Q. I saw my doctor last week and told her that I had dense breast tissue. She told me it did not increase my risk for breast cancer, but I heard on the “Today Show” last week that it did.

A. I did not see the “Today Show” episode, but I think I can clarify your comment. In my opinion, your doctor is correct in that having dense breast tissue is not an absolute risk for developing breast cancer, but it is a risk for having a small breast cancer hidden on your mammogram, and thus allowing it to grow larger before it is detected.

Picture a ship in the fog. If there is dense fog it is difficult, sometimes impossible, to see that ship. But if it is a clear day, or less foggy, it is easy to see the ship. I think this is a good analogy because normal tissue on a mammogram is white (like fog), and breast cancer on a mammogram is white, so it becomes more challenging for us to see a small cancer on a mammogram when a woman has a lot of natural background white (dense breast tissue).

The risk of getting the cancer is no greater with dense breast tissue, but the risk of not detecting the cancer is indeed greater with increasing density of tissue.

Another way to explain it is that if a woman has a 2.5-centimeter, high-grade cancer that is lymph-node positive, and she has low density breast tissue, I would wager that she has not been getting yearly mammograms. But we periodically see a 2.5-cm, high-grade cancer that is lymph-node positive in a woman with dense breast tissue that has been getting yearly mammograms. Not often, but occasionally.

Let me answer, then, the obvious question: What can I do? If you know you have dense breast tissue (it should be on your report – if not just ask your mammogram center), and you want additional peace of mind, your mammogram center should be able to offer you a screening breast ultrasound. Or if you are a high risk patient (ask your center to run a risk assessment calculator), you may benefit more from a breast MRI.

Michael J. Ulissey, M.D., is a partner at the Breast Diagnostic Centers of Auburn and Federal Way. In addition to taking care of patients locally, he continues to participate in research as an adjunct professor at the University of Texas Health Sciences Center. You can reach him at Mike@breastdiagnostic.com.