Genomic instability in the progression of sporadic nasopharyngeal carcinoma.

Abstract

Genomic instability reflecting the susceptibility of the genome to acquire multiple genetic alterations plays a major role in tumorigenesis and tumor progression. We evaluated the prognostic significance of the extent of genomic instability in nasopharyngeal carcinoma. Genomic instability was assessed by inter-simple sequence repeats polymerase chain reaction (inter-SSR PCR) in 38 patients with nasopharyngeal carcinoma. Characterization and verification of band alterations shared in different tumors were carried out by sequencing and nest PCR. 31 (81.6%) of 38 patients showed genomic alterations, and genomic instability index ranged from 0 to 16.2%. A gain-based genomic damage shared in 6 tumors was identified on chromosome 6q27, a new mutator phenotype in nasopharyngeal carcinoma. Significantly more genomic alteration was found in patients without 5-year survival than that with 5-year survival (P<0.05), suggesting that higher genomic instability predicts a poor prognosis in nasopharyngeal carcinoma. Our data suggests that genomic instability can be an early event marker in carcinogenesis of nasopharyngeal carcinoma. Also, aggravation of genomic alterations is a poor prognosis for cancer recovery.