The Outcome of Refractory or Relapsed but Not Refractory Diffuse Large B-Cell Lymphoma in China: Results from the Real-TREND Study
Authors: Wang Shuo , Wang Li , Chang CC , Hu Jianda , Zhang Xi , Zhu Qi , Cui Guohui , Qian Wenbin , Chen Bobin , Zhao Weili 
Published: October 2019

BACKGROUND. The definition and outcome of relapsed or refractory diffuse large B-cell lymphoma (DLBCL) have been ambiguous due to small sample sizes and varied definitions in previous studies[1]. The recent SCHOLAR-1 study[2] was the first large-scale analysis focusing on patients with refractory DLBCL. Patients with relapsed but not refractory DLBCL were not included in this study.

OBJECTIVE. The primary objective is to further validate the outcome of SCHOLAR-1 study, including overall survival (OS) and response rate (RR) to salvage therapy, of patients with refractory DLBCL in a different geographical location. The secondary objective is to analyze the outcome (OS) of patients with relapsed but not refractory DLBCL.

PATIENTS AND METHODS. Electronic health records of patients diagnosed with DLBCL and admitted to one of the 7 hospitals in 5 cities in southern China (Shanghai, Hangzhou, Chongqing, Wuhan, and Fuzhou) from 2010 to 2015 were reviewed. Structured data was manually collected according to a pre-defined data collection plan. Patients' survival statuses were regularly followed through telephone interviews. In this study, refractory DLBCL was defined as progressive or stable disease as the best response to any line of chemotherapy, and relapsed but not refractory DLBCL was define as a relapsed disease occurred without being refractory after disease remission. For patients with refractory DLBCL, OS was estimated from the time when the refractory status was determined. Among patients with relapsed but not refractory DLBCL, OS was estimated from the time of response evaluation in the last line of chemotherapy. RR to salvage therapy was only evaluated in patients with refractory DLBCL.

RESULTS. Among 2,711 patients with DLBCL admitted to the 7 hospitals, 461 patients were refractory and 144 were relapsed but not refractory. For all 605 patients, the median OS was 16.8 (95% CI: 14.4-21.4) months and 2-year survival rate was 43.7% (95% CI: 39.7%-48.1%). Among patients with refractory DLBCL, the median OS was 12.3 (95% CI: 10.5, 14.4) months and 2-year survival rate was 33.8% (95% CI: 29.5%-38.8%). Among patients with relapsed but not refractory DLBCL, median OS was 82.6 (95% CI: 48.5-NA) months and 2-year survival rate was 73.9% (95% CI: 66.8%, 81.8%). Patients with refractory DLBCL had significantly inferior overall survival compared patients with relapsed but not refractory DLBCL (hazard ratio [HR] 2.92, 95% CI: 2.20-3.89, p value <0.001). Among patients with refractory DLBCL, the estimated RR was 28.56% (95% CI: 20.28%-36.84%) to the next line of therapy and the estimated complete response rate (CRR) was 7.90% (95% CI: 3.02%-12.79%). RR to salvage therapy was consistently poor among subgroups in patients with refractory DLBCL.

CONCLUSION. The REAL-TREND study demonstrates poor survival and response to salvage therapy for patients with refractory DLBCL, which is consistent with the results of the SCHOLAR-1 study. But patients with relapsed but not refractory DLBCL have significantly greater chance of long-term survival.

REFERENCE. Colosia A, Njue A, Trask PC, Olivares R, Khan S, Abbe A, et al. Clinical efficacy and safety in relapsed/refractory diffuse large B-cell lymphoma: a systematic literature review. Clinical lymphoma, myeloma & leukemia. 2014;14(5):343-55.e6. Epub 2014/04/29. doi: 10.1016/j.clml.2014.02.012. PubMed PMID: 24768510. Crump M, Neelapu SS, Farooq U, Van Den Neste E, Kuruvilla J, Westin J, et al. Outcomes in refractory diffuse large B-cell lymphoma: results from the international SCHOLAR-1 study. Blood. 2017;130(16):1800-8. Epub 2017/08/05. doi: 10.1182/blood-2017-03-769620. PubMed PMID: 28774879; PubMed Central PMCID: PMCPMC5649550.

Disclosures

No relevant conflicts of interest to declare.