Abstract: Objective The aim of this study was to investigate the effect of chemotherapy on coagulation parameters and evaluate the prognostic significance of coagulation parameters in patients with small cell lung cancer(SCLC).Methods Clinical data of 210 patients with SCLC were retrospectively analyzed.Clinical features,treatment and coagulation indicators of patients were collected,including platelets(PLT),prothromboplastin time(PT),activated partial thromboplastin time(APTT),fibrinogen(FIB),thrombin time(TT),D-dimer(D-D).The hypercoagulant group was defined as having a value higher than the upper limit of normal(ULN)in PLT,D-D and FIB before chemotherapy,or a value lower than the lower limit of normal in PT,APTT and TT,and the rest of the normal group.Results There were no significant differences in age,gender,smoking history,clinical stage and other clinical features between the high-coagulation group and the normal group(P＞0.05).The coagulation indexes-PLT,FIB,and D-D decreased in the SCLC hypercoagulable group after chemotherapy intervention.The changes of FIB were statistically significant(P＜0.05),but there was no significant difference between the normal group before and after chemotherapy(P＞0.05);Performance status,clinical stage,prothrombin time and fibrinogen.were independent factors affecting the prognosis of SCLC.Patients with abnormally elevated the levels of FIB,PLT and D-D had lower survival than that in the normal group and poor prognosis.Conclusion Chemotherapy can improve the hypercoagulable state of patients with SCLC,but has no significant effect on patients with normal coagulation function.Patients with abnormally elevated coagulation parameters have shorter survival time and worse prognosis than patients with normal coagulation parameters.

Key words: Small cell lung cancer, Chemotherapy, Coagulation indicators, Retrospective study