Dear Dr. Roach: Following my last 3-D mammogram, I received a warning letter from the mammography center regarding the possible shortfall of mammograms for dense breast tissue. I’ve never received this letter in the past, but I’ve been told that it is a new requirement by insurance companies.

After doing a little research, I am very confused as to what should be done for those of us who are in this situation and want more reassurance that a normal result is truly normal.

Self-exams are also difficult given numerous cysts. There seem to be several routes that could be taken; blood tests for biomarkers, MRIs, and ultrasounds are a few examples.

My family does not have a history of breast cancer, but we do have a history of aggressive prostate cancer as described by an oncologist. I feel like I need to be a strong advocate for myself as Medicare and supplemental insurance only recommend the bare minimum.

— R.W.

Answer: My own institution has been sending out these letters for years, so I am very familiar with this question. Dense breast tissue is a risk factor for cancer and makes it harder for the mammogram to spot developing cancer within normal breast tissue.

Increased breast density by itself is not an abnormality as about half of women undergoing mammography will have dense breasts. Digital breast tomosynthesis (also called 3-D mammography) is better at imaging dense breasts than digital mammograms, and your center is already using this technique.

Choosing the right breast screening modality requires knowing your risk group. A greater than 20% lifetime chance of getting breast cancer is considered high-risk; 15% to 20% is considered intermediate; and less than 15% is average or low-risk. One common tool to help estimate risk is available at BCRiskTool.cancer.gov. A family history of prostate cancer does not significantly increase your risk.

Of the three imaging screening tools you asked about, mammography is the best-studied and has been shown in multiple trials to reduce the risk of dying from breast cancer by finding cancers early. The cancer can subsequently be removed before it has a chance to spread. The strongest evidence is for women ages 50-74; screening between 40-50 and over the age of 74 is controversial.

After my conversations with women about risks and benefits, most choose to begin screening at age 40 or 45, recognizing that there is a chance of a false-positive exam. Women over 75 should only be screened if they are in otherwise good health, in my opinion.

Because mammograms are not perfect, other imaging studies have been studied. An MRI is the most sensitive but has a high risk of false positives (in the best case, 8% to 13%). An MRI is only recommended for those who are at a high risk of breast cancer (greater than 20%).

A sonogram (also called an ultrasound) is a very reasonable test to get in addition to 3-D mammography for women with an intermediate risk and dense breast tissue. It’s my recommendation for my own patients; I offer but don’t insist on sonograms to women of average or low risk who have dense breast tissue, and some women will choose to get the scan while others will not.

Biomarkers (blood tests) may eventually become a useful part of screening, but I don’t recommend them outside of a clinical trial. Multiple studies on self-exams haven’t shown a benefit, but I have had some women physician and nurse patients who are expert examiners. They do self-exams that may be beneficial, but as you say, cysts can make these difficult to interpret.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.