This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neoplastic Disorders, Subject name: Surgery
[{'content': 'Treatment of choice for squamous cell carcinoma of anus is? \nSelect and explain. \nA. Chemotherapy, B. Chemoradiation, C. Sphincter sparing surgery, D. Monoclonal antibodies', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ANSWER: (B) ChemoradiationREF: Schwatrtz 8th ed p-1096Squamous cell carcinoma of the anal margin (distal to dentate line): treated with wide local excisionSquamous cell carcinoma of the anal canal (proximal to dentate line): chemotherapy followed by radiation (chemoradiation), abdomino perineal resection is done for residual cases.Drugs used: 5-FU, mitomycin, bleomycin, cisplatin, doxorubicinMost common anal canal cancer: squamous cell carcinoma', 'role': 'assistant'}]