Colorectal Cancer Flashcards
What is the peak age of incidence for colorectal cancer?
55-75 years.
What are the risk factors for colorectal cancer?
Polyposis syndromes (FAP, HNPCC). FHx of polyps (adenomatous polyps are pre-cancerous). IBD. Diet lacking in fruit and veg. Smoking.
What is the most common form of colorectal cancer?
Adenocarcinoma (mucinous, signet ring cell or anaplastic).
How does rectal colorectal cancer present?
PR bleed, fresh blood on surface of stool, tenesmus.
How does descending/sigmoid colorectal cancer present?
Dark red PR bleed, blood mixed with stool, change in bowel habit (increased frequency, PR mucus, variable consistency), bloating, flatulence.
How does ascending colorectal cancer present?
Iron deficiency anaemia may be the only presentation.
What is the emergency presentation of colorectal cancer?
Large bowel obstruction, perforation with peritonitis, acute PR bleed.
40% present as emergencies.
What investigations should be undertaken if colorectal cancer is suspected?
Elective colonoscopy.
Emergency CT.
Once diagnosed, staging investigations carried out by thoracoabdominopelvic CT.
CEA is not diagnostic but if raised at diagnosis and falls after resection, a secondary rise can indicate relapse.
Outline Duke’s staging.
A - Invasion confined to mucosa.
B - Infiltrate through muscle.
C - Lymph node involvement.
D - Distant mets.
What are the management options for colorectal cancer?
Curative surgical resection if no evidence of metastases (or mets potentially resectable) - colon resection with lymphadenectomy at site of cancer (whole section of bowel supplied by that artery has to be removed as lymph nodes run with the artery). Adjuvant chemo with 5-FU can improve prognosis.
Palliative treatment for non-resectable tumours - chemo to improve life expectancy and stenting to manage obstructions.
