[A case of response to panitumumab as third-line chemotherapy for multiple liver metastases and portal venal tumor embolus of rectal cancer].

A 64-year-old man who underwent rectal amputation for rectal cancer was diagnosed with multiple liver metastases and tumor embolus in the portal vein 6 months after operation. Though the patient underwent chemotherapy, mFOLFOX6, and bevacizumab+FOLFIRI, liver metastases were diagnosed as progressive disease (PD). After panitumumab+FOLFIRI was administered for three months as third-line chemotherapy, the tumor embolus completely disappeared, and liver metastases became cytoreductive on CT. The patient was judged to have achieved a partial response (PR). This case indicated that panitumumab was effective as third-line chemotherapy for unresectable recurrent rectal cancer.