In the US, close to 80 million women each year meet the guidelines for mammographic screening to detect breast cancer. The idea is that if you detect cancer at earlier stages, your survival after treatment is significantly higher than if the cancer is found at later stages. While this is true, many women are unaware that if they have dense breast tissue (~40-50% of the women in the US), cancer can be missed 50% of the time.
Smart Breast Cancer Screening for Women with Dense Breast Tissue: An “Inside Out” versus “Outside In” Approach.
It used to be that getting an annual mammogram for a woman over 40 was a simple way for her to be pro-active in monitoring her own breast health and to “catch” breast cancer in its early stages. However, doctors and scientists know now that this rite of passage is significantly more complicated than a yearly uncomfortable, and perhaps painful, xray. Some 45% of all women have naturally occurring dense breast tissue, and research has shown that this tissue can mask up to 50% of all breast cancers. Additionally, this breast tissue density is now considered to be a risk factor contributing to a higher breast cancer incidence rate. Medical professionals note that trying to detect cancer in dense breast tissue is like looking for a snowflake in a blizzard.
A major reason breast cancer is missed in women with dense breast tissue is because radiologists find it difficult to distinguish between tumor and normal dense tissue, both of which appear white on a mammogram. This challenge was illustrated by OncoTAb’s scientists during the American Society for Clinical Oncology (ASCO) Annual Meeting in Chicago earlier this year. Conference attendees who visited the OncoTAb booth (doctors included) were shown the attached images and asked to identify the dense breast mammographic image that has a tumor. Surprisingly, the medical professionals were able to find the tumor only 50% of the time. Not surprisingly, it is the same statistic as the percentage of breast cancers missed in dense breast tissue by mammograms.
Another challenge is that interpreting mammograms is highly subjective resulting in considerable variation between radiologists. A recent study described in articles mentioned on NPR and cancernetwork reported that radiologists vary widely in even the classification of breast density. Roughly one in six women had different assessments of dense versus non-dense status in consecutive mammograms interpreted by different radiologists. There are further ramifications for a woman erroneously classified as having non-dense tissue, she and her physician may not consider supplemental screening options. Unfortunately, the variation between radiologists is not limited to the classification of breast density, but also to detecting breast cancer. A scientific publication in Radiology comparing digital mammography to digital plus 3D mammography, reported considerable variation in cancer detection rates between the eight radiologists that participated in the study. While the average detection rate of these radiologists improved with the addition of 3D mammography (with two times the radiation dose), the variability between radiologists did not improve: individual radiologists missed over 40% of cancers with both approaches.
While state legislatures throughout the United States are passing laws requiring women to be notified if they have dense breast tissue, the notification is almost as inconclusive as the screening mammogram. These notifications include recommendations that women discuss supplemental screening options with their healthcare providers. As a result, women with high breast density are increasingly seeking supplemental tests such as ultrasounds. While ultrasound can detect cancers that mammograms fail to detect, they also can have false positive rates as high as 95% (UNC School of Medicine) also. These high false positives are perhaps one reason why insurers don’t usually cover supplemental screening for women with dense breasts who have a “normal” mammogram.
Instead of looking for that “snowflake in a blizzard” – perhaps let’s look at what’s in the composition of that snowflake. That’s exactly what the OncoTAb team discovered after testing blood samples of literally hundreds of women – with and without breast cancer. We found that a breast cancer cell releases a protein, tMUC1 into a women’s blood system. By looking specifically for that protein, we are able to monitor the level in the blood as well as its elevated level as the disease progresses. Instead of looking at breast cancer from the outside in, we are looking at it from the inside out.
Simple affordable blood tests, often called liquid biopsies, which can detect fragments of proteins and DNA released from tumors into circulation, hold considerable promise to address these challenges. OncoTAb’s test, the Agkura™ Personal Score, detects the tMUC1 protein in a woman’s blood system; and its level can be monitored regularly by a woman and her physician. Her dense breast tissue has NO impact on the presence – or the level – of this unique protein in her system. This test can be used to identify the appropriate women for ultrasounds. Such a screening protocol has a high probability of increasing the detection rate of breast cancer while mitigating the high false positive rates of ultrasounds.
So women with dense breasts now have a “smart” alternative to the “imaging only protocol,” The Agkura™ Personal Score: it’s screening for breast cancer from the inside out in addition to the outside in approach.