Adjuvant systemic therapy for lymph node-negative breast cancer less than or equal to 1 cm

Routine screening mammography has increased the incidence of stage I breast cancers. Many more women are being diagnosed with lymph node-negative tumors that are less than or equal to 1 cm in greatest diameter. The National Surgical Adjuvant Breast and Bowel Project recently performed a retrospective analysis of 10,302 women participating in one of five clinical trials, including women with lymph node-negative breast cancer. Of these women, 1259 had tumors less than or equal to 1 cm. The analysis of the women with tumors less than or equal to 1 cm revealed an improved relapse-free survival (RFS) if tamoxifen was given after surgery, compared with surgery alone, for women with estrogen receptor (ER)-positive tumors; and for women with ER-negative tumors, RFS was improved by delivering chemotherapy after surgery. The authors suggested that adjuvant systemic therapy should be considered for anyone with an invasive breast cancer, regardless of the size of the tumor. This paper reviews the data presented in that important, historic article, and discusses their conclusions. Also reviewed are the most recent recommendations for treatment of primary breast cancer from the International Consensus Panel that convened at the Seventh International Conference on Adjuvant Therapy of Primary Breast Cancer in St. Gallen, Switzerland. That panel also addressed the issue of adjuvant systemic therapy in women considered to have a minimal or low risk of developing recurrent disease.