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You Have Dense Breasts. Do You Need Annual Ultrasounds?

“You have dense breasts,” your doctor or mammogram technologist says — every year. Ask questions in return.

Chances are, they’ll suggest you supplement your annual mammograms with another screening test called a breast ultrasound, also referred to as a sonogram. It’s an additional way to discover breast cancer, and finding it early makes it easier to beat.

What Are Dense Breasts?

Large or small, your breasts might be hard to see through even with high-tech imaging machines. That means you have dense breasts.

Specifically, it indicates your breasts have a lot of glandular tissue. That refers mostly to the lobules and ducts used to make and deliver milk, together with fibrous tissue, which keeps the other types of tissues from moving around. The rest is fatty tissue; that shapes your breasts. We all start out with dense breast tissue, but the proportions often change over time.

There are four stages of breast density:

  • Extremely dense (10 percent of women) — Exactly what it says. Your breasts are filled with glandular and fibrous tissue. They are so cloudy that even mammograms don’t pick up every irregularity; a tumor might not be visible.
  • Heterogeneously dense (40 percent of women)— In other words, still pretty cloudy. Some masses might not show up on mammograms.
  • Fibroglandular density (40 percent of women)— That means very few parts of your breast are cloudy while others are mostly transparent on a mammogram.
  • Fatty (10 percent of women) — If your breasts are filled with mostly fat (completely see-through), imaging tests will show just about everything that’s inside.

You’re born wired to have one type of breast composition or another, although lifestyle issues might affect how your breasts evolve over the years. Age is the No. 1 influencer, along with whether you gave birth. If you were thin as a child with a low body mass index, you’re more likely to have dense breasts as an adult, and vice versa. If you take postmenopausal hormone therapy in your later years, that might lead to dense tissue, too.

In general, our breast tissue becomes less dense as we age and no longer need all those milk-producing instruments, which shrink. Still, some women maintain dense breast tissue throughout their lives.

Why Breast Density Matters

Doctors use mammograms, ultrasounds and MRIs to look beyond the skin and see abnormalities in your breasts. Those abnormalities can be tumors — cancerous or benign; some of those are “asymmetries” that look different from what’s around them. Abnormalities also might also be cysts, calcifications, inflamed lymph node  or breast tissue pointing in an odd direction, which is known as architectural distortion.

It’s easier to see these items in breasts with fatty tissue than dense tissue.

As a result, if your breast tissue is dense, your doctor might suggest doubling up and having an ultrasound in addition to a mammogram. Two tests increase the chances of finding a change, dangerous or not, in your body. Each test can reveal some irregularities the other misses.

So What About that Ultrasound?

Do you need annual ultrasounds? There is no straight answer that applies to all women. Talk to your doctor, who can make a recommendation based on your personal situation. In addition to breast density, your medical provider will look at additional factors:

  • Seek out information — Florida requires mammogram summary reports to state, “Your mammogram shows that your breast tissue is dense” if you have heterogeneously or extremely dense tissue. If you see those words, get some answers.
  • The type of mammogram — Traditional 2-D mammograms take two pictures of each breast. Newer 3-D mammograms, also called breast tomosynthesis, take multiple pictures and turn them into a movie; radiologists see pictures of sections of each breast, showing more of what’s inside. Your doctor is more likely to order an ultrasound if you’ve had the less revealing 2D mammogram.
  • Family history — Most medical organizations suggest women start getting yearly mammograms at age 40, or 10 years earlier than the age at which their youngest family member was diagnosed with breast cancer. If your relatives have had breast cancer and you have dense breast, ask about adding ultrasounds to your routine preventative care — although you’ll more likely be advised to have an MRI.
  • Dense breasts — Having dense breasts increases your risk for breast cancer. Adding ultrasounds will increase the chance of detecting cancers that are difficult to see on a mammogram alone.

Breast ultrasounds are relatively inexpensive, and they’re an easy way to supplement your annual mammogram if you have dense breasts.

If your breasts are dense and you’re at an elevated risk for breast cancer, you might be advised to have an annual MRI in addition to, or instead of, an ultrasound — six months after the mammogram so you’re checked twice yearly.

MRIs are most effective in identifying cancer, in part because of an injected substance that makes cancers show clearly. The downside: MRIs highlight so many elements that you’re more likely to have a false positive, meaning an area that looks like cancer and requires a biopsy but is harmless. A mammogram or ultrasound is like a colander, picking up only big rocks, whereas an MRI is like a sifter, picking up big rocks and pebbles — some of what it shows may be junk.

The goal is always to catch any breast cancer early so it can be treated successfully and with as little discomfort as possible. If your mammogram report says you have extremely dense or heterogeneously dense breasts, be bold about asking if you should add ultrasounds to your wellness plan.

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