The effect of resection on local failure in irradiated non-oat cell carcinoma of the lung.

From January 1969 through December 1979, 171 patients completed a course of high dose definitive radiotherapy alone for non-oat cell carcinoma of the lung. During the same period, 53 patients completed a course of definitive postoperative radiotherapy after undergoing resection of the primary tumor. The two groups were otherwise very similar with regard to patient related and tumor related variables. A detailed analysis of the incidence of clinically documented local (in-field) failure on the basis of clinical T and N stages was performed. A comparison of the incidence of local failure as the first site of failure for patients with T1-2 tumors demonstrated a statistically significant decrease in local failure in patients whose primary tumors were resected. This was true for all patients with T1-2 tumors whose failure status was known (p less than .001), for all patients known to have failed (p less than .001), and for patients whose clinical node status was other than gross mediastinal (N2) lymphadenopathy (p less than .05). Local failure was decreased in patients with clinical T3 tumors who underwent resection, but the difference was not significant (p greater than .1). Histology (epidermoid vs. non-epidermoid) had no apparent effect on the frequency of local failure, either with or without resection. A review of past experience indicates that local failure is common after definitive irradiation alone, and is due to a low rate of sterilization of the primary tumor, even with tolerance doses of irradiation. Data are presented to support a reappraisal of the role of combined resection and irradiation in future clinical trials, to reduce the present unacceptably high rate of local failure in potentially curable patients treated by irradiation alone.