Polyethylene glycol microspheres loaded with irinotecan for arterially directed embolic therapy of metastatic liver cancer

AIM To study tumor response, and tolerability of arterially directed embolic therapy (ADET) with polyethylene glycol embolics loaded with irinotecan for the treatment of colorectal cancer liver metastases (CRC-LM). Secondary objectives were to monitor quality of life, time to progression and survival of patients. METHODS Patients were included in the study if they were affected by CRC-LM, refractory to systemic chemotherapy, treated with ADET using polyethylene glycol embolics, and had liver involvement < 50%. Tumor response, performance status (PS), tumor marker antigens, and quality of life (QoL) were monitored at 1, 3 and 6 mo after ADET. QoL was assessed with the Palliative Performance Scale (PPS). RESULTS We treated 50 consecutive CRC-LM patients with ADET using polyethylene glycol embolics. Their tumor response one month after ADET was: 28% of complete response (CR), 48% of partial response (PR), 8% stable disease (SD), and 16% of progression. Tumor response 3 mo after ADET was CR 24%, PR 38%, SD 19% and progression disease (PD) 19%. Tumor response 6 mo after ADET was CR 18%, PR 44%, SD 21% and PD 18%. QoL was 90% PPS at each time point. Median time to progression for patients who progressed was 2.5 mo (range 0.8-6). Median follow-up was 14 mo (0.8-25 range). ADETs were performed with no complications. Observed side effects (mild or moderate intensity) were: Pain in 32% of patients, increase of transaminase levels in 20% and fever in 14%, whereas 30% of patients did not complain any adverse event. CONCLUSION The treatment of unresectable CRC-LM with ADET using polyethylene glycol microspheres loaded with irinotecan was effective in tumor response and resulted in mild toxicity, and good QoL.