Anal Cancer

Anal cancer develops from squamous cells lining the anus or anal canal, representing less than 1% of all cancers but rising due to HPV prevalence. Most cases stem from persistent high-risk HPV strains, transmitted sexually, with over 90% positivity in tumors. It affects women more than men and peaks after age 60, though younger cases increase with HIV.?

Symptoms

Key signs feature rectal bleeding, anal pain or itching, lumps near the anus, mucus discharge, changes in bowel habits, and incontinence. These mimic hemorrhoids, delaying diagnosis; persistent symptoms warrant endoscopy. Advanced disease adds fatigue, weight loss, and groin swelling from lymph node spread.?

Risk Factors

Primary risks include HPV infection, smoking, HIV/AIDS, immunosuppression, multiple sexual partners, and receptive anal intercourse. Other factors: prior cervical/vulvar cancer, Crohn's disease, and obesity.?

Diagnosis and Treatment

Diagnosis involves digital exam, anoscopy, biopsy, and imaging like CT/PET for staging. Standard treatment uses chemoradiation (5-FU + mitomycin), curing 80-90% early-stage cases, with surgery reserved for failures. HPV vaccination prevents most cases; five-year survival exceeds 70% overall.