Small cell carcinoma-type histology, high levels of WBC, N, alkaline phosphatase (ALP), and C-reactive protein (CRP), erythrocyte sedimentation rate, carcino-embryonic antigen, squamous cell carcinoma antigen, neuron-specific enolase (NSE) in peripheral blood, LDH, total protein (TP), glucose in pleural effusion, NLR, CAR, PE TPClR, low level of lymphocytes, mean platelet volume, and ALB in peripheral blood, CL- in pleural effusion, and LMR were significantly related to worse outcomes (all P <0.05). Here, CEACAM5 is linked to Pleural effusion.