Colorectal Cancer
Henry Yao
HMO1, Royal Melbourne Hospital
Colorectal Cancer
Epidemiology
Most common internal cancer in Western Societies
Second most common cancer death after lung cancer
Lifetime risk
1 in 10 for men
1 in 14 for women
Generally affect patients > 50 years (>90% of cases)
Colorectal Cancer
Forms
Hereditary
Family history, younger age of onset, specific gene defects
E.g. Familial adenomatous polyposis (FAP), hereditary
nonpolyposis colorectal cancer (HNPCC or Lynch syndrome)
Sporadic
Absence of family history, older population, isolated lesion
Familial
Family history, higher risk of index case is young (<50years)
and the relative is close (1st degree)
Histopathology
Generally adenocarcinoma
Risk Stratification
Risk factors
Past history of colorectal cancer, pre-existing adenoma,
ulcerative colitis, radiation
Family history 1st degree relative < 55 yo and relatives
with identified genetic predisposition (e.g. FAP, HNPCC,
Peutz-Jeghers syndrome) = more risk
Diet carcinogenic foods
Risk category (for asymptomatic pts)
Category 1 (2x risk) 1o or 2o relative with colorectal cancer
>55 yo
Category 2 (3~6x) 1o relative < 55yo or 2 of 1o or 2o
relative at any age
Category 3 (1 in 2) HNPCC, FAP, other mutations
identified
Screening
Group
Screening
Evidence
General Population
FOBT every 2 years from age 50 to 75
1A
Category 1
FOBT yearly +/- 5 yearly sigmoidoscopy
from age 50
Category 2
FOBT yearly + colonoscopy 5 yearly
from age 50 or 10 years younger than
index case
IIIB
Category 3
Variable Consult Oncology, e.g.
- FAP colonoscopy every 12 months
from 12-15 yo until age 35 then 3 yearly
- HNPCC 1~2yearly colonoscopy from
age 50 or 5 years younger than index
case
IIIB
Clinical Presentation
Depends on location of cancer
Locations
in descending colon and rectum
in sigmoid colon and rectum (i.e. within reach of
flexible sigmoidoscope)
Caecal and right sided cancer
Iron deficiency anaemia (most common)
Distal ileum obstruction (late)
Palpable mass (late)
Clinical Presentation
Left sided and sigmoid carcinoma
Change of bowel habit
Alternating constipation + diarrhoea
Tenesmus
Thin stool
PR bleeding, mucus
Rectal carcinoma
PR bleeding, mucus
Change of bowel habits
Anal, perineal, sacral pain
Constitutional symptoms
LOA, LOW, malaise
Bowel obstruction
Clinical Presentation
Local invasion
Bladder symptoms
Female genital tract symptoms
Metastasis
Liver (hepatic pain, jaundice)
Lung (cough)
Bone (leucoerythroblastic anaemia)
Regional lymph nodes
Peritoneum (Sister Marie Joseph nodule)
Others
Examination
Signs of primary cancer
Abdominal tenderness and distension large bowel
obstruction
Intra-abdominal mass
Digital rectal examination most are in the lowest 12cm
and reached by examining finger
Rigid sigmoidoscope
Signs of metastasis and complications
Signs of anaemia
Hepatomegaly (mets)
Monophonic wheeze
Bone pain
Investigations
Faecal occult blood
Guaiac test (Hemoccult) based on pseudoperoxidase
activity of haematin
Sensitivity of 40-80%; Specificity of 98%
Dietary restrictions avoid red meat, melons, horseradish, vitamin C and NSAIDs for 3 days before test
Immunochemical test (HemeSelect, Hemolex) based on
antibodies to human haemoglobins
Used for screening and NOT diagnosis
Investigations
Colonoscopy
Can visualize lesions < 5mm
Small polyps can be removed or at a later stage by
endoscopic mucosal resection
Performed under sedation
Consent: bleeding, infection, perforation (1 in 3000), missed
diagnosis, failed procedure, anaesthetic/medical risks
Warn: bowel prep, abdominal bloating/discomfort afterwards,
no driving for 24 hours
Bowel Prep
Investigations
Double contrast barium enema
Does not require sedation
Avoids risk of perforation
More limited in detecting small lesions
All lesions need to be confirmed by colonoscopy and biopsy
