Pros and Cons of Screening Mammograms

Pros and Cons of Screening Mammograms

The single most significant contributor to decreased death from breast cancer over the past fifty years has been earlier detection, primarily as a result of mammograms.

If that is the case, then why do some doctors recommend screening mammography while others dispute it’s benefits? Let’s look at the facts.

A screening mammogram is a set of two images taken of each breast in the context of no signs or symptoms of breast problems. It utilizes xrays at very low dose to generate the images. Sometimes there are enhanced screenings with ultrasound and other imaging techniques in women with dense breast tissue.

A diagnostic mammogram is imaging done in the context of a sign or concern in the breast. The films do not differ from those done in a screening mammogram, but a diagnostic procedure goes on to take additional images and often breast ultrasonography to further evaluate the question.

The decision to do a mammogram is between a woman and her physician, but it is generally agreed from many studies that women over 50 benefit from annual screening mammograms. Seventy-five % of breast cancer occurs in women over 50.

Many doctors feel that women should start yearly screening mammograms at 40 and diagnostic mammograms - evaluation of a question - can be used on any age.

Pros include

1. Proven beneficial in reducing risk of death from breast cancer in women over 40 years.

2. Newer technology such as 3D imaging, MRI and tomosynthesis improve accuracy

3. Coupled with ultrasonography and simple breast exam enhances accuracy

4. Widely available test.

Cons

1. Not every breast cancer is detectable by mammogram. Mammograms that are done properly and read by experts can miss cancers.
    

2. Mammography can be uncomfortable due to the need to compress tissue. The compression enhances the accuracy of the image, but must be balanced with the comfort of the patient.
    

3. Regular mammography has been shown to increase the number of needle biopsies and other diagnostic procedures.

These are called “false positives” by some. In my view a false positive means that cancer was suspected but found not to be the case. A “false alarm”. That is not the case with the typical call-back.

A call back to the mammography unit for further testing is a part of careful and watchful surveillance and does not imply that cancer is suspected.

It means that the radiologist cannot be certain about an area without further studies. It’s similar to seeing a dark spot in the air on a landscape photo and zooming in to see what it is. It may turn out to be a kite in the air but you couldn’t tell that until you zoomed in.

It’s the same for the radiologist: they see something on the film and know that 90% of the time it turns out to be nothing, but they are looking for the 1 in 10  that it is a concern. They have to get extra views of all 10 women to find the one with something of concern. Yes, it causes temporary concern in the 9 that have nothing. But if you are the 1 in 10, you are really grateful to that radiologist for their diligence.

In summary, properly done mammography and other breast imaging can be life saving. Younger women less than 40 don’t need screening mammography as a group. There can be cases where it is needed because of family history or other factors. Women between 40 and 50 are debated in medical circles because cancer is detected in that group less frequently than in older patients. The decision is between the woman and her physician. I recommend screening mammograms in women over 40 because I have seen hundreds of lives saved by early detection that resulted from mammograms.