Research Progress of Immune Checkpoint Inhibitors in Virus-Associated Cancer Such as Pulmonary Lymphoepithelioma-Like Carcinoma

Pulmonary lymphoepithelioma-like carcinoma （PLELC） was a rare type of primary malignant lung tumor with favorable prognosis than other types of non-small cell lung cancer. Since its first publication in 1987, a close association between the disease and Epstein-Barr virus （EBV） infection had been found. To date, no standard therapeutic strategy for this rare disease had been established. It was reported that immunotherapy had a good therapeutic effect in some virus-associated cancers, including human papilloma virus （HPV）-positive head and neck squamous cell carcinoma and EBV-positive gastric cancer. For its association with EBV infection, overexpression of programmed death ligand 1 （PD-L1） and sufficient lymphocytic infiltration, it was likely that immunotherapy could be a promising choice for PLELC. In this review, we retrospected the association of EBV and PLELC, described the therapeutic effects of immune checkpoint inhibitors in this rare disease and explore drug resistance mechanisms to immune checkpoint inhibitors.