There is no survival benefit in adding radiation therapy after lumpectomy and tamoxifen in women aged 70 years or older with early stage breast cancer, according to the results of a study published in the Journal of Clinical Oncology.
Many women with early stage breast cancer are treated with breast-conserving surgery (lumpectomy) followed by radiation therapy in order to reduce the risk of cancer recurrence; however, there has been debate as to whether radiation therapy provides benefit in older women with the disease.
To examine the best course of action in this population, researchers analyzed data from a long-term study known as Cancer and Leukemia Group B (CALGB) 9343. The data included 636 women age 70 or older with stage I estrogen receptor (ER)-positive breast cancer. All women underwent lumpectomy and then were randomly assigned to receive tamoxifen plus radiation therapy or tamoxifen alone.
The median follow-up for patients in this study is now 12.6 years. At 10 years, 98 percent of patients receiving tamoxifen plus radiation were free from local and regional recurrences, compared with 90 percent of those who received tamoxifen alone. There were no significant differences between the two groups in regards to overall survival, time to mastectomy, time to distant metastasis, or breast cancer-specific survival. The 10-year overall survival rate was 67 percent in the tamoxifen plus radiation group and 66 percent in the tamoxifen alone group.
The researchers concluded that after long-term follow-up, there appears to be limited benefit with the addition of radiation after lumpectomy in older women with early stage breast cancer. The small improvement in locoregional recurrence does not appear to translate to an advantage in overall survival, distant disease-free survival, or breast preservation. They concluded that lumpectomy and tamoxifen is a reasonable option for women over age 70 with ER-positive early stage breast cancer.
Hughes KS, Schnaper LA, Bellon JR, et al. Lumpectomy plus tamoxifen with or without irradiation in women age 70 years or older with early breast cancer: Long-term follow-up of CALGB 9343. Journal of Clinical Oncology. Published early online May 20, 2013. doi: 10.1200/JCO.2012.45.2615
Posted July 15, 2013