Dacomitinib delayed FaDu tumor growth, alone and in combination with IR.

<p>(A) FaDu-bearing mice were randomized to: (i) DMSO control; (ii) Dacomitinib (5 mg/kg/d) delivered orally on days 1 to 5; (iii) local tumor irradiation (IR; 2 Gy/treatment) delivered on days 2 and 5; or (iv) Dacomitinib plus IR. Mean tumor leg diameter (TLD) from three independent experiments (three mice per treatment group, per experiment) is reported ± SEM. ***p<0.001, negative control <i>vs</i>. Dacomitinib only, or RT only <i>vs</i>. Dacomitinib plus RT; Student's <i>t</i> test. (B) Mean mouse weight ± SEM from experiment (A). (C) Ki-67 staining was performed on treated FaDu tumors: DMSO, radiation (IR), Dacomitinib (D), or Dacomitinib plus radiation (D+IR), as from (A). Tumors were extracted from mice 24 hours after the final treatment. Ki-67 positive cells stain dark brown. The right-hand panel represents the proportion of Ki-67-positive cells for each treatment group. Ki-67 scoring was conducted by counting the number of positive tumor cells in 3 representative sections for each tumor. Mean ± SEM is reported. ***p<0.001; Student's <i>t</i> test. (D) p-EGFR staining was performed on paraffin sections, as in (C). Positive Staining for p-EGFR is brown.