Women with low-risk, node-negative, early stage breast cancer who received a shorter, more intense course of radiation therapy after breast-conserving surgery had the same risk of disease recurrence and equivalent cosmetic outcomes (appearance of the treated breast compared with the untreated breast) 10 years after treatment compared with women who received a longer, standard course of radiation therapy, according to results presented September 22 at the American Society for Therapeutic Radiology and Oncology annual meeting in Boston, Massachusetts.

The study, conducted at 10 cancer centers in Canada, involved 1,234 women who underwent a lumpectomy and were randomly assigned to receive radiation at a dose of either 50 Gy in 25 fractions over 35 days (2 Gy per fraction) or a shorter course of 42.5 Gy in 16 fractions over 22 days (about 2.66 Gy per fraction).

After 10 years of follow-up, the risk of local recurrence remained approximately the same between the two groups: 6.7 percent for women receiving the standard course versus 6.2 percent for women receiving the short course.

Seventy-one percent of women receiving the standard course had excellent or good cosmetic outcomes compared with 70 percent of women receiving the short course. A small number of women in both groups had late radiation damage to the skin or underlying tissue after 10 years of follow-up, but the incidence of late radiation damage was not statistically significantly different between the groups.

For women with early stage, low-risk breast cancer, "The shorter course of radiation therapy was associated with excellent long-term local control and limited late morbidity, similar to that seen with conventional fractionation for whole breast irradiation," the researchers concluded. "Given the benefits of convenience and cost, such an approach should be considered for women with early breast cancer."