DISEASE CHARACTERISTICS: Stage I (T1-2 N0) nonsmall cell lung cancer curatively resected and in regular follow-up for at least 6 weeks Material available for histologic review At least 1 mediastinal node station sampled or at least 2 years since surgery Any of the following histologies eligible: Squamous cell carcinoma Large cell carcinoma Adenocarcinoma (including bronchoalveolar) No small cell anaplastic component No recurrent disease or second primary No synchronous lung cancer of a different histology Concurrent registration on intergroup protocol I91-0001 allowed