Anal Cancer - TMS

Question 1

Types of anal cancer

Answer 1

• Squamous cell carcinoma - arising below the dentate line = MOST
• Adenocarcinoma - from upper anal canal epithelium and crypt glands

Question 2

What can precede anal cancer?

Answer 2

• Anal intraepithelial neoplasia - AIN
• Pre-cancerous condition
• Strongly linked with HPV infection

Question 3

What is grading of AIN dependent on?

Answer 3

• Cytological atypia degree
• Depth of atypia in dermis
• High grade is pre-malignant and can progress to invasive cancer

Question 4

RF for anal cancer

Answer 4

• HPV infection
• HIV infection
• Increasing age
• Smoking
• Immunosupression
• Crohns disease

Question 5

Clinical features of anal cancer

Answer 5

• Rectal pain
• Rectal bleeding
• Anal discharge
• Pruritus
• Palpable mass

Question 6

What can be seen in locally invasive disease?

Answer 6

• Perianal infection
• Fistula in ano
• If anal sphincters involved –> faecal incontinence and tenesmus

Question 7

Examination for anal cancer

Answer 7

• Perineal and perianal regions - any ulceration? or warts?
• Masses on PR?
• Document distance from anal verge and proportion of circumferance involved
• Examine inguinal lymph nodes

Question 8

Lymph node drainage anus

Answer 8

• Below dentate line –> superficial inguinal lymph nodes
• Anal canal and rectum above line –> mesorectal, para-aortic and paravertebral

Question 9

Investigations for anal cancer - initial

Answer 9

• Proctoscopy
• Examination under anaesthetic - assess tumour size, invasion and biopsy
• Women - smear test to exclude CIN and biopsies if signs of vulval IN
• Consider HIV test if at risk

IN = intraepithelial neoplasia

Question 10

Imaging for anal cancer - after biopsy confirms

Answer 10

• USS FNA if palpable inguinal lymph nodes
• CT thorax abdomen pelvis - for distant mets
• MRI pelvis to assess extent of local invasion (T stage)

Question 11

Management anal cancer

Answer 11

• MDT
• Chemoradiotherapy often first line - except T1N0 - wide local excision is ok
• Via external beam radiotherapy to anal canal and inguinal lymph nodes combined with dual chemo (eg mitomycin C and 5-fluorouracil)

Question 12

Surgical management anal cancer - when?

Answer 12

• Advanced disease
• Failure of chemo-radiotherapy
• Early T1N0 carcinoma

Question 13

Surgery for anal cancer

Answer 13

• Abdominoperineal resection
• Some have posterior or total pelvic exenteration (all organs in pelvis)

Question 14

F/u anal cancer after surgery

Answer 14

• Review every 3-6 months for 2 years then less regularly
• Recurrences mostly occur in first 3 years following surgery and relapse locally and regionally

Question 15

Complications of anal cancer

Answer 15

• Chemoradiation-related pelvic toxicity - dermatitis, diarrhoea, proctitis +/- cystitis
• Longer term –> fertility issues, faecal incontinence, vaginal dryness erectile dysfunction, rectovaginal fistula