During the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition, several talks were presented regarding the prognostic value of ctDNA in patients with diffuse large B-cell lymphoma (DLBCL). They were previewed in our pre-ASH summary article here. In the current article we would like to delve deeper into the results presented during two of these sessions.
Prognostic value of ctDNA in autologous stem cell graft and posttransplant plasma samples among patients with DLBCL
Although autologous stem cell transplantation may be curative for some patients with DLBCL, a significant number of patients relapse, and biomarkers are required to identify patients who are most at risk. Reid Merryman and colleagues2 investigated whether ctDNA-based minimal residual disease assessment in apheresis stem cell (ASC) and posttransplant plasma samples could predict relapse in patients with DLBCL. Immunoglobulin-based next-generation sequencing (NGS) was used to identify ctDNA within the samples.
Of the 96 patients who had ASC samples, 24% were ctDNA-positive. For these patients, the 5-year progression-free survival (PFS) was only 13% (95% CI, 3−30%), compared with 52% (95% CI, 39−63%) for patients who were ctDNA-negative. The 5-year cumulative relapse rate was 83% (95% CI, 66−99%) for the ctDNA-positive group and 39% (95% CI, 28−51%) for the ctDNA-negative group. ASC ctDNA was significantly associated with PFS (HR 2.8; p < 0.01) and was the only factor shown to be predictive following multivariate analysis (HR 2.5; p = 0.002). A similar association was seen between ctDNA positivity and overall survival (OS). Patients who were ctDNA-positive had a lower 5-year OS (51% [95% CI, 29%−69%]), compared with patients who were ctDNA-negative (66% [95% CI, 54%−75%]; p = 0.048).
Posttransplant plasma samples from 56 patients were also examined for ctDNA content and positive samples were found to be associated with increased risk of relapse. Overall, 21 patients (38%) had a median of two ctDNA-positive posttransplant samples; 86% of these patients relapsed.
We asked Reid Merryman, “can ctDNA help inform on the suitability of autologous stem cell transplantation (auto-SCT) in patients with DLBCL?” in this Lymphoma Hub podcast.