When would you consider initial induction chemotherapy (e.g. FOLFOX) followed by neoadjuvant chemoradiation, over neoadjuvant chemoradiation alone, in patients with locally advanced rectal cancer?  

At MSKCC, we now routinely recommend induction chemotherapy (8 cycles of FOLFOX) to any rectal cancer patient who requires preoperative chemoRT. Initially, we adopted this approach for patients with particularly bulky or node-positive disease (as per @Autumn J. McRee's answer above) but now do it fo...