The Emperor of All Maladies: A Biography of Cancer

by Siddhartha Mukherjee

In January 1977, five years after Cole had published her results on tamoxifen in metastatic cancer, Fisher recruited 1,891 women with estrogen receptor–positive (ER-positive) breast cancer that had spread only to the axillary nodes. He treated half with adjuvant tamoxifen and the other half with no tamoxifen. By 1981, the two groups had deviated sharply. Treatment with tamoxifen after surgery reduced cancer relapse rates by nearly 50 percent. The effect was particularly pronounced among women above fifty years old—a group most resistant to standard chemotherapy regimens and most likely to relapse with aggressive, metastatic breast cancer. Three years later, in ’85, when Fisher reanalyzed the deviating curves of relapse and survival, the effect of tamoxifen treatment was even more dramatic. Among the five-hundred-odd women older than fifty assigned to each group, tamoxifen had prevented fifty-five relapses and deaths. Fisher had altered the biology of breast cancer after surgery using a targeted hormonal drug that had barely any significant side effects.