Colon Cancer & Rectal problems Flashcards
1
Q
What is the most common colon cancer [3]
A
Adenocarcinoma
Rectum + sigmoid
Other - HNPCC / FAP
2
Q
Types of adenomas/polyps
A
Benign
Pre malignant
Tubular (75%)
Villous (10%)
3
Q
What characteristics of polyps suggest high risk of malignancy [4]
A
Large (>2cm)
Numerous
High risk dysplasia
Villous architecture
4
Q
Describe multi-step carcinogenesis in CRC [6]
A
> Normal cell undergoes mutation of adenomatous polyposis coli (APC) gene > Hyperproliferation > early adenomas > k-ras mutation then DCC mutation > Becomes intermediate then late adenoma > Mutation of p53 gene > Carcinoma
5
Q
What are the RF for colon cancer [6]
A
Age, Male Smoking, Alcohol Diet - low fibre, high red, processed meat Previous adenoma, Neoplastic polyps FH, Genetics - HNPCC / FAP IBD
6
Q
Criteria for urgent referral [4]
A
Always:
>40y/o w/ unexplained weight loss AND abdo pain
>50y/o w/ rectal bleeding with no anal symptoms
>60y/o with iron deficiency anaemia or change in bowel habit
FOB
7
Q
What do high risk features automatically get
A
Colonoscopy +- barium enema + biopsy
8
Q
What do R sided (ascending) colon cancer normally present with
A
Occult bleeding > Anaemia
Weight loss
Vague pain
Weakness
Present later as lumen can get very tight before obstruction as more liquid
9
Q
What does L sided (descending) colon cancer present with [6]
Which is more common L or R sided colon cancer?
A
Left sided colon cancer is more common
Obstruction / stricture / perforation Bleeding / mucous PR due to haemorrhage Altered bowel habit Weight loss / lethargy Tenesmus - need to evacuate PR mass
10
Q
What are common symptoms in bowel cancer [7]
A
Persistent blood Persistent change in bowel habit Persistent lower abdominal pain Anaemia Loss of appetite Bloating Mass
11
Q
What do you do if symptoms <6 weeks + <40yo
A
Watch and review
12
Q
What other investigations for colon cancer
Bloods [4]
Imaging [2]
Staging investigations [4]
A
FBC - hypochromic microcytic anaemia
FOB/qFIT (before colonoscopy)
Urine dip - ?haematuria
To rule out: LFT, TFT, coeliac
Colonoscopy & biopsy
Virtual CT colonoscopy
Staging CT MRI if below peritoneal reflection Liver MRI / USS PET if single met but chance of cure
13
Q
What are the stages of colon cancer?
[4]
A
Dukes classification & TNM combined: T1 A- limited to muscularis mucosa (MM) T2 B- extension through MM T3 C- LN T4 D- metastatic
14
Q
How do you treat Dukes A [3]
A
Endoscopic resection
Remove node for analysis
DVT and Abx prophylaxis
15
Q
How do you treat more advanced cancer [4]
A
Chemotherapy
Radiotherapy - palliation mostly or for rectal ca
Surgery = only way to cure
NSAID - reduce polyps and prevent recurrence
Biologics
16
Q
What are the complications of surgery [11]
A
GA issue Bleeding Sepsis Nerve or vessel damage DVT Wound hernia / dehiscence Obstruction, Post op ileus - give sugar before Anastomatic breakdown - day 4-5 Post-op fistula, stricture Adhesions High output stoma = volume deplete/ electrolyte imbalance
17
Q
What is the screening programme for bowel cancer [4]
A
50-74
FOBT / qFIT every 2 years
If positive = colonoscopy
Recognises Hb
18
Q
What is FAP
What is done as preventative measures to persons at risk? [2]
A
Autosomal dominant APC mutation
Annual colonoscopy from age 10
Prophylactic protocolectomy at 16
19
Q
What do you get if you are HNPCC +Ve
A
2 year colonoscopy from 25
Endometrial / colon cancer / ovarian / pancreatic
20
Q
What do you get if you have IBD
A
Colonoscopy 10 year post diagnosis
21
Q
What is considered high risk FH
A
Colon cancer in 3 FDR
5 year colonoscopy at 55
22
Q
What do you get if low risk
A
Single colonoscopy at 55
23
Q
Where does colon cancer spread too [4]
A
Local
Lymphatic
Blood - liver, lung, bone
Transcoelomic
24
Q
What factors play a role in whether anastomose or stoma [4]
A
Blood supply
Tissue tension
Sepsis
Unstable patient
25
Where is an ileostomy typically
R side
26
Where is a colostomy
L side
Flatter stump as not as acidic to skin - this tells you what it is rather than side
If need replaced will be on different sides
27
What are palliative options [3]
Chemo / RT
Diversion stoma
COlonic stenting
28
When would you do endoscopy / colonoscopy
Unexplained iron deficiency as risk of malignancy / bleeding / coeliac
29
What does pT3 mean in lab report
Pathology reports umour as stage T3
