Megestrol in Treating Patients Who Are Undergoing Radiation Therapy for Lung Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed lung cancer * Unresectable stage I-IIIB non-small cell lung cancer (NSCLC) * Resected stage I-IIIB NSCLC * Limited stage small cell lung cancer * Planned radiotherapy with a total dose of at least 5,000 cGy in fraction sizes of no greater than 200 cGy each * No distant metastases * No significant ascites, pleural effusions, or edema that would inhibit oral food intake or invalidate weight determinations PATIENT CHARACTERISTICS: Age: * Over 18 Performance status: * ECOG 0-2 Life expectancy: * More than 3 months Hematopoietic: * Not specified Hepatic: * Not specified Renal: * Not specified Cardiovascular: * No uncontrolled hypertension * No active thromboembolic disease * No myocardial infarction within the past 3 months * No prior congestive heart failure or thromboembolic events Pulmonary: * No prior pulmonary edema Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other malignancy within the past 3 years except curatively treated carcinoma in situ of the cervix or non-melanoma skin cancer * No uncontrolled diabetes with glycosylated hemoglobin greater than 10% * No Cushing's syndrome * No dietary restrictions (e.g., salt, sugar, or lipid) * No other serious medical or psychiatric illness that would preclude study PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * See Endocrine therapy Endocrine therapy: * At least 12 months since prior corticosteroids, estrogens, progestins, or other steroid hormone except as antiemetic prior to chemotherapy * No concurrent corticosteroids, estrogens, progestins, or other steroid hormone except as antiemetic prior to chemotherapy Radiotherapy: * See Disease Characteristics * No prior radiotherapy to lung Surgery: * See Disease Characteristics * More than 14 days since prior surgery