Pract Radiat Oncol. 2014;4(6):e269-78. doi: 10.1016/j.prro.2014.05.006. Epub 2014 Jul 11.
Utilization and impact of a postmastectomy radiation boost for invasive breast cancer.
Authors: Mayadev J1, Fish K2, Valicenti R3, West D2, Chen A4, Martinez S5, Phillips T6.
Additional radiation following postmastectomy radiation (PMRT) has an undefined benefit. We investigate those likely to be selected for a chest wall boost (CWB) and its effect on breast cancer survival (BCS) and overall survival (OS).
METHODS AND MATERIALS:
A total of 4747 women diagnosed from 2005 to 2009 were treated with PMRT identified from the California Cancer Registry (CCR); 2686 (57%) received a CWB. Univariate and multivariate analyses compared those receiving and not receiving a CWB for BCS and OS.
With a median follow-up of 43.6 months, patients likely to receive a CWB were stage III (P ≤ .001), grade 3/4 (P = .03), positive nodes (P = .04), HER 2+ (P =.02). CWB was not related to BCS in the univariate (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.82-1.21), multivariate (HR, 1.04; 95% CI, 0.86 -1.26) analyses, and was not related OS for the univariate (HR, 0.92; 95% CI, 0.78-1.10), multivariate (HR, 0.95; 95% CI, 0.80-1.13) analyses. However, in multivariate analysis, patients not receiving chemotherapy who had a CWB had better BCS (HR, 1.77; 95% CI, 1.11-2.83).
The majority of patients were treated with a CWB. We found no difference in BCS or OS with the addition of a CWB.