Impact of radiation therapy on survival in patients with triple-negative breast cancer

Abstract

Triple-negative breast cancer (TNBC) has a poorer prognosis compared with other sub-groups. In the current study, survival associated with locoregional treatment of females with TNBC was investigated. Specifically, 468 patients with stage I–III TNBC treated between 2002 and 2009 were identified. Data included patient and tumor characteristics, treatment received and survival. Data were compared using χ2 and Fisher’s exact tests, as well as MANOVA. Kaplan-Meier curves were generated. The study cohort had a mean age of 54±13 years old with a mean follow-up period of 51±21 months. Of 468 patients, 249 (53%) underwent lumpectomy, 63 (14%) underwent simple mastectomy (SM) and 156 (33%) underwent modified radical mastectomy (MRM). Overall, 263 (56%) received adjuvant radiation, including 178/249 (71%) following lumpectomy, 13/63 (21%) following SM and 72/156 (46%) following MRM (P<0.0001). Following control for potential confounders in univariate tests, adjuvant radiation was associated with improved overall survival in the total cohort (HR, 0.46; 95% CI, 0.31–0.68; P=0.0001). When comparing survival by surgical type, receipt of adjuvant radiation significantly improved survival in the lumpectomy group (HR, 0.30; 95% CI, 0.16–0.58; P=0.0004), but was not associated with improved survival in the SM group (HR, 0.38; 95% CI, 0.05–3.04; P=0.36) or in the MRM group (HR, 0.79; 95% CI, 0.46–1.34; P=0.38). The survival benefit of adjuvant radiation in these TNBC patients is attributed to those undergoing breast-conserving therapy. There was no benefit in either mastectomy group. These data warrant validation from prospective trials, in order to develop tailored locoregional treatment for patients with TNBC.

The value of adjuvant radiotherapy on survival and recurrence in triple-negative breast cancer: A systematic review and meta-analysis of 5507 patients

“…Individual study authors were also contacted to obtain frequencies not reported in the original article. One study [24], through personal communication with the authors, provided anonymous individual patient data which enabled its inclusion in specific subgroup analysis. The principal quantitative synthesis involved a comparison of BCT and PMRT.…”

“…The pooled HR was 0.57 (95% CI 0.36-0.88), Figure 4; moderate heterogeniety was present (Pheterogeniety =0.07, I 2 = 50.5%). There was little difference when the analysis was restricted to four studies [17,18,24,29] There was no statistically significant interaction between disease stage and BCT/PMRT on overall survival, Pinteraction= 0.983. Combining data from two studies [18,24], the effect of age at diagnosis on overall survival comparing PMRT and BCT to mastectomy only was examined, the corresponding pooled effect estimates were HR 0.30 (95% CI 0.11-0.82) and HR 0.22 (95% CI 0.04, 1.13) age <40 years, HR 0.76 (95% CI 0.37-1.58) and HR 0.38 (95% CI 0.11, 1.31) aged 40-64 years, and HR 0.67 (95% CI 0.14-3.18) and HR 0.79 (95% CI 0.22-2.76) aged ≥65 years respectively, Figure 6 (online only).…”

“…Six studies (3,184 patients) compared BCT to mastectomy only for overall survival [17][18][19]21,24,29]. The pooled HR was 0.57 (95% CI 0.36-0.88), Figure 4; moderate heterogeniety was present (Pheterogeniety =0.07, I 2 = 50.5%).…”

“…Previous studies examining recurrence and survival outcomes in patients with TNBC according to locoregional treatment status have produced conflicting results [17][18][19][20][21][22][23][24][25][26][27][28][29].…”

Competing Risks Analysis of African American Breast Cancer Patients

“…This finding contradicts Clark et al [30] who suggested that breast irradiation does not affect survival and Whelan et al [31] who suggested that radiation reduces risk. Steward et al's study [32] showed that adjuvant radiation improved survival of patients undergoing breast-conserving therapy. This finding is similar to our case where combination of surgery and radiation shows significant improvement in survival.…”