Evaluation of the effectiveness of transarterial chemoembolization irinotecan-loaded with drug-saturable microspheres for the treatment of patients with neuroendocrine tumors with liver metastases

Background: Since 2021, transarterial chemoembolization of the hepatic arteries (TACE) has been included in the recommendations of professional communities for the treatment of metastases of neuroendocrine liver tumors (NEO). However, the heterogeneity of both this group of patients and types of chemoembolization with a limited range of cytostatics used in the treatment makes it difficult to analyze the data and introduce the method into the combination therapy regimens. Aim: to study the effectiveness of transarterial chemoembolization with irinotecan-loaded drug-saturable microspheres for the treatment of patients with neuroendocrine tumors with liver metastases. Methods: A retrospective, observational, uncontrolled study of 34 patients with liver metastases from neuroendocrine cancer who underwent 52 TACE with irinotecan-loaded drug-saturable microspheres. Group 1 consisted of 15 patients who already had liver metastases at the time of the primary focus detection, group 2 included 19 patients with liver metastases having appeared some time after the detection of the primary focus. To plan and evaluate the effectiveness of chemoembolization, computed tomography and magnetic resonance imaging were used every 10-15 weeks during the systemic treatment. All the patients received systemic NEO therapy before and after the embolization. Results: An increase in the progression-free time from 101 [57; 120] and 145 [89; 263] days after chemotherapy up to 300 [134; 344] and 304 [240; 342] days after TACE in groups 1 and 2, respectively, with no difference between the groups (p=0.31 and p=0.57, respectively). We did not find a linear relationship between the doubling time of the tumor and the change in the volume of the tumor lesion (R2=0.1085 and R2=0.0265 in groups 1 and 2). When comparing the intragroup scores, there was a statistically significant difference (p=0.009, p=0.046) in the tumor volume reduction and progression-free time between the patients who underwent TACE immediately and those who underwent TACE after chemotherapy. The diagnostic and angiographic images of liver metastases varied within the same organ and depended on the size of metastases. There were no adverse events after TACE. Conclusions: TACE with irinotecan-loaded drug-saturable microspheres is an effective method for the treatment of liver metastases of neuroendocrine cancer, allowing one to increase the time without progression.