Multicenter phase 2 study of neoadjuvant chemotherapy followed by excision and observation for early rectal cancer

Organ-sparing therapy for early-stage I/IIA rectal cancer is intended to avoid functional disturbances or a permanent ostomy associated with total mesorectal excision. The multicenter phase 2 NEO trial evaluated neoadjuvant chemotherapy followed by transanal excision surgery (TES) and observation for cT1-3bN0 rectal cancer. Three months of neoadjuvant mFOLFOX6/CAPOX followed by TES was well tolerated and resulted in downstaging to ypT0/T1 cN0 tumors in 57% of patients with well to moderately differentiated adenocarcinoma and preserved mismathc repair. Overall, 79% of patients pursued an organ-sparing strategy. Two-year locoregional relapse-free survival was 90% (95% CI 58-98) and there were no distant recurrences or deaths. Quality of life and rectal function scores demonstrated almost no change compared with baseline.