Patients, clinical characteristics, and variables
Cancer Center/Cancer, lung cancer
LUNG CANCER, RECURRENCE, MONO, METASTASIS
This study was approved by the Ethics Committee of the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences. Patients who received radical surgery for lung cancer pathologically and were diagnosed with stage IA LUAD according to the eighth edition of AJCC TNM classification for lung cancer from December 2010 to October 2018 were screened for eligibility. All patients underwent surgery with negative surgical margins and lymph node dissection. Patients who received adjuvant or neoadjuvant therapies were excluded. Laboratory variables were collected 1 week before the surgery. After surgery, follow‐up of the patients was performed every 3 months for the first and second year, every 6 months for the third to fifth years, and then annually thereafter until recurrence or the last follow‐up. The endpoint was recurrence. Recurrence‐free survival (RFS) was defined as the time between the date of surgery and the date of the first recurrence and/or distant metastasis or the last follow‐up. The follow‐up ended in December 2021. Cases were divided into training and validation cohorts. The training cohort was used to build a prediction model, and the validation cohort was used to validate the model. Information of the clinical characteristics and laboratory data, including age, gender, smoking history and white blood cell (WBC), red blood cell (RBC), neutrophil count (Neut), lymphocyte count (Lymph), monocyte count (Mono), platelet count (PLT), hemoglobin (Hb), lactate dehydrogenase (LDH), albumin (ALB), NSE, CEA, CA125, Cyfra21‐1, and SCC levels, were extracted from the patients' electronic medical records. We also calculated the systemic immune‐inflammation index (SII), PLR, and NLR as following: SII = PLT × Neut /Lymph, NLR = Neut/Lymph, PLR = PLT/ Lymph.