PT - JOURNAL ARTICLE AU - Leinonen, T AU - Pirinen, R AU - Böhm, J AU - Johansson, R AU - Rinne, A AU - Weber, E AU - Kosma, V-M TI - Biological and prognostic role of acid cysteine proteinase inhibitor (ACPI, cystatin A) in non-small-cell lung cancer AID - 10.1136/jcp.2006.038711 DP - 2007 May 01 TA - Journal of Clinical Pathology PG - 515--519 VI - 60 IP - 5 4099 - http://jcp.bmj.com/content/60/5/515.short 4100 - http://jcp.bmj.com/content/60/5/515.full SO - J Clin Pathol2007 May 01; 60 AB - Background: Acid cysteine protease inhibitor (ACPI) is an intracellular protein, often linked to neoplastic changes in epithelium and thought to have an inhibitory role in malignant transformation. Aim: To analyse the expression and prognostic role of ACPI in non-small-cell lung cancer (NSCLC). Method: Histological samples from 199 patients with resected NSCLC were stained immunohistochemically for the expression of ACPI in normal and preneoplastic bronchial epithelium, and in various types of lung carcinomas. Results: A normal bronchial epithelium showed positive staining for ACPI in the basal cells, whereas the upper two-thirds of the dysplastic epithelium was ACPI positive. High staining for ACPI was found in 74% (91/123) of squamous-cell carcinomas, whereas 16% (8/49) of adenocarcinomas and 30% of (8/27) large-cell carcinomas showed the high expression of ACPI (p<0.001). Among squamous-cell carcinomas, low expression of ACPI was correlated with poor tumour differentiation (p = 0.032). In the whole tissue, reduced expression of ACPI was associated with tumour recurrence (p = 0.024). In overall survival (OS) and disease-free survival (DFS) analyses, the histological type of the tumour (both p<0.001) and stage of the tumour (p = 0.001, p = 0.013, respectively) were related to patient outcome. Low expression of ACPI in tumour cells was associated with poor OS and DFS (p<0.041, p = 0.004, respectively). In multivariate analysis, ACPI did not retain its prognostic value, whereas the traditional factors were the most important prognostic factors. Conclusions: ACPI expression is linked with the malignant transformation of the bronchial epithelium and predicts a risk of tumour recurrence as well as poor rate of survival for the patients. However, ACPI does not have any independent prognostic value in NSCLC.