New results from two clinical trials suggest that either of two types of radiation therapy after breast-conserving surgery for women with early-stage breast cancer can reduce the risk of the cancer returning. In the randomized clinical trials, both whole-breast irradiation (WBI) and accelerated partial-breast irradiation (APBI) were associated with low rates of the cancer recurring in the breast where the disease originally developed. The median follow-up ranged from more than 5 years to more than 10 years. US and Canadian researchers presented results from both trials at the San Antonio Breast Cancer Symposium on December 6. WBI is typically given to the whole breast in a series of treatments 5 days a week for 4 to 6 weeks. By comparison, APBI is given only to the part of the breast that has or had cancer in it, and the treatments are completed in a week or less.