In addition, a SCLC male with T1N2, ECOG <2, HGB <115g/L, LYMPH # between 1.1 and 3.2 × 109/L, PLT between 125 and 350 × 109/L, RBP <25 mg/L, CEA between 0 and 10 ng/mL and NSE >16.3 ng/mL was defined to be 0.024 (95% CI: 0.005–0.105), which was lower than 0.194, the patients were classified to the low‐risk group. This evidence concerns the gene CEACAM5 and small cell lung carcinoma.