A breast imaging specialist discusses breast cancer screening
If the pink ribbons on your co-workers' lapels don't jog your memory, perhaps the pink lights illuminating the Chicago skyline will.
That's right: October is National Breast Cancer Awareness Month. And while we all appreciate a reminder to show our support to those affected by breast cancer, the real measure of the campaign's success is action: getting women to schedule and undergo mammograms.
But unfortunately, due to mixed signals from the government and various health care groups, scheduling a mammogram can be fraught with uncertainty and confusion. To help demystify and clarify issues surrounding mammograms and breast health, we talked to Peter Jokich, MD, director of the Rush Breast Imaging Center.
The best detection
The gold standard for detecting small, early-stage breast cancers is still mammography, according to Jokich.
"Of the breast cancers that occur each year in the U.S., approximately 75 percent will be invasive, potentially fatal, cancers," he says. "Until we can develop a screening blood test or assay that is sensitive for tiny or early breast cancers, screening breast imaging — mammography — is the best means of very early detection.
Research supports Jokich's assertion. Evidence from clinical trials over the last several decades has shown that screening mammograms — X-rays of the breast in women who have no symptoms of breast cancer — decrease mortality from breast cancer around 30 percent.
And a 2012 published case-control study from western Australia and a separate analysis of 10 other case-control studies show that women who undergo screening mammograms on a regular basis can expect a nearly 50 percent reduction of mortality from breast cancer. So, according to that study, mammography cuts the chances of dying from breast cancer in half.
Ultrasound: better than mammogram?
"The use of ultrasounds to screen for breast cancer is a hot topic among my medical peers," Jokich says.
Screening ultrasound has been suggested for use in women with denser breast tissue, which potentially puts them at greater risk for developing cancer and also makes it harder to find the cancer; the density — or areas of whiteness on the mammogram — obscures the cancer, which also usually appears as a white area on the image.
But while ultrasound may be more adept at catching cancers in dense tissue, not to mention less expensive, the health care community currently doesn't have the trained personnel and standardized practice guidelines and protocols in place to enable ultrasound to replace mammograms. There's also the problem of ultrasound producing too many false-positive findings (that is, findings that turn out not to be cancerous).
For that reason, most breast imaging experts do not recommend screening ultrasounds for women with dense breast tissue at this time (based on the risk-benefit analysis of multiple studies, including the large ACRIN 666 trial).
"It does seem like something that could happen down the line," Jokich explains. "We need to figure out how to reduce the number of false positives first."
Breast MRI vs. mammography
Breast MRIs are even more sensitive than breast ultrasounds, meaning they can detect even more breast cancers, even in the 2 to 3 milllimeter size range.
The problem? They also find multiple spots that turn out not be cancerous, possibly even more than ultrasounds, producing more false-positive results.
MRI is also more expensive and requires an IV; the exam lasts about an hour. So, screening breast MRIs probably aren't going to be for everyone.
"Currently at Rush, we use this technology in combination with mammography on patients with the BRCA gene mutations, which puts them at a significantly increased risk of developing breast cancer in their lifetime," Jokich says.
Why MRI for this group? Because women with BRCA mutations are about five times more likely to develop breast cancer than women who don’t have BRCA mutations, spots detected at MRI are more likely to be cancerous (as opposed to false alarms).
"While the screening test can be onerous," Jokich says, "it could truly be lifesaving for this high-risk group of patients."
Controversy on when to start screening
In 2009, the U.S. Preventive Services Task Force (USPSTF) revised its guidelines, recommending that women at average risk of developing cancer undergo screening mammograms every two years beginning at age 50.
These guidelines were very controversial, and came under attack from multiple fronts. In fact, the government quickly backed away from these recommendations.
Yet when the task force announced its 2015-16 recommendations for breast cancer screening, it reiterated its 2009 recommendations for fewer mammograms. The task force calls for biennial screening for women 50 to 74, and for women in their 40s to make "informed, individualized" decisions based on their "value, preferences and health history."
