Surgery, Gemcitabine, Cisplatin, and Radiation Therapy in Treating Patients With Stage II or Stage III Non-Small Cell Lung Cancer

OBJECTIVES: * To assess overall survival and progression-free survival of patients with stage II-IIIB non-small cell lung cancer undergoing surgical resection, followed by adjuvant chemotherapy comprising gemcitabine and cisplatin, and radiotherapy. * To assess the toxicities of this regimen in these patients. * To evaluate the mRNA expression of enzymes (i.e., excision repair cross complementing protein, ribonucleotide reductase, and cytidine/deoxycytidine deaminase and kinase), which may be important in regulating the cytotoxicity of gemcitabine and cisplatin in patient tumors. * To correlate mRNA levels with progression-free survival of patients treated with this regimen. * To assess BCL2, P53, and HER2-neu expression by IHC and correlation with progression-free survival. OUTLINE: Patients undergo surgical resection of their tumor and mediastinal lymph node dissection. Patients with complete surgical eradication of their disease or pathologic evidence of microscopic residual disease proceed to adjuvant chemotherapy. Within approximately 60 days after surgical resection, patients receive adjuvant chemotherapy comprising gemcitabine IV over 30 minutes on days 1 and 8 and cisplatin IV over 1 hour on day 8. Treatment repeats every 21 days for up to 3 courses in the absence of disease progression or unacceptable toxicity. Beginning 130-144 days after surgery, patients undergo radiotherapy once daily, five days a week, for approximately 6 weeks. Tumor tissue specimens are obtained at the time of surgical resection for pharmacodynamic and biomarker correlative studies. Specimens are examined by reverse transcriptase-polymerase chain reaction to measure mRNA expression of target oncogenes (i.e., DNA repair gene ERCC-1 and M2 subunit of the DNA repair gene ribonucleotide reductase) and enzymes (i.e., cytidine/deoxycytidine deaminase and kinase). Resected specimens are also assessed by IHC for the expression of BCL2, P53, and HER2-neu genes. After completion of study therapy, patients are followed every 6 months for 5 years and annually thereafter.