Ten-year results of accelerated hypofractionated adjuvant whole-breast radiation with concomitant boost to the lumpectomy cavity after conserving surgery for early breast cancer

Abstract

Accelerated hypofractionated whole-breast radiotherapy (WBRT) is considered a standard therapeutic option for early breast cancer (EBC) in the postoperative setting after breast conservation (BCS). A boost to the lumpectomy cavity may further increase local control. We herein report on the 10-year results of a series of EBC patients treated after BCS with hypofractionated WBRT with a concomitant photon boost to the surgical bed over 4 weeks. Between 2005 and 2007, 178 EBC patients were treated with a basic course of radiotherapy consisting of 45 Gy to the whole breast in 20 fractions (2.25 Gy daily) with an additional boost dose of 0.25 Gy delivered concomitantly to the lumpectomy cavity, for an additional dose of 5 Gy. Median follow-up period was 117 months. At 10-year, overall, cancer-specific, disease-free survival and local control were 92.2% (95% CI 88.7-93.4%), 99.2% (95% CI 96.7-99.7%), 95.5% (95% CI 91.2-97.2%) and 97.3% (95% CI 94.5-98.9%), respectively. Only eight patients recurred. Four in-breast recurrences, two axillary node relapses and two metastatic localizations were observed. Fourteen patients died during the observation period due to other causes while breast cancer-related deaths were eight. At last follow-up, ≥G2 fibrosis and telangiectasia were seen in 7% and 5% of patients. No major lung and heart toxicities were observed. Cosmetic results were excellent/good in 87.8% of patients and fair/poor in 12.2%. Hypofractionated WBRT with concomitant boost to the lumpectomy cavity after BCS in EBC led to consistent clinical results at 10 years. Hence, it can be considered a valid treatment option in this setting.

Keywords: Adjuvant whole-breast radiation; Breast cancer; Concomitant boost; Hypofractionated radiotherapy; Hypofractionation; Local control.