Markers of chemoradiation resistance in patients with locally advanced head and neck squamous cell carcinoma, treated by intra-arterial carboplatin and concurrent radiation.

The onset of chemo- and/or radio-resistance in tumour cells is one of the main causes of failure of integrated treatment protocols combining intra-arterial administration of platinum derivatives and radiotherapy, and is associated with recurrent disease and/or distant metastases. In the present study, the expression of a series of markers of chemo- and/or radio-resistance was investigated in 21 patients with advanced squamous cell carcinoma of the head and neck treated with combined intra-arterial carboplatin and radiotherapy. The results were correlated with local response to treatment, recurrence and overall and disease-free survival. In non-responders or in patients presenting recurrence, caspase 8 was significantly (p 0.05) under-expressed while p-Gp (p 0.035) and MDR-3 (p 0.049) were significantly over-expressed. Tumours with unfavourable outcome more frequently over-expressed two or more anti-apoptotic factors (p-53, BCL-2, BCL-x) (p 0.01). Patients with shorter overall survival, significantly overexpressed p53 (p 0.04), LRP (p 0.038) and a larger number of trans-membrane transport proteins compared with those who survived more than one year (p 0.013). Finally, patients with the shortest disease-free survival presented over-expression of p53 (p 0.027) and BCL-x (p 0.023). Further studies are necessary to confirm the possibility, in a future perspective, of using a panel of markers of chemo- and radio-resistance to identify those patients potentially sensitive to the treatment and to avoid patients at high risk of resistance from being submitted to ineffective and toxic treatment protocols.