Prognostic and predictive value of circulating DNA for hepatic arterial infusion of chemotherapy for patients with colorectal cancer liver metastases.

Hepatic arterial infusion (HAI) of chemotherapy is an experimental treatment option for patients with colorectal cancer liver metastases (CRCLM). The current study aimed to investigate the predictive and prognostic value of cell free DNA (cfDNA) in patients with CRCLM receiving HAI with oxaliplatin and systemic capecitabine. Plasma samples from 62 patients were investigated who were included into a single arm phase II study investigating HAI treatment for patients with CRCLM. The clinical outcome of the trial has been presented previously. In brief, treatment consisted of intrahepatic infusion of oxaliplatin 100 mg/m every second week with concomitant oral capecitabine 3,500 mg/m every second week for up to 12 cycles. Blood samples were drawn at baseline and follow-up and plasma was analyzed for cell free DNA using a direct fluorescent assay. The baseline level of plasma cfDNA was 0.92 ng/µl (95% CI 0.84-1.00). Patients with a baseline value of cfDNA above the 75th quartile had a median overall survival of 2.4 years (95% CI 0.7-2.8), compared with 3.9 years (95% CI 2.8-5.9) for patients below the 75th quartile (P=0.02). The baseline level of cfDNA was significantly lower (0.91 ng/µl, 95% CI 0.76-0.98) in patients who achieved an objective response compared to non-responders (1.79 ng/µl; 95% CI 0.99-2.57; P=0.02). The current study demonstrated a possible prognostic and predictive value of cfDNA for patients with CRCLM undergoing HAI with oxaliplatin and concomitant capecitabine.