Survey Study: Exploring Adoption Rates of the 2022 I.C.C and W.H.O Myeloid Neoplasm Classifications in the U.S
Authors: Zureigat Hadil , Nurse Daniel P. , Odneck Mariah , Adcock Bridget , Rauf Asad , Batah Heya , Honnekeri Bianca , Jia Xuefei , Mercer MaryBeth , Al Hadidi Samer , Mirza Kamran M. , Mustafa-Ali Moaath K. 
Published: December 2023

Introduction: Standardizing the diagnosis of neoplasms is critical and can be achieved by having a clearly defined set of diagnostic guidelines. These guidelines play a vital role in guiding treatment choices and facilitating meaningful comparisons among patient populations in both intra- and inter-clinical trials. In 2022, two distinct pathologic guidelines for hematopoietic neoplasm classification were published, the International consensus classification (ICC) and the fifth edition of the World Health Organization (WHO HEM5) classification. Despite having major overlap, there are differences between the two guidelines, posing a potential source of confusion for clinicians.

Methods: An anonymous online survey was deployed to assess the impact of having two separate diagnostic classifications on both clinical practice and research. The survey was carefully designed to gather valuable insights from attending physicians and fellows-in-training associated with Hematology, Medical Oncology, and Hematopathology fellowship programs at various US institutions. The survey was distributed electronically via a secure link, ensuring participant confidentiality. The link was disseminated to all program directors, program coordinators, and department chiefs/heads, requesting further distribution among their respective teams. Moreover, it was disseminated using social media platforms, including Twitter and LinkedIn. A sample size was estimated to be 140 responses from hematopathologists and 148 from other specialties, using a 95% confidence interval and 8% error margin.

Results: A total of 310 responses were obtained. Of those, 228/308 (73.5%) were attendings and more than half (54%) have been in the field for over five years. A total of 239/310 (77.1%) work in a large hospital setting and 265/310 (85.5%) reported that published guidelines are important for clinical practice/management. Additionally, 246/300 (82%) agree that guidelines are important for patient selection in research studies. A total of 292/297 (98%) reported using WHO 2016 before 2022, and 68/310 (22%) reported still using it currently. Otherwise, 112/310 (36%) reported using WHO HEM5 2022 and 57/310 (18.4%) reported ICC, while 143/310 (46.1%) reported using a combination of the above. There was no association between community type (urban/suburban/rural), region (West, Southwest, Midwest, Northeast, Southeast), practice setting (Community-based, Community-based/University affiliated or University based), on choice of diagnostic guideline (p&gt;0.05).

Among respondents 131/251 (52%) reported that ICC and WHO HEM5 2022 were “somewhat” similar as opposed to similar/very similar. The most differences were reported in diagnostic criteria for MDS and AML. When asked about potential confusion resulting from having two guidelines, 45/310 (14.5%) believed it would cause confusion in clinical management, 124/310 (40%) in clinical diagnosis, 46/310 (14.8%) in trial design, and 29/310 (9.4%) in drug authorization.

Among respondents, 255/309 (82.5%) reported that the presence of two distinct classifications was discussed at their institutions, and most reported that the discussion was brought in the context of making a new diagnosis. More than half 179/310 (57.7%) describe the general opinion of their colleagues as negative, while 59/310 (19%) stated that the reaction was rather indifferent. More than half 176/308 (57.1%) of pathologists reported that their institution adopted both/either depending on style/condition. Only 60% 155/258 stated that the leadership has discussed the presence of two classifications with their faculty. Of those working in an institution where it was not brought up, 54/102 (52.9%) think it should have been discussed, and a single classification should be adopted instead.

Conclusions: There is significant variation in the adoption rate of diagnostic classification of hematologic disorders across the USA, both at an inter and intra-institutional level. Having two separate diagnostic guidelines poses a potential source of confusion for clinicians and researchers. Consequently, it is imperative to focus on future endeavors aimed at unifying diagnostic classifications to enhance clarity and consistency in the field.