Role of induction chemotherapy for locally advanced oral squamous cell carcinoma. A systematic review and meta-analysis based on the GRADE approach

A few reports have demonstrated the additional survival benefit obtained from induction chemotherapy. However, some facilities have differing opinions regarding the suitability of induction chemotherapy. The aim of this systematic review was to investigate the effectiveness of induction chemotherapy in patients with unresectable oral cancers without distant metastases. A comprehensive search of randomized controlled trials was conducted specifically targeting patients with primary unresectable oral cancer, defined as an intervention group (induction chemotherapy followed by chemoradiotherapy) and a control group (chemoradiotherapy alone). The electronic databases PubMed, Cochrane Central Register of Controlled Trials, and Ichushi-Web database were searched for relevant papers. The primary outcome was overall survival, and the secondary outcomes were progression-free survival and treatment-related deaths, all of which were judged to be of critical importance. Data available for integration were subjected to a meta-analysis, and the certainty of evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation approach. A search was conducted until February 2022, and four articles were included. The meta-analysis showed that the point estimates (95% confidence interval) of the hazard ratios were 0.87 (0.74–1.01) for overall survival, 0.85 (0.75–0.97) for progression-free survival, and 0.98 (0.97–1.00) for treatment-related death. The certainty of the evidence for each item was very low. Little data are available to support the use of induction chemotherapy before chemoradiotherapy in patients with unresectable primary locally advanced oral cancer.