Over-diagnosis of Breast Cancer - Cancer Compass an Alternate Route

Mammograms may be doing more harm than good.

Researchers from Harvard and Dartmouth stated after analyzing cancer registry data from 16 million women in 547 counties across the United States, “no evident correlation between the extent of screening and 10-year breast cancer mortality.” The researchers concluded that mammograms primarily find small, typically harmless, or non-lethal tumors, leading to widespread over diagnosis. [Harding C, Pompei F, Burmistrov D et al.

Previous estimates relating to the problem of over-diagnosis of breast cancer are varied, but a recent study published in the Oct.18 issue of the Annals of Internal Medicine found that more than half of the women who started receiving annual mammograms in their forties can expect to have a false-positive reading. A false-positive reading involves being called back for additional mammograms or to have some other diagnostic procedure; and of the women who are called back, about 7 percent will be advised to undergo a biopsy of the breast that turns out to be negative, meaning no cancer was present.

It should be noted that this study did not include women with DCIS, (ductal carcinoma in situ), which is the most commonly found breast anomaly that remains confined to the milk ducts. Additionally, many doctors feel that DCIS should not be categorized as a “cancer” at all, yet conventional treatment models recommend that the patient receive a lumpectomy, followed by radiation and hormone suppression therapies such as Tamoxifen or Arimidex in order to treat it.

The study also found that for every 2,500 women offered screening, one death from breast cancer will be prevented, but six to 10 women will be over-diagnosed and over-treated. Study leader Dr. Mette Kalager, and other knowledgeable experts say that women need to be better informed about the possibility that a mammogram will pick up cancers that would never be life-threatening when they consider having this type of screening. The problem is that doctors don’t have a good way of knowing which tumors will be dangerous.

Donald A. Berry, chairman of the department of bio-statistics at M. D. Anderson Cancer Center in Houston, said the study increased his worries about the use of highly sensitive screenings tools that continue to find cancers earlier and earlier. Unless there is some understanding of the natural history of the cancers that are found — as in which are dangerous and which are not — the result will be more treatment for cancers that would not cause harm if they were left untreated. He stated. “There may be some benefit to very early detection, but the costs will be huge — and I don’t mean monetary costs. It’s possible that we all have cells that are cancerous and that grow a bit before being dumped by the body. ‘Hell bent for leather’ early detection research will lead to finding some of them. What will be the consequence? Prophylactic removal of organs in the masses? It’s really scary.”

“Once you’ve decided to undergo mammography screening, you also have to deal with the consequences that you might be over-diagnosed,” said Dr Kalager, a breast surgeon at Norway’s Telemark Hospital and a visiting scientist at Harvard School of Public Health. “By then, I think, it’s too late. You have to get treated.” The problem of over-diagnosis has been long recognized with prostate cancer as well. “The truth is that we’ve exaggerated the benefits of screening and we’ve ignored the harms,” he said. “I think we’re headed to a place where we realize we need to give women a more balanced message: Mammography helps some people, but it leads others to be treated unnecessarily.”

“The issue is the unintended consequences that can come with our screening,” says Dr. Suzanne W. Fletcher, an emerita professor of ambulatory care and prevention at Harvard Medical School, meaning biopsies for lumps that were not cancers or sometimes treating a cancer that might not have needed any treatment at all. She says, “In general we tend to underplay them.”

In an editorial, Dr. Joann Elmore of the University of Washington School of Medicine and Dr. Suzanne Fletcher of Harvard Medical School, wrote that over-diagnosis probably occurs more often in the U.S. because American women often start having annual screenings at an earlier age and American radiologists are more likely to report suspicious findings than those in Europe. Radiologists could help this situation by raising the threshold for noting these abnormalities. A “watch-and-wait” approach has been suggested instead of an immediate biopsy, but the editorial writers acknowledge that could be a “tough sell” for some women and radiologists alike, this is because most women aren’t aware that there is such a thing as over-diagnosis and over-treatment. “We have an ethical responsibility to alert women to this phenomenon,” they wrote.

In 2009, the U.S. Preventive Services Task Force set off their own controversy when they suggested that the decision to start mammography before the age of 50 should be based upon a variety of factors, including the patient’s risk level. The American Cancer Society and Susan G. Komen foundation continued to recommend annual mammography screening for all women starting at age 40.

