Adult patients with locally advanced rectal cancer who have completed conventional
long-course chemo-radiation of 54Gy with capecitabine will be randomized 1:1 to a total
neo-adjuvant therapy (TNT) protocol or to a control group. Patients in the TNT arm will
receive 4 cycles of interval chemotherapy with FOLFIRINOX (5-FU, irinotecan, oxaliplatin)
between the end of chemo-radiation and re-staging and those in the control group will undergo
standard post-radiation care during this period. All patients will be re-staged with
colonoscopy and pelvic MRI 12 weeks after the end of chemo-radiation. Those with a complete
clinical response will be placed under a watch-and-wait protocol with digital rectal
examinations every 2 months and pelvic MRI and sigmoidoscopy every 6 months. Those wih
residual tumors will undergo resection with total mesorectal excision (TME). Patients with a
"near complete response", as defined by a multidisciplinary tumor board, will be re-staged at
week 16 or 18 after chemo-radiation before undergoing surgery. Adjuvant chemotherapy will be
done following the local standard of care.