Flow cytometric analysis of cerebrospinal fluid in adult patients with acute lymphoblastic leukemia during follow‐up

Abstract Objective To explore the value of flow cytometric ( FCM ) analysis of cerebrospinal fluid ( CSF ) in the diagnosis of central nervous system involvement in adult patients with acute lymphoblastic leukemia ( ALL ) during follow‐up. Methods A total of 2871 CSF samples from 357 adult patients with newly diagnosed ALL between the year of 2009 and 2015 were analyzed retrospectively. These patients were divided into 3 groups according to CSF results, FCM +/conventional cytology ( CC )+ group, FCM +/ CC − group, and FCM −/ CC − group, respectively. The overall survival ( OS ) of the three groups was analyzed. Results Fifteen (4.2%) and 26 (7.3%) patients' CSF samples were FCM +/ CC + and FCM +/ CC −, respectively. The remaining 316 (88.5%) patients' samples were FCM −/ CC −. The 2‐year OS for the FCM +/ CC +, FCM +/ CC −, and FCM −/ CC − groups was 40.0%, 20.6%, and 64.2%, respectively ( P < .001). There was no statistically significant difference in OS between FCM +/ CC + and FCM +/ CC − patients ( P = .195). In multivariate analysis, a high WBC count and LDH level were independent risk factors for central nervous system involvement in adult patients with ALL . Conclusions FCM demonstrated a superior sensitivity over conventional cytology in the diagnosis of central nervous system involvement in adult patients with ALL . FCM +/ CC − patients showed a similar survival with FCM +/ CC + patients, suggesting that an isolated FCM ‐positive status holds clinical significance.