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Getting A Mammogram: How Much Do You Really Know?

Woman getting mammogram

Between the pink-colored clothing you see countless people wearing to support the cause and breast cancer fundraisers happening around town, you probably know that October is Breast Cancer Awareness Month.

But how much do you actually know about getting a mammogram and breast exams to detect cancer early?

In its early stage, breast cancer usually doesn’t have symptoms. For this reason, mammography is one of the most effective ways to detect breast cancer. Additionally, breast exams—done by a health professional and by yourself—can spot abnormalities that require further checkups.

Rules for Getting a Mammogram

Guidance for when a woman should start getting mammograms used to be straightforward.

“The recommendation used to be every woman over 40 should be screened,” says Antje Greenfield, MD, a radiologist at Penn Medicine who specializes in breast imaging.

Over the last few years, screening recommendations have been under review. Experts recognize that many variables influence breast cancer risk. This includes genetic, environmental and individual factors, such as breast density.

“It no longer follows a one-size-fits-all rule,” Dr. Greenfield says.

When to Get a Mammogram

Women 40 years and older and considered average risk for breast cancer should have a screening mammogram every year and continue to do so as long as they are in good health. Screening mammograms test women with no breast cancer signs or symptoms as a means of early detection, explains the American Cancer Society (ACS).

“This is most effective in combination with monthly self-exams and an annual breast exam by a physician,” Dr. Greenfield says. Women who have a higher risk of developing breast cancer—meaning greater than 20 percent over the general population—may be recommended for mammography and additional screening, such as MRI, before age 40.

High-risk women include:

  • Those who have a known BRCA1 or BRCA2 gene mutation
  • Those who have a parent, sibling or other first-degree relative with a BRCA1 or BRCA2 mutation
  • Those who had radiation therapy to the chest when they were between the ages of 10 and 30 years

Every woman, starting in her 20s, should also have a clinical breast exam by a healthcare professional as part of her annual visit to the doctor.

Self-breast exams are also recommended, but they shouldn’t be overdone.

“Once a month in the shower or relaxed lying in bed, gently feel around your breast clockwise,” Dr. Greenfield advises. “Know what your breasts feel like and notice any changes. No more, no less.”

What to Expect During a Mammogram

Mammography devices are upright X-ray machines that take low-dose pictures of the breast to look for abnormal masses, distortion of architecture or calcifications.

During a mammogram, a technician will position your breast on top of an X-ray plate and then lowers an adjustable plastic cover on top of it. Your breast will be flattened to image as much tissue as possible. A screening mammogram typically consists of two pictures of each breast, taken in different positions.

“It may feel strange, and there maybe some pressure sensation in the breast, but the technologist will make sure that every woman is as comfortable as possible throughout the exam,” Dr. Greenfield says.

When the mammogram is done, you can leave and resume daily activities. A board-certified radiologist will analyze the image—typically within the same day—but not while you're in the department.

Waiting for the Results

Within a few days, you'll receive a letter in the mail advising you of the results and any next steps. If everything is normal, you'll be asked to return in one year for your annual routine mammogram. If doctors find something that looks different or suspicious, you and your doctor will get a phone call within a couple of days. You'll be asked to come back in for a diagnostic mammogram to investigate the abnormality. This may also include other imaging, such as ultrasound.

At the time of the diagnostic study, the radiologist will do a workup and read the images while you're there. When the workup is complete, the doctor will come in and speak with you to let you know what was found and if anything further is needed.

If an abnormality is confirmed on the additional imaging and a biopsy or other testing is recommended, it still doesn't mean cancer.

“When they get the phone call to return for additional pictures, some women panic and think that means she has cancer,” Dr. Greenfield says. “The fact is that most of the time it turns out to be nothing worrisome. The doctor just needed to see an area a little better to be sure everything is okay.”

How Effective Is Mammography?

Mammography is designed to be sensitive enough to catch breast cancer at an early stage or to find pre-cancerous conditions before they turn into cancer. With that, though, comes a chance of false-positives.

At the same time, screening mammograms fail to find about one in five breast cancers. This is very much dependent on the breast density, or the amount of glandular tissue in a woman’s breast.

Some women may take that as a reason to skip mammograms; however, Dr. Greenfield notes that one in eight women will get breast cancer in her lifetime, and breast cancer is the second leading cause of cancer death for women.

“That’s an incredibly high risk,” she says. “Screening mammography has been proven to be the most effective tool in reducing death from breast cancer—approximately 30 percent since the 1990s. That’s attributed to finding and treating it early before it has reached advanced stages.”

Also, mammography has undergone some significant technical improvements over the last decade. Most recently radiologists and physicians have implemented 3-D mammography, which detects 20 percent additional early breast cancers over 2-D mammography.

“Knowing that, you want to make sure you take advantage of the screening and the new technology behind it,” says Dr. Greenfield. “If early cancerous changes can be detected and taken care of before they become invasive or widespread, it will save your life."

What About Radiation Exposure?

Dr. Greenfield debunks the notion that women shouldn’t get mammograms because they’re concerned about radiation from the X-ray.

She explains that X-rays do entail a certain amount of radiation exposure, but the typical dose for a mammogram is about 0.4 mSv. (An mSv is a measure of radiation dose.)

To put that in perspective, people in the United States are exposed to an average of about three mSv of radiation each year, just from living on Earth.

“The internet can be a dangerous place,” Dr. Greenfield cautions.

Given the mountain of unfiltered information about breast cancer out there—and some of it may be false—Greenfield’s advice is simple.

“Be aware and informed. Take care of yourself, and don’t put it off. Talk to your doctor, and get medically and scientifically sound advice when there’s new or conflicting information out there.”

About This Blog

The Focus on Cancer blog discusses a variety of cancer-related topics, including treatment advances, research efforts and clinical trials, nutrition, support groups, survivorship and patient stories.

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