Cancer of the Anal Canal
Summary of Key Points
Staging Evaluation
• American Joint Commission on Cancer (AJCC) tumor–node–metastasis (TNM) staging system for anal cancer is a clinical staging system. Notably, the T stage is based on tumor size rather than depth of invasion as it is in other gastrointestinal cancers.
• Physical examination, evaluating the size, location, mobility, and inguinal nodal involvement, is critical in staging patients and for a baseline comparison to determine response.
• Computed tomography, sigmoidoscopy, endoanal ultrasound, and magnetic resonance imaging or positron emission tomography imaging are helpful in evaluation of the extent of the primary lesion, presence of regional nodal disease or distant metastatic disease.
