Triple-negative breast cancer: Clinical features and patterns of recurrence

Purpose: To compare the clinical features, natural history, and outcomes for women with triple- negative breast cancer with women with other types of breast cancer. Experimental Design: We studied a cohort of 1,601 patients with breast cancer, diagnosed between January 1987 and December 1997 at Women's College Hospital in Toronto. Triplenegative breast cancers were defined as those that were estrogen receptor negative, progesterone receptor negative, and HER2neu negative. The prognostic significance of triple-negative breast cancer was explored. Results: The median follow-up time of the 1,601 women was 8.1 years. One hundred and eighty of 1,601 patients (11.2%) had triple-negative breast cancer. Compared with other women with breast cancer, those with triple-negative breast cancer had an increased likelihood of distant recurrence (hazard ratio, 2.6; 95% confidence interval, 2.0-3.5; P < 0.0001) and death (hazard ratio, 3.2; 95% confidence interval, 2.3-4.5; P < 0.001) within 5 years of diagnosis but not thereafter. The pattern of recurrence was also qualitatively different; among the triple-negative group, the risk of distant recurrence peaked at similar to 3 years and declined rapidly thereafter. Among the other group, the recurrence risk seemed to be constant over the period of follow-up. Conclusions: Triple-negative breast cancers have a more aggressive clinical course than other forms of breast cancer, but the adverse effect is transient.