Differential diagnostic value of p40(ΔNp63) between lung adenocarcinomas and squamous cell carcinomas

Purpose To investigate the expression of p40(ΔNp63),TTF-1 and the value of the differential diagnostis in lung adenocarcinomas and squamous cell carcinomas. Methods The expression of p40,p63,TTF-1 in 119 lung adenocarcinomas and 107 squamous cell carcinomas were examined by EliVision immunohistochemical methods using tissue microarray. Results p40 and p63 were positive in 93. 5%(100 /107) and 94. 4%(101 /107) of lung squamous cell carcinomas,p40 was positive in 2. 5%(3 /119) of lung adenocarcinomas. The three p40-positive cases had focal reactivity in 1% ~ 5% of tumor cells,in contrast,p63 showed reactivity in26%(31 /119) of lung adenocarcinomas(1 +,20 cases,2 +,7 cases,3 +,4 cases). The positive expression rate of p40 was obviously lower than that of p63 in lung adenocarcinomas,the differences were statistically significant(χ2= 26. 9,P0. 05). TTF-1 was positive in 87. 4%(104 /119) of lung adenocarcinomas and high expression(4 +) in all three p40-positive adenocarcinomas,in contrast,among 31 p63-positive cases,25 were positive and 6 were negative for TTF-1. Conclusions The sensitivity and specificity of p40 expression are well for diagnosing lung squamous cell carcinomas. Combined detection of p40 and TTF-1 is valuable to distinguish poorly differentiated lung adenocarcinomas from squamous cell carcinomas.