Impact of prophylactic intrathecal chemotherapy on CNS relapse rates in AML patients presenting with hyperleukocytosis

Central nervous system (CNS) relapse in acute myeloid leukemia (AML) confers a poor prognosis. Despite the identification of risk factors for CNS relapse (e.g. hyperleukocytosis), there is no standard practice for CNS relapse risk reduction with intrathecal (IT) chemotherapy in patients. We compared outcomes of 50 patients who did not receive IT chemotherapy with 18 patients who did receive IT chemotherapy with a hyperleukocytosis at diagnosis (defined as white blood cell count >= 100,000 cells/mcL). There were three occurrences of CNS relapse, all within patients who did not receive prophylaxis. There was no difference in the incidence of CNS relapse between the patient cohorts (p = .560). These results highlight the low incidence of CNS relapse in our patient population that received and survived induction chemotherapy despite selecting for a high risk cohort. Furthermore, there is a need for a CNS relapse registry to standardize treatment approaches in this high-risk patient population.