10P - Tumor-infiltrating lymphocytes and tertiary lymphoid structures in oral cavity squamous cell carcinoma in non-smokers and non-drinkers: Predict clinical outcome

Background

As a result of a significant decrease in smoking prevalence in many countries, the overall incidence of head and neck squamous cell carcinoma (HNSCC) is declining. However, there is a growing recognition of an increased incidence of oral tongue squamous cell carcinoma (OTSCC) in non-smokers and non-drinkers (NSND) for reasons that are yet to be fully understood. OTSCC in NSND and smoker-drinker (SD) individuals have different molecular profiles, as well as distinct immune microenvironments, which may affect their susceptibility to targeted therapies and immunotherapy. The prognostic value of tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLS) in localized oral tongue squamous cell carcinoma (OTSCC) remains unclear. This study investigates the prognostic impact of TILs and TLS on recurrence in patients with surgically treated OTSCC in NSND.

Methods

A total of 100 patients with OTSCC underwent complete surgical resection at a single institution with a median follow-up of 35 months (IQR 12-60). TIL presence (minimal, moderate, heavy) and TLS maturation (aggregate, primary follicle, secondary follicle) were graded using brightfield H&E slides according to previously published criteria. The prognostic impact of TILs and TLS on survival was analyzed using multivariable Cox regression, adjusting for prognostic factors (tumor size, depth of invasion, grade, and surgical margin status). Multivariable logistic regression was used to evaluate these factors for associations with early recurrence (≤12 months).

Results

Heavy TIL presence was observed in 41% of cases, and TLS was present in 76%, of which 23% were mature. The presence of mature TLS was associated with reduced odds of early recurrence [OR 0.18, P=0.04], and the presence of heavy TILs was associated with improved overall survival (OS) [HR 0.26, P=0.02]. Tumors categorized as TIL-/TLS- were associated with significantly worse OS [HR 3.5, P=0.02] compared to tumors with heavy TILs or mature TLS.

Conclusions

TILs and mature TLS are independently associated with decreased rate of early recurrence for high-risk localized OTSCC. Further studies should validate these potential low-cost biomarkers.

Editorial acknowledgement

During the preparation of this work the author(s) used Chat GPT in order to checking grammar. After using this tool/service, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the publication.

Legal entity responsible for the study

The author.

Funding

Has not received any funding.

Disclosure

The author has declared no conflicts of interest.