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INTRODUCTION

Epidemiology

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Epidemiology
Incidence: 8590 (male: 2690; female: 5900. Estimated new cases for 2020 in the United States) Stage at Presentation
  1.6 per 100,000 men per year, 2.2 per 100,000 women per year Stages I/II: 48%
Deaths: Estimated 1350 in 2020 (male: 540; female: 810) Stage III: 32%
Median age at diagnosis: 62 years Stage IV: 13%
Male to female ratio: Female predominance (1:1.5–2)    

Shiels MS et al. Cancer Epidemiol Biomarkers Prev 2015;24:1548–1556

Siegel R et al. CA Cancer J Clin 2020;70:7–30

Surveillance, Epidemiology and End Results (SEER) Program, available from http://seer.cancer.gov

Work-up

All stages

  1. Digital rectal examination, sigmoidoscopy with biopsy

  2. CT scan of chest and abdomen with IV and oral contrast, pelvic CT or MRI with contrast

  3. Consider HIV testing and CD4 level if indicated

  4. Consider PET-CT scan

  5. Gynecologic exam for women, including screening for cervical cancer

NCCN Guidelines Version 2.2017 Anal Carcinoma

Positive inguinal lymph node on imaging

  1. Fine-needle aspiration or biopsy of node

Pathology

By convention, anal cancer should now refer only to squamous cell cancers arising in the anus. Earlier surgical series often did not make this distinction. Adenocarcinomas occurring in the anal canal should be treated according to the same principles applied to rectal adenocarcinoma. Similarly, melanomas and sarcomas should be treated according to the same principles applied to those tumor types at other sites

The distal anal canal is lined by squamous epithelium, and tumors arising in this portion are often keratinizing. Around the dentate line, the mucosa transitions from squamous mucosa to the nonsquamous rectal mucosa. Tumors arising in this transitional zone are often nonkeratinizing and previously were referred to as basaloid or cloacogenic

 

Clark MA et al. Lancet Oncol 2004;5:149–157

Ryan DP et al. N Engl J Med 2000;342:792–800

Five-Year Relative Survival

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Five-Year Relative Survival
Localized 81.7%
Regional 64.9%
Distant 32.2%
Surveillance, Epidemiology and End Results (SEER) Program, available from http://seer.cancer.gov

Poor Prognostic Factors

  1. Nodal involvement

  2. Skin ulceration

  3. Male gender

  4. Tumor >5 cm

  5. HPV negative and/or p16 negative

 

Ajani JA et al. JAMA 2008;299:1914–1921

Bartelink H et al. J Clin Oncol 1997;15:2040–2049

Glynne-Jones R et al. Cancer 2013;119:748–755

Rodel F et al. Int J Cancer 2015;136:278–288

Staging

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Staging

Primary Tumor (T)

TX Primary tumor not assessed
T0 No evidence of primary tumor
Tis High-grade squamous intraepithelial lesion (previously termed carcinoma in situ, Bowen disease, anal intraepithelial neoplasia II–III, high-grade anal intraepithelial neoplasia)
T1 Tumor 2 cm or less in greatest dimension
T2 Tumor more than 2 cm but not more than 5 cm in greatest dimension
T3 Tumor more than 5 cm in greatest dimension
T4 Tumor of any size invades adjacent organ(s), eg, vagina, urethra, bladder
Direct invasion of the rectal wall, perirectal skin, subcutaneous tissue, or ...

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