Q&A: Ultrasound Screening in Dense Breasts

July 28, 2014

Long-time proponent of ultrasound for breast screening, Kevin M. Kelly, MD, discusses what radiologists need to know.

According to latest research, women with dense breast tissue have a higher risk of developing breast cancer, and dense tissue can also make it difficult for early stage cancers to be detected by mammography. Several states have enacted dense breast tissue notification laws so women with dense breast tissue are informed of their risks and their options for further screening with MRI or ultrasound.

Diagnostic Imaging spoke with Kevin M. Kelly, MD, a practicing radiologist and director of breast imaging at The Breast Ultrasound Center in Pasadena, Ca. Kelly is a long-time proponent of using ultrasound for breast cancer screening and has been conducting research on its effectiveness since 1993.[[{"type":"media","view_mode":"media_crop","fid":"26101","attributes":{"alt":"Kevin Kelly, MD","class":"media-image media-image-right","id":"media_crop_3905585827305","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"2482","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"line-height: 1.538em; height: 231px; width: 200px; border-width: 0px; border-style: solid; margin: 1px; float: right;","title":"Kevin Kelly, MD","typeof":"foaf:Image"}}]]

What should physicians be telling their patients who have dense breast tissue?

About one in 300 women with dense breasts will have a cancer that is discoverable by something other than mammography, like MRI or ultrasound. Women have to know that. Mammography does a wonderful job in relatively fatty breasts, but it only gets about half of the cancers in dense breasts. So women with dense breasts should be undergoing a secondary screening. This could be with MRI or ultrasound, but ultrasounds are a lot cheaper than MRIs.

When ultrasound screening is done by the right hands, the chances of finding breast cancer are pretty close between MRI and ultrasound. If the women want to, they can go for an MRI instead, but nobody has done a study to look at women who undergo MRIs once a year for 20 years. So that has to be a consideration [because of the frequent exposure to gadolium]. But it doesn’t matter to me one way or the other – they need a secondary screening if they are concerned, either MRI or ultrasound.

Many people have expressed concerns about possible false positives from frequent screening and finding smaller cancers that may not progress, resulting in unnecessary treatment. They also mention the increased anxiety that women may experience because of the false positives. What do you say to this argument?

There are two parts to this answer. One is that there are those who say that small cancers don’t grow and there is overdiagnosis of breast cancer. DCIS, in particular, grows very slowly, if it’s grade 1 or grade 2, but grade 1 particularly. So you can make an argument about the growth. But, ultrasound doesn’t find DCIS because ultrasound doesn’t show calcifications. MRI sometimes doesn’t see the low-grade DCIS either, because it is not very vascular. So to me, that criticism is a non-argument. I'm doing a study that is not published yet that shows all invasive cancers grow significantly.

The second part is if you know what you are doing, ultrasound is closer to living pathology than anything else we have, besides a knife and a magnifying glass. We don’t see cellular detail with ultrasound, but we do see the structure of the breast, we see the ducts. We see breast tissue just as you would see on autopsy. And because of this, you should be able to do not only as well as you do with mammography in calling [the cancer] right, but maybe even a little bit better.

In my study published in European Radiology in 2010, I picked radiologists who were experienced ultrasonographers and we had a 38 percent positive biopsy rate. If you look in Europe, that’s about what it is. Well-trained radiologists should be able to have a sweet spot of somewhere between 25 and 40 percent positive biopsy rate. And remember we’re talking about only a needle biopsy.

I think we need to be detecting the cancers between 5 and 10 mm, which are stage 1 T1Bs. With those, you can just take them out. In Europe, they would not radiate. In the United States, maybe they’ll do some local radiation, maybe not. But that is what we ought to be doing.

I went to a conference in Europe in 1993 and saw how far ahead they were in understanding ultrasound and use of it than we were. And when I came back, it became clear to me that ultrasound was a huge diagnostic advantage than just trying to deal with mammography alone. This was before MRI was really any good.

Are there any age recommendations for ultrasound screening as there are for mammography screening?

To me, we’re not there yet. The number one cause of death in women in the United States – not “cancer cause of death” but cause of death period – is breast cancer in women between 35 and 54 years old. The thing about the 35-to-54-year age group is nobody is supposed to die in that group. The other high groups for death are suicide, drugs, alcohol and car accidents  - things that take you out but not in a natural way.

There is zero harm from ultrasounds. Not minimal, hardly counts chance. There’s nothing. This is what we use on fetuses and we’ve used it for 40 years. This has absolutely no side effects. You just have to be good at it because you can’t biopsy every little black dot that you see; you have to learn how to do it.

I tell my daughters, start in your 30s, probably start at 33 because cancers you find at age 35 naturally, you will see on ultrasound at age 33 – and do it once a year until you can’t stand up anymore.

What would you like to tell radiologists reading this Q & A?

This is coming. Nineteen states say that you have to inform women of the density of their breasts; this is coming.

Learn how to do ultrasound well because this is part of your job now. I’m old enough to be around for needle core biopsies. The radiologists didn’t want to do them; the surgeons didn’t want the radiologists to do them. The women said, “Wait a minute. I have a choice between having something cut out of my breast over something that might not be anything or stick a needle in it instead? Are you kidding me?” And all the radiologists who held back and said “no,” now are doing them. This is going to happen with ultrasound too. It’s going to happen.

If you go anywhere else in the rest of the world, except for the middle of Africa and Antarctica, they’re using ultrasound. In 1995, I was lecturing in Brazil. They were already using ultrasound looking for cancers. That’s 20 years ago. Where are we?

It’s my job, it’s your job, it’s everybody in this profession’s job to turn this ship around. Getting this out there only makes radiology stronger.