Pathological complete response to mFOLFOX6 plus cetuximab therapy for unresectable colon cancer with multiple paraaortic lymph node metastases

Abstract

Pathological complete response is achievable with mFOLFOX6 plus cetuximab therapy for unresectable colorectal cancer with multiple paraaortic lymph node metastases (mCRC) despite right-sided colonic origin. A 62-year-old woman with synchronous paraaortic lymph node metastases of transverse colon cancer was treated with mFOLFOX6 plus cetuximab as first-line therapy. The tumor size was markedly decreased following 6 courses of chemotherapy, and all lymph node metastases had disappeared. The patient then underwent conventional right hemicolectomy with D3 lymph node dissection plus sampling excision of the paraaortic lymph nodes. The pathological diagnosis was a complete response. The patient is currently alive 5 years after surgery with no signs of recurrence. The present study reported the apparent effectiveness of conversion therapy (surgery) with combination treatment with mFOLFOX6 plus cetuximab and radical surgery. We hypothesized that patients with different types of mCRC of right-sided colon origin may be effectively treated with anti-EGFR monoclonal antibodies.

Keywords: colon cancer; conversion surgery; neoadjuvant chemotherapy; pathological complete response.

Figure 1.

(A) Colonoscopy imaging shows hemicircular superficial elevated tumor. (B) CT colonography shows apple core sign in transverse colon as primary.

Figure 2.

Positron emission tomography-computed tomography demonstrating primary lesion and multiple lymph node metastases.

Figure 3.

(A) CT at first visit shows multiple paraaortic lymph node metastases with contrast effect. (B) Paraaortic lymph node metastases disappeared following 6 courses of chemotherapy.

Figure 4.

Operative specimen and histological profile of the primary tumor. (A) Primary lesion has almost disappeared following 6 courses of chemotherapy. (B) Low power view of section from operative specimen, showing the absence of tumor cells and the presence of fibrous tissue with the partially collected foamy histiocytes. (Hematoxylin and eosin staining; original magnification, ×40). (C) Higher magnification from the fibrotic area showing fibroblasts laying down collagen and a scattering of inflammatory cells (Hematoxylin and eosin staining; original magnification, ×100).