Colorectal Cancer

Question 2

CRC is the most common GI malignancy. What is the gender distribution of CRC? What is the average age of onset?

Answer 2

M3:1F
55-75 yoa

Question 3

What are the 4 most important polyposis syndromes a/w colorectal cancer?

Patients with a family history of colorectal cancer or are known to have any of these polyposis syndromes have to undergo more than just the screening program of the general population. What do you have to do in addition?

Answer 3

FAP - Familial adenomatous polyposis
Lynch/HNPCC - Hereditary Non-Polyposis Colon Cancer
Peutz Jegher Syndrome
Juvenile Polyposis

These patients will undergo colonoscopy starting at 40yo and then 5-10yrly after that

Question 4

FAP
What is FAP and how is it dx? How likely is it that a patient with FAP develops CRC?
How is it treated?

Answer 4

Question 5

What type of lynch syndrome causes CRC?

Answer 5

Question 6

How would you determine the likelihood of developing CRC if a patient has lynch syndrome? Go through it.

Answer 6

Question 7

What is the biggest RF for CRC other than family history and polyposis syndromes?

Answer 7

Polyps, specifically adenomatous polyps

Question 8

What are the RFs for CRC?

Answer 8

Question 9

What is the predominant histological subtype of CRC?

Answer 9

adenocarcinoma

Question 10

Are most cases of CRC sporadic or inherited?

Answer 10

Sporadic

Question 11

What are the different types of polyps along with their relative % distribution?

Which ones are neoplastic?

Answer 11

Hyperplastic: Non-neoplastic (80%)
vs
Adenomatous: Neoplastic (20%)
a) Tubular (80%)
b) Villous (10%)
c) Tubulovillous (10%)

Question 12

How would you differentiate between a tubular and a villous adenomatous polyp on colonoscopy?

Which is more common?
Which is more neoplastic?

Answer 12

Tubular (80%) is pedunculated
Villous (10%) is sessile and also hx (and colonoscopy) will show a large amount of mucous

Tubular more common Villous more malignant

Question 13

You are performing colonoscopy and find a mass protruding from the wall of the colon. What are your differentials?

Answer 13

Diverticula
Mucosal vessel
Malignancy (1 or 2)
Other stuff to BS
Polyps:
-Hyperplastic Polyps
-Adenomatous Polyps (tubular, villous and tubulovillous)
- Serrated Adenomas

Question 14

What are Sessile Serrated Adenomas?

Answer 14

Neoplastic polyps
They are Sessile (like villous) and can look hyperplastic (=> missing a possible pre-malignant mass)

Question 15

Briefly go through
Local invasion:
Lymphatic spread:
Haematogenous spread:
of CRC

Answer 15

Local invasion = T in TNM => Submucosa -> Muscularis propria -> Serosa -> Visceral peritoneum

Question 16

CT pelvis shows an incidental finding of a mass in the lwoer sigmoid colon of a 78yo female patient presenting with PR bleed, weight loss, tenesmus, constipation anc change in bowel habit. there is evidence of anaemia on examination.

Should you perform a Sigmoidoscopy or a Colonoscopy? Explain like you would in a long case

Answer 16

Colonoscopy should be performed.

3-5% of CRC are synchronous tumours which means that there may be more than 1 primary lesion present at the same time. (a/w IBD btw). This can lead to closed loop obstruction if not picked up increasing the risk of perforation.

A colonoscopy will also allow us to go further and look for more polyps which may be adenomatous or sessile serrated => to biopsy or perform polypectomy on.

Everything mentioned here is your answer for what youre looking for on colonoscopy as well

Question 17

Briefly discuss gross morphology of
L-sided:
R-sided:
CRC.

Answer 17

L-sided: Napkin ring showing stenosis
R-sided: Cauliflower appearence showing polyposis

Now that MCQ is done, this is almost useless

Question 18

What % of CRC presentations are an emergency?
What are the 3 most common emergency presentation of CRC? Which is the most common?

