Buzz about Breast Cancer Blood Test (BT test)
Rachel Spieldoch, MD
Currently one in every eight women will be diagnosed with breast cancer during her lifetime. Some women may have a genetic disposition such as BRCA1 or BRCA2 but these genetically inherited breast cancers only account for 5-10% of those diagnosed. While mammography is the current gold standard for screening, it is not a perfect test. This may be due to several limitations including differences in breast tissue among women, varied machines, technician and radiologist variability as well as the ability for cancerous cells to present differently in women. Many breast cancers are detected only after they are significantly too advanced for cure. We know that with early detection, breast cancer has a 97% survivability rate.
Many patients have been asking about the new BT test being offered in our clinic for breast cancer. The BT test is formally called a biomarker translation test. It is a multivariate blood-based multi-protein biomarker analysis for the detection of breast cancer. What does this mean? This test essentially looks at several different cancer specific proteins which have been known to have an association with breast cancer. These proteins are associated with many different functions including blood vessel growth, cell death, tumor growth, and inflammation, and immune system responses. Their levels become abnormally expressed with cancer growth.
A recent study for the BT test looked at the validity of the test in diagnosing the risk for breast cancer. The study evaluated women younger than 50 years old and women older than 50 years old. The BT test had a 97% accuracy in women less than 50 years old and an 86% accuracy in women over 50 years old. The BT test has a lower sensitivity and specificity in women over 50 years old. This means that there are more false negative results and false positive results in this age group when compared to women younger than 50 years old. However, the diagnostic usefulness of this test is very impressive.
All women are candidates for the BT test and it is recommended prior to mammography. It is particularly helpful for women with known fibrocystic disease, a family history or known genetic disposition, or a history of increased risk exposure such as prior radiation. Additionally, women with inconclusive mammogram results will benefit from BT testing.
Because this is a relatively new test with limited studies available, it is not indicated to take the place of current mammography. However, the BT test is a very innovative new tool for evaluation. The data is very exciting and suggests that a BT test when used in conjunction with mammography may significantly improve the ability to detect early breast cancer. This in turn, may ultimately decrease the amount of unnecessary breast biopsies as well as allow for women to undergo less invasive surgeries for early disease. Most importantly by detecting breast cancer early, the BT test may ultimately save the lives!