Locoregional recurrence of triple-negative breast cancer after breast-conserving surgery and radiation.

Triple-Negative Breast Cancer After Breast-Conserving Surgery and Radiation I read with interest the article by Freedman et al investigating the results of radiation on the local control of triple receptor-negative (TN) breast cancer (negative estrogen [ER], progesterone [PR], and HER-2 receptors). The authors compared 3 different groups defined by receptor status as follows: Group 1: ER or PR positive (þ); Group 2: ER and PR negative ( ) but HER-2 (þ); and Group 3: TN. The study population was comprised of 753 patients with T1 to T2 disease who were treated with breast-conserving surgery and radiotherapy. The isolated 5-year locoregional recurrence (LRR) rate, an endpoint of the study, did not significantly differ between Groups 1 (2.3%), 2 (4.6%), or 3 (3.2%) (P 1⁄4 .36). Accordingly, the authors concluded that patients with TN breast cancer were not at an increased risk for isolated LRR at 5 years. However, to evaluate more precisely the timing of disease recurrence for the 3 subgroups, the annual hazard rate of LRR should be estimated. In fact, as noted in the large study by Dent et al, although the patients with TN and other breast cancer subtypes experienced a similar rate of LRR (13% vs 12%; P 1⁄4 .77), the mean time to LRR was shorter in patients with TN tumors than other breast cancer subtypes (2.8 years vs 4.2. years, respectively; P 1⁄4 .02). A similar finding also appears possible in the study by Freedman et al when examining Figure 1, which described the actuarial total LRR between the 3 groups. Although no overall difference was found between the 3 groups (P 1⁄4 .13), all LRR in Groups 2 (HER 2þ) and 3 (TN) appeared to occur within 2 years of diagnosis. In contrast, in Group 1 (ERþ or PRþ) LRR continued to accrue for up to 6 years after diagnosis. In conclusion, despite having a risk of LRR that is similar to that of patients with other breast cancer subtypes, it appears that patients with TN breast cancer are more like to experience LRR early after diagnosis. This observation could have important clinical implications, especially in terms of follow-up policy. REFERENCES 1. Freedman GM, Anderson PR, Li T, Nicolaou N. Locoregional recurrence of triple-negative breast cancer after breast-conserving surgery and radiation. Cancer. 2009;115: 946-951. 2. Dent R, Trudeau M, Pritchard KI, et al. Triple-negative breast cancer: clinical features and patterns of recurrence. Clin Cancer Res. 2007;13:4429-4434.