August 23, 2018, New York—A blood test can predict which patients with diffuse large B cell lymphoma are likely to respond positively to initial therapy and which are likely to need more aggressive treatment for their cancer, according to a multicenter study led by researchers at the Ludwig Center at Stanford and the Stanford University School of Medicine.
The study suggests that clinicians may soon be able to determine how a patient is responding to treatment for this cancer just 21 days after starting therapy, rather than waiting until therapy is completed five to six months later.
The study, published online Aug. 20 in the Journal of Clinical Oncology, was led by Ludwig Stanford investigators Ash Alizadeh and Maximilian Diehn.
Diffuse large B cell lymphoma, a blood cancer, is the most common type of non-Hodgkin lymphoma. Although most people are cured by conventional therapy, about one-third are not. The ability to predict early which patients are likely to need more aggressive treatment would be a significant boon to both clinicians and patients.
Relatively minute quantities of ctDNA are released into the blood by dying cancer cells. Diehn and Alizadeh recently showed that ctDNA levels can also be used to predict lung cancer recurrence weeks or months before any clinical symptoms arise.
For the current study, researchers tracked ctDNA levels in 217 people with diffuse large B cell lymphoma who were treated at six medical centers in the US and in Europe. For each patient, they compared levels of ctDNA before treatment began with those after the first and second rounds of conventional chemotherapy.
They found that ctDNA was detectable in the blood prior to the initiation of therapy in 98% of the people studied, and levels dropped in all patients once treatment began. But people whose ctDNA levels dropped a 100-fold after the first round or 300-fold by the second round were much more likely to live two years or more without experiencing a relapse than those whose ctDNA levels declined more slowly.
“We are very hopeful that the approach will ultimately be extensible to most if not all cancer types,” says Diehn.
The press release from which this summary is derived can be found here.