Abstract
INTRODUCTION: FOLFOX and panitumumab combined chemotherapy plays an important role for metastatic colorectal cancer. However the usefulness of this regimen for neoadjuvant therapy is unclear. CASE REPORT: A 67-year-old man with abdominal pain and pneumaturia was diagnosed with RAS wild-type sigmoid colon cancer with urinary bladder invasion and colovesical fistulas. Because the cancer was considered to be unresectable, a transverse-loop colostomy was performed. Colonoscopy and computed tomography revealed a marked reduction in the size of the primary tumor after six courses of FOLFOX4 (oxaliplatin, leucovorin, and 5-fluorouracil) plus panitumumab. Laparoscopic sigmoidectomy and partial cystectomy were then performed. The pathological findings based on the resected specimen showed almost complete replacement of the tumor by fibrous tissue, with only a few degenerated tumor glands persisting in the submucosa. The patient's postoperative course was uneventful and he was doing well, without disease recurrence, after 36 months of follow up. CONCLUSION: To our knowledge, this is the first report of a successful curative resection in a patient with initially unresectable, locally advanced colorectal cancer who was treated with FOLFOX4 combined with panitumumab.