A Comparison of Clinical Prognostic Indices in Elderly Patients with Diffuse Large B-Cell Lymphoma Treated with a Pegylated Liposomal Doxorubicin Combination Regimen in China

BACKGROUND: There is no consensus regarding the risk stratification scores for elderly patients with diffuse large B-cell lymphoma (DLBCL). We aimed to compare the prognostic predictive ability of the current clinical scoring indices in DLBCL elderly patients treated with the R-CODP regimen (rituximab, cyclophosphamide, pegylated liposomal doxorubicin, vincristine, and prednisone). METHODS: We retrospectively collected the data of elderly DLBCL patients who received the R-CODP regimen as the first-line treatment. The efficacy of the regimen was evaluated. The Akaike information criteria (AIC), concordance index (C-index), and integrated discrimination improvement (IDI) were used to assess the fitness and prognostic performance of the current clinical prognostic indices. RESULTS: In the total of 158 patients enrolled, the median follow-up time was 6.7 years (95% CI: 6.3–7.9), and the 5-year OS was 52.8% (95% CI: 45.5%–61.2%). The International Prognostic Index (IPI), National Comprehensive Cancer Network-IPI (NCCN-IPI), and Elderly International Prognostic Index (E-IPI) were all significantly associated with OS (P < 0.001 for all). However, no significance was observed in 5-year OS in the low- vs low-intermediate-risk groups for IPI (P = 0.377), NCCN-IPI (P = 0.238), and E-IPI (P = 0.080). Compared with the IPI and NCCN-IPI, the E-IPI had the lowest AIC value of 747.5 and the highest C-index of 0.692. For predicting 5-year mortality, the E-IPI showed better performance (AUC: 0.715 for E-IPI vs 0.676 for IPI, P = 0.036), with the IDI of 6.29% (95% CI: 3.71%-8.88%, P < 0.001) and 4.80% (95% CI: 1.32%-8.28%, P = 0.007) compared to the IPI and NCCN-IPI, respectively. CONCLUSION: The E-IPI might be a better prognostic prediction model in Chinese DLBCL generics treated with R-CODP for predicting 5-year mortality. However, the IPI, NCCN-IPI, and E-IPI did not seem to be able to distinguish patients with a favorable prognosis well.