Pleural retraction and intra-tumoral air-bronchogram as prognostic factors for stage I pulmonary adenocarcinoma following complete resection

BACKGROUND AND OBJECTIVES: We have retrospectively analyzed the postoperative prognostic factors for 116 patients with stage I adenocarcinoma, with special reference to pleural retraction and intra-tumoral air-bronchogram imaged by computed tomography, which may represent the biological features of pulmonary adenocarcinoma for the retraction of surrounding tissues due to central necrosis and air space-lining growth, respectively. METHODS: The subgroups divided according to the presence of pleural retraction and/or intra-tumoral air-bronchogram on pre-operative CT were compared with respect to the postoperative disease-free survival (DFS) and other clinico-pathological factors. RESULTS: The rates of DFS at 5 years associated with 61 patients with pleural retraction and with 55 patients without pleural retraction were 64.4% and 91.3%, respectively (P = 0.0052), and those associated with 83 patients with air-bronchogram-positive tumors and with 33 patients with air-bronchogram-negative tumors were 81.8% and 64.8%, respectively (P = 0.0040). The DFS at 5 years associated with T1 (73 patients) and T2 (43 patients) were 83.6% and 64.3%, respectively (P = 0.0153). The Cox proportional hazards model analysis revealed that the presence of pleural retraction and the absence of air-bronchogram were independent factors for poor prognosis with relative risks of 7.8 and 5.1, respectively. Pathological T factor was also a significant prognostic factor with a relative risk of 3.2. Seventeen patients with pleural retraction-positive and air-bronchogram-negative tumors showed the high recurrence rate of 47.5% and a poor prognosis with DFS at 5 years of 35.1%. CONCLUSION: These results suggested that, in stage I adenocarcinoma, the degree of malignant potential may be well figured by radiological imaging, with a significant affect on susceptibility of recurrence following complete resection.