<qa>  What is the drug used for treatment of non-small cell lung cancer?Rationale: Docetaxel has some efficacy against non-small cell lung cancer NSCLC. This drug is Food and Drug Administration approved in combination with cisplatin Platinol for the treatment of unresectable, locally advanced or metastatic NSCLC in patients who have not previously had chemotherapy for this condition. Docetaxel is also approved for second line treatment of metastatic NSCLC. Research indicates that capecitabine, in combination with docetaxel, has efficacy against NSCLC. Capecitabine appears to have anti-cancer activity through several enzymes. This drug is metabolized in the body to another agent called 5-FU. During this conversion process, 5-FU requires thymidine phosphorylase TP, a cellular characteristic associated with tumor growth. There are higher levels of TP expression in tumors as compared to normal tissue. The drug administration schedule in this study is designed to optimize efficacy against the TP target through both docetaxel and capecitabine. This study will measure biological changes to TP and other enzymes to help researchers gain more information about how capecitabine and docetaxel works against NSCLC. 