(HealthDay News) — Over the long term, treatment with radiation plus tamoxifen for early-stage breast cancer leads to a small benefit in locoregional recurrence, but not in an advantage for overall survival, distant disease-free survival, or breast preservation, according to a study published online May 20 in the Journal of Clinical Oncology.
Kevin S. Hughes, M.D., from Massachusetts General Hospital in Boston, and colleagues randomly assigned 636 women (age ≥70 years) who had clinical stage I (T1N0M0 according to TNM classification) estrogen receptor-positive breast carcinoma treated by lumpectomy to receive either tamoxifen plus radiation therapy (TamRT; 317 women) or tamoxifen alone (Tam; 319 women) between July 1994 and February 1999.
The researchers found that, at 10 years of follow-up, 98% of patients receiving TamRT and 90% of those receiving Tam were free from local and regional recurrences. Time to mastectomy, time to distant metastasis, breast cancer-specific survival, and overall survival did not significantly differ between the two groups. Overall survival was 67% in the TamRT group and 66% in the Tam group at 10 years.
“With long-term follow-up, the previously observed small improvement in locoregional recurrence with the addition of radiation therapy remains,” the authors write. “However, this does not translate into an advantage in overall survival, distant disease-free survival, or breast preservation.”