Neoadjuvant chemotherapy with capecitabine combined with oxaliplatin for mid-low locally advanced rectal cancer with negative mesorectal fascia: Long-term outcomes of a prospective trial (PKUCH-R03 trial).

Objective: To evaluate the safety and efficacy of neoadjuvant chemotherapy (NCT) in mid-low locally advanced rectal cancer with negative mesorectal fascia (MRF). Methods: This prospective, single-arm phase II trial was designed and conducted at Peking University Cancer Hospital. The patients who provided consent received 3 months of NCT (capecitabine and oxaliplatin, CapOX) followed by total mesorectal excision (TME). The primary endpoint was the rate of pathological complete response (pCR). Results: From January 2019 through December 2021, a total of 53 patients were enrolled, 7.5% of whom experienced grade 3-4 adverse events during NCT. The pCR rate was 17.0% for the entire cohort, and the overall rate of postoperative complications was 37.7% (1.9% of grade IIIa patients). The 3-year disease-free survival rate was 91.4%, and 23.5% (12/51) of the patients suffered from major low anterior resection syndrome (LARS). Postoperative complications were independently associated with major LARS. Conclusions: For patients with mid-low rectal cancer with negative MRF, 3 months of NCT were found to yield a favorable tumor response with acceptable toxicity. With fair long-term survival, the NCT regimen could be associated with low rates of perioperative complications as well as acceptable anal function.