(NBC) -- E! news host Giuliana Rancic has announced she is one of the millions of American women battling breast cancer. At 36-years-old, she was about to start her third round of IVF and her doctor required a mammogram as part of the process.
"They said we need you to come back we see something. I remember where I was when I heard that I was driving to work, and it was just a kick in the stomach, and I knew something was wrong," recalled Rancic.
Her story is one of many that show the important role mammograms can play in breast cancer detection.
So it was controversial in 2009 when the US Preventive Services Task Force recommended average-risk women start screening at age fifty, instead of forty, and have the test every other year instead of annually.
"Mammograms are a great tool, but they're an imperfect tool," said Dana-Farber Cancer Institute?s Ann Partridge.
A new study highlights the risks women could face if they are screened too early and too often.
The research shows more than half of women who have yearly mammograms starting at age forty have at least one false positive.
Many of those women have a biopsy only to find out they don't have the disease.
"There more likely to have you called back for nothing, than to have you called back for an actual cancer," said Partridge.
Women who were screened every other year faced a small increased risk for catching their cancer at a later stage.
But experts say for most women that risk does not outweigh the anxiety, and expense of false positives.
"Women should discuss these issues with their doctors, and express their own preferences versus testing and taking more of a watch and wait approach," said Partridge.
And they should know that not all phone calls that follow a mammogram are bad.