Survival outcomes of surgically treated oral cavity squamous cell carcinoma patients at tertiary care hospital in Northern Thailand.

Objective: This study aimed to evaluate the survival outcomes of surgically treated oral squamous cell carcinoma (OSCC) patients with or without adjuvant therapies and factors predicting treatment outcomes from the largest head and neck cancer center in Northern Thailand.

Methods: Two hundred and sixty OSCC patients curatively treated between 2017 and 2021 were retrospectively recruited into the study to analyze the clinicopathological characteristics and oncological outcomes and compare them with historical data. A multivariate Cox proportional hazards model analysis was performed to evaluate factors affecting survival outcomes.

Results: Males were slightly predominant (58.1 %). The most common subsite was an oral tongue (48.5 %), followed by an alveolar ridge (18.5 %). Advanced stages (III-IV) presented most at 88.5 %. The majority of the patients (52.3 %) received surgery and chemoradiotherapy, followed by surgery and radiotherapy (36.9 %), and surgery alone (10.8 %). The five-year overall survival (OS), disease-specific survival, and disease-free survival were 28.8 %, 44.0 %, and 46.3 %, respectively. Age > 45, ECOG performance status 2, and positive surgical margin status were found to be independent predictors for decreased OS (aHR 1.74, 95 % CI 1.01-3.00, aHR 2.64, 95 % CI 1.22-5.68, and aHR 1.76, 95 % CI 1.18-2.63, respectively).

Conclusions: Survival outcomes of OSCC in the study remain poor compared to other studies. The high prevalence of locally advanced stage presentation and inadequate surgical margin are the main problems. Public awareness, cancer screening programs, and intraoperative specimen-driven evaluation might help obtain adequate surgical margins and improve survival outcomes.