Five readily available clinical/laboratory variables predict patients’ risk of developing chemotherapy-induced anemia, according to a prospective, observational cohort study. Findings from this study were published in Supportive Care in Cancer.
Chemotherapy is associated with the development of a number of hematologic toxicities including anemia, neutropenia, and thrombocytopenia. Specifically, chemotherapy-induced anemia has been shown to increase the likelihood of fatigue, dyspnea, depression, as well as quality of life and survival detriments. Previous studies have identified a number of predictors of chemotherapy-induced anemia, such as female sex, advanced age, low body mass index (BMI), and specific cytotoxic agents administered. However, unlike chemotherapy-induced febrile neutropenia, for which clinical practice guidelines are available to assign patients into risk groups based on specific chemotherapy regimens received as well as patient-specific risk factors, no comparable chemotherapy-related risk stratification model exists for the development of severe chemotherapy-induced anemia.
This observational cohort study included 305 consecutive patients with solid tumors or lymphoma treated with chemotherapy from February 2015 to March 2016 at a tertiary cancer center in Tehran, Iran. Results of complete blood counts (CBCs) with differential, measured at the end of each treatment cycle, were abstracted from patient medical records, and 14 clinical and laboratory variables were prospectively evaluated prior to treatment with chemotherapy. Specific chemotherapy regimens were categorized into 3 groups based on risk of severe anemia using data from pivotal trials: low risk (less than 10% risk of severe anemia), intermediate risk (10% to 20% risk of severe anemia), and high risk (greater than 20% risk of severe anemia). Severe anemia was defined as hemoglobin level of less than 8 g/dL.
Key findings of this study were that of the 1732 chemotherapy cycles evaluated, only 10.1% of patients developed severe anemia following administration of chemotherapy. A significant association was observed for high-risk chemotherapy and development of anemia (odds ratio (OR), 3.24; P =.004), but not for intermediate-risk chemotherapy (OR, 1.03, P =.951). These analyses also showed that, following adjustment for the risk of anemia associated with the chemotherapy regimen, 5 variables including low hemoglobin (<12 g/dL for men, <11 g/dL for women), low hematocrit (<36% for men, <34% for women), BMI less than 23 kg/m2, high ferritin (>300 ng/mL for men, >200 ng/mL for women), and high haptoglobin (>300 ng/mL for men, >200 ng/mL for women) were independent predictors of severe chemotherapy-induced anemia. Of the patients developing severe anemia following chemotherapy, only 6.5% did not have at least one of the predictors.
Some of the limitations of the study, identified by the investigators, were the small number of patients included and the few severe anemia events per variable. In addition, inclusion of patients with many different cancer types may have made it more difficult to clearly identify specific predictors of chemotherapy-induced anemia.
In commenting on their results, the investigators noted that while the results were promising “clinical judgment should not be affected by these results before validation. Further research is required to include these candidate predictors in a single multivariable model.”
Razzaghdoust A, Mofid B, Peyghambarlou P, et al. Predictors of chemotherapy-induced severe anemia in cancer patients receiving chemotherapy [published online April 16, 2019]. Support Care Cancer. doi: 10.1007/s00520-019-04780-7