[Construction and Evaluation of Risk Prediction Model of Delayed Excretion in Adult Acute Lymphoblastic Leukemia Patients Treated with High-Dose Methotrexate].

Objective: To explore the risk factors for delayed excretion in adult acute lymphoblastic leukemia (ALL) patients treated with high-dose methotrexate (HD-MTX), and construct a risk prediction model to improve the safety of clinical medication.

Methods: From March 2010 to March 2023, 39 adult ALL patients who received 74 courses of HD-MTX chemotherapy in our hospital were analyzed retrospectively. The blood concentration of MTX was monitored by high-performance liquid chromatography (HPLC) at 0, 20 and 44 h after the end of MTX infusion. According to the MTX concentration of 44 h, the patients were divided into excretion delay group (≥0.3 μmol/L) and non-excretion delay group ( < 0.3 μmol/L), and the incidences of side effects were compared between the two groups. Clinical data and the results of laboratory test were collected. The risk factors associated with delayed MTX excretion were screened, and the independent risk factors for delayed excretion were identified by logistic regression analysis. A nomogram prediction model was established by R software based on the risk factors, and the predictive value of the model was also evaluated.

Results: A total of 27 courses of delayed excretion occurred in 74 courses of chemotherapy. As compared with the non-excretion delay group, the incidences of mucosal injury and nephrotoxicity increased significantly in the excretion delay group (both P <0.05). The dosage of MTX, blood uric acid level, and MTX peak concentration (i.e., blood drug concentration at 0 h after the end of MTX infusion) were independent factors influencing delayed MTX excretion. Based on these three independent factors, a nomogram prediction model was established for delayed MTX excretion. Calibration curve, concordance index (C-index), area under curve (AUC), and decision curve analysis showed that the model performed well. The model had showed good consistency and discrimination.

Conclusion: The incidence of delayed MTX excretion during HD-MTX chemotherapy in adult ALL patients is relatively high. The nomogram model based on the screened independent risk factors can be used to evaluate the risk of delayed excretion, timely identify individuals with high-risk of delayed excretion and adjust rescue measures combined with detection of MTX concentration to reduce the occurrence of side effects and ensure the safety of chemotherapy.