Some people with early breast cancer can skip radiation or removal of armpit lymph nodes without increased risk for recurrence, researchers reported at the San Antonio Breast Cancer Symposium.

In two trials, researchers used Oncotype gene expression profiles to classify breast cancer patients as having a low or high risk for recurrence after surgery. A study of 171 people with ductal carcinoma in situ (noninvasive malignant cells) found that 95% of those with low risk scores who skipped radiation did not experience recurrence over five years.

In the second study, which enrolled people with Stage I breast cancer, all but two of the 186 low-risk patients who omitted radiation had no recurrence. A third study included 1,556 people whose breast cancer had spread to regional lymph nodes, but nodes became negative after presurgery chemotherapy. Five years later, patients randomly assigned to skip regional node irradiation and those who received radiation were about equally likely to remain free of recurrence (92% versus 93%), and overall survival was the same.

Finally, the SENOMAC trial included more than 2,500 early breast cancer patients with one or two positive sentinel lymph nodes. They underwent surgery, and most also received nodal radiation and hormone therapy. They were randomly assigned to undergo extensive lymph node removal, known as completion axillary lymph node dissection, or not. After four years, recurrence-free survival rates were similar in both groups (89% and 90%), but those who did not undergo lymph node removal were less likely to develop lymphedema.