Low Representation and High Disease Burden in Underrepresented Minority Participants in the Mympn Registry

Introduction:

Myeloproliferative neoplasms (MPNs) are heterogenous chronic myeloid malignancies that include essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF). Little is known about outcomes in underrepresented minority (URM) MPN patients, particularly in the real-world setting. We address this gap by utilizing the myMPN Patient Registry to investigate the features and outcomes of URM in the myMPN patient registry.

Methods:

The myMPN patient registry was created by the MPN Research Foundation’s myMPN Steering Committee utilizing the Genetic Alliance platform. Participants register online and complete questions regarding their MPN as well as authorize data use. Patients reported variables including disease features and genetic mutations with the registry. The MPN10 score (J Clin Oncol. 2012;30(33):4098-4103) was used to assess patient reported symptom burden. Data was analyzed using SPSS. Mean differences were analyzed by Chi-squared and t-test analysis.

Results:

Participant Demographics: Since its initiation in September 2017, the registry has captured 968 participants (as of data cutoff of 10/1/19), of which 54 (5.6%) were URM. URM participants comprised a lower than anticipated proportion of the myMPN registry when compared to the US population (24%), or when compared to recent large US MPN cohorts where race and ethnicity were reported (16%; Blood Adv. 2020 Jun 23;4(12):2567-2576). Minorites were 2/3rds female with a median age of 57 (range 19-86), which was similar to the overall registry. Minorities were Hispanic/Latino (21, 39%), Black/African American (12, 22%), Asian (14, 25%), American Indian/Alaskan Native (4, 7%), and other (3, 6%). Patients were well educated, with the majority having received at least some college education.

Disease Characteristics: URM respondent diagnoses included ET (21, 39%), PV (17, 31%), and MF (16, 30%), proportions similar to the entire myMPN registry. Patients typically received care at an academic medical center (19) or large tertiary medical center (19). Common current treatments included hydroxyurea (9 ET, 7 PV, 1MF), ruxolitinib (0 ET, 2PV, 6 MF), interferon (2 ET, 1 PV, 0 MF), anagrelide (1 ET, 0 PV, 0 MF), but with most patients receiving aspirin or observation only (8 ET, 6 PV, 9 MF). Minority individuals represented 1/14 patients who reported a thrombotic event during the registry (TIA) and 3/28 of patients who reported a bleeding event (gut and arm bleeding). Symptom scores by MPN subtype of minority patients had a mean MPN10 score of 1.76 (1.53 ET, 1.76 PV, 1.89 MF).

Minority patients vs all registry participants: When comparing minority data to the registry as a whole, minority patients were significantly younger (median age 55 vs 61, t-test p=0.006). Gender was similar between the two patient groups (67% versus 62% female). Minority patients were more likely to receive care at a large academic medical center or large/regional tertiary care center than at a local/community hospital compared to patients in the general registry (chi-squared p=0.008). Although non-significant, there was a trend towards URM participants taking no therapy or aspirin as their sole therapy.

Conclusions:

This represents one of the first analyses of URM in a patient-reported registry to date in MPN populations. Significant differences were observed between URM registry participants with regards to age and location of MPN care compared to all registry participants. Hispanic, Black, Asian, and Native Americans comprise a lower percentage of the myMPN registry participants compared to their state or national US population percentages, or compared to those reported in published MPN research cohorts. URM myMPN registry participants may have higher burden of disease, higher JAK2 mutation rates, yet have lower rates of therapy. Ongoing efforts will be directed at understanding the basis of the lack of representation of URM in the myMPN registry, and enhancing recruitment of URM to the myMPN registry. Further data collection is ongoing in regards to outcomes of URM patients with MPNs, particularly thrombotic risk which has been previously noted to be high in URM MPN individuals (Clin Lymphoma Myeloma Leuk. 2016 Jun;16(6):350-7). The myMPN registry is an ongoing valuable resource for all stakeholders who are invested in advancing treatment and outcomes for individuals with MPN.