Figure 1. A breast tumor harboring mutant KRAS does not demonstrate molecular endocrine resistance.
A) Chemical structure of letrozole B) Sanger sequencing traces of KRAS codon 12 in the left and right bilateral tumors, before and after 2 weeks of letrozole therapy. C) Plot of Ki67 scores in left and right breast tumors before and after 2 weeks of letrozole therapy. Ki67 IHC was scored by 3 blinded independent pathologists to account for variability in scoring. Bars represent mean ± s.d. D) Representative IHC of Ki67 in left and right breast tumors before and after 2 weeks of letrozole therapy.