Treatment often varies based on the number of positive nodes.
The study was conducted at Fox Chase Cancer Center in Philadelphia, Pennsylvania. In the study, a model is provided to determine the probability of four or more positive nodes in a patient. The presence of four or more positive axillary nodes is considered an indication for the addition of radiation treatment to the supraclavicular region in patients undergoing breast conservation therapy, and the chest wall and regional nodes in the post-mastectomy setting. Each had stage I or II breast cancer and underwent an axillary dissection as part of their treatment. A minimum of 10 lymph nodes was examined in each patient.