Plichta JK, et al. - Clinical and pathological stage discordance rates were determined and factors associated with discordance were assessed among adults with clinical stages I-III breast cancer identified from the National Cancer Data Base. Researchers defined concordance as cTN=pTN (discordance: cTN≠pTN). The analysis revealed clinical and pathological stage discordance in nearly one-third (31.8%) of patients. They noted upstaging in 8.7% and downstaging in 23.1%. Stage discordance was noted to be correlated with tumor grade, histology and biomarker status.