Sher-e-Kashmir institute of medical sciences

1. SHER-I-KASHMIR INSTITUTE OF MEDICAL
SCIENCES
CLINICAL FEATURES AND INVESTIGATIONS
IN
CARCINOMA COLON
PREPARED BY
DR IFRAH AHMAD QAZI

2. INTRODUCTION
 Most common malignancy in gastrointestinal tract
 More common in females
 Age related increase in incidence ( mean age ~ 70-75 years)
(1) Maingot’s Abdominal Operation ; 12th edition; Section V ; Chapter 36 , p

3. CLINICAL FEATURES

4. SYMPTOMS
 Absent until late stage
 Subtle and vague
 Abdominal pain
 Rectal bleed
 Recent change in bowel habits
 Involuntary weight loss
Falterman KW, Hill CB, Markey JC, Fox JW, Cohn I Jr. Cancer of the colon, rectum, and
anus: a review of 2313 cases. Cancer 1974;34:951–9

5.  Less common symptoms
 Nausea and vomiting
 Malaise
 Anorexia
 Abdominal distention

6.  Symptoms depend upon :
 Cancer location
 Cancer size
 Presence of metastasis
Posner MC, Steele GD Jr, Mayer RJ. Adenocarcinoma of the colon and rectum. In: Zuidema GD, editor. Shackelford’s surgery of the alimentary
tract. 5th edition. Philadelphia: WB Saunders; 2002. p. 219–36

7.  Left colon cancer :
 Constrictive in nature
 Cause partial or complete obstruction as lumen narrower
and stools better formed
 Partial obstruction can sometimes produce paradoxical
diarrhoea
 More distal cancers produce gross rectal bleed

8.  Right colon cancer :
 Causes occult blood loss or melena
 Iron deficiency anaemia and symptoms associated with it
 Distal ileal obstruction
 Advanced cancer causes cancer cachexia
 Involuntary weight loss
 Anorexia
 Muscle weakness
 Feeling of poor health
 Cappell MS. Colon cancer during pregnancy: the gastroenterologist’s perspective. Gastroenterol Clin North Am 1998;27:225–56.
 Harewood GC, Ahlquist DA. Fecal occult blood testing for iron deficiency: a reappraisal. Dig Dis 2000;18:75–82.
 Theologides A. Cancer cachexia. Cancer 1979;43:2004–12

9. SIGNS
 Signs tend to present in advanced stages
 Signs related to anaemia :
 Pallor
 Koilonychia
 Cheilitis
 Glossitis
 Signs of hypoalbuminemia
 Peripheral oedema
 Ascitis
 Anasarca
 Hypoactive or high pitched bowel sounds suggesting
obstruction
 Palpable abdominal mass
 Rectal cancer may be palpable on digital rectal exam

10. DIAGNOSIS

11. 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

12. 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

13. SCREENING

14. INVESTIGATIONS
 Routine biochemical tests :
 Haemogram
 Serum electrolytes
 Blood glucose
 Liver function tests
 Coagulation profile
 Anaemia of undetermined etiology warrants evaluation for colon ca
 Vomitting and diarrhoea may produce electrolyte imbalance
 Liver function test usually normal
 In case hepatic metastasis, alkaline phosphate may be elevated
 Lactate dehydrogenase levels are also increased in colon ca
• Jonsson PE, Bengtsson G, Carlsson G, Jonson G, Tryding N. Value of serum 5-nucleotidase, alkaline phosphatase and gammaglutamyl
transferase for prediction of liver metastases preoperatively in colorectal cancer. Acta Chir Scand 1984;150:419–23.
• Ioannou GN, Rockey DC, Bryson CL, Weiss NS. Iron deficiency and gastrointestinal malignancy: a population-based cohort study. Am J
Med 2002;113:276–80.

15. CARCINOEMBROYONIC ANTIGEN ( CEA) LEVELS
 Moderate sensitivity and poor specificity
 Very high levels in advanced disease
 Preoperative testing to be done to :
 Determine cancer prognosis
 To determine baseline levels for postop comparison
 Elevated pre-op levels – poor prognosis
 Failure to normalise after surgery – incomplete resection
 Sustained and progressive rise after post-op normalisations -
recurrence
• Fletcher RH. Carcinoembryonic antigen. Ann Intern Med 1986;104:66–73.
• Arnaud JP, Koehl C, Adloff M. Carcinoembryonic antigen (CEA) in diagnosis and prognosis of colorectal carcinoma. Dis Colon
Rectum 1980;23:141–4.
• Koch M, Washer G, Gaedke H, McPherson TA. Carcinoembryonic antigen: Usefullness as a postsurgical method in the detection
of recurrence in Dukes stages B2 and C colorectalcancers. J Natl Cancer Inst 1982;69:813–5.

