Anal Cancer Management

Question 1

What is the anal canal?

Answer 1

• Runs downwards and backwards to the anal orifice
• 3-4cm long
• Extends from rectum to the junction with hair bearing skin of perianal region
• Walls are composed of internal sphincter of involuntary and external voluntary muscle
• ## 3 major lymphatic pathways

Question 2

Histology of anal cancer

Answer 2

• 4 x more frequent in the canal that in perianal skin

- Mostly squamous cell carcinomas

Question 3

What are aetiological considerations of anal cancer?

Answer 3

• most are associated with HPV
• Potentially sexually transmitted factors
• smoking

Question 4

What are the signs and symptoms of anal cancer?

Answer 4

• Bleeding from the anus
• Pain, discomfort, itching around anus
• Small lumps around the anus
• Discharge of mucus
• ulcers
• difficulty controlling your bowels
• About 1 in 5 people with anal cancer have no symptoms

Question 5

How does anal cancer present?

Answer 5

• Mostly non-specific
• Bleeding, discharge and discomfort
• 1/4 aware of a mass
• Malignant Melanoma might present as pigmented, polypoid and firm ( might resemble haemorrhoids)

Question 6

How does anal cancer tend to spread?

Answer 6

• Principally local invasion followed by lymphatic spread

- Nodal involvement is more common in anal canal lesions than in marginal tumours.

Question 7

Anal Cancer staging?

Answer 7

T1 = Less than 2cm
T2 = More than 2cm less than 5cm 
T3 = Tumour is more than 5cm
T4 = Tumour of any size that has spread to surrounding tissues or organs

Stage 1 = Cancer only affects the anus and is less than 3cm
Stage 2 = Cancer is bigger than 3cm but has not spread from the anus
Stage 3A = Cancer has spread to lymph nodes in the groin and pelvis or lymph nodes close to the anus OR nearby organs
Stage 3B = Cancer has spread to lymph nodes in groin and pelvis AND to nearby organs
Stage 4 = Cancer has spread to nodes in the abdomen and to other parts of the body

Question 8

How is stage 1 and 2 anal cancer treated?

Answer 8

• <1cm, local resection, maybe brachy

- >1cm or involved anal sphincter = chemoradiation

Question 9

How is stage 3A anal cancer treated?

Answer 9

• Chemoradiation and surgery

Question 10

How is stage 3B and 4 anal cancer treated?

Answer 10

• Chemoradiation, surgery or a combination.

- Combination is usually reserved for epidermoid cancers of the anal canal - preserves anal function