Prognostic Role of Depth of Invasion Stratification Beyond the 10 mm Threshold in Tongue Carcinoma.

OBJECTIVES

The aim of this study is to define the prognostic role of further stratification in oral tongue and floor squamous cell carcinoma (OTFSCC) with a pathological DOI > 10 mm.

METHODS

A retrospective multicenter study was conducted on patients with a pDOI > 10 mm. Patients were stratified into three groups based on pDOI values: Group A (11-20 mm), Group B (21-30 mm) and group C (> 30 mm). The association between stratified pDOI and various histopathological features was investigated, along with disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). Univariable and multivariable Cox regression analyses were applied to estimate the hazard ratio (HR).

RESULTS

A total of 108 patients were included. Seventy-six patients (70.4%) were in Group A, 22 (20.4%) in Group B, and 10 (9.2%) in Group C. The association between the stratified pDOI and ENE (p = 0.004), lymph node burden (LNB) (p = 0.011) and lymph node ratio (LNR) (p = 0.026) resulted statistically significant. Five-year DSS resulted in 72.5% for Group A, 53.3% for Group B, and 25.9% for Group C. Univariable analysis showed that a pDOI > 30 mm was associated with a statistically significant increased risk of recurrence (HR = 8.32, p = 0.000) and mortality from disease (HR = 3.61, p = 0.014).

CONCLUSION

The stratification of OTFSCCs with a pDOI > 10 mm was statistically significantly associated with ENE, LNB, and LNR. Pathological DOI > 30 mm emerged as a negative prognostic factor for DFS and DSS.

LEVEL OF EVIDENCE: Level 3.