Now that it's no longer October, I will post my annual awareness message about mammograms and how they aren't enough for many women.
This year when you schedule your mammogram and show up for the test, don't stop there. When you get the little postal card that says you're okay, pick up the phone and call the doctor who ordered the exam.
Ask your doctor or the nurse to send you or read you the entire radiologist report. If it mentions you have dense breasts (sometimes stated as "scattered fibroglandular densities"), ask your doctor if you need a follow up test such as an ultrasound or MRI to actually see inside your breasts.
The problem is that both breast density and cancer show up white on a mammogram. I've heard it said that "you could hide a Buick" inside breast density and never know it's there. So if you have dense breasts (up to 40 percent of women do), it could be preventing a good reading of your mammogram. And, no, density has nothing to do with how large or small your breasts are. It's generally a fact of being younger (premenopausal), though it can apply to older women, too. As we age breast density turns to fat, and fat is easy to see through on a mammogram.
More and more states are passing laws that make health care providers inform women if they have dense breasts, and for good reason--not only does this make reading a mammogram difficult, it also increases your chance of developing breast cancer.
Having to think about, then schedule and get a mammogram every year is not fun, but the fact is if you stop there, there's a chance you aren't getting the effective breast surveillance you might think you are.
This article provides more information and also states that there is contention around the issue, but as one whose two, 2.5 cm cancerous lumps didn't show at all on a mammogram but were revealed by an ultrasound, with a followup MRI showing even more areas of concern, I think you can guess where I come down on this.