Sequence analysis of ctDNA in NHL to monitor tumour progression and evolution

NHL (non-Hodgkin lymphoma) is the fifth and sixth most prevalent cancer in Canada diagnosed annually among men and women respectively. With current conventional treatment, the five year survival rate is 67%. However, continued observations post-treatment are needed due to the risk of patient relapse. Liquid biopsies provide an effective, non-invasive means for such observations. Here, we evaluated the efficacy and utility of circulating tumour DNA (ctDNA) in relapsed patients with NHL. We detected ctDNA in at least one plasma sample from 90.9% of patients tested. We showed a significant increase in ctDNA was associated with a lack of treatment response. We demonstrate the utility of ctDNA to facilitate genetic characterization and direct observation of tumour heterogeneity and evolution. These results support the utility of ctDNA as a biomarker for tumour progression and as a substrate to study the genetic dynamics of NHL tumours over the course of treatment.