A retrospective study: the prevalence and prognostic value of anemia in patients undergoing radiotherapy for esophageal squamous cell carcinoma

BACKGROUND: The relationship between anemia and outcomes after radiotherapy has not been systematically addressed. The study aimed to assess the prevalence and prognostic value of anemia in patients receiving primary radiotherapy for esophageal squamous cell carcinoma (ESCC). METHODS: A total of 103 patients with ESCC were retrospectively reviewed. Anemia was defined as a hemoglobin level <12 g/dl for men and <11 g/dl for women. The 3-year and 5-year overall survival (OS) and disease-free survival (DFS) were analyzed between the anemic and non-anemic groups using the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: No significant differences were observed in patient characteristics between the anemic and non-anemic groups. The prevalence of anemia was 29.1%. The 3-year and the 5-year OS were 43% and 37%, respectively, in the non-anemic group, and 20% and 17%, respectively, in the anemic group. The 3-year and the 5-year DFS were 37% and 26%, respectively, in the non-anemic group, and 13% and 10%, respectively, in the anemic group. Survival analysis using the Kaplan-Meier method showed that there was significant difference between anemia and non-anemia (P < 0.02). In a multivariate analysis, anemia was identified as a highly significant prognostic factor for 3-year OS (hazard ratio 1.916; P = 0.012) and 3-year DFS (hazard ratio 1.973; P = 0.007), independent of T stage and the status of lymph nodes, and 5-year OS (hazard ratio 1.705; P = 0.027) and 5-year DFS (hazard ratio 1.980; P = 0.005), independent of TNM stage and the status of lymph nodes. CONCLUSIONS: Anemia before primary radiotherapy was associated with poor prognosis and an increased risk of relapse, which may serve as a new prognostic factor for ESCC.