Figure 2.

Kaplan-Meier estimates and plots of overall survival probabilities by COX expression (A), celecoxib treatment in COX-2-expressing tumors (B), KRAS mutation status (C), and cetuximab/panitumumab treatment in KRAS wild-type tumors (D). COX-2 was assessed using immunohistochemistry. KRAS mutation was assessed using polymerase chain reaction–based DNA sequencing. KRAS negative and positive represent wild-type and mutant tumors, respectively.

Abbreviations: COX, cyclooxygenase; EGFR, epidermal growth factor receptor; Neg, negative; Pos, positive; Rx, prescription.