ABCA3 Phenotype in Non-Small Cell Lung Cancer Indicates Poor Outcome.

BACKGROUND: ATP-binding cassette transport protein A3 (ABCA3) is expressed in non-small cell lung cancer (NSCLC). We hypothesize that high-level ABCA3 expression may have a negative prognostic impact in patients with NSCLC.

METHODS: In 89 patients with NSCLC and curative intended surgery, we analyzed postoperative immunohistochemistry staining of primary tumors (anti-ABCA3) and clinicopathological parameters. We used a unidimensional four point score (FPS) system for intensity assessment and, furthermore, a combined bidimensional scoring of intensity and quantity resulting in the positive index (PI).

RESULTS: Former or never-smokers were more likely to have intermediate or strong ABCA3 unidimensional expression (FPS) compared with current smokers (p < 0.01). Patients >65 years of age had a higher probability of intermediate/strong ABCA3 expression (FPS) than younger patients (p < 0.05). In PI measurement, there were no significant correlations between ABCA3 and clinicopathological parameters. Patients with high-level PI had a significantly worse disease-free survival as well as overall survival than patients with low-level PI (p < 0.05).

CONCLUSIONS: High-level PI of ABCA3 in NSCLC showed poor disease-free and overall survival in this patient cohort, potentially indicating the relevance of ABCA3 in lung cancer. This observation needs to be validated in larger series.