Spread

The spread of colonic cancer is variably:

• lymphatic:
  • most common
  • through mesenteric and para-aortic nodes, and eventually, the thoracic duct
  • may involve supraclavicular nodes in late stages
• direct extension:
  • through the bowel wall into adjacent structures, e.g. small intestine, stomach, duodenum, ureter, bladder, uterus, abdominal wall
• haematogenous spread:
  • 10-15% of cases
  • to liver in 75%, lung, or bone
• transcoelomic spread:
  • through the serosa and tumour cells into the peritoneal cavity forming local deposits of malignant nodules
  • the recto-vesical or recto-uterine pouches are often involved and on digital rectal examination can be felt as a hard shelf - Plummer's shelf
  • other common sites include omentum, and ovaries - Krukenberg tumour
• intraluminal metastasis:
  • exfoliated cells may become trapped in an anastomotic suture or staple line during operation "anastomotic recurrence".