LAUSR

In contrast to rectal cancer, preoperative (neoadjuvant) chemoradiotherapy is not used routinely in the treatment of colon cancer. We present a case of a locally invasive tumour of the ascending colon completely resected following neoadjuvant chemoradiotherapy. A 48-year-old man with well-controlled hypertension presented in November 2014 with right iliac fossa pain due to a locally advanced colonic tumour. Computed tomography images demonstrated a 10-cm mass arising from the caecum and ascending colon, which invaded the right psoas muscle, anterolateral abdominal wall and retroperitoneum. The tumour appeared inseparable from the right common iliac vessels and ureter. Intense fluorodeoxyglucose (FDG) uptake was noted on positron emission topography scanning in the para-aortic lymph nodes, but there was no evidence of metastatic disease (Figs 1,2). Histopathology and immunohistochemistry analysis confirmed a moderately differentiated mucinous adenocarcinoma of likely colonic origin. Preoperatively, the patient completed six cycles of chemoradiotherapy (a total of 48.6 Gy of intensity modulated radiotherapy (IMRT), combined with 5-fluorouracil), which he tolerated well. Restaging imaging demonstrated partial metabolic response with visible decrease in the size of the primary tumour, and a complete response in the lymph nodes (Figs 1,2). A complete metabolic response is defined as a return of visible FDG uptake in the lesion to a level equivalent to or lower than in the surrounding normal tissues. Two months after completion of chemoradiotherapy, the patient underwent an extended right hemicolectomy with resection of the lower border of the second part of the duodenum, en bloc right ureterectomy and partial jejunectomy. Psoas muscle, duodenum and jejunum were densely adherent to the tumour, and their resection was necessary to ensure clear margins (Fig. 3). The right kidney was decompressed with a nephrostomy. Histopathology confirmed a T4 mucinous tumour with extensive invasion of the surrounding structures, including a 55-mm segment of the ureter. There was a near-complete pathological response to the neoadjuvant therapy in the primary tumour. There was no evidence of disease seen in the resected duodenum and small bowel. Resection margins were at least 5-mm clear of disease. There was no evidence of metastases in any of the 13 lymph nodes resected. The patient was discharged home on day 12 following an uneventful recovery; renal function remained normal and the surgical wound has healed well.