Computed tomographic images reflect the biologic behavior of small lung adenocarcinoma:: They correlate with cell proliferation, microvascularization, cell adhesion, degradation of extracellular matrix, and K-ras mutation

Background: We previously reported that the computed tomographic M/L ratio (area of the tumor in the mediastinal computed tomographic image/area of the tumor in the lung Computed tomographic image) of small peripheral lung adenocarcinoma is correlated with patient prognosis. Methods: Immunostaining for p53, bcl-2, Ki-67, vascular endothelial growth factor, CD34, matrix rnetalloproteinase 2, matrix metalloproteinase 9, tissue inhibitor of matrix metalloprotemase 2, and mutation of K-ras was assessed in 131 surgically resected, primary peripheral lung adenocarcinomas of 30 mm or less in maximum diameter to clarify the relationship between computed tomographic findings and biologic activities. Results: The numbers of patients with high labeling indexes of Ki-67 and high expression of vascular endothelial growth factor, CD34, matrix metalloproteinase 2, and matrix metalloproteinase 9 in the solid-type group (computed tomographic M/L ratio >= 50%) were significantly higher than those in the faint density-type group (computed tomographic M/L ratio < 50%; P = .04 for Ki-67, P = .03 for vascular endothelial growth factor, P = .0009 for CD34, P = .001 for matrix metalloprotemase 2, and P = .00001 for matrix metalloproteinase 9). The number of patients with high levels of CD44v6 or tissue inhibitor of matrix metalloproteinase 2 staining in the faint density-type group was significantly higher than that in the solid-type group (P = .02 for CD44v6 and P = .01 for tissue inhibitor of matrix metalloprotemase 2). Independent variables capable of predicting computed tomographic M/L ratio included CD34, matrix metal loproteinase 2, matrix inetalloproteinase 9, and tissue inhibitor of matrix metalloproteinase 2 (P = .0093, P = .0003, P = .0027, and P = .01, respectively; binary logistic regression analysis). Conclusions: Our results suggest that the computed tomographic image of small lung adenocarcinoma is correlated with biologic activities and thus provides possible prognostic information.