A comprehensive analysis of the association between anemia and systemic inflammation in older patients with cancer

Purpose Our study aimed to comprehensively analyze the association between anemia and systemic inflammation in older patients with cancer. Methods This multicenter prospective cohort study included 4955 older patients with cancer between 2013 and 2020. Logistic regression analysis was performed to investigate risk factors of anemia, reporting odds ratios (ORs), and 95% confidence intervals (CIs). Comprehensive survival analyses, including Kaplan–Meier curve, Cox proportional risk model, and subgroup analysis, were performed. Results The participants’ median age was 70.0 (interquartile range [IQR]=67.0–74.0) years, with 3293 (66.5%) males and 1662 (33.5%) females. There were 1717 (34.7%) older patients with cancer diagnosed with anemia. High neutrophil-to-lymphocyte ratio (NLR) was an independent risk factor associated with anemia (adjusted OR=1.97, 95%CI=1.73–2.24, P <0.001). In older patients with cancer and different anemia levels, the median overall survival was significantly shorter in those with a high NLR. In multivariate Cox analysis, high NLR served as a negative factor, independently affecting survival. The anemia-inflammation prognostic grading system showed a significant survival discriminative performance in older patients with cancer. After adjusting for confounders, high grades were independent risk factors for survival (grade 2: hazard ratio [HR] = 1.38, 95%CI = 1.26–1.52, P <0.001; grade 3: HR=1.82 95%CI = 1.59–2.09, P <0.001). This grading system was beneficial in determining survival in patients with lung, digestive tract, and urogenital cancers. Conclusions Increased systemic inflammation is an independent risk factor for anemia. A high inflammatory status is also associated with poor survival in older cancer patients at different anemia levels. The anemia-inflammation grading system is beneficial for determining the prognosis in older patients with cancer.