To evaluate the benefits and the drawbacks of post-operative radiotherapy in completely resected Stage I (a and b) non-small cell lung cancer (NSCLC).

Patients with pathological Stages Ia and Ib NSCLC have been randomized into two groups: Group 1 (G1) received adjuvant radiotherapy, Group 0 (G0) the control group did not receive any adjuvant therapy. Local control, toxicity and survival have been evaluated.

Between July 1989 and June 1997, 104 patients with pathological stage I NSCLC have been enrolled in this study. Fifty-one patients were randomized to G1 and 53 to G0. Six patients have been excluded from the study due to incomplete follow-up data. Regarding local control, one patient in the G1 group had a local recurrence (2.2%) while in the G0 12 local recurrences have been observed (23%). Seventy-one percent of patients are disease-free at 5 years in G1 and 60% in G0 (P=0.039). Overall 5-year survival (Kaplan-Meier) showed a positive trend in the treated group: 67 versus 58% (P=0.048). Regarding toxicity in G1, six patients experienced a grade 1 acute toxicity. Radiological evidence of long-term lung toxicity, with no significant impairment of the respiratory function, has been detected in 18 of the 19 patients who have been diagnosed as having a post-radiation lung fibrosis.

Adjuvant radiotherapy gave good results in terms of local control in patients with completely resected NSCLC with pathological Stage I. Overall 5-year survival and disease-free survival showed a promising trend. Treatment-related toxicity is acceptable.