16. FAECAL OCCULT BLOOD TESTING ( FOBT)
 Traditional mainstay of screening for colon cancer
 Based on increased microscopic rectal bleeding in patients with
colon cancer compared with patients without colonic bleed
 Tested by calorimetric assay of reaction on guaiac catalysed by
pseudoperoxidase in blood
 Sensitivity under ideal circumstances – 85%
• Church TR, Ederer F, Mandel JS. Fecal occult blood screening in the Minnesota Study: sensitivity of the screening test. J Natl
Cancer Inst 1997;89:1440–8.

17. Advantages :
 Low cost
 Test simplicity
 Noninvasiveness
 Safety
Disadvantages :
 Low specificity
 Moderate sensitivity ( 85%)

18.  Sensitivity improved by :
 Performing test on three different occasions
 Avoiding ascorbic acid for several days
 Performing test on fresh stool or by rehydrating the stool
 Specificity improved by :
 Avoiding ingestion of broccoli, cauliflower , red meat
 Avoiding therapy with aspirin for 3 days before test
 Withholding iron therapy for several days
 Despite of its flaws, FOBT is an important armamentarium of colon
cancer screening because of test safety and convenience

19. CONTRAST ENEMA
 Valuable adjunct to colonoscopy for near obstructing colonic
lesions
 Ideally , barium-air double contrast technique used after bowel
preparation
 In acute settings and where there is suspicion of perforation,
barium is contraindicated due to risk of peritonitis
 In these cases water soluble contrast ( gastrograffin) is used

20. FINDINGS
 Fixed filling defect with destruction of mucosal pattern in an
annular configuration ( apple core sign )

21. Advantages :
 Visualises the anatomic position of the lesion more accurately
 Better passage through even severe obstructed lesion
 Commonly reach upto caecum
 Superior in visualising diverticula or suspected fistula
Disadvantages :
 Inability to take biopsy
 Inability to detect small lesion
Air Contrast Barium enema image shows
pouches (called diverticula) in the wall of the
colon

22. FLEXIBLE SIGMOIDOSCOPY
 Flexible sigmoidoscopy every 3 to 5 years recommended in
conjunction with annual FOBT for screening of colon cancer in
average risk patients
 Role is becoming increasingly limited in screening of colon cancer
due to :
 Proximal half of colon not visualised and about 1/3 to ½ of lesions
are proximal to sigmoid colon
 Recent shift of colon cancers to right side of colon
 Most proximal lesions do not have synchronous distal lesions
 Finding cancer on sigmoidoscopy mandates full colonoscopy to
diagnose synchronous lesions

23. DIAGNOSTIC COLONOSCOPY
 Has evolved as method of choice for evaluation of large intestine
 Recommended for screening of patients > 50 years old at average
risk for colon cancer
 Highly sensitive in detecting large ( >1 cm ) polyps, with miss rate of
about 6%
 Moderately sensitive in detecting diminitive ( < 0.6 cm ) polyps, with a
miss rate of about 27%
 Colon cancers are rarely missed because of their large size as
compared to adenomas

24. Indications of colonoscopy :
Surveillance in persons with average and high risk for colon cancer
Faecal occult blood
Iron deficiency anaemia
Haematochezia
Malaena with nondiagnostic UGI endoscopy
After finding colonic polyps on sigmoidoscopy
Adenocarcinoma metastasis to liver with unknown primary
Follow up after colonoscopic removal of large sessile colonic polyp
Abnormal radiographic study ( contrast enema, virtual colonoscopy)
Colonic stricture
Intraoperative colonoscopy to localise lesion for surgical removal

25.  In colonoscopy, Polyps are characterised by :
 Size
 Color
 Number
 Segmental location
 Intramural location ( mucosal or submucosal)
 Presence or absence of stalk ( pedunculated or sessile )
 Superficial appearance

