The importance of radiation therapy for older women with early breast cancer

The importance of radiation therapy for older women with early breast cancer is controversial.  We identified 8,724 women in a large population-based registry who were age 70 and older and treated with conservative surgery for small (less than 2 cm in size), estrogen receptor positive or unknown, invasive breast cancer.  A total of 73% received radiation after conservative surgery.  We found that women who received radiation were less likely to develop an ipsilateral breast tumor recurrence and also less likely to undergo salvage mastectomy.  At five years, the risk of recurrence and/or mastectomy was 5% for women who did not receive radiation and 1% for women who did receive radiation.  At eight years, the risk of recurrence and/or mastectomy was 8% for women who did not receive radiation and 2% for women who did receive radiation.  Women ages 70 to 79 without significant comorbid illness were most likely to benefit from radiation, with a number needed to treat of 21 to 22.  In addition, we found that the following characteristics were associated with a higher risk of recurrence and a greater absolute benefit from radiation: (1) lobular histology, (2) tumor size greater than 2.0 cm, (3) estrogen receptor negative status, and (4) age 66 to 69 years.  Radiation should be strongly considered for women with any of these characteristics.

Bibliographical reference:

Smith BD et al.: "Effectiveness of radiation therapy for older women with early breast cancer", J Natl Cancer Inst. 2006 May 17;98(10):681-90

Benjamin D. Smith
Department of Therapeutic Radiology, Yale-New Haven Hospital, New Haven, CT, USA