Breast Cancer Screening Guidelines Changing again

Furore in the colleges and societies, as the US preventive services task force releases it's new breast cancer screening guidelines, following the release of a paper in the Annals of Internal Medicine today

Their recommendations for starting screening at 50 (for women without a family history of breast cancer) with mammograms every 2 years, and ending at 74 years, more closely mimics the recommendations for screening in European countries, and broadly similar to the UK NHSBSP.

The task force is an independent panel of experts in prevention and primary care appointed by the federal Department of Health and Human Services.

The guidelines were published in today's (Nov 16, 2009) edition of the Annals of Internal Medicine

In order to formulate its guidelines, the task force used new data from mammography studies in England and Sweden and also commissioned six groups to make statistical models to analyze the aggregate data. The models were the only way to answer questions like how much extra benefit do women get if they are screened every year

Dr. Karla Kerlikowske, a professor in the department of medicine, epidemiology and biostatistics at the University of California, San Francisco said "The message for most women is to forgo routine mammograms if they are in their 40s.

Starting at age 50, Dr. Kerlikowske said, “the message is to get 10 mammograms in a lifetime, one every two years.” That way they get the most benefit and the least harm from the test. If women are healthy, she added, they might consider having mammograms every two years until age 74.

Nearly two-thirds of all women in their 40s had mammograms within the last two years, as did 72 percent of women age 50 to 65, according to an editorial by Dr. Kerlikowske that accompanies the report.

The Society of Breast Imaging and the American College of Radiology, the American Cancer Society, and many other respected professional organizations, have voiced strong opposition to the changes proposed in the articles.

It is the opinion of the SBI leadership that adopting these guidelines would result in a major step backward in women's healthcare and increased deaths from breast cancer.

Immediately, they provided a number of guidance documents and statements as follows (which is a model for speedy response to crises) -


STATEMENT FROM THE AMERICAN COLLEGE OF RADIOLOGY AND THE SOCIETY OF BREAST IMAGING:
USPSTF Mammography Recommendations Will Result in Unnecessary Breast Cancer Deaths Each Year

Talking Points in response to USPSTF Statement

Detailed ACR Statement on Ill Advised and Dangerous USPSTF Mammography Recommendations: Mammography Screening References

American Cancer Society Statement

Komen Screening Statement 11-16-09

NCI Statement

Rethinking strategies for breast and prostate cancer screening

Twenty years of screening for breast and prostate cancer—the most diagnosed cancers for women and men—have not brought the anticipated decline in deaths from these diseases, argue experts in an opinion piece published Wednesday in the Journal of the American Medical Association

In an article published yesterday (Oct 21, 2009) in JAMA, Laura Esserman et al, one of our UCSF breast surgeons, and leader of the ATHENA project in the University of California, discuss whether we should be reconsidering looking at our screening tools for both breast and prostate cancer, and be more intelligent in their use.


"Screening does provide some benefit, but the problem is that the benefit is not nearly as much as we hoped and comes at the cost of over-diagnosis and over-treatment," said Laura Esserman, MD, professor of surgery and radiology, director of the University of California, San Francisco (UCSF) Carol Franc Buck Breast Care Center.

We acknowledge that screening is not perfect, as there are a proportion of women who are screened but would never die of the disease (lead time bias). Also there are the group of women who present as interval cancers due to their very different biology. These women still get their mammograms at the proscribed times, but tend to develop cancer between their screening tests.

"We need to focus on developing new tools to identify men and women at risk for the most aggressive cancers, to identify at the time of diagnosis those who have indolent or 'idle' tumors that are not life-threatening,"

Periodic screening may find some tumors early, but patients may not be screened often enough for lethal tumors to be detected in time to prevent death, leading the authors to conclude: "Without the ability to distinguish cancers that pose minimal risk from those posing substantial risk and with highly sensitive screening tests, there is an increased risk that the population will be over-treated."

The authors suggested that to improve screening, "a new focus is recommended for research and care to identify markers that discriminate minimal-risk from high-risk disease (and) identify less aggressive interventions for minimal-risk disease to reduce treatment burden for patients and society."

The authors made the following recommendations for early cancer detection and prevention:

• Develop tests to distinguish between low-risk and lethal cancers.
• Reduce treatment for low-risk disease. “Diagnosing cancers that don't kill the patient has led to treatment that may do more harm than good,” they wrote.
• Develop tools for physicians and patients to help them make informed decisions about prevention, screening, biopsy and treatment.
• Offer treatments individually tailored to a patient's tumor.
• Work to identify the people at highest risk for cancer and use proven preventive interventions.

