Activation of EGFR signalling can lead to increased transcription of COX-2. Increased COX-2 transcription results in enhanced production of PGs, including PGE2, which in turn can activate EGFR initiating a positive feedback loop. Although majority of HNSCC over-express EGFR, the clinical responses to EGFR targeting agents have been modest. When the mechanisms of intrinsic resistance are identified like the mutations in the EGFR receptor, alternative therapeutic approaches should be employed. In preclinical studies, combining an inhibitor of COX-2 with an inhibitor of EGFR tyrosine kinase was more effective than either agent alone in suppressing tumor formation. Acquired resistances that may be amenable to pharmacological intervention include deregulation of EGFR degradation, constitutive activation of overlapping signal transduction pathways, especially cMET/HER3, the PI3K/Akt resistance pathway, angiogenesis and epithelial to mesenchymal transition. Preclinical data suggest that COX-2 inhibitors can affect most of the described acquired EGFR resistance pathways.