Bowel Cancer

Question 1

Which of the following symptoms are typical of acute appendicitis?

1. Vomiting preceding abdomen pain
2. Dull pain near the navel or the upper or lower abdomen that becomes sharp as it moves to the lower right abdomen
3. Temperature 39 degrees Celcius
4. Dull or sharp pain anywhere in the upper or lower abdomen, back, or rectum
5. Loss of appetite

Answer 1

2. Dull pain near the navel or the upper or lower abdomen that becomes sharp as it moves to the lower right abdomen. This is usually the first sign but only occurs in 50% of cases
3. True - Loss of appetite is often associated with nausea and vomiting soon after pain begins

Question 2

From the list below, what are the 6 red flags for colonic cancer
Older age
Obesity
Unexplained weight loss]Change in bowel habit in a person over 60 years
Rectal bleeding
Family history of bowel cancer
Smoking
Rectal or abdominal mass
Anaemia

Answer 2

1. Unexplained weight loss
2. Change in bowel habit in person over 60 years
3. Rectal bleeding
4. Family history of bowel cancer
5. Rectal or abdominal mass
6. Anaemia

Question 3

Which of the following statements are true about acute abdominal pain in the elderly?

1. Medical causes of abdominal pain are uncommon. .
2. Tend to present early in the course of their illness. .
3. Serious pathology more likely
4. Morbidity and mortality in older patients presenting with acute abdominal pain are high. .
5. Aortic aneurysm and bowel ischaemia are more prevalent in the elderly. .
6. Tend to show less specific symptoms and signs.

Answer 3

3-6

Serious pathology more likely

Morbidity and mortality in older patients presenting with acute abdominal pain are high. .

Aortic aneurysm and bowel ischaemia are more prevalent in the elderly. .

Tend to show less specific symptoms and signs

Question 4

How does bowel cancer present?

Answer 4

Presentation of bowel cancer:

• Rectal bleeding/mucus
• Change in bowel habit
• Abdominal/ rectal mass
• Iron deficiency anaemia
• Intestinal obstruction
• Abdominal pain
• Anal symptoms
• Tenesmus
• Weight loss

Question 5

What other differentials have similar symptoms to bowel cancer?

Answer 5

• Fissure
• Haemorrhoids
• IBD
• Gastroenteritis
• Other causes of anaemia
• Malabsorption (pancreatic, coeliac disease)
• Sexually transmitted infections
• Other masses e.g. bladder, uterus, ovary
• Anal cancer
• Other masses in rectum e.g. cervix, prostate

Question 6

Which symptoms indicate a high risk of bowel cancer and urgent two-week referral?

Answer 6

• > 6WK change bowel habit and bleeding any age l
• Change bowel habit (loose) >6/52 & >60 years
• Rectal bleeding without anal symptoms >60 years
• Palpable right sided mass any age
• Palpable rectal mass any age
• Unexplained Iron deficiency anaemia any age

Question 7

Which symtpoms indicate a low risk of bowel cancer but still require two-week referral?

Answer 7

• No IDA rectal or palpable mass
• Rectal bleeding & anal symptoms, no change bowel habit, all ages
• Rectal bleeding obvious external cause all ages
• Change bowel habit without rectal bleeding

Question 8

How is bowel cancer diagnosed?

Answer 8

FBC (? Microcytic anaemia)
Faecal occult blood

Barium enema

a. Safe and cheap
b. Almost 100% caecal imaging, less accurate for viewing left colon and small polyps

Colonoscopy
Expensive
90% caecal intubation, but better than barium enema for viewing sigmoid colon and small polyps
1 in 2000 perforations

CT/ MR virtual colonoscopy
Used in elderly patient who may not be suitable for enema or colonoscopy

DNA test for FAP (once >15 years old)

Question 9

Who is eligible for the bowel cancer screening program and what does it involve?

Answer 9

Based on faecal occult blood test (FOBT), colonoscopy
Aged 60-69, 2 yearly
- From the screening approx. 2% are positive for FOB
- Of these 2% who go on to have a colonoscopy, 10% are found to have colorectal cancer (>50% Dukes A) and 40% have adenomas (polyps or growths in the bowel)

Question 10

What are the predisposing factors of bowel cancer?

Answer 10

Neoplastic polyps
IBD
Genetic predispositions (e.g. FAP, HNPCC)

Age – almost 9 in 10 cases of bowel cancer occur in people aged 60 or over

Diet – a diet high in red or processed meats and low in fibre can increase your risk

Weight – bowel cancer is more common in people who are overweight or obese

Exercise – being inactive increases your risk of getting bowel cancer

Alcohol and smoking – a high alcohol intake and smoking may increase your chances of getting bowel cancer

Family history – having a close relative (mother or father, brother or sister) who developed bowel cancer under the age of 50 puts you at a greater lifetime risk of developing the condition; screening is offered to people in this situation, and you should discuss this with your GP

Question 11

What are the main treatments for bowel cancer?

Answer 11

Surgery – the cancerous section of bowel is removed; it’s the most effective way of curing bowel cancer and in many cases is all you need

Chemotherapy – where medication is used to kill cancer cells

Radiotherapy – where radiation is used to kill cancer cells

Biological treatments – a newer type of medication that increases the effectiveness of chemotherapy and prevents the cancer spreading

Question 12

What is the benefit of removing polyps/adenomas?

