality is that every woman is at risk for breast cancer, and this risk tends to increase over time. It’s important to understand and regularly update your health information related to breast cancer risk throughout your life with your doctor. To get the conversation started, here are some points to talk to your doctor about:
- family history of breast or other related cancers (ovarian, melanoma)
- any test results for abnormal genes linked to a high risk of breast cancer
- results of past breast biopsies, even if they were benign
- personal history of being treated with radiation to the face and/or chest before age 30
- breast density
- weight, if you’re overweight or obese
- level of physical activity
- any use of postmenopausal combined hormone replacement therapy (HRT)
- alcohol consumption, if you regularly drink more than 3 alcoholic beverages per week
- the amount of processed food and trans fats you eat
- your smoking history
- whether or not you had a full-term pregnancy or breastfed
Breastcancer.org stands by its recommendation that all women have mammograms annually starting at age 40. We also believe that monthly breast self-exam and annual physical exams by a doctor are essential parts of an overall breast cancer screening strategy. If you’re at high risk for breast cancer, you should talk to your doctor about starting annual mammograms at a younger age and consider other screening tools (such as MRI or ultrasound) to maximize the opportunity for early detection.
For more information on mammograms, including where to get one and the benefits and risks, visit the Breastcancer.org Mammograms page.