Overdiagnosis of Breast Cancer an ongoing problem in women's healthcare
Dr. Cutler's message on published study challenging mammograms in Archives of Internal Medicine (10/2011)
In a recent Today Show Health segment; "Mammograms plummet among women under 50", Dr. Nancy Snyderman answered questions on the recent studies from the U.S. Preventive Services Task Force (USPSTF) recommending women over 50 get mammograms every two years...
When Dr. Cutler was researching and writing her recent book, Hormones and Your Health, she discussed the 2002 recommendations of the same task force. Although it had commissioned a review that provided actual data which suggested no benefit to yearly mammograms over regular clinical examination by a competent physician the task force incongruously recommended regular mammograms . Dr. Cutler looked at the studies, evaluated the data to include in her 2009 book and concluded the data showed mammograms can do more harm than good compared with competent medical exams.
For that reason...the change this week of their position is welcome, if 10 years overdue, and still generates an incomplete message for women over forty about the risks of mammogram screening.
Dr. Snyderman during the Q&A for Today answered a question about screening at age 40;
"As someone with no family history, if I just turned 40, I might consider waiting until age 50 to get screened. But for women who are anxious, have lumpy breast or large breasts you might want to start screening earlier after considering your options. Just understand that it might not be necessary. Radiation exposure has a cumulative effect and the risk of false- positive results and unnecessary biopsies is not a negligible one."
Below is a relevant excerpt from Dr. Cutler's 2009 book on this topic:
From Chapter 10; Protecting the Breasts...
Does mammography reduce mortality rates? Maybe not.We hear that more breast cancers are occurring, but what this really means is that more breast cancer is being “discovered” when mammograms are used to search for it. Breast cancer screening seems to explain recent increases in breast cancer detection.219 If you’re looking for something (such as cancer) and you look regularly, chances are, you’re more likely to find it.
Does mammography reduce the devastating experiences of developing incurable metastatic breast cancer or having a mastectomy or does it lower mortality rates? The science behind such claims has not proved that it has.
In 2002, the U.S. Preventive Service Task Force commissioned a review of everything published up until that time, in order to update its recommendations. The task force findings were sobering to me:368
Nevertheless, the task force ended up recommending yearly mammograms. But looking at the same data, I come to somewhat different conclusions. In my opinion, the public information is unbalanced and falsely marketed when it suggests that mammographic screening is always good, leads to early detection, and implies that early intervention thereby improves lifespan. This message contradicts the data.869, 870
- There were no randomized, controlled treatment-outcome trials. In other words, no current breast cancer treatment had been proved effective.
- The efficacy of early treatment on reducing death rates has not been established.
- The quality of published data ranged from poor to fair, with numerous flaws limiting any conclusions about mammography’s usefulness.
- Early treatment following either a clinical exam or a mammography was equally effective in reducing the risk ratio of death (by 3 percent) when 50- to 59-year-olds were randomly assigned to either group.
- Breast self-exams increased visits to doctors, but the resulting interventions did not affect the death rates.368
Can a Mammography Hurt You? Yes.
Stress effects. Adverse effects include anxiety, discomfort, loss of work, and increased stress if one is called back for additional tests that reveal no disease. Stress itself is now recognized to generate a cascade of endocrine responses (such as a reduced ability to fight infection) that increase a person’s vulnerability to many diseases, including cancer.846
Radiation exposure. Recent estimates from the U.S. Preventive Services Task Force state that radiation from 10 annual mammograms will cause 8 deaths from breast cancer for every 100,000 women.368 Since 25 deaths per 100,000 women per year occur from breast cancer, 8 fewer would be substantial. Although infrared imaging is painless and has been touted as a useful noninvasive new method of detecting pathology, unfortunately it is not very specific.590 Neither is ultrasound useful as a screening tool.
The “costs” of biopsies. More than one million breast biopsies are performed each year in the United States and 80 percent of these yield a benign outcome.590 Biopsy costs vary from under $1,000 to several thousand dollars. What does the stress “cost” the woman? I think the economic waste is stunning for the individual, and the economic gain is substantial to those who profit from these tests.
The costs of incompetence. Women who choose screening by mammography should select a competent evaluating center.399 In the United States, radiology physicians are required to read only 480 mammograms per year in order to fulfill the Mammography Quality Standards Act. In the United Kingdom, physicians must read more than 5,000 mammograms a year to maintain certification. This tenfold lower certification standard required of U.S. physicians may well explain the excess false positives that U.S. women suffer. Although the open surgical biopsy rate is two to three times higher in the United States than the United Kingdom, the cancer detection rate is similar.722 Lots of unnecessary biopsy procedures may be profitable for some people but not for you; they are bad for your health.
Mammograms are stressful. The WHI analysis reported that 36 percent of Premarin and 28 percent of placebo users had been called back to evaluate “abnormal” mammograms in the first 7 years.741 That is surely stressful. And worse yet is scheduling and then undergoing a biopsy has been recently shown to hurt the immune system for several months afterward.846 This means that a biopsy itself inhibits a part of the cancer-fighting machinery of an intact, healthy woman.
Is There Benefit to Finding Smaller Tumors Earlier?
In Norway, investigators concluded that the increased detection from screening led to a dramatic overdiagnosis, not to an improvement in life circumstance.869, 870 There was some good news about HRT regarding mammograms that show calcifications. Taking hormones did not affect the malignancy rate for women who showed calcifications that were “indeterminate” when diagnosed at a routine screening.466
By 2004, in the Journal of the American Medical Association, Dr. Lisa M. Schwartz commented that finally, there is a growing awareness among physicians that cancer screening is a double-edged sword. If early detection of breast cancer and the resulting treatment fail to lengthen life and harm its quality, is it useful to detect it?684
In California, among the 13-million-member HealthNet HMO, mammograms were reported to detect small tumors at earlier stages than would otherwise be found without frequent mammographic screening. The discovery of smaller tumors, however, did not increase the number of surgeries that conserve breasts, as had been expected from “early detection.”441
In a Swedish study, a slight reduction in the death rate was attributed to earlier treatment.569 The study did not test whether teaching women self-examination would have been just as good. Yet exactly this finding was reported when the Canadian National Breast Cancer screening study compared mammography to self-examination.519
What you should know: The data suggest to me that for reducing the future death rate from breast cancer, having one clinical exam by a competent clinician, followed by regular self-examination, is just as protective as four or five annual mammograms without any self-examination. Some women will prefer a mammogram; others, a self-exam. And there is no radiation in a self-exam.But women should not believe it is unanimously accepted that annual mammograms are required. Discuss this with your physician. Remember, it is effective treatment, not detection, of breast cancer that decreases the death rate.