Neoadjuvant chemoradiotherapy (CRT) is the standard of treatment for locally advanced rectal cancer, but it delays administration of systemic chemotherapy, leading to high incidence of distant metastases. To enhance systemic chemotherapy and avoid the damage of radiation, full dose of neoadjuvant chemotherapy regimens with mFOLFOXIRI or mFOLFOX6 were both under investigation. Here, we aimed to compare the safety and efficacy of preoperative chemotherapy with mFOLFOXIRI versus mFOLFOX6 in locally advanced rectal cancer.
Prospectively maintained databases of patients from two clinical trials (NCT01211210 and NCT02217020) underwent preoperative treatment for locally advanced rectal cancer in a single center were included. Those had received mFOLFOXIRI or mFOLFOX6 chemotherapy alone preoperatively was selected for this study, including 90 patients with mFOLFOXIRI and 119 patients with mFOLFOX6. All patients had undergone total mesorectal excision. A comparative analysis was performed after the implementation of propensity score matching on the 2 main cohorts (mFOLFOXIRI and mFOLFOX6).
A total of 209 patients were enrolled in the study. After propensity score matching, 180 patients were selected. 90 patients were comparable in the two groups. Higher pathologic complete response rate was observed in mFOLFOXIRI group than that of mFOLFOX6 group (16.7% vs. 5.6%, p = 0.03), although the tumor downstaging (ypT0-2N0M0) rate was comparable in this two group (41.1% vs. 37.8%, P = 0.76). The anal preservation rate was similar between the two groups (87.8% vs. 89.2%). Higher incidence of grade 3/4neutropenia (42.2% vs. 10%, P < 0.001) was shown in mFOLFOXIRI group than that of mFOLFOX6 group.
Preoperative mFOLFOXIRI chemotherapy showed higher pCR rate than that of mFOLFOX6. The tumor downstaging rate was comparable between the two regimens. But the adverse events were more common in mFOLFOXIRI group. Whether the intensive regimen would improve the survival is unknown. Further follow-up is needed.
Clinical trial identification
NCT01211210 and NCT02217020.
Legal entity responsible for the study
Has not received any funding.
All authors have declared no conflicts of interest.