Why A Breast Cancer Drug Sometimes Fails

Scientists have discovered why the drug tamoxifen doesn’t work against breast cancer in some women. Normally, tamoxifen “flips a switch” that stops a tumor from growing. But in about 1 in 3 women, this switch is turned back on, and the drug doesn’t work. Researchers say a genetic test based on the research is about five years away. That would allow doctors to predict which women should take tamoxifen for their breast cancer. About 182,000 women will be diagnosed with breast cancer this year, and 40,500 will die from the disease.