Background: T3 tumors can be divided into several subgroups depending on the type of anatomical structure invaded: chest wall, mediastinal pleura, or main bronchus. The aim of this study was to analyze the characteristics and prognosis of each subgroup of T3 tumors.
Methods: The results of surgical treatment were retrospectively analyzed for 261 patients with T3 non-small cell lung cancer invading either the mediastinal pleura or parietal pericardium by direct extension (mediastinal pT3, n = 68), or main bronchus (bronchial pT3, n = 68), or chest wall (chest wall pT3, n = 125) that were operated on between 1984 and 1996. Complete resection including radical mediastinal lymph node dissection was intended in all patients. One patient had segmentectomy, 91 had lobectomy (34.9%), and 169 had pneumonectomy (64.8%). One hundred and fifty-eight patients received adjuvant radiation therapy and 7 patients received both adjuvant chemotherapy and radiation therapy. Actuarial survival curves were drawn using the Kaplan-Meier method and risk factors for late death were identified.
Results: In-hospital mortality was 6.1%. Follow-up was 98% complete. Global 5-year survival was 28%, with survival being not significantly different among the three subgroups: 34.9%, 30.6%, and 22.5% (p = 0.19) in the bronchial pT3, mediastinal pT3, and chest wall pT3 subgroups, respectively. Resection margins were microscopically invaded in 33 patients (12.6%). Seventy-four patients had N1 involvement (28.4%) and 78 patients had N2 involvement (29.8%). N0 involvement was more prevalent in the chest wall pT3 subgroup, whereas N1 involvement was more prevalent in the bronchial pT3 subgroup and N2 involvement was more prevalent among patients with mediastinal invasion. Pathologic factors influencing the 5-year survival were tumor size (p = 0.03) and N involvement (p = 0.003). Histology, type of surgical resection (lobectomy versus pneumonectomy), and use of adjuvant therapy did not influence survival significantly.
Conclusions: Five-year survival was not significantly different among the three subgroups of pT3 non-small cell lung cancer, although bronchial pT3 tumors tended to have a better prognosis and chest wall pT3 tumors tended to have a worse prognosis. The pathologic characteristics of each pT3 subgroup seems different. Further research is warranted to explore the pathologic and biological factors influencing prognosis for each pT3 subgroup.