ABSTRACT
Breast cancer was formerly thought to be a disease that progressed in a predictable manner. The breast itself was affected first; then after a time, the disease progressed to the lymph nodes, where it remained in place. It is worth noting that in the 1920s and 1930s several small series of patients treated with breast tumor excision plus breast irradiation were reported within larger series of postoperative radiation patients. While the results in these small groups of patients were encouraging, the observation was never followed up in this country. Therefore, the treatment of breast cancer was left almost entirely in the hands of the surgeon, who was armed with a radical operation. It was in this setting that change began to occur. Several reasons can be cited to explain the rapid increase in the use of nonmastectomy treatment for primary breast cancer. Over the past 30 years, medical science has developed a new understanding of the biology of breast cancer.
