colorectal cancer Flashcards
epidemiology of colorectal
4th common cancer
1 in 15
non modifiable RFs
- age - highest in 85 over
- FH (1st dgree relattive <40 or 2 or more have it )
- — Familial Adenomatous Polyposis (FAP) - AD - formation fo hundreds of polyps by the age of 30-40 mutation of APC on chromosome 5
- — Lynch syndrome Hereditary NonPolyposis Colorectal Cancer -AD - from 25 or five years before the age when your youngest relative
- IBD
- African and American
modifiable RFs
- Diet
- red meat
- low fibre, high fat
- garlic, milk, calcium may be protective
- obesity
- alcohol
- diabetes - TYPE 2
- smoking
Pathology
aetiology
adenocarcinomas common
others squamous cell sarcomas - CT - leiomyosarcoma carcinoid - slow growing neuroendocrine lymphomas
aetiology
- loss of tumour suppressor gene APC
- activation of RAS oncogene
- loss of tumor suppressor gene DCC
- Loss of gene p53
- Additonal mutants
Symptoms of colorectal cancer
according to location
right colon
left colon
Sx - bleeding - change in bowel habit - tenesmus - abdo mass weight loss
Signs
- PR mass
- abdominal mass
- anaemia
right colon Sx - Weight loss Weakness Rarely obstruction Sign - iron deficiency anaemia
left colon Sx - Constipation Abdominal pain Decreased stool calibre Alternating bowel habit Rectal bleeding Si - Bright red PR bleeding Large bowel obstruction
Rectum Sx - Obstruction Tenesmus Bleeding Sign - Bright red PR bleeding Palpable mass on rectal exam
Diagnosis and stagining
gold standard
Tissue - colonoscopy GOLD STANDARD and biopsy
if they have a major comorbidity - offer flexible sigmoidoscopy then barium enema.
CT colonography
staging - CT assess invasion and metastases
rectal cancer MRI - local staging - identify high risk of recurrence
above fails - transanal US
CEA
barium enema -> apple core
Mx
surgery if after resection they hace RFs for recurrence -> give them DFU and oxiplatin - colon
rectal surgery APER - neoadjuvant radio
radiotherapy - before to reduce or after reduce recurrence
chemo - neoadjuvant or adjuvant capecitabine
Biological and targeted therapy - EGFR cetuximan
who is referred via the cancer pathway referral
when may it be considered
- they are aged 40 and over with unexplained weight loss and abdominal pain or
- they are aged 50 and over with unexplained rectal bleeding or
- they are aged 60 and over with:
- iron-deficiency anaemia or
- changes in their bowel habit, or
- tests show occult blood in their faeces
- there is a rectal or abdominal mass
- there is an unexplained anal mass or anal ulceration
- patients < 50 years with rectal bleeding AND any of the following unexplained symptoms/findings:
- abdominal pain
- change in bowel habit
- weight loss
- iron deficiency anaemia
screening for colorectal cancer
every 2 years to all men and women aged 60 to 74 years in England, 50 to 74 years in Scotland.
- a type of faecal occult blood (FOB) test which uses antibodies that specifically recognise human haemoglobin (Hb)
- used to detect, and can quantify, the amount of human blood in a single stool sample
- patients with abnormal results are offered a colonoscopy
FIT -
SEs of chemo
myelosuppression mucositis peripheral neuropathy neutropenic sepsis nausea vomiting diarrhoea constipation
SEs of cetuximab/panitumab
Skin toxicity Acneform rash Dry skin Hair growth disorders Pruritus Nail changes Fatigue Allergic reaction
Prognosis
Stage I – 85-95%
Stage II – 60-80%
Stage III – 30-60%
Stage IV – 7%
TNM staging
T1 the tumour is confined to the submucosa
T2 the tumour has grown into (but not through) the muscularis propria
T3 the tumour has grown into (but not through) the serosa
T4 the tumour has penetrated through the serosa and the peritoneal surface.
If extending directly into other nearby structures (such as other parts of the bowel or other organs/bodystructures) it is classified as T4a. If there is perforation of the bowel, it is classified as T4b.
Nodes:
N0 no lymph nodes contain tumour cells
N1 there are tumour cells in up to 3 regional lymph nodes
N2 there are tumour cells in 4 or more regional lymph nodes
Metastases
M0 no metastasis to distant organs
M1 metastasis to distant organs
Dukes A: tumour confined to bowel wall
Dukes B: tumour extends across bowel wall
Dukes C: involvement of regional lymph nodes
C1: only a few nodes near the site of primary growth, no proximal nodes involved
C2: proximal nodes involvedDukes
D: distant metastases
colon often mets to liver
rectum often mets to lungs
Late problems after GI cancer Mx
rectal bleeding • faecal incontinence • urgency • diarrhoea • constipation • flatulence • abdominal pain • painful bowel movements
