Nonrandom DNA copy number changes related to lymph node metastases in squamous cell carcinoma of the lung.

Lung cancer is one of the most common malignancies and cancer-related death worldwide. Lymph node metastasis is the main cause of treatment failure. Although many studies were performed to evaluate genetic events associated with development and progression of lung cancer, molecular mechanism still remains poorly defined. In the present study, using comparative genomic hybridization (CGH) technique, we described the pattern of DNA copy number changes in a cohort of 42 primary squamous cell carcinomas (SCC) of the lung. A direct comparison of non-metastatic (T1N0M0) and metastatic (T1N1-2M0) tumors was performed to define chromosomal imbalances related to lymph node metastases. Some genetic alterations were observed more frequently in metastatic than in non-metastatic tumors, including losses at 11q, 16p, 16q, 19p and gains at 4q, 7q, 12p, 13q, 18p. The gain at 7q with the smallest common altered region 7q31.2-q32, was found to be directly associated with lymph node involvement (p=0.0407). We suggest that the established chromosomal region harbors two putative tumor suppressor genes WNT2 and c-Met. An overexpression of these genes seems to be involved in inducing the invasive growth and metastatic potential of SCC of the ring.