Prediction of adverse events during intensive induction chemotherapy for acute myeloid leukemia or high-grade myelodysplastic syndromes.

Intensive chemotherapy for newly diagnosed acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) is associated with significant treatment-related morbidity and mortality. Herein, we investigate how pretreatment characteristics relate to early adverse outcomes in such patients, studying 205 consecutive individuals receiving curative-intent induction chemotherapy with cytarabine and an anthracycline ("7 + 3"; n = 175) or a "7 + 3"-like regimen (n = 30). Among the entire cohort, baseline grade 4 neutropenia (i.e., absolute neutrophil count <500 cells/µL) was associated with development of fever (P = 0.04), documented infection (P < 0.0001), and bacteremia (P = 0.002) but not requirement for intensive care unit-level care; after exclusion of the 30 patients who received "7 + 3"-like induction, baseline grade 4 neutropenia remained associated with documented infection (P < 0.0001) and bacteremia (P = 0.0005). Among patients achieving a complete remission with the initial treatment cycle, grade 4 neutropenia was associated with delayed neutrophil count recovery (P < 0.0001). Low monocyte and lymphocyte counts at baseline were similarly associated with increased risk of documented infection or bacteremia. After adjustment for age, gender, disease type, cytogenetic/molecular risk, and performance status, the risk of fever, documented infection, or bacteremia was 1.87 (95% confidence interval: 1.04-3.34; P=0.04)-fold, 4.95 (2.20-11.16; P<0.001)-fold, and 3.14 (0.99-9.98; P=0.05)-fold higher in patients with initial grade 4 neutropenia. Together, our studies identify severe baseline neutropenia as a risk factor for infection-associated adverse events after induction chemotherapy and may provide the rationale for the risk-adapted testing of myeloid growth factor support in this high-risk AML/MDS patient subset.