The Real-Word Treatment Outcome of Symptomatic Lymphoplasmacytic Lymphoma/ Waldenström Macroglobulinemia in Chinese Patients

Objective:lymphoplasmacytic lymphoma/Waldenström Macroglobulinemia(LPL/WM) is a rare and incurable lymphoid malignancy. The treatment outcomes in Chinese patients had never been studies. In this study, we systematically reviewed the treatment outcome in a consecutive cohort from a single center in the past 20 years to explore the efficacy of different treatment regimens in real word in China. Methods:The clinical data of 269 newly diagnosis patients with LPL/WM admitted to our hospital in the past 20 years (2000-2020) were retrospectively analyzed. Therapy efficacy and survival were compared between different groups. Results:The median age of 269 patients was 62 years (range 32-87) and the male to female ratio was 2.7(196/73). Nearly half patients were high risk group of ISSWM (48%). Of 269 patients,192 patients received combined chemotherapy.The most common symptoms for initial chemotherapy wereanemia(75.7%), thrombocytopenia (36.9%), followed by IgM-related (33.7%) and constitutional symptoms(21.2%).Of the 192 patients, 109 patients received the novel agents for first-line therapy,83 patients received traditional chemotherapy.180 of192 patients would evaluated. The overall response rate(ORR) and major response rate(MRR) in the novel agent group were significantly higher than the traditional group(ORR:81.7% vs 61.8%,P=0.003; MRR:68.3% vs 48.7%,P=0.008) .In the traditional group, 41 patients received oral alkylating agent-based therapy and 42 patients received conventional intravenous cytotoxicity agents-basedtherapy. The ORR and MRR in the intravenous group were higher than oral group(ORR:75% vs 47.2%,P=0.013;MRR:62.5% vs33.3%,P=0.011).With a median observation time of 36 months, the median overall survival (OS) and progression-free survival (PFS) were 60 months and not reached in the novel agent groups which were also significantly higher than traditional groups(PFS: 60 vs 42,P=0.009,OS:NR vs 89,P=0.000). Intriguingly, In the traditional group, the PFS and OS were no significantly differentbetween conventional intravenous and oralgroup(PFS oral vs intravenous: 42 vs 40,P=0.849,OS oral vs intravenous:62vs 114,P=0.260). In novel agent group, 36 patients had received RCHOP regiment,20 patients received DRC,21 patients received BCD,8 patients received BRD,16 patients received TCD and 8 patients received RFC regiment. Patients who received RCHOP,DRC,BCD,BDR or RFC had similar ORR (82%-87.5%)which were slightly higher than TCD (58.3%)regiment. The median PFS and OS in different subgroups were also similar. But BDR regiment showed a trend of better OS(5 year 100%) and TCD showed a worse OS(5 year 46.4%). For all the patients, 35 patients received maintenance therapy, including 16 patients with rituximab maintenance and 19 patients with thalidomide maintenance. Maintenance was associated with better PFS(60 vs 47,p=0.083) and OS(5 year OS were 96.3% and 64.8%,p=0.006) and patients who received rituximab maintenance had better survival than thalidomide maintenance. In novel agent subgroup, maintenance with rituximab also had a trend of better PFS and OS. But maintenance thalidomide had no significantly different with no maintenance group. Conclusion:Combined with novel agent can tremendously improve the short-term and long-term therapeutic effects in Chinese LPL/WM patients. Different novel agent regiment might had similar efficacy, BRD regiment had a trend of better survival. Maintenance with rituximab would further improve the effect even in novel agent age. Disclosures No relevant conflicts of interest to declare.