When the U.S. Preventive Services Task Force (USPSTF) released new recommendations in 2009 calling for less frequent screening mammograms for women under age 50, the news caused quite a ruckus.
Many women’s health organizations, such as Our Bodies Ourselves, National Women’s Health Network and Breast Cancer Action, applauded the new guidelines — and had, in fact, been recommending the same approach for pre-menopausal women for many years. But understanding the science behind the logical, if somewhat counter-intuitive, recommendations requires a nuanced analysis.
Now, a New York Times examination of breast cancer cases explains, in very personal terms, the problems with diagnosing breast cancer — especially early detection methods, which are “prone to both outright error and case-by-case disagreement over whether a cluster of cells is benign or malignant.”
As a result, pathologists are over-diagnosing and doctors are over-treating small growths in the breasts that are often benign.
While the initial reaction might be, “Wait, isn’t it better to treat all potential signs of cancer than leave them untreated?” the NYT does a good job explaining the very real dangers that can result. Moreover, the root problem is that we still don’t have a truly accurate diagnostic tool, and diagnosis can vary depending on one person’s reading of a tiny speck.
As the Times explains, ductal carcinoma in situ, or DCIS (also called Stage 0 or non-invasive cancer) was a rare diagnosis before the 1980s, but today more than 50,000 women per year in the United States alone are told they have DCIS. Typically the abnormal cells in the breast ducts are removed via surgery — which can result in disfiguration of the breast — along with drugs and radiation. DCIS may progress to a more invasive cancer about 30 percent of the time, according to estimates in the Times article, but in some women it can take decades to do so.
Stephanie Saul’s reporting chiefly concerns pathologists, who are responsible for determining whether cells from a biopsy are malignant:
Advances in mammography and other imaging technology over the past 30 years have meant that pathologists must render opinions on ever smaller breast lesions, some the size of a few grains of salt. Discerning the difference between some benign lesions and early stage breast cancer is a particularly challenging area of pathology, according to medical records and interviews with doctors and patients.
Diagnosing D.C.I.S. “is a 30-year history of confusion, differences of opinion and under- and overtreatment,” said Dr. Shahla Masood, the head of pathology at the University of Florida College of Medicine in Jacksonville. “There are studies that show that diagnosing these borderline breast lesions occasionally comes down to the flip of a coin.”
There is an increasing recognition of the problems, and the federal government is now financing a nationwide study of variations in breast pathology, based on concerns that 17 percent of D.C.I.S. cases identified by a commonly used needle biopsy may be misdiagnosed. Despite this, there are no mandated diagnostic standards or requirements that pathologists performing the work have any specialized expertise, meaning that the chances of getting an accurate diagnosis vary from hospital to hospital.
In the face of studies that have shown the high risk of misdiagnosis (in anywhere from 7.8 to 20 percent of cases, depending on the study), the College of American Pathologists is vowing to start a voluntary certification program for pathologists who read breast tissue. But as Saul notes, “Some pathologists have found the response to these types of studies slow and inadequate” — especially since studies going back as far as 2002 have revealed the problem.
The physical and psychological scarring that ensues is, in many cases, unnecessary — along with the potential long-term effects of radiation therapy.
Where you live and what kind of insurance coverage you have can also affect the accuracy of the diagnosis. Rural, community hospitals are more likely to have less experienced pathologists on staff. And insurers have not encouraged second opinions.
“Some insurance plans pay as little as $10 to pathologists who are performing second opinions on DCIS,” Saul notes in response to a comment left by “MK,” who made an excellent point: “If insurers had a requirement that any slides in which cancer was suspected were automatically sent to a board-certified pathologist, it would save patients having to search for a second opinion and save the insurers the cost of unnecessary treatment.”
It should be noted that percentages of misdiagnosis, as Saul reminds “MK,” includes both false negatives and false positives. Under-diagnosis and under-treatment is also an issue. The danger of a positive diagnosis, however, goes beyond whether it is false:
Fear compounds the confusion, and even though D.C.I.S. is 90 percent curable, there is growing concern that women and their doctors opt for more aggressive surgery, radiation and drug therapy than is needed.
A mastectomy is sometimes offered as an option for D.C.I.S., although experts say it is usually not advisable unless the D.C.I.S. is large or appears in several sites in the breast.
Yet more women who are faced with the diagnosis of D.C.I.S. become so fearful that they elect to have both breasts removed, often against their doctor’s recommendations.
“The patient gets paralyzed with a fear of cancer,” Dr. Masood said. “They want the breast off.”
Among women who had surgery for D.C.I.S., the rate of double mastectomy rose to 5 percent in 2005, from 2 percent in 1998, according to a study last year.
Dr. Ira J. Bleiweiss, chief of surgical pathology at Mount Sinai Medical Center in New York, said that ideally, all breast cancer diagnoses would be referred for a second opinion. He warns patients and their doctors: “Don’t rush to the operating room.”
In related news …
New Study Links Breast Cancer Risk, Household Products: Speaking of caution and prevention, a new study in Environmental Health found a higher breast cancer risk among women with higher use of household cleaning products.
The study by Silent Spring Institute was based on telephone interviews with 787 women diagnosed with breast cancer and 721 comparison women. Many of the products contain endocrine disrupting chemicals or mammary gland carcinogens, making them suspect as contributors.
There are, of course, limitations inherent to this type of study, including the potential for recall bias. Researchers recommend further study.
Julia Brody, executive director of the Silent Spring Institute, said, “When women are diagnosed with breast cancer, they often think about what happened in the past that might have contributed to the disease. As a result, it may be that women with breast cancer more accurately recall their past product use or even over-estimate it. Or, it could also be that experience with breast cancer influences beliefs about its causes. For example, women diagnosed with breast cancer are less likely to believe heredity contributes ‘a lot’, because most are the first in their family to get the disease.”
Plus: Interested in taking action — personally and politically? The Silent Spring Institute offers a number of action kits full of helpful information, including how to reduce risks in your home.
Recommendation to Revoke Avastin: An FDA advisory committee has recommended revoking approval of the drug Avastin, for which the FDA had given conditional approval in 2008 to treat breast cancer (part of an accelerated process for drugs that treat life-threatening diseases but have less than complete evidence of effectiveness).
If the FDA, which usually follows these recommendations, takes the very unusual step of revoking approval of a drug, Avastin will still be available, since it is approved for a variety of other cancers. This would leave it open to “off-label” use for breast cancer, but insurers would be reluctant to pay for it and it would no longer be part of a program that caps its annual cost to patients.
Breast Cancer Action program manager Kimberly Irish responds to the decision: “We agree with the committee’s recommendation, and we’re saddened that after all this time there’s still no good option to offer patients when current treatments have failed.” Read the written comments BCA sent to the committee here (PDF).