"Unfortunately, the task force recommendations are putting the risks of anxiety due to false positive mammography results and the risk of over-treatment above the benefits of potentially finding a small cancer," Jokich says. "Adding to this problem, the task force is basing its recommendations on old randomized controlled trials using oudated technology (film/screen or analog mammography as used in the 1970s and 1980s)."
There has never been a randomized controlled trial using modern digital mammography as practiced in the U.S., according to Jokich. But he believes that if such a study were conducted, it would show convincingly that mammography saves lives.
So when should women start?
Jokich cites these reasons why women should start having annual mammograms at age 40:
- Ninety-five percent of breast cancers occur after the age of 40 — not 50.
- Breast cancer among women in their 40s tends to be more aggressive and faster-growing than in older women, because premenopausal women still have circulating estrogen, which can fuel breast cancer. It's therefore important to catch these cases early.
"We know from our own practice here at Rush how often cancers are detected in women in their 40s," he says. "So it just doesn't make sense to wait until 50."
Once you start, don't stop
Jokich also recomends that women continue annual mammography well into old age, as long as screening is not burdensome due to other health issues.
Limiting screenings to every other year puts older women at risk for more advanced, and harder-to-treat, breast cancers. While these types are the minority, and breast cancer typically developes at a slower pace in older women, two years is too much time to allow such cancers to go undetected for women unlucky enough to develop them.
"If you are in relatively good health and have reason to believe you will live another five to 10 years, keep going for annual screenings even in your 70s and 80s," Jokich says.
For the time being, the U.S. Congress has halted implementation of the task force's recommendations so the issues they raise can be debated and clarified. Therefore, insurance companies, Medicare and Medicaid will be obligated to continue covering screening mammography at the same level, removing a potential financial obstacle for women to receive annual screenings.
And many preventive services for women are covered by the Affordable Care Act, including mammography screenings.
If you have a health insurance plan or insurance policy beginning on or after Sept. 23, 2010, breast cancer mammography screenings every one to two years must be covered without your having to pay a copayment or co-insurance or meet your deductible. This applies only when these services are delivered by a network provider.
"If you have private insurance, I would advise checking with your provider to see exactly how often screening mammograms are covered," Jokich advises. "Yearly mammograms are also covered by Medicare if you are a member who is 40 years of age or older."
If you aren't insured, some states and local health programs — as well as some employers — provide free or low-cost mammography screenings. The National Breast and Cervical Cancer Early Detection Program, for example, provides such screenings.
Barriers to screening
Lack of insurance, inconvenient hours and locations of mammography facilities all keep women from getting mammograms.
But that's not the whole story. "Women with no symptoms or family history often don't see the need to get screened on a regular basis and many worry about radiation exposure," Jokich says.
The truth is that 75 percent of women who develop breast cancer have no significant risk factors for breast cancer or family history. That, Jokich says, is something to consider for women in their 40s who are being told to make their own decisions about whether to undergo mammography — as the task force recommends.
As for the fear of radiation exposure during mammography, the dose is very low. The benefits of detecting breast cancer early far outweigh the risks of developing cancer as a result of radiation exposure (potentially up to four cases per 1,000,000 women).
Addressing racial disparity
"There are certainly racial gaps when it comes to breast cancer," Jokich says.
For example, while white women are more likely to get breast cancer, black women are more likely to die from it, with many black women first receiving medical attention during the later, more advanced stages of disease when it’s more difficult to treat.
In this study co-authored by David Ansell, MD, MPH, chief medical officer at Rush, investigators found that regular mammographic screening can contribute to the narrowing of differences among black and white women when it comes to when, or during what stage, they get medical attention for breast cancer.
These findings support the idea that more black women die from breast cancer than white women because of irregular screenings or the quality of the mammogram as opposed to the nature of the cancer itself.
"By promoting access to routine and regular high-quality mammography screening, the health care community, government, insurance companies, private organizations, etc., can help ensure women get treatment for breast cancer in its earlier stages," Jokich says. "And that could make all the difference.