New Breast Cancer Screening Guidelines 2009

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By Linda Shiue

This week, the United States Preventive Services Task Force (USPSTF) issued new guidelines for breast cancer screening.  These guidelines reverse some of the previous recommendations that were issued 7 years ago.  The earlier recommendations recommended mammography starting at age 40, every 1-2 years.

The new guidelines recommend for the average risk woman:

1. 1.  biennial (every 2 year) mammograms for women ages 50-74
2. 2.  standard film mammography, with no added benefit from either digital mammography or MRI

They recommend against

1. 1.  routine mammography in women ages 40-49
2. 2.  annual mammography
3. 3.  breast self examination (BSE)

The USPSTF is an independent panel of experts in preventive medicine and primary care, appointed by the federal Department of Health and Human Services.  The Task Force issues guidelines on preventive health care based upon a rigorous review of scientific evidence.  The new breast cancer screening guidelines were based upon the available scientific evidence and new statistical analyses and modeling.

What does this mean for you?

If you are like many women, you may rejoice at the opportunity to dodge your annual mammogram until age 50, as many women find this to be an uncomfortable test.  You may also not have to feel defensive about not doing a monthly breast self-examination.  But what should you make of the new recommendations? How do they apply to you?

What is breast cancer screening and why do we do it?

Breast cancer is the most common cancer in women and the second leading cause of death from cancer.  According to the CDC, in 2005 (the most recent year for which data is available) there were more than 186,000 women diagnosed with breast cancer in the US, and more than 41,000 US women died of breast cancer.

Screening refers to testing for a disease in people without any symptoms.

With any screening test, we can have both false positive (looks abnormal but is not) and false negative results (looks reassuringly normal but misses actual disease).

Breast cancer screening is designed to detect breast cancer at its earliest stages, to increase the chances of cure.  Early detection can save lives.

Breast cancer screening has traditionally been talked about as the triad of

1. 1.  Breast Self Exam (BSE)
2. 2.  Clinical Breast Exam (CBE) by your doctor
3. 3.  Mammography

Screening sounds good.  Why shouldn't we do it?

The new guidelines still recommend screening, just less of it.  There were several reasons for this, but the bottom line is that the committee felt that for many women, the harms outweigh the benefits. According to the Task Force's analyses, one breast cancer death is prevented for every 1,904 women age 40 to 49 who are screened for 10 years, compared with one death for every 1,339 women age 50 to 74, and one death for every 377 women age 60 to 69.  The benefit of screening, preventing deaths from breast cancer, was compared to the following potential harms:

1. 1.  BSE- several studies demonstrated no benefit from teaching women to examine their own breasts for lumps each month. Potential harms were felt to include "false-positive results, which lead to anxiety, unnecessary visits, imaging, and biopsies."
2. 2.  CBE- the Task Force states that there is "insufficient evidence" to recommend for or against going to your doctor for your annual breast exam.  The potential harms would be the same as with the BSE.
3. 3.  Mammography- these x-rays of the breasts may be uncomfortable for women, and also involve exposure to radiation.  These were not the primary reasons cited by the USPSTF in narrowing the group of women for whom they recommend screening mammography.  The main reason is the fairly high incidence of false-positive results, which can lead to overtreatment.  The mammogram is a picture, after all, and often things which look worrisome on this picture will end up being benign or insignificant after a biopsy is done.  In fact, up to 80% of breast biopsies done following an abnormal mammogram end up being benign.  While getting good news after a breast biopsy is a relief, this comes at the price of potential complications of the surgical procedure, unnecessary worry from when the woman is alerted of a potential abnormality on her mammogram, to when the biopsy is done, to receiving the results.

In summary, the USPSTF states: "A biennial schedule preserves most of the benefit of annual screening and cuts the harms nearly in half. A longer interval may reduce the benefit."

Who should still get annual mammograms, and before age 50?

The USPSTF considers this to be a very small group of women who are felt to be at very high risk for developing breast cancer:

1. 1.  those carrying a genetic mutation, BRCA1 or BRCA2
2. 2.  those with a history of exposure to a large amount of radiation to the chest
3. 3.  those with many family members with breast cancer

That said, breast cancer does occur in women in their 40s, and sometimes even younger.

How Will the New Guidelines Affect You?

It is not clear at this time.  While the USPTF has issued these guidelines, two other organizations, the American Cancer Society and the American College of Radiology, still recommend annual mammograms starting at age 40.  The Secretary of the Department of Health and Human Services, Kathleen Sebelius, has also spoken out against these new recommendations.  Whether the new recommendations will affect insurance payment for annual mammograms remains to be seen.   Your personal risk factors and level of risk tolerance will also affect your decision on when to start getting screened, and how often you want to get a mammogram.   You may decide that you accept the potential harms of getting screened beyond the new recommendations and will continue getting screened as you have been, or you might feel comfortable with the new guidelines.  You can discuss your individual risk with your doctor.  It is also important to remember that these guidelines refer to screening only.  If you notice a lump or other symptoms in your breast, you should see your doctor for further evaluation.