There are lots of ways to detect breast cancer.

There is monthly self examination.

There is physician or nurse physical breast examination. To do it properly it takes 15 minutes.

Then there is Mammography.

Alas, it misses some cases. And there is a question if the radiation risk and expense is worth it in women under 45.

You see, those cancers, thanks to the high level of female hormones, grow quickly and often metastasize quickly. So the chances of finding a tumor in an age group where there are few cancers but lots of lumps mean you get lots of false positives (meaning more tests or even biopsies). But if you biopsy, you end up with scar tissue, that can mimic cancer on examination. Too many biopsies, and you end up with a distorted breast.

In younger women, we screened with ultrasound. But this too has it’s limitations.

So doctors have debates on what test to use, and I’ll rattle off some studies here to show you have to spend a lot of money and do a lot of tests to find one cancer.

So in today’s USA TODAY, we read the findings of screening with a mammogram and an ultrasound:

In such women, mammograms found cancer in eight out of 1,000 women screened. Adding an ultrasound let doctors find cancer in 12 out of 1,000, said the study, which was financed by the Avon Foundation and the National Cancer Institute. Together, the tests found 78% of cancers.

Pretty good results, but we still see that 12% of cancers were missed.

So is there a better test? Yes, the MRI of the breast.

Very expensive, very sensitive, but again many false alarms.

A study in JAMA (Journal of the AMA) gives the odds of having a false alarm (in medicine, this is called a false positive test). Let’s go back to those figures.

You screen 1000 women with mammography. Eight have cancer but twenty five end up getting biopsies of normal tissue.

If you do ultrasound with the mammogram, you find 4 more cancers: But you end up with 68 women having a normal biopsy.
But some women are considered “high risk”.

The risk of a woman getting breast cancer is roughly ten percent.

But in some families, the chance of getting cancer is 80%. They are starting to test for genes to screen these women:

Having one first-degree relative (mother, sister, or daughter) with breast cancer approximately doubles a woman’s risk. Having 2 first-degree relatives increases her risk about 5-fold….A woman with cancer in one breast has a 3- to 4-fold increased risk of developing a new cancer in the other breast or in another part of the same breast.

Other things that increase the risk are having no children, or children late in life, not breast feeding, using hormones after menopause,  being overweight, alcohol abuse, having had radiation treatment to the chest, and simply getting older.

So some groups now recommend screening high risk women with the MRI of the breast.
This link reports a study of 171 high risk women in the Radiological Clinics of North America.
Sixteen lumps were biopsied and found to be normal, and six of the lumps were cancer.

All six of the cancers were detected with MRI, while two cancers were detected with mammography and only one cancer was detected with ultrasound. The four cancers found in women with dense breast tissue were only detected with MRI.

So if it were me, I’d have the MRI.

This independent report from the ECRI Institute analyzed several studies in the medical literature. The total number of high risk women in all the studies was 1920, but since some were screened twice, the total number of screening exams was over 3000. They found adding MRI to the regular mammogram picked up 2.3 times as many cancers, but again it also led to a lot more negative biopsies. For finding ten cancers, you had to do 16 biopsies that turned out to be normal.

So the American Cancer Society
suggests that if you are high risk, you might want to start considering getting screening MRI’s starting at age 30.

For women with ordinary risk, they still recommend starting yearly mammograms at age 40.

For more information the National Cancer Institute page has lots of links and papers to read.

And remember: A mammogram costs approximately $100-200, whereas a breast MRI costs $1000-1500, and is not available everywhere. (I remember authorizing one at the local hospital, only to find that the only hospitals with expertise in taking and reading the subtle changes were 200 miles away…so we had to repeat the test).

So in normal women, figure $100 time 1000 women to find 8 cancers.  .

For MRI in high risk women, it comes to a lot more ($1500 times 171 women to find six cancers.

This is just one example of why health care is getting to be so expensive.

But when I started medical school, detection was by a woman finding a lump. The only treatment was radical mastectomy, and the cancers were found so late that the cure rate was only 40%. So things have improved over the last 40 years. Nowadays, but if caught early the cure rate is now 80%.

So get your yearly mammogram, and if you fit into the “high risk” criteria, you may want to talk to your doctor about having an MRI.

Nancy Reyes is a retired physician living in the rural Philippines. Her website is Finest Kind Clinic and Fishmarket. 

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