Performed with sigmoidoscopy
Second line in patients who failed / cannot undergo
colonoscopy
Other Imaging
CT colonoscopy
Endorectal ultrasound
Determine: depth, mesorectal lymph node involvements
No bowel prep or sedation required
Help choose between abdominoperineal resection or ultra-low
anterior resection
CT and MRI staging prior to treatment
Blood tests
FBE anaemia
Coagulation studies for surgery
UECr - ?take contrast, ?NAC required
Tumour marker CEA
Useful for monitoring progress but not specific for diagnosis
Management
Pre-operative
Bowel prep picolax, go lytely, fleet
Normally 1 day prior
Partial obstruction 2~3 days prior
Complete obstruction intra-operative lavage
Antibiotics prophylaxis (up to 24 hours post-op)
Ampicillin
Metronidazole
Gentamicin
DVT/PE prophylaxis
Arterial supply
Resection
Management
Caecum or ascending colon
Right hemicolectomy
Vessels divided ileocaecal and right colic
Anastamosis between terminal ileum and transverse colon
Transverse colon
Close to hepatic flexure right hemicolectomy
Mid-transverse extended right hemicolectomy (up to
descending) + omentum removed en-bloc with tumour
Splenic flexure subtotal colectomy (up to sigmoid)
Descending colon
Left hemicolectomy
Vessels divided inferior mesenteric, left colic, sigmoid
Management
Sigmoid colon
High anterior resection
Vessels ligated inferior mesenteric, left colic and sigmoid
Anastomoses of mid-descending colon to upper rectum
Obstructing colon carcinoma
Right and transverse colon resection and primary anastomosis
Left sided obstruction
Hartmanns procedure proximal end colostomy (LIF) +
oversewing distal bowel + reversal in 4-6 months
Primary anastamosis subtotal colectomy (ileosigmoid or
ileorectal anastomosis)
Intraoperative bowel prep with primary anastomosis (5% bowel
leak)
Proximal diverting stoma then resection 2 weeks later
Palliative stent
Rectal Cancer
Options
Low anterior resection
Transanal local excision
Abdomino-perineal resection
Palliative procedure
Factors influencing choice
Level of lesion distance from dentate line, <5cm requires
abdomino-perineal resection to obtain adequate margin
Note: only 3% of tumours spread beyond 2cm
Grade poorly differentiated larger margin
Patient factors incotinence
Mesorectal node status resect if LN mets
Rectal Cancer
Anterior resection
Upper and mid rectum cacinoma
Sigmoid and rectum resected
Vessels divided inferior mesenteric and
left colic
Mesorectum resected
Coloanal anastomosis
High intraperitoneal anastamosis
(upper 1/3 of rectum)
Low extra-peritoneal anastomosis
Post-op recovery
Increased stool frequency
12-18 month to acquire normal bowel
function
1~4% anastamotic leak
Rectal Cancer
Abdominoperineal resection
Larger T2 and T3 or poorly differentiated
tumour
Rectum mobilised to pelvic floor through
abdominal incision
Sigmoid end colostomy
Separate perianal elliptical incision to
mobilise and deliver anus and distal
rectum
Vessels ligated inferior mesenteric
Rectal Cancer
Hartmanns procedure
Acute obstruction
Palliative
Transanal local exision
Early stage
Too low to allow restorative surgery
En block resection for locally advanced colorectal carcinoma
(remove adherent viscera and abdominal wall)
Palliative procedures
Diverting stoma
Radiotherapy
Chemotherapy
Local therapy laser, electrocoagulation, cryosurgery
Nerve block
Staging
TNM Staging
Stage 0 Tis N0 M0 i.e. small tumour within the lining of the colon
or rectum
Stage 1 T1 N0 M0 or T2 N0 M0 i.e. tumour has invaded layers of
the colon without spread beyond wall
Stage 2 T3 N0 M0 or T4 N0 M0 i.e. tumour has spread beyond
wall and into nearby tissue but no LNs
Stage 3 Any T with any N but M0 i.e. spread to nearby LNs but not
to other organs
Stage 4 Any T with any N and M1 i.e. spread to other organs (e.g.
