Tumor mutational burden predictability in head and neck squamous cell carcinoma patients treated with immunotherapy: systematic review and meta-analysis.

BACKGROUND: Tumor mutational burden (TMB) has been demonstrated to predict the response to immune checkpoint inhibitors (ICIs) in various cancers. However, the role of TMB in head and neck squamous cell carcinoma (HNSCC) has not yet been specifically addressed. Since HNSCC patients exhibit a rather limited response to ICIs, there is an unmet need to develop predictive biomarkers to improve patient selection criteria and the clinical benefit of ICI treatment. METHODS: We conducted a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. HNSCC cohort studies were selected when TMB prior to ICI treatment was evaluated, TMB cutoff value was available, and the prognostic value of TMB was evaluated by time-to-event survival analysis. A total of 11 out of 1960 articles were analyzed, including 1200 HNSCC patients. RESULTS: The results showed that those patients harboring high TMB exhibited a significantly superior overall response rate (OR = 2.62; 95% CI 1.74-3.94; p < 0.0001) and a survival advantage (HR = 0.53; 95% CI 0.39-0.71; p < 0.0001) after ICI treatment. CONCLUSION: This is the first meta-analysis to demonstrate a higher response and clinical benefit from ICI therapy in HNSCC patients with high TMB.

Tumor-Intrinsic Perinuclear LOXL2: Prognostic Relevance and Relationship with YAP1 Activation Status in Oral Squamous Cell Carcinoma.

INTRODUCTION: Lysyl oxidase-like 2 (LOXL2) expression and function is frequently altered in different cancers but scarcely explored in oral squamous cell carcinoma (OSCC). This prompted us to investigate the clinical relevance of LOXL2 expression pattern in OSCC and also a possible crosstalk with Hippo/YAP1 pathway signaling. METHODS: Immunohistochemical analysis of LOXL2 protein expression was performed in 158 OSCC patient samples, together with Yes-associated protein 1 (YAP1) activation status. Correlations with clinicopathological parameters and patient survival were assessed. RESULTS: Tumor cell-intrinsic LOXL2 expression showed two distinct expression patterns: diffuse cytoplasmic staining (64.6%) and heterogeneous perinuclear staining (35.4%). Remarkably, perinuclear LOXL2 staining was significantly associated with lymph node metastasis, advanced clinical stage and perineural invasion. Moreover, patients harboring tumors with perinuclear LOXL2 expression exhibited significantly poorer disease-specific survival (DSS) rates, and perinuclear LOXL2 positivity gradually increased in relation to YAP1 activation. Patients harboring tumors with concomitant perinuclear LOXL2 and fully active YAP1 exhibited the worst DSS. Multivariate Cox analysis further revealed combined perinuclear LOXL2 and fully active YAP1 as a significant independent predictor of poor DSS. CONCLUSION: Tumor-intrinsic perinuclear LOXL2 emerges as a clinically and biologically relevant feature associated with advanced disease, tumor aggressiveness, and poor prognosis in OSCC. Moreover, this study unprecedentedly uncovers a functional relationship between perinuclear LOXL2 and YAP1 activation with major prognostic implications. Notably, combined perinuclear LOXL2 and fully active YAP1 was revealed as independent predictor of poor prognosis. These findings encourage targeting oncogenic LOXL2 functions for personalized treatment regimens.

Lectin-like Transcript-1 (LLT1) Expression in Oral Squamous Cell Carcinomas: Prognostic Significance and Relationship with the Tumor Immune Microenvironment.

Lectin-like transcript-1 (LLT1) expression is detected in different cancer types and is involved in immune evasion. The present study investigates the clinical relevance of tumoral and stromal LLT1 expression in oral squamous cell carcinoma (OSCC), and relationships with the immune infiltrate into the tumor immune microenvironment (TIME). Immunohistochemical analysis of LLT1 expression was performed in 124 OSCC specimens, together with PD-L1 expression and the infiltration of CD20+, CD4+, and CD8+ lymphocytes and CD68+ and CD163+-macrophages. Associations with clinicopathological variables, prognosis, and immune cell densities were further assessed. A total of 41 (33%) OSCC samples showed positive LLT1 staining in tumor cells and 55 (44%) positive LLT1 in tumor-infiltrating lymphocytes (TILs). Patients harboring tumor-intrinsic LLT1 expression exhibited poorer survival, suggesting an immunosuppressive role. Conversely, positive LLT1 expression in TILs was significantly associated with better disease-specific survival, and also an immune-active tumor microenvironment highly infiltrated by CD8+ T cells and M1/M2 macrophages. Furthermore, the combination of tumoral and stromal LLT1 was found to distinguish three prognostic categories (favorable, intermediate, and adverse; p = 0.029, Log-rank test). Together, these data demonstrate the prognostic relevance of tumoral and stromal LLT1 expression in OSCC, and its potential application to improve prognosis prediction and patient stratification.

Combined PIK3CA and SOX2 Gene Amplification Predicts Laryngeal Cancer Risk beyond Histopathological Grading.

