Neoadjuvant Immunotherapy for Head and Neck Squamous Cell Carcinoma: Expecting Its Application in Temporal Bone Squamous Cell Carcinoma

Survival Outcomes of Temporal Bone Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVE

Temporal bone squamous cell carcinoma (TBSCC) is a rare malignancy with poor prognosis, and optimal treatment for advanced cases is uncertain. Our systematic literature review aimed to assess 5-year survival outcomes for advanced TBSCC across different treatment modalities.

DATA SOURCES

EMBASE, Medline, PubMed, and Web of Science.

REVIEW METHODS

A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for articles published between January 1989 and June 2023.

RESULTS

The review yielded 1229 citations of which 31 provided 5-year survival data for TBSCC. The final analysis included 1289 patients. T classification data was available for 1269 patients and overall stage for 1033 patients. Data for 5-year overall survival (OS) was 59.6%. Five-year OS was 81.9% for T1/2 and 47.5% for T3/4 (P < .0001). OS for T1/T2 cancers did not significantly differ between surgery and radiation (100% vs 81.3%, P  = .103). For advanced-stage disease (T3/T4), there was no statistical difference in OS when comparing surgery with postoperative chemoradiotherapy (CRT) (OS 50.0%) versus surgery with postoperative radiotherapy (XRT) (OS 53.3%) versus definitive CRT (OS 58.1%, P  = .767-1.000). There was not enough data to assess the role of neoadjuvant CRT.

CONCLUSION

Most patients will present with advanced-stage disease, and nodal metastasis is seen in nearly 22% of patients. This study confirms the prognostic correlation of the current T classification system. Our results suggest that OS did not differ significantly between surgery and XRT for early stage disease, and combined treatment modalities yield similar 5-year OS for advanced cancers.

Lymphatic endothelial cell-mediated accumulation of CD177+Treg cells suppresses antitumor immunity in human esophageal squamous cell carcinoma

Regulatory T (Treg) cells are critical in shaping an immunosuppressive microenvironment to favor tumor progression and resistance to therapies. However, the heterogeneity and function of Treg cells in esophageal squamous cell carcinoma (ESCC) remain underexplored. We identified CD177 as a tumor-infiltrating Treg cell marker in ESCC. Interestingly, expression levels of CD177 and PD-1 were mutually exclusive in tumor Treg cells. CD177+ Treg cells expressed high levels of IL35, in association with CD8+ T cell exhaustion, whereas PD-1+ Treg cells expressed high levels of IL10. Pan-cancer analysis revealed that CD177+ Treg cells display increased clonal expansion compared to PD-1+ and double-negative (DN) Treg cells, and CD177+ and PD-1+ Treg cells develop from the same DN Treg cell origin. Importantly, we found CD177+ Treg cell infiltration to be associated with poor overall survival and poor response to anti-PD-1 immunotherapy plus chemotherapy in ESCC patients. Finally, we found that lymphatic endothelial cells are associated with CD177+ Treg cell accumulation in ESCC tumors, which are also decreased after anti-PD-1 immunotherapy plus chemotherapy. Our work identifies CD177+ Treg cell as a tumor-specific Treg cell subset and highlights their potential value as a prognostic marker of survival and response to immunotherapy and a therapeutic target in ESCC.