TY - JOUR AB - Complement factor B (CFB) serves a pivotal role in the alternative signaling pathway of the complement system and exerts a key role in the labelling of target particles, resulting from effective clearance of the target. The present study aimed to investigate the association between low expression levels of CFB and the clinical features and survival status of patients with lung adenocarcinoma (LUAD). Patient data were based on RNA‑sequencing and clinical data from The Cancer Genome Atlas database. All patients were divided into two groups based on the median expression of CFB. Kaplan‑Meier curve and univariate Cox regression analyses were used to investigate the association between CFB and survival status. Gene set enrichment analysis was used to examine the effects of CFB expression on signaling pathway impairment. Furthermore, reverse transcription‑quantitative PCR (RT‑qPCR) and western blotting were used to verify the relative expression levels of CFB in LUAD tissues. The data revealed that residual tumor classification, Karnofsky performance score and cancer stage were associated with overall survival, and that Karnofsky performance score and stage were associated with disease‑free survival. The results demonstrated that high expression levels of CFB were associated with increased patient overall and disease‑free survival according to both continuous and categorical models. The results of multivariate analysis identified that high expression levels of CFB were associated with increased overall and disease‑free survival according to both the continuous model [hazard ratio (HR), 0.48; 95% confidence interval (95% CI), 0.25‑0.93; P=0.029 for overall survival; HR, 0.29; 95% CI, 0.15‑0.59; P=0.001 for disease‑free survival] and the categorical model (HR, 0.46; 95% CI, 0.22‑0.93; P=0.031 for overall survival; HR, 0.25; 95% CI, 0.12‑0.55; P=0.001 for disease‑free survival) after adjusting for corresponding covariates (residual tumour classification, Karnofsky performance score and stage). Furthermore, the results of both RT‑qPCR and western blotting indicated that the relative mRNA and protein expression levels of CFB in lung tumor tissues were downregulated compared with those in adjacent non‑tumor tissues. Collectively, the present results suggested that CFB expression was an independent predictor of overall and disease‑free survival in patients with LUAD. AD - Yunnan Key Laboratory of Laboratory Medicine, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China Department of Environment-Related Health, Yunnan Center for Disease Control and Prevention, Kunming, Yunnan 650034, P.R. China Health Management Center, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China Department of Clinical Laboratory, Kunming Children's Hospital, Kunming, Yunnan 650228, P.R. China AU - He,Chenglu AU - Li,Ya AU - Zhang,Ruixian AU - Chen,Jing AU - Feng,Xingxing AU - Duan,Yong DA - 2021/06/01 DO - 10.3892/ol.2021.12739 IS - 6 JO - Oncol Lett KW - complement factor B lung adenocarcinoma bioinformatics overall survival disease‑free survival PY - 2021 SN - 1792-1074 1792-1082 SP - 478 ST - Low CFB expression is independently associated with poor overall and disease‑free survival in patients with lung adenocarcinoma T2 - Oncology Letters TI - Low CFB expression is independently associated with poor overall and disease‑free survival in patients with lung adenocarcinoma UR - https://doi.org/10.3892/ol.2021.12739 VL - 21 ER -