Anal Cancer Flashcards
(25 cards)
What is anal cancer?
A malignancy which lies exclusively in the anal canal, bordered by the anorectal junction and the anal margin.
What type of cancer constitutes 80% of anal cancers?
Squamous cell carcinomas (SSCs)
What are other types of anal cancers besides SSCs?
- Melanomas
- Lymphomas
- Adenocarcinomas
How does lymphatic drainage vary in anal cancer?
Anal margin tumours spread to the inguinal lymph nodes; proximal tumours spread to pelvic lymph nodes.
What is the annual incidence of anal cancer in the UK?
About 1.5 in 100,000.
Which population shows a rising incidence of anal cancer due to HPV infection?
Men who have sex with men.
What is the male to female ratio of anal cancer incidence?
1:2 male:female ratio.
What is the average age of presentation for anal cancer in the UK?
85-89 years.
What percentage of patients present with lymph node involvement at diagnosis?
30-40%.
What percentage of anal cancer cases present with extrapelvic metastases at diagnosis?
5-8%.
What causes 80-85% of SSCs of the anus?
HPV infection, especially HPV16 subtype.
What factors increase the risk of HPV infection in anal cancer?
- Anal intercourse
- High lifetime number of sexual partners
Who is at a greater risk of anal cancer related to HIV?
Men who have sex with men and those taking immunosuppressive medication for HIV.
Who else is at a higher risk of anal cancer?
Women with a history of cervical cancer or cervical intraepithelial neoplasia (CIN).
What is a common presentation symptom of anal cancer?
- Perianal pain
- Perianal bleeding
- A palpable lesion
- Faecal incontinence
What may a neglected tumour in a female present with?
A rectovaginal fistula.
What are the key investigations for anal cancer?
- Digital rectal examination
- Anoscopic examination with biopsy
- Imaging modalities (CT, MRI, endo-anal ultrasound, PET)
What does the T stage assessment for anal cancer include?
Examination, including a digital rectal examination, anoscopic examination with biopsy, and palpation of the inguinal nodes.
What is Tis in the T staging of anal cancer?
Carcinoma in situ.
What does T1 represent in T staging?
Tumour 2 cm or less in greatest dimension.
What does T2 represent in T staging?
Tumour more than 2 cm but not more than 5 cm in greatest dimension.
What does T3 represent in T staging?
Tumour more than 5 cm in greatest dimension.
What defines T4 in T staging?
Tumour of any size that invades adjacent organ(s) but direct invasion of the rectal wall, perirectal skin, subcutaneous tissue, or the sphincter muscle(s) is not classified as T4.
What is the most common neoplasm in anus?
Squamous cell carcinoma