Answer 18

40% of CRC present as an emergency
Large Bowel Obstruction (most common)
Haemorrhage/acute PR bleed
Perforation +/- Peritonitis

Question 19

Go through all the symptoms that you would like to elicit while taking a history from an elderly patient with a long-standing PR bleed

Case = CRC

Answer 19

dont forget to ask about screening!

Question 20

What is the screening protocol for CRC in Ireland?

What % of positive tests will be CRC?

Answer 20

10% are CRC
1/3 will show polyps on colonoscopy

Question 21

A patient presents with a PR bleed, what 2 bedside investigation must you do?

Answer 21

FOB
+DRE to rule out peri-anal differentials + check for blood to see if frank or mixed with stool, whether there is an empty rectum (obstruction), or any palpable masses.

Question 22

What tumour marker is associated with CRC? Briefly discuss this tumour marker and its use in the realm of CRC (3 main things)

Answer 22

CEA (carcinoembryonic antigen) is a non-specific tumour marker that is common among many cancers including colorectal cancer.

It has no use in diagnosing or staging of the cancer. It is only used to
1) Pre-op prognosis
2) Assess completeness of resection (should fall significantly post-op)
3) Monitor for disease relapse

Question 23

What CEA level pre-op would indicate a poor prognosis?

Answer 23

CEA >5

Question 24

Go through the TNM and Duke’s Staging for CRC

Answer 24

Question 25

How will you stage CRC

Answer 25

Question 26

Patient comes to your OPD with bleeding PR and is not well. You decide she needs admission. What investigations will you run (all)

Answer 26

Question 27

Not everyone with CRC receives chemotherapy. Neoadjuvant chemotherapy is performed for which types of CRC? What is the neoadjuvant therapy? Adjuvant therapy is given to which patients with CRC? What is the Adjuvant therapy? What about radiotherapy? Is that relevant here?

Answer 27

Neoadjuvant chemotherapy: Only for rectal CRC with Oxaliplatin (for colon, it is a case by case basis) Adjuvant chemotherapy is given for patients with +ve LN metastasis or evidence of vascular invasion (=> NM). Most common is 5FU but also Oxaliplatin. => FOLFOX In terms of radiotherapy, it is only done adjuvant (obviously) and also for rectal tumours => in total: Rectal get neoadjuvant + adjuvant chemotherapy + Adjuvant radiotherapy All other CRC dont get anything unless they have N or M.

Question 28

80% of CRC tumours are resectable. In certain cases it hasnt metastasised but has invaded far enough locally for a radical surgery. What is this radical surgery? What technique is used + what is removed? What is the specific indication to choose this surgery over the less radical ones?

Answer 28

Pelvic exenteration which involves removal of the rectum, part of the colon, and any other structures in the area with possible invasion such as the vagina, bladder, prostate, anus, uterus etc... This is performed via TME (Total Mesorectal excision) which is the technique and is performed when the tumour invades beyond the Mesorectal Fascia!!

Question 29

I want you to list all the surgeries performed in the treatment of CRC along with the indications to do each

Answer 29

APR - Anorectal or lower rectal tumours <5cm from the anal verge Low/ultralow anterior resection - Lower rectal tumours >5cm from anal verge High Anterior Resection - Upper rectum and Sigmoid tumours Hartmann's Procedure - Upper rectum and Sigmoid tumours Left Hemicolectomy - Tumours in the descending colon and distal transverse colon Right Hemicolectomy - Tumours in the ascending and proximal transverse colon Pelvic exenteration via TME - Tumours invading beyond the mesorectal fascia

Question 30

You are about to perform surgery on a patient with CRC. Your colleague asks you if you need them to contact plastics. When will you need to contact plastics? What is the flap called (2) and state which is better?

Answer 30

Plastics are needed for the flap in an APR procedure => for anorectal tumours or rectal tumours <5cm from anal verge IGAP (Inferior gluteal artery perforators) from the buttocks and is preferrable due to the amount of tissue that may be harvested) VRAM (vertical rectus abdominus myocutaneous)

Question 31

What is involved in an APR procedure? What does it stand for btw?

