Predictors of recurrence, and the impact of adjuvant radiation therapy on survival in early stage (pT1-2, N0) oral cavity squamous cell carcinoma: A matched pair analysis.

BACKGROUND

Early stage constitutes around 40 % of all oral cavity squamous cell carcinoma (OSCC). While the role of adjuvant therapy in advanced cases is well established, its role in early-stage disease remains controversial and is institutional based. Despite treatment advances, the 5-year Disease Free Survival (DFS) falls short of 80 %.

METHODS

An ambispective observational study was conducted on all early stage (pT1-2, N0) OSCC who underwent curative surgery of the primary and neck from 2019 to 2024 at a tertiary oncology care centre. Patients with a history of radiation, recurrence, neoadjuvant chemotherapy or positive margins were excluded. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Secondary outcomes were factors associated with recurrence, radiation-induced toxicity, and quality of life.

RESULTS

1260 OSCC were operated during the study period. 357(28 %) were early stage, and 274 were eligible for analysis. 52(18.9 %) patients had recurrence. 3-year-OS was 92 % and 3-year-DFS was 74 %. Tongue subsite (p = 0.034), depth of invasion (DOI) > 5 mm (p = 0.012), and peri-neural Invasion (PNI) (p = 0.036) were significant predictors of recurrence on multi-variate analysis. On matched-pair analysis patients who received adjuvant radiotherapy had lower rates of recurrence (16.9 % vs 24.6 %, p = 0.2815). Odds of recurrence increased from low to intermediate to high Brandwein-Gensler score (OR - 0.54 vs 0.89 vs 1.54, p = 0.4332).

CONCLUSION

Tongue/FOM subsite, DOI > 5 mm, and PNI are aggressive features in early-stage OSCC. Adjuvant therapy can help to achieve improved disease control. There is a pressing need to establish definitive indications for adjuvant therapy in pT1-2, N0 OSCC.