Roles of hepatectomy for colorectal liver metastases with necrotic foci caused by prior anti-cancer therapies

Recent advances in chemotherapy for colorectal cancer prolonged survival. Tumor necrosis may develop as a side effect of chemotherapeutic agents. Recently, radiofrequency ablation sometimes indicated to patients with colorectal liver metastasis, when hepatectomy cannot be performed due to impaired hepatic functional reserve or general condition. We experienced hepatectomy for colorectal liver metastasis containing necrotic foci which was induced by anti-cancer drugs and radiofrequency ablation. Massive liver necrosis and abscess developed in a patient with initially unresectable large liver metastasis 6 months after induction of mFOLFOX6 and bevacizumab. Chemotherapy was discontinued due to systemic inflammatory responses. Extended right hepatectomy resulted in both resection of the tumor and significant improvement of septic condition. Chemotherapy was re-started after the operation. Bevacizumab targeted to tumor-related vascular endotherial cells might be responsible for the massive tumor necrosis. Another patient with chronic renal dysfunction underwent radiofrequency ablation for colorectal liver metastasis 2 cm in diameter in the segment 7. Three months after ablation, the tumor grew very rapidly to 6 cm in diameter. After extended posterior sectorectomy of the liver, blood CEA levels were normalized. Resected specimen showed a massive tumor growth around the necrotic foci of radiofrequency ablation. Hepatectomy played significant roles in these patients with necrotic foci of the liver. Decision and timing of hepatectomy are very important to save the patient.