A gene expression profile for non-smoking and non-drinking patients with head and neck cancer.

OBJECTIVE: A small subset of patients with head and neck squamous cell carcinoma are non-smoking and non-drinking and have distinct clinical characteristics. We aimed to identify a possible different genetic profile for these patients when compared with their smoking and drinking counterparts. MATERIALS AND METHODS: The gene expression data previously detected from primary tumors located in the oral cavity and oropharynx, using DNA microarray was analyzed for their differential expression between non-smoking and non-drinking patients (n = 15) and smoking and drinking patients (n = 89). Student's T-test (P < 0.05) and 10-fold cross-validation procedure (100 times repeated) were performed to determine differentially expressed genes. RESULTS: Non-smoking and non-drinking patients were older, mostly female and had oral cavity-localized tumors, whereas smoking and drinking patients were younger male patients with 81% oral cavity and 19% oropharynx tumors. A set of 49 differentially expressed genes were detected. Among others, seven genes related to interferon-gamma were upregulated and two genes linked to NFKB pathway were downregulated. CONCLUSIONS: Differentially expressed genes in non-smoking and non-drinking patients possibly indicate the presence of a different cellular response to carcinogenic events in these patients. Further studies are warranted to validate this gene set and explore possible therapeutic implications to improve prognosis for these patients.