Mammogram Misses: Dense Breast Tissue Explained

EUGENE, Ore. -- Laura Caldwell is a survivor. The married mom of three is in remission after a six-month battle with stage three breast cancer. The diagnosis came last October, six weeks after Laura had a normal mammogram.

"The surgeon told me that I probably had had it for two years," Laura said. "So it could have been caught earlier if I had known that I needed to look a different way."

Caldwell and her husband, Hugh, asked the doctor how this could happen. It turned out, Caldwell had dense breast tissue. Dense breast tissue can hide a tumor on a mammogram. According to the American Cancer Society it can increase a woman's risk of breast cancer.

Doctor Mike Milstein is a radiologist at Oregon Medical Group where Caldwell was diagnosed.

"I looked at this case," said Milstein. "Even in retrospect, you cannot see on the mammogram, the cancer, and it does happen. It affects me in a way that makes me very upset."

Doctors aren't required to tell women if they have dense breast tissue in all but three states. Oregon is not one of them. The Caldwell's are part of a growing group advocating congress to pass a federal bill that would require doctors to tell patients when they have it.

The American College of Radiology says the bill could have unintended consequences. Milstein said the problem is measuring breast tissue density is difficult.

"We're just making an estimate and the estimate is not very accurate and it's not very precise," Milstein said.

Breast density is included in a mammography report, but patients have to specifically ask their doctors to see those results.

"There is a lot of debate as to whether this estimate should be made readily available or not," said Milstein. "My opinion is if it's in the report, then I think women should have easy access to it. The important thing is the issues behind it have to be understood."

If a woman is identified as having dense breast tissue, she may undergo ultra sounds in addition to mammograms, but not always. Milstein said studies that follow those woman show extra tests have not significantly reduced deaths from breast cancer and oftentimes result in false positives.

What should women do? Milstein said continue to get mammograms. Ask your doctor to see the report and keep doing monthly self exams.

Laura did all that and the mammograms still never caught her cancer.

"It happens and when it does it's a failure of what we have to offer now, but there's really not a lot we can do," said Milstein.

Luckily, Caldwell's treatment seems to be working.