September 29th, 2010
08:31 AM ET
Every weekday, a CNNHealth expert doctor answers a viewer question. On Wednesdays, it's Dr. Otis Brawley, chief medical officer at the
Question asked via e-mail:
Is it really worth it to get a mammogram? Should I be getting mammograms?
There have been a number of articles in the press about mammography, and this has caused me to get quite a few questions about breast cancer screening.
Mammography, which is an X-ray of the breast tissue, is a technology that has been available since the 1950s. It was first used to get a better look at a breast in which there was a concern that a cancer might be present. Mammography can find some breast cancers when they are small and most treatable by surgery. Over time, a number of clinical studies showed that asymptomatic women given regular mammography have a lower breast cancer death rate compared with women who do not get mammography. Due to a lot of research done over the past three decades, we have developed better treatments for breast cancer. We can even cure some tumors that were almost always deadly just 20 years ago.
Breast cancer death rates have been falling for two decades in the U.S. and Europe. The average risk of breast cancer death for an American woman has declined by 30 percent from 1990 to 2007. We have good evidence that risk of death is falling for three reasons: screening with mammography and clinical breast examination; improvements in treatment of all stages of breast cancer; and increased awareness that any breast mass that a woman notices should be evaluated by a health care provider.
Breast awareness is very different from the monthly breast self-examination that was once advocated. Monthly self-examination has been abandoned in favor of breast awareness after several clinical trials showed that monthly self-examination did not save lives.
Very recently, a study done by a well-respected group of scientists was published, suggesting that mammography contributes less to the decline in mortality than it did a decade or two ago. Bottom line: The study did not say mammography is now worthless. One of the study authors, Dr. Howard Zellen, a noted cancer clinical trial researcher, said he still recommends mammography screening.
The message really is that women should practice all aspects of breast cancer prevention and early detection, and we should all support research efforts to improve mammography and find better ways of screening. Awareness and a woman feeling a mass may be especially important in younger women. Indeed, there are studies showing that most women diagnosed with early stage disease in their 40s are diagnosed when they seek medical help after feeling a breast lump while dressing or showering. It may be many of these cancers would have been caught had these women received mammograms, but we don't have the studies to show that.
Although breast self-awareness is critically important, it does not negate the impact that mammography has on reducing mortality from breast cancer.
The American Cancer Society and the National Comprehensive Cancer Network, which is a collaboration of America's major cancer centers, have separately commissioned experts to look at the scientific data and issued statements recommending women get a high-quality mammogram annually beginning at age 40. Both note that a high-quality mammogram includes review of previous studies. Both note that women should be informed of the limitations of mammography.
Although those groups have recommended annual mammography and clinical breast examination by a health care provider starting at age 40, other respected organizations have pointed out that mammography is a far better test for women age 50 and over.
There was a lot of controversy over this issue last year, when the U.S. Preventive Services Task Force issued its screening guideline. The task force recommended that routine biannual mammography start at age 50 and that women in their 40s who are concerned about breast cancer should have a conversation with their physician and possibly start mammography in their 40s.
As with any test, there are limitations and downsides to mammography. There are some cancers that will be missed. There will be some women inconvenienced by being called back and given extra testing, only to learn that they do not have a problem. There will even be some women who get treatment for pre-cancerous conditions that never would have become cancer.
I like to point out that if the current screening, treatment and awareness available were to be used by all Americans, experts estimate, more than 60,000 and perhaps as many as 120,000 breast cancer deaths could be prevented over the next decade. This still means 450,000 women will die from breast cancer over the next decade. This points to the fact we should use what we have now and work for better screening and better treatment.
It is also important to note that 35 percent to 40 percent of women who should be getting mammography are not. This means at least 20,000 to 40,000 women will die of breast cancers that could have been prevented through screening done over the next 10 years.
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.