Summary![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Anal cancer is a rare tumor. Risk factors include infection with human papillomavirus (HPV), immunodeficiency, and receptive anal intercourse. The most common clinical features are rectal bleeding (up to 45% of cases), pruritus ani, and tenderness or pain in the anal area. Anal cancer presents mainly as squamous cell carcinoma and in rare cases as adenocarcinoma or other non-epidermoid cancers. Depending on the exact localization and stage, it requires excision and/or radiochemotherapy. If the condition is treated in its early stages, the prognosis is favorable.
Epidemiology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Incidence: ∼ 8,000 cases diagnosed per year in the US [1]
- More common in HIV-positive individuals and men who have sex with men
Epidemiological data refers to the US, unless otherwise specified.
Etiology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
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Risk factors
- Immunodeficiency (e.g., HIV)
- Receptive anal intercourse
- Smoking
- HPV infection (esp. types 16 and 18)
Clinical features![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Rectal bleeding (most important initial symptom)
- A lump or tumor around the anus
- Pruritus ani
- Tenderness, pain in the anal area
- Fecal incontinence
- History of anorectal condyloma
Diagnostics![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
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Physical examination
- Inspection
- Digital rectal exam
- Invasive procedures
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Staging [2]
- Endosonography, abdominal CT, pelvic MRI, chest x-ray/CT, PET scan
- Women with anal cancer should also undergo a gynecologic examination for screening for cervical cancer.
Pathology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Histology: primarily squamous cell carcinoma; rarely adenocarcinoma or other non-epidermoid cancers
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Location
- Above the anal verge: anal canal tumors
- Below the anal verge: anal margin tumors
Treatment![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
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Anal canal cancer [3]
- Treatment of choice: radiochemotherapy
- Recurrent cancers are treated surgically.
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Anal margin cancer
- If possible, local excision with safety margin
- Advanced tumor
- (Neoadjuvant) radiochemotherapy
- Subsequent resection depending on the size of the tumor
- In some cases, remission may be achieved with radiochemotherapy alone.
Complications![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
We list the most important complications. The selection is not exhaustive.
Prognosis![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Anal cancer of the dentate line: The 5-year survival rate after radiochemotherapy is > 80%.
- Anal cancer of the anal verge: The prognosis is favorable if complete local excision is possible. The 5-year survival rate after rectal amputation is approx. 50%.
References:[5]