1. Henry Yao HMO1, Royal Melbourne Hospital
Colorectal Cancer
Henry Yao
HMO1, Royal Melbourne Hospital

2. 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)

3. 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

4. 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-Jegher’s 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

5. 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 yo until age 35 then 3 yearly
- HNPCC – 1~2yearly colonoscopy from age 50 or 5 years younger than index case

7. Clinical Presentation
Depends on location of cancer
Locations
⅔ in descending colon and rectum
½ 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)

8. Clinical Presentation
Left sided and sigmoid carcinoma
Change of bowel habit
Alternating constipation + diarrhoea
Tenesmus
Thin stool
PR bleeding, mucus
Rectal carcinoma
Change of bowel habits
Anal, perineal, sacral pain
Constitutional symptoms
LOA, LOW, malaise
Bowel obstruction

9. 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

10. 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

11. 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, horse-radish, 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

12. 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

13. Bowel Prep

14. 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

15. 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

16. 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

17. Arterial supply

18. Resection

19. 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

20. 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
Hartmann’s 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

21. 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

22. 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

23. 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

24. Rectal Cancer Hartmann’s 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

25. 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)
Duke’s staging
Duke A – tumour confined to bowel wall
Duke B – tumour invading through serosa
Duke C – lymph node involvement
Distant metastasis

27. 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

28. 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 ⅓ of rectum remove only and no stoma as anus is functional
Local excision for superficial cancers
Follow-up
Same as colon cancer

29. 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)

30. 5 yr survivals Prognosis T1 = >90%, T2 = >80%. T3 = >50%
LN involvement = 30~40%
Distant mets = <5%

31. 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

32. 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
Google images

33. Thanks You and Questions

34. © Copyright The University of Melbourne 2011

35. “Doc, I have noticed some blood in my stool.”
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?

36. 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
Meckel’s diverticulum, small bowel angiodysplasia

37. 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

38. 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

39. Case Scenario
Doc, I’ve been noticing blood in my stool for 6 months now.
The blood seems to be mixed in the stool.
I’ve also noticed some constipation recently. This is unusual for me. I usually go every day.