Wang Haofei, Wu Hua, Cai Kaican, Ju Qun, Wang Wujun
Department of Cardiothoracic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China.
J BUON. 2012 Oct-Dec;17(4):729-34.
To investigate the prevalence of phosphatidylinositol 3-kinase (PIK3CA) gene amplification in lung cancer, and to explore its prognostic value.
A total of 647 lung tumor samples from 290 patients were included in the study. The ratio of PIK3CA signals/centromere 3 signals in cancer cells was estimated by fluorescence in situ hybridization (FISH7rpar; analysis.
Both gains and amplifications were significantly more frequent in squamous cell (gains: 19.4%; amplifications: 34.1%; p<0.0001) and large cell carcinoma (gains: 22.4%; amplifications: 20.4%; p<0.0001) compared with adenocarcinomas (gains 3.0%; amplifications: 4.0%). Conversely, adenocarcinomas displayed significantly more frequent deletions of the PIK3CA locus than the other two histologic types (p<0.0001). No clear correlation between PIK-3CA status and the pT stage, pN stage or the degree of tumor differentiation was found. Ki67 significantly increased with increasing of PIK3CA copy number: 47 tumors with a PIK-3CA deletion had a mean Ki67 of 16, while 103 tumors with PIK3CA amplification showed a mean Ki67 of 28 (p=0.004). Significant association between cell proliferation and PIK-3CA was found (p<0.05). However, no significant correlation was seen between patient survival and PIK3CA amplifications, deletions and gains.
PIK3CA amplifications in large cell and squamous cell carcinomas were significantly higher compared with adenocarcinomas. The results suggest that PIK-3CA could be a promising target for selective lung cancer therapy.
