Comparison of Malignant Grades Between Pure and Partially Invasive Types of Clinical Stage Ia Lung Adenocarcinoma

Abstract

ABSTRACT Aim: The pesent study aimed to investigate the malignant significance of lepidic component presence in predominantly invasive lung adenocarcinoma which comprise Methods: Among 347 consecutive patients with completely resected clinical stage IA lung adenocarcinoma, we excluded those with adenocarcinoma in situ, minimally invasive and lepidic predominant invasive adenocaricinoma. We finally assessed 167 patients with predominantly invasive lung adenocarcinoma. We analyzed the clinicopathological characteristics and prognoses of patients with 49 pure invasive tumors without lepidic growth and 118 partially invasive tumors with it. Results: Pure invasive tumors were associated with male sex, small tumor size, high maximum standardized uptake and pleural as well as lymphatic invasion. Nontheless, the invasive component size of both tumor types were similar. The predominant subtypes of pure and partially invasive tumors were papillary, 17 (34.7%) and 53 (44.9%); acinar, 10 (20.4%) and 51 (43.2%); solid, 19 (38.8%) and 11 (9.3%) and micropapillary, 3 (6.1%) and 3 (2.5%), respectively (P Conclusions: Among predominantly invasive stage IA lung adenocarcinoma, the malignant potential was higher for pure invasive tumors and the prognosis was poorer than for partially invasive tumors when the invasive components were of equal sizes. The presence or absence of a lepidic component reflects a difference in subtype predominance and can help to decide the malignant grade of lung adenocarcinoma. Disclosure: All authors have declared no conflicts of interest.