RESULTS: A total of 45226 SCLC patients were identified. After applying the exclusion criteria, 867 postoperative patients were included and analyzed. In the multivariate analysis, prognostic factors were age, sex, surgery, radiation sequence, tumor diameter, tumor extension, T stage, N stage, number of lymph node examination, grade of pathological differentiation and metastasis, which were used to established nomograms. The C-index of the nomogram incorporating tumor size and extension was 0.7063 (95%CI 0.6812-0.7314), which was higher than other conventional classifications such as AJCC TNM Classification, VALSG and IASLC staging systems. The validation of the nomogram demonstrated that it had an ideal predictive accuracy.