liver and lungs)
Dukes staging
Duke A tumour confined to bowel wall
Duke B tumour invading through serosa
Duke C lymph node involvement
Distant metastasis
Colon Cancer Summary
Wholistic care
Education and counselling (about risk in family members as well)
Lifestyle management diet changes
Support from cancer council
Surgical (hemicolectomy, stents for palliation)
Stage 0 and 1 surgical resection only with NO adjuvant chemo (NNT to high and SE
of chemo too high)
Stage 2,3,4 surgery, chemotherapy, radiotherapy, targeted therapy
Prepare patient for surgery explain diagnosis, surg under GA, hospital for 7d, bowel
prep, proph antibiotics, primary anastomosis, may require colostomy or ileostomy to
facilitate healing but temp and only for 12wk, risk is infection, bleeding, anastomotic
leak, mortality
Medical
Adjuvant chemo FOLFOX (folinic acid, 5-FU, oxaliplatin) increase 5yr survival, be
wary of oxaliplatin causing peripheral neuropathy
Biological therapy anti-VEGF (bevacizumab), EGFR inhibitor (cetuximab)
Radiotherapy for palliation or liver mets
Follow-up
Aim to detect local recurrence, metastasis or new primary
CEA only useful if high b4 surg and low after surg
FOBT, repeat CT, colonoscopy according to hospital protocol
Rectal Cancer Summary
Wholistic care, conservative, (same colon cancer)
Medical and Surgical
Neoadjuvant chemo-radiotherapy to reduce size and sterilize
area b4 surgery to reduce risk of recurrence
Abdominal perineal resection (APR) require permanent
colostomy as anus is removed
Low anterior resection (LAR) sphincter sparing surgery, upper
of rectum remove only and no stoma as anus is functional
Local excision for superficial cancers
Follow-up
Same as colon cancer
Complications
Liver metastasis resection, embolisation,
chemotherapy, RFA, cryotherapy
Local invasion perineal and pelvic pain
Bowel obstruction
Palliated surgically (colectomy, stoma, stent placed
endoscopically) or else syringe driver (mix of
analgesic, anti-emetic, anti-spasmotic)
Fistula to skin or bladder
Rectal discharge and bleeding
Hypoproteinaemia (from poor appetite and absorption
peripheral oedema)
Poor appetite (steroids can help)
Prognosis
5 yr survivals
T1 = >90%, T2 = >80%. T3 = >50%
LN involvement = 30~40%
Distant mets = <5%
Hereditary Colorectal Cancer
Familial adenomatous polyposis
FAP account for <1% of all colorectal cancers
Due to mutation of the adenomatosis polyposis coli (APC) gene
Numerous adenomas appear as early as childhood and virtually 100%
have colorectal cancer by age 50 if untreated
Hereditary non-polyposis colorectal cancer / Lynch syndrome
More common than FAP and account for ~1-5% of all colonic
adenocarcinomas
Due to a mutation in one of the mismatch repair genes
Earlier age onset of colorectal cancer and predominantly involve the right
colon
HNPCC also increases the risk of
Endometrial, ovarian, breast ca
Stomach, small bowel, hepatobiliary ca
Renal pelvis or ureter ca
References
Fry et al., Chapter 50 Colon and Rectum, Sabiston Textbook
of Surgery 18th Edition
Tjandra et al., Chapter 24 Colorectal cancer and adenoma,
Textbook of Surgery 3rd Edition
http://www.cancer.org.au//aboutcancer/cancertypes/colorectalca
ncer.htm
Google images
Thanks You and Questions
Copyright The University of Melbourne 2011
Case Scenario
70 year old male
Presented to clinic
Doc, I have noticed some
blood in my stool.
What are your differential diagnoses?
What do you want to ask on history?
Differential diagnosis
Common causes
Haemorrhoids
Colorectal cancer
Diverticular disease
Anorectal pathology
Haemorrhoids, anal fissure, anorectal cancer, anal prolapse
Colonic pathology
Colorectal polyp/cancer, diverticular disease, angiodysplasia
Colitis (IBD, infective, pseudomembranous colitis, ischaemic,
radiation)
Post-surgery (e.g. polypectomy)
Small intestine and stomach pathology
Massive upper GI bleed haematochezia
Meckels diverticulum, small bowel angiodysplasia
History
Seven characteristics of HOPC
Key questions to sort out
Age of onset
Quality
Insidious onset, mixed in with stool VS
Intermittent, only with hard stools, blood on paper and
bowl and dabs of blood on top of stool
Colour
Black and tarry, associated with offensive smell
Maroon red
Bright red
Torrential
Past history of haemorrhoids, bowel cancer
Family history of bowel cancer, breast cancer
Other history and examination
Other things to ask:
Risk factors for haemorrhoids constipation, heavy lifting, chronic
cough, pregnancy
Other features of colorectal cancer
Other features of colitis pus and mucus in stool, fever, chills,
sweats
Past medical history
Abdominal Examination
Tenderness
Masses
PR Examination
Anorectal pathology
Colour of blood on finger
Polyps in rectum
Case Scenario
Doc, Ive been noticing
blood in my stool for 6
months now.
The blood seems to be
mixed in the stool.
Ive also noticed some
constipation recently. This
is unusual for me. I
usually go every day.
