[1807] Alveolar Trapping in Non Small Cell Carcinoma of Lung

FM Izquierdo, N Moreno, E Honrado, ML Herranz, MA Canizares, F Gonzalez, E Alvarez. Hospital de Leon, Leon, Spain; Hospital Gregorio Maranon, Madrid, Spain; Hospital Xeral, Vigo, Pontevedra, Spain

Background: Histologic features have been studied as prognostic factors in non small cell lung carcinomas (NSCC). Alveolar trapping (AT) inside the tumor is a known phenomenon but its relationship with other features and survival has been very little studied. We study it in a series of NSCC.
Design: We evaluated AT in 552 NSCC from two hospitals. It was graded as scanty (1), moderate (2) or abundant (3); extension of the trapping as peripheral (1), between the periphery and 2 mm inside the neoplasm (2) and more than 2 mm inside. Stroma (1 scanty, 2 moderate and 3 abundant), necrosis (0 absent, 1 scanty, 2 moderate and 3 abundant) and growing into adjacent alveoli (1 present, 2 absent) were evaluated. We have follow-up of 473 of the 552 cases (median 51 months). We compare these histological features between them, with histologic type and 5 year global survival.
Results: 260 of the 552 cases were squamous cell carcinomas (SC), 220 adenocarcinomas (AC), 32 large cell (LCC), 18 bronchioloalveolar (BAC), 18 adenosquamous (ASC), 1 mixed AC and small cell and 2 unclassified (UCC). AT was found in 141 cases (27%) [118 SC, 11 AC, 6 LCC, 5 ASC and 1 UCC]. In 35 (24.82%) AT was scanty (1), in 54 (38.29%) grade 2 and in 52 (36.87%) grade 3; the extension in 11 (7.8%) peripheral (1), in 22 (15.6%) grade 2 and in 108 (76.59%) grade 3. The stroma was scanty (1) in 24 cases (17.02%), (2) in 91 (64.53%) and (3) in 26 (18.43%). Necrosis was absent (0) in 10 (7.09%), (1) in 30 (21.27%), (2) in 55 (39%) and (3) in 45 (31.91%). AT is more common in SC (p<0.0001). Grade and the extension were related between them (p<0.0001), necrosis was more abundant in cases with AT (p<0.0001) and cases with AT showed more often growing into adjacent alveoli (p<0.0001). We have data of survival in 473 cases (106 with AT). Patients with scanty AT had worse 5 year survival (p=0.046). Likewise patients with only peripheral AT (p=0.02). At the multivariate study cases with AT grade 1 versus grade 2 and 3 show HR (increase of mortality) 1.97 (CI95% 1.020-3.834) (p=0.044).
Conclusions: Alveolar trapping is common in NSCC, more frequent in SC and in cases with necrosis and alveolus to alveolus spreading. The grade and extension of AT were significantly related. Patients with abundant and extensive AT have better survival.
Category: Pulmonary

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 255, Wednesday Morning


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