Modelling the impact of liver regeneration on hepatoblastoma patient-derived-xenograft tumor growth

Background Twenty percent of children with hepatoblastoma (HB) have lung metastasis at diagnosis. Treatment protocols recommend surgical removal of chemotherapy-refractory lung nodules, however no chronological order is established. As hepatectomy is followed by release of growth factors, it has been proposed that partial hepatectomy (PH) could boost local or distant residual tumor growth. Methods To evaluate the impact of PH on distant tumor growth, PH was performed in mice subcutaneously implanted with a HB patient-derived xenograft (PDX). The influence of PH on tumor growth at primary site was assessed by performing PH concomitantly to HB PDXs orthotopic implantation. Results Subcutaneously implanted HB PDX failed to show any influence of hepatectomy on tumor growth. Instead, intrahepatic tumor growth of one of the 4 HB PDXs implanted orthotopically was clearly enhanced. Cells derived from the hepatectomy-sensitive HB PDX exposed to hepatic growth factor (HGF) showed increased proliferation rate compared to cells derived from a hepatectomy-insensitive model, suggesting that the HGF/MET pathway could be one of the effectors of the crosstalk between liver regeneration and HB growth. Conclusion These results suggest that hepatectomy can contribute to HB growth in some patients, further studies will be necessary to identify biomarkers predictive of patient risk of PH-induced HB recurrence. Impact Key message : Cytokines and growth factors secreted following partial hepatectomy can contribute to intrahepatic tumor growth in some hepatoblastoma models. What does it add to the existing literature : It is the first article about the impact of liver regeneration induced by partial hepatectomy on hepatoblastoma local or distant tumoral growth in nude mice. What is the impact : It is important to identify the secreted factors that enhance tumor growth and to define biomarkers predictive of patient risk of partial hepatectomy-induced hepatoblastoma recurrence.