Purpose: To determine the prognostic significance of triple negative breast cancers with respect to locoregional relapse and distant metastasis in conservatively managed breast cancer patients.
Patients and methods: A database of conservative managed (conservative surgery followed by radiation) patients, in whom all three markers (estrogen receptor, progesterone receptor, and HER2/neu) were available, was reviewed. Patients were classified as triple negative if they tested negative for all three markers. Of 482 patients with all three markers available, 117 were classified as triple negative.
Results: As of September 2005, with a median follow-up time of 7.9 years, of the 482 patients in the study, there have been 53 in-breast relapses, 10 nodal relapses, 77 distant relapses, and 69 deaths. At 5 years, the triple negative cohort had a poorer distant metastasis-free rate compared with the other subtypes (67% v 82%, respectively; P = .002). Triple negative subtype was an independent predictor of distant metastasis (hazard ratio = 2.14; 95% CI, 1.31 to 3.53; P = .002) and cause-specific survival (hazard ratio = 1.79; 95% CI, 1.03 to 3.22; P = .047). There was no significant difference in local control between the triple negative and other subtypes (83% v 83%, respectively). Of 99 BRCA-tested patients in this cohort, 10 had deleterious mutations in BRCA1, and seven had mutations in BRCA2. Of 10 BRCA1 patients, eight were triple negative, whereas only one of seven BRCA2 patients was triple negative (P < .001).
Conclusion: Patients classified as triple negative have a poor prognosis. However, there was no evidence that these patients are at higher risk for local relapse after conservative surgery and radiation. Patients with BRCA1 mutations develop predominantly triple negative tumors.