Analysis of the expression of LAG3 in the tumor microenvironement of aggressive salivary gland carcinomas

Introduction In particular, aggressive salivary gland tumors such as salivary duct carcinoma (SDC), adenocarcinoma NOS (ANOS), and adenoid cystic carcinoma (ACC) more often lead to unresectable local recurrences and distant metastases and thus the need for systemic tumor therapy. Analysis of treatable molecular alterations and immunologic processes of the tumor and surrounding stroma may help improve patient prognosis.

Patients and Methods Our study examined the expression of LAG3 particularly in SDC (n=14), ANOS (n=27), and ACC (n=34). Sections were stained using anti-LAG3 IgG and CD8 and TP53 monoclonal antibodies. Expression was correlated with pathologic characteristics and patient follow-up.

Results High LAG3 expression on tumor-infiltrating T lymphocytes was particularly evident in SDC (64.3%) and ANOS (38.9%), less so in ACC (17.6%). The highest LAG3 positivity was present in lymphogenically metastatic ANOS and SDC with pN3 stage. In patients with ACC, LAG3 expression correlated with shorter disease-free survival.

Conclusions  LAG3 is detectable at high rates in the tumor microenvironement, particularly in SDC and ANOS. Therapy with LAG3 inhibitors could be used as a potential starting point for new and effective systemic immunotherapies especially for patients with advanced disease of the entities described above.

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Artikel online veröffentlicht:
12. Mai 2023