The role of radiation therapy after local excision of invasive and noninvasive breast cancer.

Data from randomized and nonrandomized studies demonstrate that the addition of breast irradiation after local excision of invasive and noninvasive breast cancers markedly reduces the breast failure rate. Local excision with breast irradiation remains the standard approach for breast-conserving therapy for both invasive and noninvasive cancers. Some data suggest that there might be patient subgroups that could be treated with local excision without radiotherapy, but additional studies are necessary to better define these groups.