A Case of Early Anal Canal Cancer with Pagetoid Spread with Different Antitumor Effects of Chemotherapy on Different Metastatic Sites

: A 78-year-old man visited our hospital with a prolapsed hemorrhoid. He was referred to the dermatology unit due to the thickness and redness of the perianal skin. He was diagnosed as having extra mammary Paget's disease by skin biopsy. After a biopsy of the anal polyp was performed to investigate the primary site, he was diagnosed with early anal canal cancer with Pagetoid spread and underwent a radical operation. Abdominoperineal resection with skin(D2 prx D3 lymphadenectomy) was performed with perineal reconstruction using a gracilis muscle graft. Postoperative surveillance without adjuvant therapy was performed because the pathological stage was stage I. Two years and 2 months after surgery, multiple liver metastases were found, and the patient was diagnosed with multiple liver, bone, and lymph node metastases(K-ras and UGT1A1 wild type)on PET. XELOX plus bevacizumab was used as first-line treatment and the liver metastases showed remarkable shrinkage; however, disease progression occurred in the bone. IRIS plus bevacizumab was started as second-line therapy but grade 3 hematotoxicity was observed during the first course. After 4 courses, it was difficult to maintain the therapy due to toxicity and cancer-related pain. The liver metastases had almost disappeared but the patient died 11 months after the initiation of chemotherapy.