Figure 3

mRNA-based combined quantitative determination of human epidermal growth factor receptor 2 (HER2) and estrogen receptor 1 (ESR1) mRNA. Cases with a pCR are marked as dark spots. (A) Total of 217 cases. (B) Centrally HER2-positive cases (n = 158). In this group a total of 21 cases (13.3%) were HER2-negative by mRNA analysis; the pCR rate of those 21 cases was only 23.8%. The pCR rate in those 137 cases that were HER2-positive by mRNA analysis was 50.4%, (P = 0.03, two-sided Fisher's exact test). (C, D, E) All 217 cases: different distribution patterns of HER2 mRNA with a continuous distribution in ESR1-positive tumors (D) and a more dichotomous distribution in ESR1-negative tumors (E). STEPP analysis for all 217 tumors (F), ESR1-positive tumors (G) and ESR1-negative tumors (H). HER2 mRNA levels were linked to pCR rate in the group of ESR1-positive tumors with a continuously increased pCR rate. pCR, pathological complete response; STEPP, subpopulation treatment effect pattern plot.