Answer 31

APR - Abdominoperineal Resection It involves the removal of the anal canal and the sphincter complex +/- part of the sigmoid colon !! leaving the patient with a permanent End-Colostomy. !!Plastics are also working in conjunction to create and fit a flap (triangular).

Question 32

What is involved in a Ultra-low: Low: Anterior resection

Answer 32

Ultra-low: Lower 1/3 of rectum Low: Lower 2/3 of rectum Anterior resection: Removal of above leaving patient with loop ileostomy for delayed defunctioning Image is not the best. It is somewhere between a low and high anterior resection idk man

Question 33

What is involved in a High anterior resection

Answer 33

Removal of the sigmoid colon + upper 1/3 of the rectum with direct anastomosis of descending colon to lower 2/3 of rectum Image is not the best. It is somewhere between a low and high anterior resection idk man

Question 34

What is involved in a Hartmann's procedure?

Answer 34

Proctosigmoidectomy + creation of a rectal pouch with temporary End-colostomy for later defunctioning when appropriate

Question 35

What is the risk of having a rectal pouch/stump?

Answer 35

Pelvic sepsis and peritonitis as it can get infected easily

Question 36

I have a tumour in my sigmoid colon. How will you decide if I should do a high anterior resection or a Hartmann's procedure?

Answer 36

High anterior resection involves direct anastomosis whereas a hartmann's procedure involves the formation of a rectal pouch for delayed anastomosis => Stoma needs to be created while the anastomosis heals => things to consider are patient factors, extension of tumour, complications (e.g. perforation => hartmann's) patient willingness to have and manage stoma etc... Honours: It is also important to note that 60% only get reversed and 40% do not and hence will have a permanent End-colostomy

Question 37

What is involved in a Left Hemicolectomy: Right hemicolectomy:

Answer 37

Left hemicolectomy = Removal of descending colon + Distal 1/3 of transverse colon Right hemicolectomy = Removal of ascending colon (and if extended right hemicolectomy) + Proximal 2/3 of transverse colon

Question 38

I have a tumour in my transverse colon, right about in the middle. How will you determine if I should undergo a left or right hemicolectomy?

Answer 38

It is based on the blood supply of where the tumour is and what is needed to be resected therefore whether the supply is from the superior (=> right) or inferior (=> left) mesenteric artery.

Question 39

Youve finished managing the patient with CRC. All good now! Whats the followup regimen (3 things)

Answer 39

1) OPD review or followup with GP regularly 2) CT Scan Annually for 3 years 3) COlonoscopy at 1 year and then 3-yrly after that

Question 40

What is the full management of Colorectal Ca? (Answer will include all surgeries, indications, and what is involved in each surgery so if you want to test them, say them all)

Answer 40

Dont forget the part of excising any metastasis e.g. to liver or lung (lobectomy) Dont forget the specifics of the chemo therapy and the RADIOTHERAPY (rectal only adjuvant) => in total: Rectal get neoadjuvant + adjuvant chemotherapy + Adjuvant radiotherapy All other CRC dont get anything unless they have N or M.

Question 41

Im sure youve noticed that the surgeries for CRC tumours located distally typically require stomas. Why is that? Answer like a long case

Answer 41

As we move distally blood supply becomes more scarce and watershed areas are more dominant and hence more easily compromised. This leads to necrosis, poor healing etc... Especially for patients with multiple comorbidities or poor wound healing (trap) => anastomotic leak. Creating a stoma gives the body ample time to heal. Honours would discuss how peristalsis exacerbates the anastomotic leak just like for an oesophagectomy

Question 42

Briefly discuss the palliative care regimen for CRC

Answer 42

Question 43

What margins will you leave post-colorectal surgery?

Answer 43

10cm margins should be left for any cancer in the colon. + Ideally R0 margins after sending samples to the pathologist to confirm negative margins