SAN ANTONIO -- Researchers at The University of Texas M. D. Anderson Cancer Center have developed two genomic tests to better predict how breast cancer patients will respond to chemotherapy or hormonal therapy.
In presentations Dec. 14-15 at the San Antonio Breast Cancer Symposium, the research team reports on a highly sensitive multiple-gene test designed to predict response to chemotherapy, performed before surgery at M.D. Anderson, and a genomic index that gauges 10-year survival for patients who receive post-operative hormonal therapy with the drug tamoxifen.
"We are moving these tests toward clinical trials, where we can measure improvements in treatment response and track how physicians and patients use this information to make better decisions about treatment," says one of the team leaders, Lajos Pusztai, M.D., Ph.D., associate professor in M. D. Anderson's Department of Breast Medical Oncology.
The team developed a multi-gene predictor for pathological complete response (absence of cancer after chemotherapy), by analyzing 82 women who received preoperative paclitaxel and fluorouracil-doxocrubicin-cyclophsophamide (T/FAC), the standard of care for chemotherapy. Pusztai says the team analyzed 780 different combinations before winnowing the test down to a small set of genes.
The test was then applied to 51 new patients who received identical T/FAC treatment. It accurately predicted 12 of 13 patients who achieved a complete response. Of the 28 patients the test predicted would have residual cancer, 27 had breast cancer after treatment, indicating a high negative predictive value. "That's important, because if you knew in advance that you were unlikely to benefit from this standard chemotherapy, then you might choose a different treatment or an investigational drug," Pusztai says.
The test also predicted that 23 patients would achieve complete response, when only 12 did, mainly because the remainder had
Contact: Scott Merville
University of Texas M. D. Anderson Cancer Center