Many patients with diffuse large B-cell lymphoma (DLBCL) may be cured by autologous stem cell transplant, but as many as half eventually relapse. New research presented by Reid Merryman, MD, and colleagues at the 2020 American Society of Hematology (ASH) Annual Meeting & Exposition suggests that patients whose blood or stem cell samples harbor circulating tumor DNA (ctDNA) may be more likely to experience disease relapse (Abstract 531).
The findings indicate that testing for tumor DNA within a patient’s stem cells or blood may be helpful for patients with DLBCL, regardless of whether they’re eligible for a transplant or have already undergone one. The results could support studies of alternative treatments, such as chimeric antigen receptor T-cell therapy, in clinical trials for patients whose stem cells test positive for tumor DNA. Patients who test positive after a transplant may benefit from prompt interventions to guard against relapse.
Reid Merryman, MD
“Testing for tumor DNA is a powerful technique that can give us information that can be helpful in terms of prognosis, and that may be a platform in the future for further personalizing therapies to minimize the risk of relapse for patients with lymphoma,” said Dr. Merryman, of Dana-Farber Cancer Institute.
Study Design and Results
Researchers hypothesized that DNA shed from tumor cells into the bloodstream could be an indicator of risk of relapse. To determine whether that is the case, they tested for tumor DNA in blood and tissue samples from patients both before and after transplant and compared relapse rates among those who tested positive and those who did not.
The study included 154 patients with DLBCL who had undergone an autologous stem cell transplant. Researchers analyzed stem cell samples from the transplants and blood samples collected after transplant.
They found that patients who had evidence of ctDNA within their stem cell samples often fared poorly after transplant. At 5 years after undergoing a transplant, just 13% were still in remission; the rest had relapsed.
“This suggests that patients identified prior to transplant as having evidence of ctDNA should be treated with therapies other than transplant,” said Dr. Merryman. “This is an important area to explore as part of a future clinical trial.”
Similarly, the presence of tumor DNA in blood samples collected after transplant often indicated a poor prognosis. Of the 20 patients found to have tumor DNA in their blood, 17 went on to relapse. On average, the DNA was detected about 2 months before the relapse occurred.
“This could provide us with some lead time for interventions that may be able to preempt relapse from occurring,” concluded Dr. Merryman. “As in the case of tumor DNA found prior to transplant, the potential value of such interventions needs to be explored in clinical trials.”
Disclosure: For full disclosures of the study authors, visit ash.confex.com.
