Mutations of the adenomatous polyposis coli gene in areca quid and tobacco-associated oral squamous cell carcinomas in Taiwan

Background: Adenomatous polyposis coli (APC) gene mutations have been demonstrated not only in colorectal tumors but also in a variety of human cancers. Methods: To elucidate the possible roles of APC gene mutations in oral squamous cell carcinomas (OSCCs), we examined 40 untreated human primary OSCCs using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing assays. Results: By screening nearly one-half of the coding region (codons 279-1673, including the MCR) of the APC gene, five missense mutations and a 1-base pair deletion were detected in five (12.5%) tumors, resulting in five amino-acid substitutions or a truncation of the APC protein. All patients with APC mutations were both areca quid chewers and tobacco smokers (P = 0.049). Conclusions: These results suggest that APC mutations may also contribute to the carcinogenesis of at least some OSCCs in Taiwan, especially for the users of areca quid and tobacco.