A Case of Panitumumab-Responsive Metastatic Rectal Cancer Initially Refractory to Cetuximab
A 64-year-old man was initially diagnosed with rectal cancer and liver metastasis. He underwent rectal amputation and partial hepatectomy, and pelvic node metastasis was pathologically diagnosed. Two months after the resection, he received first-line adjuvant chemotherapy comprising 5-flurouracil, leucovorin and oxaliplatin (mFOLFOX6). One year and 9 months later, computed tomography with contrast enhancement revealed multiple pulmonary and right femoral lymph node metastases. Second-line chemotherapy comprising 5-flurouracil, leucovorin and irinotecan (FOLFIRI) plus bevacizumab was begun, and he was free from progression for 2 years and 11 months. At that point, imaging studies revealed progressive disease (PD) as evidenced by metastatic lesions. Third-line chemotherapy comprising cetuximab combined with CPT-11 was then begun. The lesions showed a partial response after 3 months, and the patient was free from progression for 1 year and 6 months.\nThe metastatic lesions then showed gradual growth and the patient again developed PD. He began to suffer from severe right femoral pain, and panitumumab therapy was begun. After 2 months, the femoral pain had diminished, the multiple pulmonary lesions had been markedly reduced and a portion of the lesions had disappeared (fig. ).\nThe patient's partial response status was maintained for 6 months. Although the pulmonary lesions began to progress again, the patient has been alive for 5 years and 6 months since the first operation (fig. ).