Background: Controversy persists about whether additional induction chemotherapy (ICT) before neoadjuvant chemoradiation (NCRT) yields improved oncological outcomes. We performed a systematic review and meta-analysis to compare ICT+ NCRT+ surgery(S) with NCRT+ S in patients with locally advanced rectal cancer (LARC).
Methods: We searched the PubMed, EMBASE, Cochrane Library, and China Biology Medicine (CBM) databases. The data were analyzed with Stata version 12.0 software.
Results: We identified 9 relevant trials that enrolled 1538 patients. We detected no significant difference in the 5-year overall survival (OS) (OR 1.50, 95% CI 0.48-4.64), disease-free survival (DFS) (OR 1.03, 95% CI 0.73-1.46), local recurrence (LR) (OR 0.80, 95% CI 0.45-1.43), and distant metastasis (DM) rates (OR 1.03, 95% CI 0.55-1.93) between patients who did and did not receive ICT. The addition of ICT before NCRT had a similar pathological complete response rate compared to NCRT (OR 1.26, 95% CI 0.90-1.77). Our findings suggest that between the ICT + NCRT+S and NCRT+S groups, ICT improved the incidence of grade 3 to 4 toxicity effects (OR 4.81, 95% CI 2.38-9.37), but between the ICT + NCRT+S and NCRT+S+ adjuvant chemotherapy (ACT) groups, ICT might reduce toxicity (OR 0.19, 95% CI 0.08-0.50). ICT had no significant impact on surgical complications (OR 0.97, 95% CI 0.63-1.51).
Conclusions: The addition of ICT before NCRT seemingly shows no survival benefit on patients with LARC, and might increase the toxicity.
Keywords: Induction chemotherapy; Meta-analysis; Neoadjuvant therapy; Rectal cancer; Systematic review.