Prognostic value of circulating tumor DNA in lymphoma: a meta-analysis

Circulating tumor DNA (ctDNA) can be used to evaluate the prognosis of lymphoma. However, there is no uniform consensus about the mechanistic role that ctDNA plays in the prognosis of lymphoma. This meta-analysis explores the prognostic value of ctDNA in lymphoma, especially in diffuse large B cell lymphoma (DLBCL). All relevant reports published as of May 14, 2020, were retrieved by searching electronic databases in Pubmed, Embase and Cochrane Library. The prognostic value of ctDNA was evaluated using meta-analysis. Revman 5.3 software was used for prognostic data extraction and analysis. Eight studies, including a total of 767 lymphoma patients, were enrolled in this meta-analysis. Five out of eight studies investigated the association between ctDNA levels and progression-free survival (PFS) in 501 lymphoma patients, indicating that high levels of ctDNA were significantly associated with poor PFS (HR 2.24, 95%CI: 1.63-3.08, P < 0.00001). We conducted a subgroup analysis of 379 patients with DLBCL across three of the studies and came to the same conclusion (HR 2.01, 95%CI: 1.42-2.85, P < 0.0001). Two studies with a total of 192 lymphoma patients described the association between ctDNA levels and event-free survival (EFS), showing that high levels of ctDNA were also associated with adverse EFS (HR 4.53, 95%CI: 1.79-11.47, P = 0.001). The remaining two studies analyzed the potential clinical value of ctDNA for predicting the overall survival time (OS) of DLBCL patients, demonstrating that high levels of ctDNA correlated with inferior OS (HR 3.09, 95%CI: 1.50-6.35, P = 0.002). Our meta-analysis showed that high levels of ctDNA were associated with poor prognosis in patients with lymphoma, especially DLBCL.