There were 500 breast cancers diagnosed in 464 patients. Thirty-six patients (8%) had bilateral breast cancer with 9 (2%) synchronous and 27 (6%) metachronous primaries. In 80 patients, the ipsilateral internal mammary nodes were explicitly treated. Initial breast cancer treatment choices impacted subsequent treatment decisions for the contralateral breast in only 2 of 464 patients (0.4%) in the study: 2 of 80 patients (2.5%) whose internal mammary nodes were treated, and 2 of 27 patients (7