The PIK3CA and SOX2 genes map at 3q26, a chromosomal region frequently amplified in head and neck cancers, which is associated with poor prognosis. This study explores the clinical significance of PIK3CA and SOX2 gene amplification in early tumorigenesis. Gene copy number was analyzed by real-time PCR in 62 laryngeal precancerous lesions and correlated with histopathological grading and laryngeal cancer risk. Amplification of the SOX2 and PIK3CA genes was frequently detected in 19 (31%) and 32 (52%) laryngeal dysplasias, respectively, and co-amplification in 18 (29%) cases. The PIK3CA and SOX2 amplifications were predominant in high-grade dysplasias and significantly associated with laryngeal cancer risk beyond histological criteria. Multivariable Cox analysis further revealed PIK3CA gene amplification as an independent predictor of laryngeal cancer development. Interestingly, combined PIK3CA and SOX2 amplification allowed us to distinguish three cancer risk subgroups, and PIK3CA and SOX2 co-amplification was found the strongest predictor by ROC analysis. Our data demonstrate the clinical relevance of PIK3CA and SOX2 amplification in early laryngeal tumorigenesis. Remarkably, PIK3CA amplification was found to be an independent cancer predictor. Furthermore, combined PIK3CA and SOX2 amplification is emerging as a valuable and easy-to-implement tool for cancer risk assessment in patients with laryngeal precancerous lesions beyond current WHO histological grading.

Low-Level Expression of p-S6 Is Associated with Nodal Metastasis in Patients with Head and Neck Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer. The incidence of metastasis for cSCC is estimated to be around 1.2-5%. Ribosomal protein S6 (p-S6) and the p21 protein (p21) are two proteins that play central roles in other cancers. These proteins may be equally important in cSCC, and together, these could constitute a good candidate for metastasis risk assessment of these patients. We investigate the relationship of p-S6 and p21 expression with the impact on the prognosis of head and neck cSCC (cSCCHN). p-S6 and p21 expression was analyzed by immunohistochemistry on paraffin-embedded tissue samples from 116 patients with cSCCHN and associations sought with clinical characteristics. Kaplan-Meier estimators and Cox proportional hazard regression models were also used. The expression of p-S6 was significantly inversely associated with tumor thickness, tumor size, desmoplastic growth, pathological stage, perineural invasion and tumor buds. p21 expression was significantly inversely correlated with >6 mm tumor thickness, desmoplastic growth, and perineural invasion. p-S6-negative expression significantly predicted an increased risk of nodal metastasis (HR = 2.63, 95% CI 1.51-4.54; p < 0.001). p21 expression was not found to be a significant risk factor for nodal metastasis. These findings demonstrate that p-S6-negative expression is an independent predictor of nodal metastasis. The immunohistochemical expression of p-S6 might aid in better risk stratification and management of patients with cSCCHN.

Prognostic value of preoperative inflammatory ratios in early glottic cancer treated with transoral laser surgery.

BACKGROUND: There is growing evidence regarding the prognostic utility of ratios such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammatory index (SIII) in head and neck squamous cell carcinoma (HNSCC). However, most studies to date include heterogeneous series with different treatments or tumor subsites. METHODS: We collected data from 201 patients with stage I-II glottic squamous cell carcinoma treated with transoral laser surgery. NLR, PLR, and SIII were calculated from preoperative cell blood count, cut-off points were obtained by ROC curve analysis, and survival rates were calculated. RESULTS: High NLR (p = 0.012) and SIII (p = 0.037), but not PLR (p = 0.48), were associated with worse disease-specific survival (DSS). A similar trend was observed with overall survival (OS), although it did not reach statistical significance. On multivariable analyses, both high NLR (HR = 3.8, 95% CI = 1.5-9.9, p = 0.006) and high SIII (HR = 2.77, 95% CI = 1.1-6.9, p = 0.03) were significantly associated with shortened DSS. CONCLUSIONS: Preoperative NLR and SIII emerge as independent prognostic biomarkers for early-stage surgically treated glottic tumors and could guide individualized follow-up.

VAV2 orchestrates the interplay between regenerative proliferation and ribogenesis in both keratinocytes and oral squamous cell carcinoma.

VAV2 is an activator of RHO GTPases that promotes and maintains regenerative proliferation-like states in normal keratinocytes and oral squamous cell carcinoma (OSCC) cells. Here, we demonstrate that VAV2 also regulates ribosome biogenesis in those cells, a program associated with poor prognosis of human papilloma virus-negative (HPV-) OSCC patients. Mechanistically, VAV2 regulates this process in a catalysis-dependent manner using a conserved pathway comprising the RAC1 and RHOA GTPases, the PAK and ROCK family kinases, and the c-MYC and YAP/TAZ transcription factors. This pathway directly promotes RNA polymerase I activity and synthesis of 47S pre-rRNA precursors. This process is further consolidated by the upregulation of ribosome biogenesis factors and the acquisition of the YAP/TAZ-dependent undifferentiated cell state. Finally, we show that RNA polymerase I is a therapeutic Achilles' heel for both keratinocytes and OSCC patient-derived cells endowed with high VAV2 catalytic activity. Collectively, these findings highlight the therapeutic potential of modulating VAV2 and the ribosome biogenesis pathways in both preneoplastic and late progression stages of OSCC.