Blood nutritional and immune indices in lung cancer: a narrative review of prognostic significance, treatment response, and clinical applications

Lung cancer is the No.1 malignant tumor with the highest morbidity and mortality in the world. The prognosis of lung cancer depends not only on the tumor itself and the treatment, but also on the nutritional and immune status of the patients. Nutritional status can affect the quality of life and response to therapy, while immune status can also affect the biological behavior of tumor spread and metastasis by changing the microenvironment. Abnormal nutrition and immune response can interact with each other to reduce body's response to anti-cancer treatment and promote tumor progression. In recent years, with the increasing attention to this field, a large number of tumor-related prognostic indicators have emerged based on inflammatory immune and nutrition-related tests such as prognostic nutritional indicators and immune inflammation indicators. Researchers attempted to use these composite indexes to comprehensively assess the prognosis of lung cancer patients and guide clinical treatment decisions. This review synthesizes recent studies on the prognostic value of nutrition and immunity indexes for lung cancer, so as to identify optimal indicators for clinical application for lung cancer patients to evaluate their prognosis after the therapies and to help doctors make better intervention strategies.