Triple-Negative Breast Cancer (Tnbc) And Residual Disease (Non-Pcr): Does Size Matter?

106 Background: TNBC is associated with distinctly worse survival rates than non-TNBC unless a pCR is achieved (Liedtke C et al. J Clin Oncol. 2008;26:1275-1281) or almost achieved (Symmans WF. J Clin Oncol. 2007;25:4414-4422). Recent pooled analyses pointed out that pCR defined as "no invasive and no in situ residuals in breast and lymph nodes" can best discriminate between patients with favorable and unfavorable outcomes (Minckwitz von G. J Clin Oncol. 16 April 2012). However, no differentiation has been made with regard to the prognosis within the category of "gross disease" (non-pCR, > 5 mm) after primary systemic therapy (PST).In this retrospective case series study, we analyzed 506 non-pCR patients out of a cohort of 16,196 patients with neoadjuvant or adjuvant chemotherapy from breast units of the West German Breast Center (WBC) at 24 months after surgery.Overall survival (OS) differed significantly between the non-pCR groups ypT1 a (88%) and ypT1b,c (both 77%) likewise the disease-free survival (DFS) was 79% versus 63% (p< 0.05) at 24 months after surgery. Beyond ypT1-stage, we found that ypT1+2 and ypT3+4 set up two significantly distinct groups in OS and DFS, with OS rates of 79% for ypT1+2 and 60% respectively 68% for ypT3 and ypT4. DFS rates were alike differing with 68 % and 62 % for ypT 1 and ypT2 from both ypT3 and ypT4 (20% and 28%). Distant disease free survival (DDFS) was markedly superior in ypT1a (93%) and ypT1b (88%) versus ypT1c (77%). Stage-dependent DDFS was 82% for ypT1 respectively 81% for ypT2 and thus significantly different from stages ypT3 and ypT4 (43% and 52%) (p< 0.05).Risk stratification currently is made dichotomously: pCR and non-pCR. However it does not differentiate within the group of non-pCR. This case cohort trial investigates the prognosis of non-pCR according to the actual size of the residual disease. Overall survival at 24 months after surgery has to be differentiated between the groups ypT1a and ypTb,c and moreover between ypT1+2 and ypT3+4. This is to our knowledge the largest case cohort study analyzing the effect of gross residual disease on prognosis of patients with TNBC demonstrating: size does matter.