Correlative analyses between EGFR pathways and stroma-tumor profiles in head and neck cancer patients (HNSCC) on postoperative radiotherapy plus cisplatin (PORTc) plus or minus gefitinib (GORTEC-GETTEC CARISSA trial): Implications for sensitivity to gefitinib.

TPS268 Background: PORTc is the standard treatment for resected poor-prognosis HNSCC. However, numerous patients fail. Anti-EGFR agent gefitinib is radiosensitizing. Gefitinib has FDA approval for EGFR-mutated lung cancer patients. CARISSA aims are: test the PORTc-gefitinib combination + identify a HNSCC subgroup sensitive to gefitinib. Prior CARISSA communication showed similar compliance to PORTc and no excessive toxicity. EGFR tyrosine-kinase domain mutations are anecdotic in HNSCC; Braf and Ras require investigations. Preliminary reports suggest that PTEN, pAkt, Ecadherin confer resistance to gefitinib in HNSCC. Human papilloma virus and tumor-stroma-EGFR pathways profiles are yet partially unknown in HNSCC despite publications on the role of stroma (matrix, tumor-activated fibroblasts) in tumor progression, invasiveness. The availability of operative samples was a unique opportunity to investigate the overall tumor behavior and response to gefitinib in regards to recent enlightenments on tumor biolog...