An evaluation of the prognostic significance of alpha-1-antitrypsin expression in adenocarcinomas of the lung: an immunohistochemical analysis.

Expression of alpha-1-antitrypsin (AAT) in tumour cells of 102 surgically resected lung adenocarcinomas was examined by immunohistochemical method using anti-AAT antiserum. While only 13 cases (13%) were negative for AAT expression, 89 cases (87%) contained AAT at varying degrees. The degree of AAT-positive tumour cells was significantly higher in advanced cases than in early cases. Clinical follow-up study of the patients, particularly in stage I, showed that strongly AAT-positive cases have poor prognosis than weak-to-moderately AAT-positive or AAT-negative cases. Thus, AAT expression status in tumour cells of lung adenocarcinoma may be a biological marker of prognostic significance in regard to tumour growth.