The Association amongst ‘Triple Negative’ Breast Cancers, Lymph Node Metastasis, Disease Free and Overall Survival

Abstract ‘Triple negative' breast cancer (TNBC) has fewer specific targets for systemic therapy. We hypothesized that patients with TNBC have an increased incidence of sentinel lymph node (SLN) metastases and decreased disease-specific and overall survival. Method: Pertinent clinical, pathologic and follow-up data from all breast cancer patients undergoing SLN biopsy from 1995 through 2008 were prospectively accrued and retrospectively analyzed. Overall survival was determined by Kaplan-Meier and regression analysis with particular attention to TNBC compared to “receptor positive breast cancer” (RPBC) that expressed any of the three targets: ER, PR and/or Her-2/neu. Results: 1,971 patients treated by standard loco-regional and systemic therapies were followed for 1 to 16.4 years. 230 (11.7%) patients had TNBC. Median and mean follow-up times for all patients were 54 and 59.7 months, respectively. There was no significant difference in the rate of SLN metastases between TNBC and RPBC (p=0.564). In the univariate analysis TNBC demonstrated a higher incidence of lymphovascular invasion (LVI) (p=0.016), larger tumor size (p<0.001), and higher grade (p<0.001). Age and tumor grade were significantly different in the multivariable model (p=0.009 and p<0.001, respectively). TNBC increased the odds of distant metastases by 2.15 fold; however this was not statistically significant (p=0.063). There was a 2.71-fold increased risk of cancer death in the TNBC group in the first 8 years after initial treatment. Overall survival tended to be worse but did not reach statistical significance (p=0.079). Conclusion: Patients with TNBC had an increased mortality in the first eight years after treatment when compared to patients with RPBC. There was no difference in rates of SLN metastasis.