<prompt> Treatment of choice for squamous cell carcinoma of anus is?ChemotherapyChemoradiationSphincter sparing surgeryMonoclonal antibodies  <response>: 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 