Predictive biomarkers for immunotherapy in nasopharyngeal carcinoma: from tumor microenvironment to macroenvironment

The introduction of PD-1 blockades to chemotherapy and radiotherapy has shown promising outcomes in patients with nasopharyngeal carcinoma, but anti-PD-1 therapies are only effective in a small proportion of patients, indicating the need for reliable predictive biomarkers of benefit from immunotherapy. Here, we summarized recent advances in immunotherapy for nasopharyngeal carcinoma and studies on potential predictors that correlated with treatment response or long-term survival after immunotherapy, including biomarkers in both the tumor microenvironment and the tumor macroenvironment. Some of these biomarkers have been validated as truly predictive of immunotherapy benefit using cohorts from randomized controlled trials, while others still require further validation of their predictive value. We also summarized the challenges and future directions of biomarker studies, hopefully facilitating the development of predictive biomarkers for immunotherapy that can eventually enter clinical practice.