The document summarizes a clinical trial comparing the treatments erlotinib and gefitinib for non-small cell lung cancer. It found that erlotinib improved overall survival compared to standard chemotherapy, with a median survival of 6.7 months for erlotinib versus 4.7 months for chemotherapy. Erlotinib also prolonged progression-free survival compared to chemotherapy. The study provides support for using erlotinib or gefitinib as treatments for non-small cell lung cancer.