Curative resection for locally advanced sigmoid colon cancer using neoadjuvant chemotherapy with FOLFOX plus panitumumab: A case report

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.