New tech finds tumors mammograms miss

Carrying a tune is a talent that runs in Marcia Maring's family.

"My whole family majored in music," said Marcia Maring, a breast cancer survivor.

Unfortunately that isn't the only trait passed down through the generations.

"My aunt was 40 years old when she had breast cancer. Then my mother developed breast cancer," said Maring.

A few years ago, a mammogram found Marcia also had breast cancer. Like 25-percent of women, she has dense breast tissue which makes it hard to detect tumors.

"In fact, in those women mammography can miss one out of every two cancers," said Dr. Deborah Rhodes, Mayo Clinic, Rochester.

A team of doctors at the Mayo Clinic developed molecular breast imaging or MBI. Women get an injection of a radioactive tracer that travels to the tumor cells and lights them up.

"It's like seeing a lighthouse. You see this beacon in the breast and it's very easy to pick up the tumor," said Michael O'Connor, Ph.D, Mayo Clinic, Rochester.

In a study of more than 900 women, molecular breast imaging picked up three-times as many cancerous tumors as a mammogram.

"We've shown we can detect even very small cancers those that are under 10 millimeters," said Carrie Hruska, Ph.D., Mayo Clinic, Rochester.

"In about 10 percent of the cases we would also find additional small tumors that the mammogram was missing," said Dr. Rhodes.

Which is exactly what happened to Marcia. In the study, the MBI found a second tumor the mammogram missed. It changed her course of treatment.

"I didn't realize that the mammogram only had picked up the central tumor," said Maring.

After surgery and chemo Marcia's a healthy mom getting ready to send her kids off to college.

"It's gonna be a new chapter in our lives," said Maring.

Doctors say the new procedure is also more comfortable than a mammogram because it uses less pressure. Researchers hope to make it available to the public within the next few years.

Web Extra Information: Seeing Breast Cancer Clearly


A screening mammogram is an X-ray of the breast used to detect breast changes in women who have no signs or symptoms of breast cancer. It usually involves two X-rays of each breast. Mammograms make it possible to detect tumors that cannot be felt.

Mammograms can also find tiny deposits of calcium in the breast that sometimes indicate the presence of breast cancer. Women age 40 and older should have mammograms every one to two years. Women who are at a higher than average risk of breast cancer should talk with their health care providers about whether to have mammograms before age 40 and how often to have them.


Even though mammography can detect tumors that cannot be felt, finding a small tumor does not always mean that a woman's life will be saved. Mammography may not help a woman with a fast-growing or aggressive cancer that has already spread to other parts of her body before being detected. In addition, mammograms aren't always completely accurate.

False negatives occur when mammograms appear normal even though breast cancer is present. Overall, mammograms miss up to 20 percent of the breast cancers that are present at the time of screening. False negatives occur more often in younger women than in older women because the dense breasts of younger women make breast cancers more difficult to detect in mammograms.

As women age, their breasts usually become more fatty and breast cancers become easier to detect with screening mammograms. False positives occur when mammograms are read by a radiologist as abnormal, but no cancer is actually present. All abnormal mammograms should be followed up with additional testing to determine if cancer is present.


Cancer turns up five-times more often in women with extremely dense breast than in those with the most fatty tissue, a recent study shows. On mammograms, fat looks dark, but dense tissue is light, like tumors so it can hide the cancers. This means that density is a true risk factor, along with other strong predictors like age and genetics. In a study published in the New England Journal of Medicine, women with at least 75 percent dense breasts showed five times more likelihood of cancer than women with less than ten percent density. Cancers were 18 times more likely in women with the densest breasts within the first year after mammograms.


In the largest-ever study to compare molecular breast imaging to mammography, researchers showed that MBI can detect three-times as many cancers in women who have dense breast patterns on their mammograms and are at increased risk of breast cancer. MBI is a relatively new screening method. Patients are injected with a short-living radioactive agent that is absorbed by breast tissue.

This agent is tracked with a specialized camera that can distinguish healthy tissue from breast cancer tumors, as cancer cells absorb more of the radioactive agent than healthy cells. MBI is currently available at a limited number of cancer centers, but its availability is growing. Nine hundred and forty women were included in this study and were screened with both MBI and mammography. Participants had to meet two criteria. First, their breasts were determined to be dense by a previous mammogram. Second, they had an increased risk of breast cancer. A total of 13 tumors in 12 patients were detected; eight by MBI alone, one by mammography alone.

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