T3N1 SCAC Case Study: Clinical Decision-Making Through a Real-World Case Discussion

Case Study - Locally Advanced Disease

This case presents a woman aged 55 years with T3N1M0 stage IIIA squamous cell carcinoma of the anal canal (SCAC), demonstrating typical presentation with rectal pain, bleeding, and mass sensation over 3 months. Imaging revealed a 4.8-cm primary tumor extending to perianal skin with suspicious perirectal lymph nodes, confirmed by high-resolution anoscopy showing moderately differentiated p16-positive squamous cell carcinoma. PET-CT demonstrated hypermetabolic activity in both primary lesion and regional lymph nodes.

The case exemplifies why definitive chemoradiation is preferred over primary surgical resection, particularly avoiding abdominoperineal resection and permanent colostomy in a relatively young patient. Key factors supporting chemoradiation include the established efficacy in achieving complete responses, organ preservation potential, and successful outcomes even with bulky disease. The multidisciplinary approach considers sphincter function preservation and quality-of-life outcomes.

Supportive care measures during chemoradiation include comprehensive patient education about expected toxicity progression, proactive pain management balanced with bowel function maintenance, hydration support, and management of radiation-induced skin toxicity with measures like sitz baths. Regular monitoring at minimum on days 1, 15, and 28 allows for timely intervention and potential mitomycin dose omission if toxicity becomes prohibitive, with treatment breaks coordinated between medical and radiation oncology teams.