Rectal and anal carcinomas

Question 1

What are the risk factors for colorectal cancer

Answer 1

Family history
Increasing age
Smoking
Diet high in red meat
Medical conditions - IBD, Linch syndrome

Question 2

What are the different histological types of colorectal acncers

Answer 2

Adenocarcinoma - most common
Lymphoma
Carcinoid
Sarcoma

Question 3

What are the symptoms of colorectal cancers

Answer 3

Per rectal bleeding - painless, stool mixed with blood
Change in bowel habits
Loss of weight
Change of stool calibre
Feeling of incomplete evacuation
Tenesmus

Back pain - Due to tumour pressuring nerve trunks
Urinary symptoms - due to bladder involvement
Malaise
Pelvic pain

May present as emergency - bowel obstuction

Question 4

What is the clinical examination of rectal carcnomas

Answer 4

General examination
Local examination - Digital rectal exam
- Distance from anal verge
- Mobility and fixation of tumour
- Circumferential involvement of the lumen

Protoscopy
Sigmoidoscopy
Colonoscopy
Biopsy for histological confirmation

Question 5

How is staging of rectal cancer done

Answer 5

Chest and abdo xray
CT scan (chest, abdo, pelvis) to evaluate distal spread
MRI pelvis for local staging
Endorectal US - assess local extent of early T1/T2 tumours and lymphnodes

Question 6

What are the other investigations for rectal cancer

Answer 6

FBC
U&E
LFT - to see if liver will be able to metabolise chemo drugs
HIV
Carcinoembryonic Antigen - tumour marker. Not diagnostic but used for follow up monitoring

Question 7

What are the factors that are considered for surgery of rectal cancer

Answer 7

Patient factors: patients fitess

Disease factors: Position of the tumour from anal verge
….

Question 8

Explain the 2 surgeries for rectal cancers

Answer 8

Abdominoperineal resection
- Performed for lower third/very low rectal cancer
- When not possible to obtain clear distal resection margjn and preserve the anal sphincter
- Colostomy for rest of life

Anterior resection
- Resection of the upper or middle third rectal tumour is done through a laparotomy.
- A primary anastomosis is done.
- The anal sphincter is preserved and thus normal anatomy and anal function is preserved.

Question 9

What are the indications of a local trans anal resection for rectal cancer

Answer 9

• Lesions within 8cm of the anal verge.
• Less than 4cm in diameter.
• Well or moderately well differentiated.
• Mobile and non ulcerated lesions.
• No evidence of nodal involvement

Question 10

What is the management of anal cancer

Answer 10

Radiotherapy or slavage APR resection