The management of adenocarcinoma of the small intestine depends primarily on tumour location. Which of the following statements concerning surgical management are true?

Optimal surgical treatment of adenocarcinoma of the small intestine requires wide, segmental resection, including the draining nodal system. For most duodenal adenocarcinomas, a radical pancreaticoduodenectomy (Whipple procedure) is necessary to incorporate peinent draining lymph nodes. Although local excision of villous adenomas of the periampullary area has been repoed, the presence of invasive carcinoma warrants wider resection as a pancreaticoduodenectomy. Distal ileal carcinomas are drained by lymph nodes along the ileocolic aery and are best managed by right hemicolectomy. Jejunal and ileal carcinomas are removed with segmental resections with adequate margins on the bowel and wide resection of the mesentery with associated lymph nodes down to the superior mesenteric aery.