Colorectal cancer Flashcards
Colorectal cancer aetiology
Originate from the epithelial cells lining the colon or rectum, most commonly an adenocarcinoma
Most colorectal cancers develop via a progression of normal mucosa to adenoma to invasive adenocarcinoma
Certain genetic mutations have been implicated in predisposing individuals to colorectal cancer:
- Adenomatous polyposis coli (eg. FAP)
- Hereditary nonpolyposis colorectal cancer (HNPCC)
Colorectal cancer risk factors
Increasing age
Male gender
Family history
Inflammatory bowel disease
Low fibre diet
High processed meat intake
Smoking
Excess alcohol intake
Colorectal cancer clinical features
Right-sided colon cancers - abdominal pain, IDA, palpable mass in RIF, often present late
Left-sided colon cancers - rectal bleeding, change in bowel habit, tenesmus, palpable mass in LIF/PR exam
Colorectal cancer referral criteria
Urgent investigation of suspected bowel cancer if:
- > /= 40 years with unexplained weight loss and abdominal pain
- > /= 50 years with unexplained rectal bleeding
- > /= 60 years with IDA/change in bowel habit
- positive occult blood screening test
Colorectal cancer screening
Screening is offered every 2 years to men and women aged 60-75 years
FIT test is used - utilises antibodies against human Hb to detect blood in faeces
Colorectal cancer Ix
Lab tests - routine bloods, CEA
Imaging - CT colonography
Gold standard for diagnosis - colonoscopy with biopsy
Staging Ix - CT scan, MRI rectum, endo-anal ultrasound
Colorectal cancer general mx
MDT discussion
Only definitive curative option is surgery, although chemotherapy and radiotherapy have an important role as neoadjuvant/adjuvant treatments, alongside their role in palliation
Colorectal cancer surgical mx
Mainstay of curative management for localised bowel cancer:
- right hemicolectomy or extended right hemicolectomy
- left hemicolectomy
- sigmoidcolectomy
- anterior resection
- AP resection
- Hartmann’s procedure - complete resection of the recto-sigmoid colon with the formation of an end colostomy & closure of the rectal stump
Colorectal cancer chemotherapy
Indicated typically in patients with advanced disease
Systemic therapy for metastatic colorectal cancer is tailored with patient-specific and disease-specific predictive markers
Newer biologic agents or immunotherapies are being developed
Colorectal cancer radiotherapy
Can be used in rectal cancer, most often as neo-adjuvant treatment & can be given alongside chemotherapy
Colorectal cancer palliative care
Very advanced colorectal cancers will be managed palliatively, focusing on reducing cancer growth & ensuring adequate symptom control
