Analysis of the relationship between Ki-67 expression and chemotherapy and prognosis in advanced non-small cell lung cancer

Lung cancer has become the leading cause of cancer-related death across China and worldwide (1,2). Approximately 80% of lung cancers are non-small cell lung cancer (NSCLC), which includes adenocarcinoma (ADC) and squamous cell carcinoma (SQCC). Lung cancer is still a major health threat faced by humans, and most patients are already in the late stages of the disease at the time of diagnosis (3). The objective response rate (ORR) of first-line chemotherapy for advanced NSCLC is 15–50% (4). According to previous studies, the median survival time ranges from 7.7 to 10.3 months, and the 1-year survival rate is approximately 30% (4,5). Ten years have passed since those studies were published, and cures for glandular cancer have changed because of the discovery of molecular markers that affect the disease’s biological behaviours (6,7). For example, epidermal growth factor receptor (EGFR) mutations serve as biomarkers for the use of tyrosine kinase inhibitors (TKIs), which have established TKIs as a first-line treatment for EGFR-positive NSCLC (8). The discovery of the anaplastic lymphoma kinase (ALK) rearrangement has laid the foundation for the development of TKIs that are aimed at ALK. Crizotinib has become the first-line treatment for patients with ALK rearrangement-positive tumours (9)