A Successful Case of Conversion Therapy after Chemotherapy for Advanced Rectal Cancer with Inguinal Lymph Node Metastasis

Abstract A70-year-old man was diagnosed with lower rectal cancer with right inguinal lymph nodemetastasis. Surgical resection was not suitable for this patient. Chemotherapy(IRIS plus bevacizumabfollowed by XELOX plus bevacizumab)was administered for 16 months. After the chemotherapy, the rectal tumor and lymph nodeswelling were significantly reduced and distant metastasis was not observed on CT scans. Therefore, the tumor was considered to be resectable and abdominoperineal resectionof the rectum with lymph nodedissection was performed. On histopathological examination, cancer cells partially remained in the rectal tumor and lateral lymph nodes, although there were no cancer cells in the inguinal lymph nodes. The patient is alive without recurrence a year later. In cases with a good response to chemotherapy, conversion therapymay become an important therapeutic option.