A Meta-analysis of Surgical Outcomes of T4a and Infranotch T4b Oral Cancers

Objective: To determine the overall surgical outcomes of infranotch T4b oral cancers and compare them with T4a oral cancers. Methods: PubMed, EMBASE and Cochrane databases from 2000 to 2022 were systematically searched. Clinical studies reporting at least one outcome following curative surgery and adjuvant therapy for comparison of patients with either infranotch T4b (IN–T4b) or T4a tumour. The heterogeneity of the included studies was determined using Tau-squared, Chi-squared, and the Higgins I 2 test. The random effects model was used to determine the log odds ratio (logOR). Results: The systematic review comprised 11,790 patients from 16 included studies. Seven studies were included in the meta-analysis (n = 11,381). For IN–T4b patients, the pooled 2 and 5 year overall survival (OS) were 59.3% and 53.2%, 2 and 5 year disease-free survival (DFS) 57.9% and 48.4%, 2 and 5 year disease-specific survival (DSS) 72% and 68%, and 2 and 5 year local control (LC), 47% and 56%, respectively. There was no statistically significant difference in 2 year OS [logOR = 0.28 (−0.47, 1.03), p = 0.46, confidence interval (CI) = 95%], 5 year OS [logOR = 0.7 (−0.4, 1.8), p = 0.54, CI = 95%], 2 year DFS [logOR = 0.22 (−0.35, 0.79), p = 0.45, CI = 95%], 5 year DFS [logOR = 0.17 (−0.42, 0.77), p = 0.57, CI = 95%], 2 year LC [logOR = 0.47 (−0.33, 1.26), p = 0.25, CI = 95%] and 5 year LC [logOR = 0.34 (−0.31, 0.99), p = 0.31, CI = 95%] between IN–T4b and T4a oral cancers. Conclusion: Results of this meta-analysis suggest that IN–T4b oral cancers have similar outcomes to T4a oral cancers, which supports down-staging IN–T4b cancers to T4a cancers.