The effect of chemotherapy-induced anemia on dose reduction and dose delay.

Purpose: To evaluate moderate (grade 2, hemoglobin <10 g/dl) and severe (grade 3+, hemoglobin <8 g/dl) anemia as potential risk factors for DDR in the first line course of chemotherapy. While chemotherapy-induced neutropenia has been shown to be associated with dose delay/reduction (DDR) in several studies, the effect of anemia is less well studied.

Methods: We identified 3955 Kaiser Permanente patients diagnosed with incident non-Hodgkin's lymphoma (n = 574), breast (n = 2043), lung (n = 463), gastric (n = 113), ovarian (n = 204), or colorectal cancers (n = 558) between 2010 and 2012. Generalized linear mixed effects models were used to study the effect of anemia in subsequent cycles, adjusting for demographics, comorbidities, chemotherapy cycle, neutropenia, thrombocytopenia, and liver and renal function.

Results: We found that moderate (grade 2) to severe (grade 3-4) anemia increased the risk of DDR in subsequent chemotherapy cycles [odds ratio (OR) = 1.46, 95 % CI (1.32, 1.62) and OR = 2.02 (1.41, 2.89)], respectively, compared to grade 1 or no anemia. Both stage I-III and IV patients with grade 2 or greater anemia were at higher risk for DDR than patients with grade 1 or no anemia [ORstage IV, grade 2 = 1.94 (1.58, 2.38); ORstage IV, grade 3/4 = 2.83 (1.42, 5.62) and ORstage I-III, grade 2 = 1.33 (1.18, 1.49); ORstage I-III, grade 3-4 = 1.81 (1.18, 2.76)].

Conclusions: These results provide insight into novel risk factors for chemotherapy dose modification that may inform clinicians on management strategies to optimize treatment outcomes.