Prognostic analysis of 
PD, ≤118.8)LMR(<4.59
REGRESSION
As shown in Table COX regression analysis of clinical characteristics in connection with OS in the training cohort of SCLC.The best efficacy to first‐line chemotherapy(SD + PD vs. CR + PR)Stage(ES‐SCLC vs. LS‐SCLC)LDH (U/L)(>250 vs. ≤250)Hemoglobin (g/L)(<120 vs. ≥120)Age(>65 vs. ≤65)Sex(male vs. female)Smoking history(Yes vs. No)RDW(<14.3 vs. ≥14.3)PLR(>118.8 vs. ≤118.8)LMR(<4.59 vs. ≥4.59)PNI(<397.0 vs. ≥397.0)CEA (ng/mL)(>4.3 vs. ≤4.3)LCR(<0.39 vs. ≥0.39)