Initial experience with novel Embocure Plus microspheres for transarterial chemoembolization (TACE) of liver metastatic colorectal cancer tumours – a clinical and in vitro study

Introduction
Transarterial chemoembolization (TACE) is currently recommended for unresectable intrahepatic tumours with no vascular invasion or metastasis to other organs. It is based on drug-eluting microspheres pre-loaded with chemotherapeutics, which are injected selectively into vessels supplying the tumour, to embolize them inducing ischaemia, and elute the drug, to induce tumour response. We present our initial experience with novel irinotecan-loaded Embocure Plus microspheres in patients with metastatic colorectal cancer tumours in the liver, and their effect on HCT-116 cell cultures in vitro.

Material and methods
Three consecutive male patients (median age 62 [50-76] years) with liver metastatic colorectal cancer tumours were selected. All patients had a pre-procedure contrast-enhanced computed tomography, confirming multiple metastatic liver tumours (mean tumour diameter = 42 mm; range: 14-77 mm) and periprocedural dyna-CT scans for rapid treatment results assessment. In vitro: Human colon HCT116 cancer cell line was cultured, irinotecan loaded Embocure Plus microspheres were added. Cultures were assessed after 24 hours and 72 hours of incubation in normoxia or hypoxia.

Results
All embolizations were technically successful, and no complications were observed. Stabilization of the targeted metastatic liver tumours in all patients was noted. In vitro: Significant decrease of the growth of HTC 116 cell lines were observed in controls compared to cells treated with Embocure Plus loaded with irinotecan in normoxia and hypoxia after 48 and 72 hours. We observed a tendency for less inhibited cell proliferation in low-oxygen conditions.

Conclusions
TACE therapy of liver metastatic tumours shows satisfactory results and a low complication rate. Embo­cure Plus microspheres are safe and technically feasible for superselective chemoembolization of metastatic colorectal cancer liver tumour. Dyna-CT can be used for assessment of treatment results during repeated TACE procedures.