Construction and validation of a nomogram for predicting recurrence of diffuse large B cell lymphoma

Purposes: To explore recurrence-risk factors of diffuse large B cell lymphoma (DLBCL) and construct a risk nomogram for predicting recurrence and risk stratification. Materials: and Methods: A retrospective analysis was performed on 228 DLBCL patients who achieved complete remission after initial treatment between January 2015 and December 2019. Univariate and multivariate analyses were applied to identify recurrence-related risk factors from the pretreatment evaluation factors covering patients’ demographic characteristics, clinical manifestations, serological indicators, pathological and immunohistochemical results. A nomogram was developed based on the above results and validated by the concordance index (C-index), the receiver operating characteristic (ROC) curve, and the calibration curve. Results: : Fifty of 228(21.9%) cases recurred during follow-up. Three recurrence-risk factors including BCL2 expression (P=0.013), Ann Arbor stage (P=0.011), LDH level (P=0.038) were identified from multivariate analysis and entered the final nomogram “ABL-nomogram”. The C-index of the ABL-nomogram was 0.808, higher than that of IPI system (0.717) and NCCN-IPI system (0.714). And the 1-year, 2-year, 3-year, and 4-year areas under ROC(AUC) were 0.851, 0.859, 0.843, and 0.791, respectively. The calibration curves also showed a good discrimination capability and accuracy. DLBCL could be divided into four subgroups (G1, G2, G3, G4) with significant differences in recurrence risk based on the total points calculated from ABL-nomogram. Conclusions: : ABL-nomogram incorporating the three independent risk factors (BCL2 expression, Ann Arbor stage and LDH level) for DLBCL recurrence, had a better ability to assist risk stratification and identify DLBCL patients with high recurrence risk than IPI system or NCCN-IPI system.