30
What does yP
After neoajuvant treatment
31
ANATOMY
SMA 2nd part of duodenum to 2/3 tranverse
IMA supplies the rest to superior rectum
Marginal artery supplies whole gut
SMA = L1
IMA = L3
32
What are the flexures of the colon
Hepatic
| Splenic
33
What are the nodes of the colon
Same as arterial supply
| Level of resection determined by nodes invollved
34
What is difference between end stoma or loop
End = irreversible
| Loop is to defunction
35
What side is more likely to need temp stoma
L side
36
What side tend to do worse
R side as SMA blood supply
37
If person presents obstructed / perforation what do you do
Anastomosis is difficult
Stent = option
Loop stoma then fix at later date
38
When can you anastomose even in emergency
Ileo-caecal
39
What is Hartmanns procedure for
Ruptured sigmoid with colostomy
40
When do you do left hemicolectomy [3]
Splenic
Descending
Colon to colon
41
When do you do R hemicolectomy [3]
Caecal
Transverse
Ileo-cooln
42
What tumour marker for disease progression
CEA
43
When do you do urgent referral within 2 weeks [4]
>40 weight loss and abdominal pain
>50 bleed
>60 anaemia or chang in bowel
+ve QFIT
44
When should you consider referral [2]
Mass
| <50 PR bleed / abdominal pain / change in bowel / weight loss / anaemia
45
What is used post op for analgesia and why
Epidural as reduced time for normal gut transit to return
46
How do you check anastomoses has worked
Gastrograffin enema
47
How does anastomotic leak present [6]
```
Usually day 4-5
Septic peritonitis depending on size, Fever
Faecal / other material in drain bag
Pain, Guarding
No bowel movement
Hypotension, Tachycardia
```
48
How do you Dx [2]
Gastrograffin
| CT
49
How do you Rx
Surgery
50
What do you do if wound breaks down [3]
Surgery
Emergency if deep and bowel showing
Can pack if superficial
51
Indications for not doing colonoscopy
Do CT colonography if unfit for colonoscopy eg 6 months post MI / COPD
52
Surgical options for colonic tumours
Right hemicolectomy
Left hemicolectomy
Sigmoid colectomy
Hartmann's procedure
53
Surgical options for rectal tumours [4]
Surgery:
- Anterior resection
- Abdominal perineal resection
- Defunctioning loop colostomy
+/- neoadjuvant RT
54
Advanced cancer [5]
```
Stents
Surgical bypass
Diversion stoma
Palliative RT, chemo
Cetuximab, pantitumumab (anti-EGFR agents)
```
55
What are the symptoms of haemorrhoids [4]
Symptoms of acutely thrombosed external hemorrhoids [3]
Fresh painless bleeding after defaecation (on stool, tissue dripping)
Itchy
Mucous discharge
Lump in anus
Acutely thrombosed external hemorrhoids:
Signifcant pain
Purple / oedematous
Tender subcutaneous perianal mass
56
What are the RF for haemorrhoids [5]
| What are anal cushions? [3]
```
Obese, Pregnant
Age
Weight lifting
Excessive straining due to constipation
Lack of fibre
```
Anal cushions
- 3 discontinuous patches of spongy vascular tissue
- Major arteries feed into at 3, 7, 11 o'clock (lithotomy)
- Cushions are prone to trauma so blood loss is from capillaries below lamina propria of anal cushion
57
How do you Dx haemorrhoids
Outline the 4 degrees of hemorrhoids
What are differentials for haemorrhoids? [3]
```
Digital rectal exam
1 = not out of canal
2 = spontaneously reducible
3 = manually reducible
4 = cannot reduce
```
Differentials:
Colitis
Cancer
Unlikely to be abscess or fissure as painful
58
Management of haemorrhoids
1st degree [3]
2-3rd degree [4]
4th degree [2]
1st degree:
- Increase fluid and fibre
- Topical LA
- Topical steroids
2nd-3rd degree:
- Rubberband ligation
- Injection sclerotherapy
- Infra-red coagulation
- Doppler guided hemorrhoidal artery ligation
4th degree:
- Excisions haemorrhoidectomy
- Stapled hemorrhoidopexy
59
Pathogenesis hemorrhoids
What differentiates between internal and external? [4]
Disruption and dilation of anal vascular cushions, may strangulate
* Internal: above dentate line (no sensory supply) so not generally painful
* External: below dentate line and prone to thrombosis which can be painful
60
Investigations [2]
What is excisions hemorrhoidectomy? [2]
Comparison between stapled vs excisions [2]
Proctoscopy to view internal hemorrhoids
Sigmoidoscopy to identify pathology higher up
Excisional haemorrhoidectomy:
- excision of piles +/- ligation of vascular pedicles
- day case but need 2w off work
Stapled hemorrhoidpexy is...