When cancer isn’t cancer (Ductal Carcinoma In Situ)

In a new report commissioned by the U.S. National Cancer Institute (NCI), that was published in the Journal of the American Medical Association (JAMA), identified over-diagnosis and misdiagnosis of cancer as two major causes of this growing breast cancer epidemic, which together have led to the needless treatment of millions of otherwise healthy individuals with chemotherapy, radiation or surgery.

The report dropped some major bombshells; such as acknowledging the fact that sometimes breast cancer isn’t really breast cancer at all, but is rather a benign condition known as ductal carcinoma in situ (or DCIS). Untold millions of women with DCIS have been misdiagnosed as having breast cancer, and subsequently received treatment for a condition that most likely never would have caused them any health problems. And similarly, men, are diagnosed with high-grade prostatic intraepithelial neoplasia (HGPIN), which is a type of premalignant precursor to cancer that is commonly mistreated as if it were an actual cancer.

“The practice of oncology in the United States is in need of a host of reforms and initiatives to mitigate the problem of over-diagnosis and over-treatment of cancer, according to a working group sanctioned by the National Cancer Institute,” explains Medscape.com about the study. “Perhaps most dramatically, the group says that a number of pre-malignant conditions, including ductal carcinoma in situ and high-grade prostatic intraepithelial neoplasia, should no longer be called ‘cancer.'”

Radiation exposure- another topic not addressed in the latest research concerns the unique carcinogenicity of having mammography x-rays. Contrary to conventional assurances that radiation exposure from mammography is trivial and similar to having a chest X-ray, or about 1/ 1,000 of a rad (radiation-absorbed dose). The routine practice of taking four films for each breast results is about 1,000-fold greater exposure. One rad, focused specifically on each breast rather than the entire chest, exposes pre-menopausal women to a total of about 10 rads for each breast when screened over a ten year period. Present day radiation risk models that are used to assess the known breast cancer risk associated with mammography against the purported benefits do not take this into account.

BRCA and Radiation exposure- in regards to patients who carry the BRCA1/BRCA2 gene mutations – radiation exposure can interfere with the DNA self-repair mechanisms that are needed to reduce the carcinogenicity that is associated with having mammograms. It is possible that the harms associated with mammography for this specific group may be exponentially higher than the conventional medical community presently understands and is communicating to their patients. It is possible that that x-ray based mammography screenings have been planting the seeds of future radiation-induced breast cancer within these exposed populations.

Biopsy is an imperfect science– a recent study highlights the fact that pathology is an imperfect science. Pathologists correctly diagnosed abnormal, precancerous cells about half the time, no better than a coin toss, said lead author Dr. Joann Elmore, a University of Washington researcher. Treatment for this condition typically includes frequent monitoring and sometimes medication. About a third of these cases were misdiagnosed as not worrisome or normal, while 17 percent were deemed more suspicious or cancer. Since as many as 160,000 U.S. women each year are diagnosed with this condition, the results suggest many may be getting inappropriate treatment, Elmore said. “This should be a call to action for pathologists and breast cancer scientists” to improve and refine definitions of breast tissue abnormalities.

The financial cost of over-treating breast cancer

A new report estimates that the U.S. spends about $4 billion a year on unnecessary medical costs due to mammograms that generate false alarms, and on treatment of certain breast tumors unlikely to cause problems. The study published in the journal Health Affairs breaks the cost down as follows: $2.8 billion resulting from false-positive mammograms and another $1.2 billion attributed to breast cancer over-diagnosis. That’s the treatment of tumors that grow slowly or not at all, and are unlikely to develop into life-threatening disease during a woman’s lifetime. The cost estimates only cover women ages 40-59.

Breast cancer is the second most common cause of death from cancer among American women, claiming nearly 41,000 lives a year. Annual mammograms starting at age 40 have long been considered standard for preventive care, because cancer is easier to treat if detected early. But recently there’s been disagreement about regular screening for women in their 40s. It parallels the medical debate about the pros and cons of prostate cancer screening for men. Study authors Mei-Sing Ong and Kenneth Mandl say their findings indicate that the cost of breast cancer over-treatment appears to be much higher than previously estimated. Their $4 billion figure is the midpoint of a range that depends upon assumptions about the rates of false-positive mammograms and breast cancer over-diagnosis. Read more with this link.