In what situations, if any, would you treat locally advanced (non metastatic) anal cancer with induction chemotherapy followed by chemoRT rather than chemo/RT by itself?  

Hard to know. I would offer that it is a rare event for me to consider induction chemotherapy prior to chemoradiotherapy at this point. Part of it stems from an honest lack of faith in chemotherapy relative to the effectiveness of radiotherapy/chemoradiotherapy, which has complete response rates in ...

Very few scenarios. Utilizing neoadjuvant chemotherapy would likely not change the radiation field.