Trajectory of chemotherapy for patients with EGFR wild-type advanced pulmonary adenocarcinoma: a single-institution retrospective study

BACKGROUND: Pulmonary adenocarcinoma, recently benefited by new cytotoxic and molecularly targeted drugs, has been classified by driver mutations, such as EGFR mutations. The aim of this study was to research the proportions of patients treated with first- to third-line chemotherapy and to find influential factors for the introduction of chemotherapy and survival benefit from chemotherapy. MATERIALS AND METHODS: Data were collected retrospectively on patients who met the following criteria: adenocarcinoma, diagnosed between June 2007 and March 2015 at our hospital, stage IIIB or IV, and EGFR wild type. A nonchemotherapy group of patients who did not receive chemotherapy was compared with a chemotherapy group of patients who received it. The patients who had received first- to third-line chemotherapy between June 2007 and November 2015 at our hospital were also analyzed. RESULTS: During the study period, 46 patients did not receive chemotherapy, while 148, 89, and 48 received first-, second- and third-line chemotherapy, respectively. As predictive factors for unlikely chemotherapy, multivariate logistic analysis detected Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2, hemoglobin <13.2 g/dL, creatinine clearance (Ccr) <50.4 mL/min, and CRP ≥0.53 mg/dL. As factors predicting shorter survival after chemotherapy, multivariate Cox proportional-hazard analyses detected age ≥75 years, ECOG PS ≥2, lower lymphocyte counts, and higher CRP for the first line; female, higher neutrophil counts, lower lymphocyte counts, reduced Ccr, hyponatremia, and shorter interval between first- and second-line chemotherapy for the second line; and age ≥75 years, body mass index <18.5 kg/m(2), higher neutrophil counts, lower lymphocyte counts, hyponatremia, higher lactate dehydrogenase, and higher CRP for the third line. CONCLUSION: Approximately 76% of patients were treated with first-line chemotherapy. Of those patients, 61% and 34% proceeded to second- and third-line chemotherapy, respectively. For patients with poor PS, anemia, reduced Ccr, and higher CRP, it is difficult to introduce chemotherapy.