Chapter 48: Anus- Anal Cancer

Question 1

Identify the following:

Answer 1

Question 2

What is the most common carcinoma of the anus?

Answer 2

Squamous cell carcinoma (80%)

(Think: ASS = Anal Squamous Superior)

Question 3

What cell types are found in carcinomas of the anus?

Answer 3

• Squamous cell carcinoma (80%)
• Cloacogenic (transitional cell)
• Adenocarcinoma/melanoma/mucoepidermal

Question 4

What is the incidence of anal carcinoma?

Answer 4

Rare (1% of colon cancers incidence)

Question 5

What is anal Bowen’s disease?

Answer 5

Squamous cell carcinoma in situ

Question 6

How is Bowen’s disease treated?

Answer 6

With local wide excision

Question 7

What is Paget’s disease of the anus?

Answer 7

Adenocarcinoma in situ of the anus

(Think: P.A. = Paget’s Adenocarcinoma)

Question 8

How is Paget’s disease treated?

Answer 8

With local wide excision

Question 9

What are the risk factors for anal cancer?

Answer 9

• Human papilloma virus
• condyloma
• herpes
• HIV
• chronic inflammation
  
  • fistulae
  • Crohn’s disease
• immunosuppression
• homosexuality in males
• cervical/vaginal cancer
• STDs
• smoking

Question 10

What is the most common symptom of anal carcinoma?

Answer 10

Anal bleeding

Question 11

What are the other signs/symptoms of anal carcinoma?

Answer 11

• Pain
• mass
• mucus per rectum
• pruritus

Question 12

What percentage of patients with anal cancer is asymptomatic?

Answer 12

≈25%

Question 13

To what locations do anal canal cancers metastasize?

Answer 13

Lymph nodes

liver

bone

lung

Question 14

What is the lymphatic drainage below the dentate line?

Answer 14

Below to inguinal lymph nodes (above to pelvic chains)

Question 15

Are most patients with anal cancer diagnosed early or late?

Answer 15

Late (diagnosis is often missed)

Question 16

What is the workup of a patient with suspected anal carcinoma?

Answer 16

• History
• Physical exam:
  
  • digital rectal exam
  • proctoscopic exam
  • colonoscopy
• Biopsy of mass
• Abdominal/pelvic CT scan
• transanal U/S
• CXR
• LFTs

Question 17

Margin cancer

Answer 17

Anal verge out 5 cm onto the perianal skin

Question 18

Canal cancer

Answer 18

Proximal to anal verge up to the border of the internal sphincter

Question 19

How is an anal canal epidermal carcinoma treated?

Answer 19

NIGRO protocol:

• Chemotherapy (5-FU and mitomycin C
• Radiation
• Postradiation therapy scar biopsy 6 to 8 weeks post radiation therapy[XRT]

Question 20

What percentage of patients have a “complete” response with the NIGRO protocol?

Answer 20

90%

Question 21

What is the 5-year survival with the NIGRO protocol?

Answer 21

85%

Question 22

What is the treatment for local recurrence of anal cancer after the NIGRO protocol?

Answer 22

• May repeat chemotherapy/XRT or
• salvage Abdominoperineal resection (APR)

Question 23

How is a small (<5 cm) anal margin cancer treated?

Answer 23

Surgical excision with 1-cm margins

Question 24

How is a large (>5 cm) anal margin cancer treated?

Answer 24

Chemoradiation

Question 25

What is the treatment of anal melanoma?

Answer 25

Wide excision or APR (especially if tumor is large) ± XRT, chemotherapy,postoperatively

Question 26

What is the 5-year survival rate with anal melanoma?

Answer 26

<10%

Question 27

How many patients with anal melanoma have an amelanotic anal tumor?

Answer 27

Approximately one third, thus making diagnosis difficult without pathology

Question 28

What is the prognosis of anal melanoma?

Answer 28

<5% 5-year survival rate