- less pain and quicker return to normal activities
- increased risk of recurrence and prolapse
61
What causes anal fissure [5]
```
Hard feces*
Trauma
Crohns
Anal cancer
Syphilis
```
62
What are the symptoms of anal fissure [3]
1. Pain
2. Bleeding after defection typically in posterior midline ie 6 o'clock position when patient in lithotomy
3. Itching
63
How do you Dx fissure
Digital rectal exam
64
Treatment:
Acute fissure [4]
Chronic fissure
3rd line treatment? [2]
Acute <6w:
- Laxatives
- High fibre diet
- Lubricants before defecation
- Ointment, Topical anaesthetic
Chronic >6w:
- Topical NO / GTN / CCB (relaxes anal sphincter)
If no improvement by 8w:
- Botulinum toxin
- Internal Sphincterotomy
65
Internal Sphincterotomy complications [2]
Flatus incontinence in 30%
Faecal incontinence can occur in females if previous pregnancy or pelvic floor damage
66
What causes peri-anal abscess [4]
Types of peri-anal abscess [4]
Causes:
- IBD
- STI
- Blocked anal gland
- E.coli / S.Aureus
Types
- Perianal
- ischiorectal
- Intersphincteric
- Supralevator
67
What are the symptoms of abscess [4]
Perianal pain - worse sitting
Swelling
Perianal erythema
Fever + severe pain differentiate from fissure
68
What are the RF for abscess [4]
IBD, DM, Steroids
Diverticulitis
PID
Malignancy
69
Investigations for abscess [5]
(usually not required)
```
Digital rectal exam
Blood cultures, CRP
Colonoscopy for underlying cause
MRI
Transperineal USS
```
70
How do you treat abscess [3]
Drain abscess
Pain relief
Abx not usually needed
71
What are the complications of abscess
Fistula
72
What causes fistula in ano [7]
```
Perianal sepsis
Crohns
Abscess
TB
Diverticular disease
Rectal ca
Immunocompromised
```
73
What are the symptoms of fistula [4]
Pain, Skin irritation
Smelly discharge
Passing pus or blood in stool
Bowel incontinence
74
How do you Dx fistula [5]
```
Digital rectam exam
Proctoscopy
Endoanal USS
MRI/CT
Infection screen
```
75
Fistula in ano treatment
- Conservative: when is it indicated? [2], describe 3 components of conservative
- What are 2 interventions you can do?
- What would you do for Crohn's with fistula?
Conservative if low and no sphincter involvement, no IBD
- TPN / nutrition if high volume
- Octreoide - reduce volume of pancreatic secretions
- Permacol paste
- Fistulotomy
- Excision
- Crohns: draining Seton suture prevents recurrent sepsis
76
What are the symptoms of anorectal cancer? [4]
What type of cancer is it most commonly?
Describe tendency to metastasize [2]
(if neglected can present as a rectovaginal fistula in women)
Subacute onset
- perianal pain
- bleeding or ulcer
- palpable lesion or faecal incontinence
Squamous cell carcinoma makes up 80%
Local lymphatic spread common
Distant spread rar
77
How do you investigate anorectal cancer [6]
Staging [4]
DRE
Procotscopy / sigmoidoscopy
Biopsy
HIV serology
CT / MRI to stage
Endoanal USS and PET
78
How do you treat squamous anorectal cancer [2]
Chemo - 5-FU, cisplatin
| Radiotherapy
79
How do you treat adenocarcinoma [3]
Chemo + RT
| Laparoscopic resection
80
What are the RF for anorectal cancer [6]
```
HPV 16, 18
Cervical cancer or CIN
Smoking
Weakened immune system
MSM
PID infection
```
81
Anterior [1] vs abdominal perineal resection [3]
| Indications
Abdominal perineal if
- Sphincter invovled
- Very low
- 2cm clearance margin
If upper rectum = anterior resection (colorectal)
Often temp stoma to allow time to heal
82
What causes solitary rectal ulcer [3]
Constipation
Straining
Ulceration
83
Pruritus Ani
Ax [5]
Mx [3]
Causes:
- Fissures, fistula
- Incontinence, poor hygiene
- Tight pants
- Threadworm
- Dermatoses, lichen sclerosis
Mx
- Careful hygiene
- Anaesthetic cream
- Moist wipe after defecation
84
Complications of anorectal cancer
Recto-vaginal fistula
85
What do you do if presents obstructed in anorectal cancer [2]
De-function stoma until can stage cancer
| Don't resect as won't be able to anastomose
86
Acutely thrombosis of external hemorrhoids mx
| Natural course?
- If presents within 72h, consider referral for excision
- Otherwise manage with stool softeners, ice packs, analgesia
- Symptoms usually settle within 10 days
