These data showed the following factors were correlated with a poor prognosis: age>65 years, male patients, KPS≤80 points, positive smoking history, anemia (a hemoglobin value<12.0 g/dl in men and 11.0 g/dl in women), lymphocyte counts<1.65×109/L, NLR>3.18, LMR≤2.615, LDH>216.5 U/L, ALP>119.5 U/L, NSE>15.2 ng/ml, absence of surgery, absence of thoracic irradiation, chemotherapy cycles<4, metastatic sites≥2 and extensive disease (Table 2). Here, ENO2 is linked to anemia.