Pathological stage grouping of patients with resected carcinoma of the lung

Abstract

Data from a series of 569 patients with “curative” resection of non-oat cell tumors were analyzed by the life-table method to evaluate the validity of the postresection pathological staging classification suggested by the American Joint Committee. The cell types were as follows: squamous, 305; adenocarcinoma, 172; large cell, 73; and mixed, 19. Each patient was assigned a pathological TN classification on examination of the resected specimen (all patients were judged clinically to have no distant metastases—M0). There were 173 lesions classified as T1 N0, 37 as T1 N1, 212 as T2 N0, 115 as T2 N1, and 32 as either T3 with any N or N2 with any T. In analyzing the data, we identified a subset of lesions (25), initially staged as T2 N0, which were small central lesions, 3 cm or less, located distal to a lobar takeoff. Regardless of the presence of atelectasis or pneumonitis to the hilar area, patients with these lesions had a survival rate similar to that of patients with more peripherally located lesions of similar size. Three-year survival rates of 66.5% and 68.5% respectively, were noted in these two groups of patients, as compared to a 53.6% rate for the patients with lesions larger than 3 cm, which could be classified as T2 N0 regardless of their location. When lymph nodes were affected (N1), patients with small central lesions (20) had a better survival rate than the patients with either T1 N1 or other T2 N1 lesions. It is therefore suggested that all small central lesions, 3 cm or less, distal to a lobar takeoff be considered T1 lesions. Patients with T1 N1 lesions had a 3 year survival rate of only 36.7%, which is similar to the 39.8% 3-year survival rate of those with T2 N1 lesions. The other patients in Stage I had a much better survival rate: Patients with T1 NO lesions had 3 and 5 year survival rates of 68.5% and 54.4%, and those with T2 N0 lesions, 53.6% and 40.0%, respectively. Therefore, it would appear more appropriate to classify these patients as having Stage II rather than Stage I disease.