The roles and controversies of radiation therapy in breast conserving therapy for breast cancer

Breast conserving therapy (BCT) is defined as a combination of conservative surgery for resection of the primary tumor, followed by radiation therapy (RT) for the eradication of residual microscopic disease in the breast. At NIH Consensus Development Conference in 1990, BCT was recognized as the preferred treatment for the majority of women with Stage I and II breast cancer. RT is a potent locoregional treament and its role in BCT in reducing local recurrence is already established. On the other hand, the influence of RT on survival outcome has not yet been closely demonstrated so far. RT appears to be useful as neoadjuvant therapy, and also as exclusive local treatment for patients achieving complete regression (CR) after neoadjuvant chemotherapy. The other possible role of RT is to use it as an alternative to axillary dissection in patients with clinically uninvolved nodes. The question of the appropriateness of using RT in all BCT cases is raised. Since the subgroup of patients who would not deserve any benefit by RT has not yet identified, RT should be delivered as standard treatment following breast conserving surgery for early stage breast cancer.