Gastrointestinal Cancer

Question 1

Discuss the aetiology of gastrointestinal tumours (emphasis on colorectal cancer)

Answer 1

• Majority sporadic
• Increasing age (rare < 40 years)
• Large adenomatous polyp > 1cm, villous/ tubulovillous
histology 
• Family history - FAP/HNPCC
• Inflammatory bowel disease
• Previous pelvic radiotherapy
• Lifestyle factors – obesity, inactivity, diet, smoking, 
alcohol

Question 2

Discuss familial adenomatous polyposis (FAP)

Answer 2

• Autosomal Dominant
• < 1% colorectal cancer
• Multiple colonic adenomas
• 90 % untreated will develop colon cancer 
by 45 years
• Mutation APC gene, chromosome 5
• Attenuated form, less adenomas, older 
average age of colon cancer, 54

Question 3

Discuss HNPCC (Lynch Syndrome)

Answer 3

• Lynch Syndrome
• Autosomal Dominant
• More common – 3-4% of colorectal cancer
• Mutation in DNA mismatch repair genes
• Associated with tumours particularly in right colon
• Synchronous/metachronous tumors
• Extra-colonic cancers associated

Question 4

How do right-sided colonic tumours present (late-stage)?

Answer 4

• Vague abdominal aching
• Anaemia (iron loss by chronic
  microscopic bleeding)
• Weakness
• Weight loss

Question 5

How do left-sided colonic tumours present (late stage)?

Answer 5

• Constipation or diarrhoea
• Abdominal pain (colicky pain)
• Obstructive symptoms
  (nausea/vomiting)
• May get fresh blood

Question 6

How do rectal tumours present (late-stage)?

Answer 6

• Change in bowel movements
• Rectal fullness
• Urgency
• Bleeding
• Tenesmus
• Pelvic pain (later stage)

Question 7

Recall the red flag criteria for suspected cancer pathway referral (seen within two weeks)

Answer 7

• Faecal occult blood positive in faeces
• > 40 years with unexplained weight loss/abdominal pain
• > 50 years with unexplained rectal bleeding
• > 60 years with iron deficient anaemia or changes in bowel habit
• Consider in all adults with rectal or abdominal mass
• Consider in adults <50 years with rectal bleeding and any of the following: abdominal pain, change in bowel habit, weight loss, iron-deficiency anaemia.

Question 8

Describe the colorectal cancer screening programme in Northern Ireland

Answer 8

• Faecal occult blood (FOB) test sent with instructions
• Aged 60-74 (every 2 years)
• 2/100 will have positive result
• Sent for further investigation (repeat FOB/qFIT then colonscopy)

Question 9

Which tumour marker is used to monitor colorectal cancers?

Answer 9

Carcinoembryonic antigen (CEA)

Question 10

When a colonscopy identifies a lesion what other radiological investigations may be required?

Answer 10

• CT chest/abdomen/pelvis
• MRI
• PET scan
• CT colonography

Question 11

Identify the use of both TNM staging in colorectal cancer

Answer 11

Primary Tumour (T):
Tis = confined to mucosa
T1 = confined to sub-mucosa
T2 = confined to muscularis propria
T3 = confined to sub-serosa
T4 = extension to adjacent organ

Regional lymph nodes (N):
NX Regional nodes cannot be assessed
N0 No regional lymph node metastases
N1 Metastasis in 1 to 3 regional lymph nodes
N2 Metastasis in 4 or more regional lymph nodes

Distant Metastases (M):
MX Distant metastasis cannot be assessed
M0 No distant metastasis
M1 Distant metastasis

Question 12

Identify the use of both Duke’s staging in colorectal cancer

Answer 12

Dukes A: invasion into but not through the bowel wall (90% 5 year survival)
Dukes B: invasion through the bowel wall but not involving lymph nodes (70% 5 year survival)
Dukes C: involvement of lymph nodes (30% 5 year survival)
Dukes D: widespread metastases

Question 13

How is stage 1 CRC managed?

Answer 13

Surgical intervention only

Question 14

How is stage 2 CRC managed?

Answer 14

Surgical intervention:

• Adjuvant chemotherapy (2-4% improvement in cure rates)
• Offer patients clinical trial participation

Question 15

How is stage 3 CRC managed?

Answer 15

• Surgical intervention
• Chemotherapy
• 10-15% improvement on survival

Question 16

How is stage 4 CRC managed?

Answer 16

• Palliative surgery if appropriate
• Palliative chemotherapy
• Multi-modal therapies to try to cure limited metastatic disease

Question 17

What are the pre-treatment investigations of rectal cancer?

Answer 17

• Same as colorectal cancer
• Colonoscopy
• Biopsy
• CT chest/abdomen/pelvis
• MRI pelvis

Question 18

How is rectal cancer staged?

Answer 18

• MRI pelvis

- Helpful for assessing operability and need for neo-adjuvant chemotherapy

Question 19

How is rectal cancer managed?

Answer 19

• Surgery:
– Total Mesorectal Excision is surgical procedure of choice
• Radiotherapy:
-Evidence suggests that giving radiotherapy
before surgery is better than delivering this afterwards
– Short course preoperative radiotherapy (reduces local
recurrence)
• Delivered over 5 days in week before surgery
Long course pre-operative chemoradiation:
• Aim to shrink tumour before surgery- allow clear margins for resection

Question 20

Where to colorectal cancers most frequently metastasise to?

Answer 20

1. Liver
2. Abdominal lymph nodes
3. Lung
4. Peritoneum
5. Ovary

Question 21

What are a patient’s options with distant metastases?

Answer 21

• Palliative chemotherapy
– Yes (if fit)
– Importance of Performance status
• Consider surgery if oligometastatic
– Liver resection
• Radiofrequency ablation for liver or lung 
metastates
• Selective Internal radiation therapy (SIRT) 
- radioembolisation
• Importance of MDM discussions