Genomic tests increase accuracy of breast cancer diagnosis

The latest generation of genomic tests for breast cancer can improve physicians' ability to diagnose the disease and more precisely tailor each patient's treatment, according to a study being presented at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium (SABCS). The study examined the first commercially available genomic tests to determine the molecular subtype of a breast cancer tumor.

Researchers concluded that these relatively new genomic tests can more accurately classify breast cancer tumors. That in turn can help doctors better predict what type of treatment is best for that cancer subtype.

Genomic testing is part of the revolution in personalized medicine. It uses a patient's tumor genomic profile and other information to individualize treatment with the goal of better clinical results and overall cost savings. Genomic tests examine tumor tissue and the activity of groups of genes within the tumor, to provide a more comprehensive view of the cancer and treatment options.

The study findings also suggest that some breast cancer patients who are currently prescribed chemotherapy after surgery may be able to avoid that therapy and its risks.

"We now have a better tool for determining which patients do not need to undergo treatments such as chemotherapy, when that treatment would be expensive and would not be useful to that particular patient," said medical oncologist Massimo Cristofanilli, M.D., FACP, lead author of the study and chief of the breast service line at Fox Chase Cancer Center, in Philadelphia.

Chemotherapy risks include immediate side effects, discomfort, and long-term damage, including a possible second cancer. Several studies have concluded that chemotherapy provides no real benefit for many breast cancer patients because of their cancer subtype and low risk of recurrence.

"These research findings contribute to our understanding of how cancer grows and how that growth can be stopped, and the findings will help us treat more patients more successfully," said Stefan Gluck, M.D., Ph.D., FRCPC, a medical oncologist at the University of Miami.

With the new genomic tests, physicians will be able to more precisely employ the sophisticated treatments that have been developed for breast cancer, said Dr. Cristofanilli: "Our sophisticated therapies mean nothing if we cannot apply them to patients appropriately. This newer panel of genomic tests enables us to better classify patients. That will help improve outcomes, because we will be more precisely applying the right treatment to the right patient."