Answer 12

Removal of polyps has a positive impact on preventing bowel cancer development. The distribution of polyps in the cancer correlates to the development of bowel cancer. Patients who have adenomas often have a dominant genetic susceptibility to developing polyps and then later developing cancers from the polyps. There is generally a 5-year age difference between patients who have a polyp and those who develop bowel cancer.

• Rectal adenoma removed = 2.3 x relative risk of developing colorectal cancer
• Rectal adenoma not removed = 8 x relative risk of developing colorectal cancer

Question 13

What is Familiar adenomatous polyposis (FAP)?

Answer 13

FAP is a genetic condition where patient develop ‘carpet like’ distribution of polyps throughout the colon. Overtime, 1-2 of these polyps will progress to develop cancer.
FAP affects 1 in 7000 and is autosomal dominant (95% penetrance) and patients are likely to develop colorectal cancer in their 20-30’s

Question 14

What other genetic conditions are associated with polyps?

Answer 14

K-ras mutations

• GTPase signal transducer (oncogene)
• 10% = <5mm adenomas
• 50-60% = >10mm adenomas
• 60% develop colorectal cancers

P53 tumour suppressor gene

• Increase in response to cellular stress
• Arrests cell cycle/ induces apoptosis (BAX)
• Rarely mutated in adenomas

Question 15

What is Hereditary Non-polyposis colorectal cancer (HNPCC)?

Answer 15

• Inherited mutation in MMR genes
• Problem in ‘spell checking’ the DNA sequence. Normally these areas are corrected for, but if there is a mutation then correction cannot occur and these faulty areas are repeated and eventually develop bowel cancer
• Genome is replication error prone (“microsatellite instability”)
• Affects 1 in 500 population, commonly age 30-50
• MLH1, MSH2 account for 90%
• Mutation seen in 15% “sporadic” CRCs
• 70-80% penetrance
• Proximal colon bias
• Rapid adenoma-carcinoma progression (2-5 years)
• Favourable prognosis if detected early therefore need to be aware of family history

Question 16

Which part of the bowel does bowel cancer most commonly affect?

Answer 16

Caecum (22%)
Ascending colon (12%)
Transverse colon (10%)
Descending colon (7%)
Sigmoid colon (35%)
Rectum (14%)

Question 17

How is bowel cancer staged?

Answer 17

The stage of a cancer means how big the cancer is and whether it has spread. It is important because treatment is often based on the stage of a cancer.
Bowel (colorectal) cancer can be staged according to the Dukes’ system. You may hear your specialist talking about your bowel cancer as a Dukes’ A, B, C or D.

Dukes’ A: the cancer is only in the innermost lining of the colon or rectum or slightly growing into the muscle layer

Dukes’ B: the cancer has grown through the muscle layer of the colon or rectum

Dukes’ C: the cancer has spread to at least one lymph node in the area

Dukes’ D: means the cancer has spread to somewhere else in the body, such as the liver or lung. Some doctors prefer to call cancer this stage 4, or advanced bowel cancer

Question 18

How is bowel cancer staged (TNM)

Answer 18

The TNM staging is an alternate system that is used across the world. TNM stands for Tumour, Node, Metastasis and in the UK doctors use the 5th version of the TNM bowel cancer staging system.

The T stages describe the size of the tumour. In T1, the cancer has grown no further than the inner layer of the bowel. In T2, it has grown into the muscle layer of the bowel wall. In T3, it has grown into the outer lining of the bowel wall or into organs or body structures next to the bowel. In T4, it has grown into other parts of the bowel, other organs or body structures near the bowel, or the tumour has broken through the membrane covering the outside of the bowel.

The N stages describe whether there are cancer cells in the lymph nodes. N0 means no lymph nodes containing cancer cells. N1 means that 1 to 3 lymph nodes close to the bowel contain cancer cells. N2 means there are cancer cells in 4 or more lymph nodes that are further than 3cm away from the main tumour in the bowel OR there are cancer cells in lymph nodes connected to the main blood vessels around the bowel.

There are two M stages. M0 means the cancer has not spread to other organs and M1 means the cancer has spread to other parts of the body.

Question 19

What is an ileostomy, when is it indicated and what are the two main types?

Answer 19

An ileostomy is where the small intestine is diverted through an opening in the abdomen. Ileostomies are formed to either temporarily or permanently stop digestive waste passing through the full length of the small intestine or colon.

Indications:
– to allow the small intestine or colon to heal after it’s been operated on – for example, if a section of bowel has been removed to treat bowel cancer
– to relieve inflammation of the colon in people with Crohn’s disease or ulcerative colitis
– to allow for complex surgery to be carried out on the anus or rectum

There are two main types of ileostomy:
1. Loop ileostomy – where a loop of small intestine is pulled out through a cut (incision) in your abdomen, before being opened up and stitched to the skin to form a stoma
2. End ileostomy – where the ileum is separated from the colon and is brought out through the abdomen to form a stoma
Alternatively, it’s sometimes possible for an internal pouch to be created that’s connected to your anus (ileo-anal pouch). This means there’s no stoma and stools are passed out of your back passage in a similar way to normal.

Ileostomies are often sprouted, found in the Right iliac fossa, continuously effluent and mostly liquid based.

Question 20

How does Duke’s staging correlate with Prognosis?

Answer 20

Dukes A = 90% (*50% of these patients are detected by the cancer screening program)

Dukes B = 70-80%
Dukes C = 50-60%
Dukes D = 5-10%