Retrospective analysis of the effect of first-line bevacizumab treatment on survival and prognosis of patients with advanced non-small cell lung cancer treated with second-line immunotherapy

Lung cancer is the leading cause of cancer death globally, and outcomes for patients diagnosed with advanced non-small-cell lung cancer (NSCLC) are poor despite recent advances in treatment. Chemotherapy is one of the basic treatments by using one or more cytotoxic drugs to destroy or inhibit the growth and division of malignant cells. However, the efficacy of chemotherapy in NSCLC is limited. At present, there is a lot of evidence that the combination of anti-angiogenic drugs with chemotherapy can further prolong the survival time of patients. Angiogenesis is defined as the formation of new blood vessels from preexisting vessels and has been characterized as an essential process for tumor cell proliferation and viability. The mechanism of anti-angiogenesis drugs is to disrupt the vascular supply and starve tumor of nutrients and oxygen, primarily through blockade of VEGF/VEGFR signaling. Bevacizumab is the first available anti-angiogenic agent, which can block the interaction of vascular endothelial growth factor (VEGF) with its receptors, thereby inhibiting the activation of VEGF signaling pathways that tumor blood vessel development.
In recent years, Immunotherapy, which harnesses the power of the immune system of human body to fight against cancer, has changed the landscape of cancer therapy. The most effective immunotherapy agents currently used against advanced NSCLC are drugs known as checkpoint inhibitors, which are antibodies blocking PD-1 or PD-L1. PD-1 is a protein found on T cells in the blood. T cells are an important part of the body’s immune response, attacking foreign particles. When PD-1 is bound to another protein, PD-L1, it stops T cells from attacking foreign cells such as cancer cells. However, the efficacy for anti-PD-1/PD-L1 immunotherapy is relatively low (objective response rate <20%). Pre-clinical studies have shown that anti-angiogenic drugs, such as bevacizumab, are able to boost the immune system and improve the efficacy of immunotherapy. Therefore, we will explore whether the use of anti-angiogenic drugs followed by immunotherapy can further improve the survival of patients.