A new study has reported that omission of radiation treatment after breast-conserving surgery (typically, lumpectomy) has been more common in recent years, especially among women who have a significant risk of breast cancer recurrence. The study was designed to determine which invasive breast cancer patients do not receive radiation treatment after breast-conserving surgery in the U.S. Radiotherapy after breast-conserving surgery is associated with a significant reduction in recurrence in the same breast, as well as breast cancer-specific mortality, in women with early stage breast cancer.

To conduct the study, the authors used data from the Surveillance, Epidemiology, and End Results (SEER) registry. The pool included 294,254 women with stage I through III breast cancer who received breast cancer surgery in the U.S. between 1992 and 2007. The rate of radiation therapy was determined and multivariate analysis was used to identify independent predictors of omission of radiation treatment.

The majority of the women (57%) were treated with breast-conserving surgery. However, 21.1% of those who underwent breast-conserving surgery did not receive radiation treatment afterwards. The omission of radiation treatment increased significantly between 1992 (15.5%) and 2007 (25%). Women with increased cancer stage, age less than 55 years, high-grade tumors, large tumors, positive or untested lymph node status, African-American or Hispanic race, and negative or unknown estrogen receptor (ER) status were significantly less likely to receive radiation treatment. Significant geographic variation was also found in the likelihood of radiation treatment. The authors conclude that the omission of radiation treatment after breast-conserving surgery has been more common in recent years, especially among women who have an increased risk of breast cancer recurrence. This trend represents a serious health care concern because of the potential increased risk of local recurrence and breast cancer mortality.