“The paucity of therapeutic options” for women with triple-negative breast cancer “emphasizes the urgent need to optimize the current locoregional management of patients with [triple-negative breast cancer] and reduce their risk of locoregional recurrence,” noted the authors of a Canadian study reported in the Journal of Clinical Oncology. The study, which involved 768 patients treated at a single cancer center and identified from the Alberta Cancer Registry, found that women with T1-2N0 triple-negative breast cancer treated with modified radical mastectomy without radiation had a significantly increased risk of locoregional recurrence compared to women treated with breast-conservation therapy, consisting of lumpectomy and adjuvant radiation therapy. The median age of the women was 56, although the study included a high percentage of younger women, with 40% of the women younger than 50 years at time of diagnosis.
At a median follow-up of 7.2 years, 155 patients (20%) had disease progression, 77 patients (10%) experienced locoregional recurrence, 103 (13%) developed distant metastases, and 123 (54 with locoregional recurrence and 69 with distant metastases) died as a result of disease progression. Univariate analysis revealed that patients who had breast-conservation therapy (319, or 42%), had a 5-year locoregional recurrence–free survival rate of 94%, compared to 85% for patients who had modified radical mastectomy (287, or 37%), and 87% for patients who had modified radical mastectomy plus radiotherapy (162, or 21%).
Independent Prognostic Factor
Multivariate analysis comparing modified radical mastectomy with breast-conservation therapy found that lymphovascular invasion and positive lymph nodes were associated with increased locoregional recurrence, and adjuvant chemotherapy was associated with decreased risk of locoregional recurrence. Modified radical mastectomy without radiotherapy was the only independent prognostic factor associated with increased risk of locoregional recurrence compared with breast-conservation therapy, the authors reported.
The authors noted that their study requires further validation from prospective clinical trials addressing the issue of locoregional management and risk of locoregional recurrence specifically in triple-negative breast cancer, which may lead to tailoring of locoregional treatment based on risk of recurrence in this setting. ■
Abdulkarim BS, et al: J Clin Oncol. July 5, 2011 (early release online).