Radiotherapy following modified radical mastectomy significantly improves locoregional control in patients with Rec-/HER-2+ locally advanced breast cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the risk of locoregional recurrence ( LRR ) and role of radiotherapy for patients with estrogen receptor?negative and human epidermal growth factor receptor 2?overexpressed ( Rec?/HER?2+) locally advanced breast cancer ( LABC ) . Methods A retrospective analysis was performed on the clinical data of 294 patients with Rec?/HER?2+LABC from 1999 to 2011. All patients were treated with modified radical mastectomy ( MRM ) . Of them, 239 patients received postmastectomy radiotherapy and 55 patients did not. Locoregional recurrence?free survival ( LRRFS) and overall survival ( OS) , as well as LRR, were compared between the two groups. The Kaplan?Meier method was used to estimate survival and recurrence rates, and the log?rank test was used for survival difference analysis and univariate prognostic analysis. Multivariate prognostic analysis was performed using the Cox regression model. Results The 5?year sample size was 162. Fifty?six patients developed LRR. The 5?year LRRFS and OS rates were 79. 7% and 70. 0%, respectively. Postmastectomy radiotherapy significantly increased the 5?year LRRFS rate ( 85. 1% vs. 56. 0%, P=0. 000) , but did not significantly increase the 5?year OS rate ( 71. 3% vs. 64. 2%, P= 0. 441 ) . Multivariate analysis indicated that postmastectomy radiotherapy was the only independent prognostic factor associated with increased LRRFS ( RR=0. 303, 95% CI:0. 166?0. 554, P=0. 000). Conclusions Patients with Rec?/HER?2+ LABC treated with MRM alone appear to be at a significantly increased risk of LRR compared with those treated with MRM followed by radiotherapy.