Abstract 424P
Background
Bone involvement in oral cancer indicate T4a as per AJCC 8thedition TNM staging, potentially influencing outcomes and guiding treatment strategies. This study aims to evaluate the impact of histological bone involvement on local-regional control and to identify clinical and pathological factors affecting disease outcomes in patients with or without bone involvement, utilising real-world data from a large patient cohort.
Methods
This retrospective analysis utilised prospectively collected data from 3900 oral cancer patients from 2015 – 2021, of which 521 underwent segmental mandibulectomy. Various Clinical and pathological parameters affecting disease outcomes and differences in recurrence rates (local, regional, distant) were analysed. Statistical analyses included chi-square tests for categorical variables, multinomial and logistic regression analyses for evaluating the impact of clinical and pathological factors on outcomes, and Cox regression analysis to identify predictors of disease-free survival (DFS). Survival curves for DFS were generated, and significance was assessed using the Log Rank test.
Results
In a cohort of 521 oral cancer patients undergoing segmental mandibulectomy, of which 258 patients had histological bone involvement. 221(42.4%) patients had disease relapse with a mean follow-up of 21 months. Patients with bone involvement showed significant nodal involvement (p=0.04) compared to 263 patients without. Recurrence rates were similar in both groups (p=0.41), with local, regional, and distant recurrence rates showing no difference. Though not statistically significant, DFS was lower in patients with bone involvement (mean: 44.1 months vs 52.7 months, p=0.322). Predictors of worse outcomes included perineural invasion (PNI, OR: 1.47, p=0.046) and lymph vascular invasion (LVI, OR: 0.5, p=0.003) in patients without bone involvement, and PNI is the only significant factor affecting DFS in patients with bone involvement (OR: 1.69, p=0.03).
Conclusions
Histological bone involvement in patients with oral cancer is of limited prognostic value. Recurrence rates did not differ significantly with or without bone involvement. PNI is a significant predictor of disease outcomes.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.