Identification of a immune-related genes signature for survival prediction in stage I lung adenocarcinoma

Background With the popularization of low-dose spiral computed tomography (CT), an increasing number of stage I lung cancers have been discovered. Although most of the patients with stage I lung adenocarcinoma have a favorable prognosis, some patients still have a poor prognosis of recurrence and metastasis after surgery. The immune system has been shown to play an important role in the development of cancer. Our aim is to identify a reliable prognostic signature of immune-related genes that can predict prognosis and help in the individualized management of patients with stage I lung adenocarcinoma. Methods In this study, the immune-related genes were first extracted by the ImmPort database. Subsequently, these genes were screened using univariate Cox regression and LASSO regression to identify prognostic signatures, followed by construction of a prognostic model using multivariate Cox regression. A nomogram was developed to predict the prognosis of stage I lung adenocarcinoma and to evaluate the nomogram differentiation and accuracy using the receiver operating characteristic curve, clinical decision analysis and calibration curve. The model was validated in two independent data sets: GSE31210 and GSE30219. Then, patients were stratified based on median risk scores, and differential expression genes between the two groups were analyzed. Finally, the enrichment analysis and the immune infiltration analysis were performed. Results In this study, we found 29 immune-related genes and developed a gene signature with poor prognosis in stage I lung adenocarcinoma. Our model was validated using two independent datasets and demonstrated robust performance with good AUC values and clinical utility. Enrichment analysis indicated that immune-related genes signature has multifaceted effects on stage I lung adenocarcinoma, especially related to tumor development, proliferation, and metastasis. Patients in the high-risk group had higher tumor purity, lower matrix, estimated and immune scores, suggesting a potentially immunosuppressive tumor microenvironment. Conclusion This study constructed a gene signature related to immunity in stage I lung adenocarcinoma and analyzed its impact on tumor development and its relationship with the tumor microenvironment. The findings can contribute to a more precise survival risk stratification and personalized clinical management for stage I lung adenocarcinoma patients. Furthermore, we provide related opinions for future immune-related research by elucidating potential underlying mechanisms.