Heterogeneity of Minimal/Measurable Residual Disease (MRD) Practices in Adult B-Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) in the United States

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.4478-4478
• Main Authors: Hidalgo-Lopez, Juliana E., Roboz, Gail J., Wood, Brent, Borowitz, Michael, Jabbour, Elias J., Velasco, Kelly, Elkhouly, Ehab, Adedokun, Babatunde, Zaman, Faraz, Iskander, Karim, Logan, Aaron C.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-144353

Background: MRD testing in BCP-ALL is critical for appropriate patient management, but little is known regarding sample acquisition and testing heterogeneity across clinical practice settings. These factors may impact the quality and reliability of MRD assessment. Methods: Thirty-minute online surveys were conducted in May 2021 with hematologists/oncologists (HEME/ONCs) in the United States in both academic (acad) and community (comm) settings. Respondents were licensed physicians board certified in oncology and/or hematology who treated ≥2 BCP-ALL patients/year or ≥10 patients in the past 5 years, with over 25% of time spent in the clinical setting; pediatric HEME/ONCs were excluded. Survey enrollment is ongoing, with interim results presented here; a related survey for pathologists (PATHs) is underway. Results: HEME/ONC respondents (acad n=40, comm n=57, from 29 states) had been practicing as specialists for a median of between 11-15 years (choices were ranges, eg 6-10, 11-15, min-max was 1-34 years), and typically spent over 75% of their time in the clinic; 94% of respondents had ≥5 BCP-ALL patients/year and 92% ordered MRD tests for ≥5 patients/year. Typical timepoints for MRD testing included the end of induction/suspected complete remission, the end of consolidation, and at suspected disease progression; testing after the end of consolidation was infrequent in both groups (Table). Testing for MRD at the end of consolidation was notably more frequent in the academic setting. In both settings, the HEME/ONC ordering the MRD test generally also performed the bone marrow collection procedure (acad: 78%, comm: 56%). Resources consulted on bone marrow collection best practices included UpToDate (21%), ASH and ASCO (13%), NCCN guidelines (13%), and hematology/oncology journals. About half of practices had defined institutional protocols for bone marrow collection (acad: 55%, comm: 47%), nearly all of which were developed internally. The amount of bone marrow sample collected showed high variability, ranging from 1-10 draws (median=3) and 1-30 mL sample per draw (median=5 mL). While 49% of HEME/ONCs performed 5 draws and/or >6 mL per draw. In both settings, the first pull was identified and labeled in 35% of procedures; in those cases, the first-pull samples were used primarily for MRD testing in 60% of cases as recommended by NCCN guidel