Antineoplastic Combined Chemotherapy Protocols/therapeutic use; Carcinoma, Non-Small-Cell Lung/drug therapy; Lung Neoplasms/drug therapy; Small Cell Lung Carcinoma/drug therapy; Adenocarcinoma/drug therapy; Adenocarcinoma/mortality; Adenocarcinoma/pathology; Aged; Carcinoma, Large Cell/drug therapy; Carcinoma, Large Cell/mortality; Carcinoma, Large Cell/pathology; Carcinoma, Non-Small-Cell Lung/mortality; Carcinoma, Non-Small-Cell Lung/pathology; Carcinoma, Squamous Cell/drug therapy; Carcinoma, Squamous Cell/mortality; Carcinoma, Squamous Cell/pathology; Deoxycytidine/administration & dosage; Deoxycytidine/analogs & derivatives; Docetaxel; Female; Follow-Up Studies; Glutamates/administration & dosage; Guanine/administration & dosage; Guanine/analogs & derivatives; Humans; Lung Neoplasms/mortality; Lung Neoplasms/pathology; Male; Neoplasm Staging; Pemetrexed; Prognosis; Retrospective Studies; Small Cell Lung Carcinoma/mortality; Small Cell Lung Carcinoma/pathology; Survival Rate; Taxoids/administration & dosage; Treatment Outcome; Gemcitabine