[Comparison of the characteristics in recurrence and metastasis between bronchioloalveolar carcinoma and other lung adenocarcinomas]

Abstract

Background & objective: The histological definition of bronchioloalveolar carcinoma (BAC) has been changed recently by the revised World Health Organization (WHO) classification. Although bronchioloalveolar carcinoma is a subtype of lung adenocarcinoma, its biological features are better than those of other lung adenocarcinomas. This study was to analyze differences in metastatic activity between bronchioloalveolar carcinoma and other lung adenocarcinomas.

Methods: The expression of E-Cadherin, Collagen IV, vascular endothelial growth factor receptor-2 (VEGFR-2), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in 28 specimens of stage I bronchioloalveolar carcinoma confirmed pathologically and 40 specimens of other stage I lung adenocarcinomas were detected by immunohistochemistry. Their correlations to tumor recurrence and metastasis were analyzed.

Results: The 5-year survival rate was significantly higher in ths patients with bronchioloalveolar carcinoma than in the patients with other lung adenocarcinomas (88.7% vs. 57.3%, P < 0.05). The intrathoracic recurrence rate was significantly higher and the extrathoracic metastasis rate was significantly lower in the patients with bronchioloalveolar carcinoma than in the patients with other lung adenocarcinomas (75% vs. 33.3%, 25% vs. 66.7%, P < 0.05). The positive rates of Collagen IV, E-Cadherin and TIMP-1 were significantly higher in bronchioloalveolar carcinoma than in other lung adenocarcinomas (78.6% vs. 42.5%, 78.6% vs. 40.0%, 67.5% vs. 42.9%, all P < 0.01). The positive rate of VEGFR-2 was significantly higher in other lung adenocarcinomas than in bronchioloalveolar carcinoma (85.7% vs. 77.5%, P < 0.05). There was no significant difference in the positive rate of MMP-9 between bronchioloalveolar carcinoma and other lung adenocarcinomas (85.0% vs. 78.6%, P = 0.494).

Conclusion: As compared with other lung adenocarcinomas, stage I bronchioloalveolar carcinoma is less aggressive in clinical behavior and likely to develop intrathoracic recurrence, with less extrathoracic metastases and better prognosis.