26.  Polyp characteristics at colonoscopy provides important clues
regarding polyp histology and malignant potential
 Hyperplastic polyps are small, pale, unilobular and located in
rectum

27.  Adenomas are larger, redder, multilobular and distributed
throughout colon
A typical tubular adenoma in the colon Picture of Familial Adenomatous Polyposis

28.  Villous adenomas are large, bulky, sessile, shaggy, soft, velvety,
and friable

29.  Advanced colon cancer typically appears either as :
 large, exophytic mass because of intraluminal growth
 a colonic stricture because of circumferential growth
 Malignant strictures are ulcerated, indurated, asymmetric and
friable and have irregular or overhanging margins
Exophitic colon cancer
A malignant stricture (adenocarcinoma) in
the transverse colon

30. Disadvantages of colonoscopy :
 Expensive
 Invasive
 Uncomfortable and requires sedation and analgesia
 Small, but significant, risk of serious complications
 Requires a team of technician, nurse and trained
colonoscopist
 Requires patient preparation for 24 hours before test

31. Complications :
Diagnostic colonoscopy-associated perforation.
 Complication rate is about 5 %
 Most common major complications are GI bleed and
perforation
 Most colonic perforations require surgery but conservative
management with parenteral fluids, antibiotics and surgical
backup occasionally suffices

32. COMPUTED TOMOGRAPHY
 Standard modality to image the abdomen in colorectal ca
 CT is highly sensitive (90%) and specific ( 95%) in detecting
liver metastasis > 1cm
 CT is only moderately accurate in detecting T staging ( 74%)
and N staging ( 50-70 %)

33. CT showing multiple liver metastasis( arrows) in a patient
of Colon cancer

34. MAGNETIC RESONANCE IMAGING
 Superior to CT in detecting liver metastasis
 More sensitive than CT, particularly in detecting small
metastasis
 Sensitivity is increased even more in contrast enhanced
MRI as the metastatic lesion is enhanced due to high
vascularity
 Usually reserved for characterizing ambiguous hepatic
lesions detected on abdominal USG or CT

35. MRI (T2 with fat suppression) demonstrating rounded
high-intensity metastatic lesions (arrows) throughout the
liver in a patient with known colon cancer

36. COLONIC ULTRASONOGRAPHY
 Endoscopic ultrasound is much more useful for T and N
staging of rectal cancer as compared to colon cancer
 Most patients with colon cancer without distant mets
undergo colonic resection irrespective of T or N stage
 Colonic endosonography is also technically more demanding
and time consuming

37. Endoscopic ultrasound showing tumour in sigmoid colon

38. NEW AND EVOLVING
INVESTIGATIONS

39. STOOL GENETIC MARKERS
 This technique has showed clinical promise in preliminary
clinical studies
 Based on detection of cancerous DNA in stool specimen
 DNA from colon cancer is shed in greater quantities in the
faecal stream than normal mucosa
 Minute quantities of DNA in stool can be amplified by PCR
technique

40.  The DNA can then be assayed for detection of mutations of
colon cancer ( like APC, p53, K-ras )
 Sensitivity in different studies ranges from 71-91 %
 It has the potential of non-invasiveness and user
friendliness
 Technique need refinement and testing in large clinical trials

41. VIRTUAL COLONOSCOPY
 Introduced by Vining in 1994
 CT images are obtained in prone and supine position during a
prolonged breath hold
 CT images are then reformatted into three dimensional
endoluminal images simulating the traditional colonoscopic view
 There is a wide discrepancy in sensitivity an specificity in different
studies
 Accuracy of virtual colonoscopy is a function of polyp size. More
accurate in detecting lesion >10mm than lesion < 5mm

42. Virtual colonoscopy image of the inside of a colon. The red
colored area indicates a polyp detected by computer-aided
detection (CAD)
Computerized Tomographic Colonography (CTC) images of a
colon (left, with the patient scanned supine; right, with the patient
scanned prone). The red colored area indicates a polyp detected
by computer-aided detection (CAD).

43. Advantages :
 Noninvasive
 Sedation and analgesia not required
 Safe with hardly any reported complication
 Can visualise extracolonic, intraabdominal organs and thus can
provide simultaneous cancer staging
Disadvantages :
 Inability to take biopsy
 Inability to remove polyps for HPE and definitive therapy