A study of phosphorylated ERK1/2 and COX‐2 in early stage (T1–T2) oral squamous cell carcinomas

Background: Histomorphological grading at the invasive front of oral squamous cell carcinomas (OSCCs) may provide useful prognostic information. In the present study, we investigated the presence and prognostic value of activated phosphorylated extracellular signal‐regulated kinases 1 and 2 (p‐ERK1/2) and cyclo‐oxygenase‐2 (COX‐2) both at the invasive front and in central/superficial parts of OSCCs. Methods: Using immunohistochemistry, we assessed the presence of p‐ERK1/2 and COX‐2 in 53 early stage OSCCs. Clinical data were recorded prospectively. The end point was disease‐free survival. Results: p‐ERK1/2 staining was present in almost all tumours. The staining was mostly nuclear in the cells of the invasive front and either nuclear or nuclear/cytoplasmic in central/superficial tumour parts. COX‐2 was observed in almost all tumours (98%) and the staining was often restricted to focal areas. Most tumours were COX‐2 negative at the invasive front. The lowest P‐value in survival analyses was P = 0.06 for p‐ERK1/2 at the invasive front. COX‐2, the histomorphological grading systems and TNM stage were of no prognostic value. Conclusion: p‐ERK1/2 was present in almost all tumours and p‐ERK1/2 may be a prognostic marker at the invasive front of OSCCs. In early stage OSCCs, most tumours did not express COX‐2 at the invasive front.