L08 - Pre-operative chemotherapy in locally advanced but technically resectable oral cavity squamous cell carcinoma: a meta-analysis

Abstract

Preoperative chemotherapy, in locally advanced but still technically resectable oral cavity carcinomas, is a treatment strategy that could aid in improving treatment outcomes, although the results of the few available studies are still controversial This meta-analysis was aimed at evaluating the effectiveness and safety of preoperative chemotherapy prior to surgery in locally advanced oral cavity cancer The systematic review and meta-analysis were conducted on phase III Randomized Controlled Trials only. The included studies compared preoperative chemotherapy (test) which can be followed by surgery with or without postoperative radiotherapy versus up-front surgery without preoperative chemotherapy (control) followed or not by postoperative radiotherapy. Primary Outcomes for comparison were the Overall Survival (OS), Diseases Free Survival (DFS), Locoregional recurrence Free Survival (LRFS). Subgroup meta-analysis was also executed with the aim to evaluate the clinically N2 patients and the complete pathologic response patients. The effect size of the intervention for time-to-event outcomes was calculated by the pooled hazard ratio (HR), with confidence interval of 95%. Only two studies corresponded to the inclusion criteria. In accordance to the Cochrane risk table both studies were considered at low risk of bias. Results of the meta-analysis for Overall Survival did not show a significant benefit in the pre-operative chemotherapy group (experimental) versus the control group (pooled HR 0.86, 95%CI 0.25,2.99, p value 0.81). The same results were evident when DFS outcome was analyzed (pooled HR 0.87, 95%CI 0.32,2.87, p value 0.78). Also the loco-regional relapse was not significantly different between the two groups (Risk Ratio 0.98, 95%CI 0.74,1.31, p value 0.71). A subgroup meta-analysis was then performed for the clinically N2 patients (cN2). In this case a statistically significant difference in favor of the pre-operative chemotherapy group was evident both for OS (pooled HR 0.42, 95%CI 0.18,0.98, p value 0.04) than for DFS (pooled HR 0.55, 95%CI 0.33,0.92, p value 0.02). Finally, a subgroup meta-analysis was performed for the patients with pathologic complete response. A statistically significant difference was shown favoring the pre-operative chemotherapy group (pooled HR 0.25, 95%CI 0.22,0.28, p value <0.000001). In conclusion benefit of pre-operative chemotherapy can be shown only in patients with cN2 disease and in patients with a pathologic complete response.