As part of the ATHENA project we are looking at these aspects across the whole of the University of California medical centers (UCSF, UCLA, UC Irvine, UC Davis and UC San Diego).
This is a mix of researcher and clinicians who are trying to put research to clinical use (bench to bedside medicine)

Targeting screening tests to the at risk population may give better outcomes with fewer so called "false positives" from screening, thereby benefiting the screened women the most. It will also save us from overtreating some of the lower risk/indolent cancers that occur.

NCI commentary is available in their bulletin

CAD and Screening Mammography: ready for prime time?

In this months RADIOLOGY, Robyn Birdwell and Liane Philpotts share their different viewpoints on CAD and screening mammography. Both are well known mammographers in the North East, with Robyn being a guest of the RCR Breast Group at November's Annual Scientific Meeting

In the first of the two articles, Robyn Birdwell talks about the various CAD studies, and how the proponderance of data supports the use of CAD in screening mammography, and that "Having a system to aid the human eye that does nottake vacations, is not vulnerable to fatigue or environmental distractions, is without, emotion, and is designed specifically to assist the very human eye to "look over here" seems like a good idea"
The Preponderance of Evidence Supports Computer-aided Detection for Screening Mammography
Robyn L. Birdwell
Radiology 2009;253 9-16
http://radiology.rsna.org/cgi/content/full/253/1/9?etoc

In the second editorial article, Liane Philpotts points out that recalling patients from screening is sometimes more of an art than a science, and I am sure that many experienced radiologists would share her view.

One of the main issues with CAD is the necessary high false-positive rate of CAD prompts which subsequently means that the specificity is low, and we have the distracting factor of many false calls, while also knowing that not all cancers are picked up by CAD

Understanding of the limitations of computer-aided detection is important for those interpreting mammograms; this cautious approach to the use of computer-aided detection should help optimize this presently imperfect system and minimize the possible detrimental effects

Can Computer-aided Detection Be Detrimental to Mammographic Interpretation?
Liane E. Philpotts
Radiology 2009;253 17-22
http://radiology.rsna.org/cgi/content/full/253/1/17?etoc

Informing patients about breast cancer screening - risks of overdiagnosis

A recent posting on the NHS National Prescribing Centre website blog addresses the issues of possible overdiagnosis of inconsequential cancers found as part of routine screening.

Blog link here

It is estimated that approximately 30% of breast cancers found at screening are of low grade and metastatic potential (low oncotype score) which may never kill the patient, and are therefore counted as being overdiagnosis.

Various tools are available to help primary care providers and others wishing to assist women to make informed decisions about whether to have screening or not.

Patient decision aids may help to guide women make the decision alongside the literature from the NHSBSP

Do some screen-detected breast cancers spontaneously regress?

An article in this weeks Archives of Internal Medicine from the Norwegian Screening Programme, discuss how there is an excess of cancers in the screened population, and how some of these regress spontaneously

Arch Intern Med. 2008;168(21):2311-2316

it appears that some breast cancers detected by repeated mammographic screening would not persist to be detectable by a single mammogram at the end of 6 years. This raises the possibility that the natural course of some screen-detected invasive breast cancers is to spontaneously regress

Mammography screening of the elderly - controversies

Last month a paper was published in the Journal of Clinical Oncology entitled - Mammography Before Diagnosis Among Women Age 80 Years and Older With Breast Cancer from MD Anderson Cancer Center in Texas.

The study found that among those who had a mammogram every year or two before their diagnosis, 68 percent found the cancer at an early stage, compared with 33 percent of those who skipped mammograms altogether.

Their conclusion was that regular mammography among women > or = to 80 years of age was associated with earlier disease stage, although improved survival remains difficult to demonstrate. Health care providers should consider discussing the potential benefits of screening mammography with their older patients, particularly for those without significant comorbidity.

This sparked coverage by the New York Times, which did a good job of presenting the pros and cons of screening the elderly. Considering that the end point for measuring a screening program is mortality reduction, then it should be looked at in a proper light rather than just concentrating on reducing morbidity from the disease.

We have the occasional patient in San Francisco having screening mammograms in their eighties, similar to the NHS BSP in the UK, where patients can self refer. With the rising elderly population, and better breast-awareness, it may well be that we do more mammography in the elderly and reduce morbidity than we do for now.