Breast density a big factor in exams

By Gillian Slade on November 2, 2018.

gslade@medicinehatnews.com  @MHNGillianSlade

A mammogram is only 50 per cent effective in identifying breast cancer if you have dense breasts, says a local radiologist.

More than a decade ago a U.S. congresswoman diagnosed with breast cancer raised awareness about mammograms not detecting all breast cancers in those with dense breasts, said Dr. Mark Gripp, radiologist, BGSA Radiology Inc. in Medicine Hat.

We have known this for about 10 or 15 years, said Dr. Marc Trudeau, oncologist in Medicine Hat.

Dr. Brian Goldman, host of the CBC radio show “White Coat Black Art”, recently interviewed Michelle Di Tomaso (co-founder of Dense Breasts Canada) who was diagnosed with advanced breast cancer in 2014 after receiving an “all-clear” report from a mammogram just weeks before.

Di Tomaso discovered the lump herself while in the shower. It took an ultrasound and biopsy to diagnose advanced cancer. She was then told her dense breasts had prevented the cancer from showing up on the mammograms she’d been having regularly for years.

Di Tomaso questioned why she’d never been informed of having dense breasts and the implications. She has been on a mission since then to have women told whether they have dense breasts.

In Medicine Hat every mammogram report specifies whether a women has dense breasts, and all you have to do is ask your family doctor for a copy of your mammogram report, said Gripp.

The National Cancer Institute says “dense breast tissue has more fibrous and glandular tissue than fat. There are different levels of breast density, ranging from little or no dense tissue to very dense tissue. The more density, the harder it may be to find tumors or other changes on a mammogram.”

About half of all women over 40 have dense breasts and in general it is genetic, according to the NCI’s website.

The value of knowing your breast density is that you are then aware of your increased risk of developing breast cancer and that it is more difficult to diagnose in a mammogram.

“The implication is you should be screened more aggressively,” said Gripp.

It also opens the conversation about the frequency of screening weighed against any concerns about radiation exposure, said Gripp.

When observing dense breast tissue in a mammogram, Gripp considers the patient’s family history in deciding whether an ultrasound would be appropriate as well. An ultrasound statistically detects about 15-30 per cent of breast cancers but also identifies benign conditions.

The value of a mammogram is that it still detects some breast cancers even in dense breasts, and it is the best diagnostic tool in detecting breast cancer in the early stages, said Gripp.

Doing an ultrasound as well means a risk, about 8 per cent, of having a “false positive” result that would mean having an unnecessary biopsy to rule out cancer, said Gripp. For the woman going through that process there is a lot of stress, not to mention the procedure.

Women who know their breast density can have a conversation with their family doctor, based on their family history of breast cancer, to determine what tests they would like to have, said Gripp.

Cancer does not grow overnight and some lumps can be detected by a physical examination, which Trudeau sees as part of the approach to screening along with mammography, ultrasound and even MRI. None of these tests are 100 per cent accurate, he notes.

The protocols established for screening are based on highly skilled authorities determining what is the best for the majority of people, said Trudeau. The National Institutes of Health in Bethesda Maryland is one such organization.

“A mammogram is an X-ray of the breast and has proven to be the most effective way to detect breast cancer,” reads an emailed statement from Alberta Health Services. “Early detection allows for a greater number of options for treatment and a better chance of survival.”

There is value in getting a mammogram regularly. These provide a radiologist with a picture of how the breast is changing over time, said Gripps. As we age breast density also declines.

One in eight women have a risk of being diagnosed with breast cancer in their life time. It is still the second leading cause of cancer deaths, said Gripp.

The older you are the higher the risk of developing breast cancer. Between the ages of 20 and 30 your risk is one in 1,695. Between the ages of 70 and 80 it is one in 24.

Toward Optimized Practice is a website that provides guidelines for Alberta physicians (see link below) and includes recommendations for breast cancer screening.

http://topalbertadoctors.org/cpgs/2886567

http://www.densebreastscanada.ca/

https://www.cancer.gov/publications/dictionaries/cancer-terms/def/breast-density

https://www.cancer.gov/types/breast/breast-changes/dense-breasts

https://www.nih.gov/about-nih/contact-us

30
-29

Comments are closed.