Association Between ctDNA Detection and Tumor Burden in Advanced Kidney Cancer
The sum of the longest diameter (SLD) of all measurable lesions—a surrogate for tumor burden—was higher in a group of patients with metastatic renal cell carcinoma with detectable circulating tumor DNA (ctDNA), and increasing SLD may be associated with a higher number of genomic alterations, according to research presented by Manuel Caitano Maia, MD, of the Instituto do Câncer do Estado de São Paulo, at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 4582).
According to the investigators, a previous study of 224 patients with advanced renal cell carcinoma reported detectable ctDNA in 79% of patients, but the clinical factors associated with detection are still unknown. Data were obtained from 32 patients with stage IV renal cell carcinoma who received ctDNA profiling as part of routine clinical care. Patients had received a median of two prior lines of therapy.
In the study, ctDNA was detected in 16 patients (50%), with a median of 2 genomic alterations per patient. Patients with detectable ctDNA had a higher SLD than patients with no detectable ctDNA (99.6 vs. 50.0 mm). Additionally, all three patients with brain metastases had ctDNA detected.
“Further validation of these findings may help identify appropriate patients for ctDNA assessment and maximize yield in clinical practice,” Dr. Maia and colleagues concluded.