Lower GI cancer

Question 1

What is the epidemiology of colorectal cancer

Answer 1

• Most common GI cancer
• 4th most common cancer
• 2nd most common cause of cancer death

Question 2

What are the types of colorectal cancer?

Answer 2

• adenocarcinoma - most common
• lymphoma
• carcinoid
• sarcoma

Question 3

What causes colorectal carcinoma

Answer 3

• Adenomatous Polyposis Coli (APC) gene
  
  • tumour suppressor gene
  • assoc. c Familial Adenomatous Polyposis (FAP)
• Hereditary Nonpolyposis Colorectal Cancer (HNCC)
  
  • DNA missmatch repair gene
    *

Question 4

What is the adenoma-carcinoma sequence?

How long does it last?

Answer 4

• Normal epithelium > abnormal epithelium > small adenoma > large adenoma > colonic carcinoma
• 10-15 years

Question 5

What are the RF of colorectal cancer?

Answer 5

• Non modifiable
  
  • Age
  • FHx
• Modifiable
  
  • IBD
  • low fibre diet
  • high process meat intake
  • High alcohol intake
  • smoking

Question 6

What are the clinical features of colorectal cancer?

Answer 6

• Change in bowel habit
• Rectal bleeding
• weight loss, abdominal pain, iron def anaemia

Right sided specific (present late)

• Anaemia
• wt loss
• RIF mass

Left sided specific (present early)

• rectal bleeding
• change in bowel habits
• tenesmus
• LIF mass
• PR abnormal

Question 7

According to NICE guidelines, when should pts be reffered for urgent Ix of suspected bowel cancer?

Answer 7

• equal to or more 40yrs c unexplained weight loss and abdominal pain
• equal to or more 50 yrs c unexplained rectal bleeding
• equal to or more 60 yrs c iron def anaemia or change in bowel habit

Question 8

What will your differential diagnosis be for colorectal cancer?

Answer 8

• IBD
• Haemorrhoids

Question 9

Explain the colorectal cancer screening

Answer 9

• every 2 yrs to men and women 60-75 yrs old
• Faecal Immunochemistry Test (FIT) used - use antibodies against human Hb
• If +, pt offered an appointment c specialist nurse & colonoscopy

Question 10

WHat Ix would you order for colorectal cancer?

Answer 10

Bedside

• Bloods
  
  • Routine
  • Tumour marker: CEA

Imaging

• Colonoscopy + biopsy - gold standard
• flexible sigmoidoscopy - if pt x tolerate colonoscopy
• CT chest-abdo-pelvis - for mets
• MRI rectum - assess invasion of rectal cancer
• Endo-anal USS - assess suitability of trans-anal resection

Question 11

Describe the Duke’s staging

Answer 11

• A : confined beneath muscularis propria
• B : extend through muscularis propria
• C : involve regional lymph node
• D : involve distant mets

Question 12

Is Duke staging still used?

Answer 12

TNM staging is preffered

Question 13

What are the surgical options for colorectal cancer?

Answer 13

• Right hemicolectomy/ extended hemicolectomy
  
  • caecal tumors, ascending tumours, transverse tumours
• Left hemicolectomy
  
  • descending colon
• Sigmoidcolectomy
  
  • sigmoid colon
• Anterior resection
  
  • high rectal tumours - >5cm from anus
  • c defunctioning loop ileostomy
• Abdominoperianal Resection (AP)
  
  • low rectal tumours - <5cm from anus
  • permanent colostomy
• Hartmann’s procedure (recto-sigmoid resection, end colostomy, rectal stump closure)
  
  • recto-sigmoid tumours
    *

Question 15

What blood vessels are removed for the surgeries in colorectal cancer?

Answer 15

• Right/extended hemicolectomy
  
  • ileo colic, right colic, middle colic vessels (SMA branches)
• Left hemicolectomy
  
  • left branch of middle colic vessels (SMA/SMV)
  • left colic vessels (IMA/IMV)
• Sigmoidcolectomy
  
  • IMA

Question 16

What are the palliative options for colorectal cancer?

Answer 16

• endoluminal stenting - relieve acute bowel obstruction
• stoma formation -

Question 17

What is the epidemiology for anal cancer

Answer 17

• Rare
• 4% of colorectal cancer

Question 18

What are the type of anal cancer

Answer 18

• squamous cell carcinoma - below dentate line (most common)
• adenocarcnoma - above dentate line
• melanoma

Question 19

What is the precancerous condition of anal cancer

Answer 19

• Anal intraepithelial neoplasia

Question 20

What is the risk factor for anal intraepithelial neoplasia?

Answer 20

• HPV

Question 21

What are the RF for anal cancer?

Answer 21

• HPV
• HIV
• Age
• Smoking
• Crohn’s

Question 22

What are he clincial features of anal cancer?

Answer 22

• rectal pain
• rectal bleeding
• palpable mass
• pruritis
• anal discharge
• perianal infection
• fistula in ano

Question 23

What will you find on ex of anal cancer?

Answer 23

• ulceration - perianal region
• PR exam - mass felt
• Lymphadenopathy - inguinal lymph node swelling
  *

Question 24

Where does lymph below dentate line drain to?

Answer 24

• superficial inguinal lymph node

Question 25

Where does lymph above dentate line drain into?

Answer 25

• mesorectal
• para-aortic
• para-vertebral

Question 26

What Ix would you perform for anal cancers?

Answer 26

Bedside

• HIV test
• Smear test - exclude cervical intraepithelial neoplasia

Imaging

• USS guided fine needle aspiration
• CT chest-abdo-pelvis
• MRI pelvis- assess extend of invasion

Special test

• Protoscopy
• Examination Under Anaesthetic

Question 27

What are the Mx options for anal cancers

Answer 27

First choice treatment

• Local excision
• Chemo-radiotherapy

Surgical - for advanced disease

• abdominoperineal resection (APR)

Question 28

What cx arise from anal cancer?

Answer 28

• chemoradiation related pelvic toxicity
  
  • dermatitis
  • proctitis
  • diarrhoea
• infertility
• vaginal dryness
• erectile dysfunction
• rectovaginal fistula