Significance of thyroid transcription factor 1 and Napsin A for prompting the status of EGFR mutations in lung adenocarcinoma patients

BACKGROUND: To evaluate the prompting value of thyroid transcription factor 1 (TTF-1) and Napsin A for the status of epidermal growth factor receptor (EGFR) mutations in an independent cohort of lung adenocarcinomas (LUADs) when genetic testing is unavailable. METHODS: In this study, 976 untreated primary LUADs were retrospectively reviewed. The clinical and pathological data, including age, gender, smoking history, predictive values of TTF-1 and Napsin A, EGFR status, and tumor-node-metastasis (TNM) stage were obtained through medical records available in Shanxi Province Cancer Hospital. All patients were divided into 2 groups, a mutant group (n=362) and wild-type group (n=614), according to their EGFR status. The clinical data and the expression of TTF-1 and Napsin A were compared between the 2 groups. TTF-1 and Napsin A are detected by fully automated IHC.PCR was carried out to detect the EGFR mutation. Univariate and multivariate logistic regression analyses were undertaken to distinguish independent factors of EGFR mutations. RESULTS: A total of 362 cases (37.1%) of EGFR mutations were detected, which were more frequent in females, never smokers, lymphatic metastasis, distant metastasis, and the positive expression of TTF-1 and Napsin A. Multivariate analysis indicated that females [odds ratio (OR), 1.950; 95% confidence interval (CI): 1.2958 to 2.938; P=0.001], never smokers (OR, 2.040; 95% CI: 1.345 to 3.094; P=0.001), and the positive expression of TTF-1 (OR, 2.366; 95% CI: 1.440 to 3.887; P=0.001) and Napsin A (OR, 2.295; 95% CI: 1.448 to 3.638; P<0.001) were effective prompting for EGFR mutations. CONCLUSIONS: The positive expression of TTF-1 and Napsin A had the prompting value for EGFR mutations in patients with LUAD, and the indicators could be combined with other clinical characteristics to enhance the prediction of the EGFR status in LUAD.