Treatment will continue until participants experiences disease progression, unacceptable toxicity or withdraws consent and will include chemoradiation (28 days) followed by FOLFOXIRI x 8 cycles (16 weeks). A cycle is defined as an interval of fourteen days, except for Cycle 1 spanning fourteen days which includes eight cycles of FOLFOXIRI treatment prior to surgery. For participants experiencing unacceptable FOLFOXIRI or chemoradiation related toxicity, yet obtaining therapeutic benefit, participants will be allowed to continue treatment, if well tolerated at the discretion of the investigator.~Upon discontinuation of study treatment, participants will receive safety follow-up assessments approximately 30 and 90 days later. Once the 90-day safety follow-up is complete, participants will enter the survival follow-up period where they will continue to be followed approximately every three months until death, withdrawal of consent, or overall study completion. Patients will be followed for survival for 36 months from enrollment.
To evaluate the safety and preliminary efficacy of Preoperative ChemoRadiation and FOLFOXIRI and to Escalate Complete Response for Rectal Cancer patients.Go through laboratory and medical tests to verify eligibility to enter the study, receive the experimental combination of drugs (chemoradiation (capecitabine and radiation) + FOLFOXIRI (Oxaliplatin, leucovorin, irinotecan, and fluorouracil) prior to surgery and undergo laboratory tests and study procedures on specified days during the study period, complete end of study evaluations and tests, and participate in post-study follow up every three months for three to four years. The time in the study will take approximately four to six hours during pre-study, study and end of study visits.