<prompt> Treatment of choice for squamous anal carcinoma isAbdominoperineal resectionLaserChemoradiotherapyPlatinum based chemotherapy  <response>: Radiotherapy with concurrent chemotherapy Chemoradiotherapy is the standard of care for patients with nonmetastatic squamous cell anal cancer. Most patients treated with chemoradiotherapy have an excellent prognosis. Nigro Regime :Initial radiotherapy for 3 weeks 3000 rads 30 Gy total to perineum and pelvis. Then chemotherapy--5 FU, for 4-5 days; is a radiosensitizer, staed on 1st day of as 1000 mgm2 continuous infusion. Mitomycin C is 15 mgm2 as single dose on 1st day of . Reference : page 987 SRBs manual of surgery 5th edition 