Brett Parkinson, MD, Medical Director of Intermountain Healthcare’s Intermountain Medical Center Breast Care Center, says there are now as many different screening recommendations as there are professional organizations that advise patients on best practices for the early detection of breast cancer.
There’s a lot of confusion about screening mammography guidelines — which impacts women and their healthcare providers, and which negatively impacts the number of women who get potentially life-saving mammograms.
Dr. Parkinson addressed the opening session of the 2018 Society of Breast Imaging/American College of Radiology’s National Symposium in Las Vegas last month — and dispelled common myths about screening mammography with hard science.
Utah’s mammography rate is low — so it’s important to share scientifically accurate advice. Since Utah ranks as one of the lowest states for screening mammographies in the United States, Dr. Parkinson says it’s urgent to share the American College of Radiology’s message that women of average risk for breast cancer should be screened annually, beginning at age 40.
Since the United States Preventive Services Task Force, or USPSTF, issued a controversial recommendation in 2009 that screening mammography shouldn’t routinely begin until age 50, and should be provided only every other year until age 74, primary care providers have been at a loss as to what to tell their patients about detecting breast cancer at the earliest stage possible.
“Everybody suffers when science is ignored,” says Dr. Parkinson. “At the conference, I presented the science behind our recommendation to begin annual screening at 40 and explained the solid research behind it to bust the myths about screening.”
Breast Cancer Myth #1
The overriding myth, propagated by the USPSTF, is that the harms of screening before the age of 50 and after the age of 74 may outweigh the benefits. “Nonsense,” says Dr. Parkinson. “We know from multiple randomized controlled clinical trials that regular screening saves lives, and that 40 percent of the years of life lost occur in women under age 50.”
Dr. Parkinson points out that the incidence of breast cancer doubles between the ages of 35 and 40, and it increases with every decade of life.
“Age 40 is a good time to start to start screening as approximately 20 percent of breast cancers occur in many women under 50, most of whom are in their 40s,” he says. “Since most major medical organizations no longer recommend self-examination, or even clinical breast examination by a doctor, those cancers will be missed unless a woman is screened.”
In the last 25 years, the death rate from breast cancer has decreased by about 35 percent. That’s largely due to the widespread availability of screening mammography.
“If you take into account the results of more recent studies, which include women who have actually been screened, instead of those just ‘invited’ to be screened, the decrease in death rate approaches 50 percent,” Dr. Parkinson adds.
Breast Cancer Myth #2
Another commonly circulated myth Dr. Parkinson debunked is that 10 to 50 percent of breast cancers are over-diagnosed, which means some tumors may not be lethal if left untreated. Dr. Parkinson is adamant when he says: “There is no documented case of an invasive breast cancer that has regressed without treatment.”
The science behind the over-diagnosis controversy is wrong, since it was based on the faulty premise that the underlying incidence of breast cancer hasn’t changed, which resulted in more diagnoses than would be expected, Dr. Parkinson says. “We have tumor data registry dating back to 1940 that disproves that,” he says.
Breast Cancer Myth #3
Dr. Parkinson says the so-called “harms” of screening aren’t actually harmful, which is another common myth. One of the harms cited by the USPSTF is the false positive mammogram. When a woman is called back from screening for additional tests, it’s not really a false positive examination. Those examinations are interpreted as “incomplete,” not positive, he says.
“A false positive is when a test says a woman has cancer and she doesn’t. When a thousand women are screened, 100 will be called back for additional views and/or an ultrasound. Only 15 of those 1,000 women will undergo biopsy, and five of them will have cancer. The rest will be told everything is okay,” say Dr. Parkinson. “So, to find one cancer from screening, we have to do three biopsies, which isn’t bad.”
When Dr. Parkinson began his practice in 1991, all women with suspicious mammographic abnormalities had to undergo surgery for diagnosis. The diagnosis is now made by needle biopsy, usually performed by a radiologist with imaging guidance. The “harms” have actually decreased, since women who don’t have cancer don’t have to undergo the risks of surgery and general anesthesia, Dr. Parkinson says.
Breast Cancer Myth #4
Another concern cited by the USPSTF, and a common myth, is that the anxiety that a woman experiences when being called back for an abnormal screening mammogram should override the benefit of screening mammography.
Dr. Parkinson says studies have shown that an overwhelming majority of the women would gladly endure of a few days of anxiety — the time between the screening mammogram and the problem-solving diagnostic follow-up — in order to find an early breast cancer.
He thinks the idea that women can’t handle such anxiety is sexist. “You never hear scientists talking about men not being able to cope with equivocal or false positive results of prostate screening,” he says.
Breast Cancer Myth #5
Dr. Parkinson says he still talks to women who choose not to be screened because of the myth that screening may cause breast cancer. “The risk of dying from breast cancer, which is very real since one in eight women will develop the disease, dwarfs the theoretical risk that the small radiation dose from a mammogram will induce malignancy,” he says. The real risk is about the same as taking a round-trip flight to Paris, he adds.
Breast Cancer Myth #6
He’s also concerned that some women won’t be screened because they have dense breast tissue, and think mammography is ineffective in dense breast tissue. “Not true,” he says. “Although screening is less sensitive in dense tissue, it still picks up most breast cancers, and now that we have 3-D mammography, we can find even more cancers in women with dense and very dense tissue.”
Breast Cancer Myth #7
Dr. Parkinson says the myth that screening isn’t cost-effective is simply not true. “What isn’t cost-effective is finding a late-stage breast cancer, one that will be expensive to treat. You can find five early breast cancers for the same price as treating a late-stage cancer, so you do the math,” he says.
Breast Cancer Myth #8
The final myth he addressed at the national conference is that it’s okay to screen women every other year instead of annually. The American Cancer Society’s position paper on mammography screening, which was published in JAMA in October 2015, says mortality increases by 20 percent when mammographies are provided every other year instead of every year, he says.
Dr. Parkinson says there’s some irony in his use of the word “myth” in a scientific talk. However, in this day and age when science is being challenged by unfounded claims, myth-busting is a useful skill he intends to use for the sake of his patients.
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