Disparities in Clinical Outcomes in Patients with Newly Diagnosed Acute Myeloid Leukemia Treated in Public Versus Private Services in Brazil: Analysis of the Brazilian Acute Myeloid Leukemia Registry

Introduction:

The Brazilian healthcare system is divided into private and public sectors, the latter known as the Sistema Único de Saúde. Around 70% of the Brazilian population exclusively depends on public health services, and the treatment of oncological diseases can be challenging in this setting due to its high demanding infrastructure and funding. To our knowledge, there are no multicentric studies in Brazil comparing clinical outcomes between patients treated on public and private services. Our aim in this report is to compare early mortality (<30 days after treatment initiation), progression-free survival (PFS), and overall survival (OS) between patients treated in public or private services in Brazil.

Methods:

This study enrolled patients from the Brazilian Acute Myeloid Leukemia Registry, a national ambispective study involving patients aged 18 years or older with a diagnosis of acute myeloid leukemia (AML) without previous treatment (excluding acute promyelocytic leukemia and leukemias of ambiguous lineage). The study was supported by the Brazilian Association of Hematology, Hemotherapy, and Cellular Therapy (ABHH). Prognostic stratification followed the European Leukemia Net (ELN) 2017 guidelines.

Results:

A total of 235 cases were analyzed, with 93 (36%) patients from private healthcare and 142 (60.4%) from public healthcare. The median age at diagnosis for cases treated in the public setting was 52.5 years (range 18-74), while in the private setting it was 61 years (range 19-89). There was a slight predominance of cases in females (54.9%) compared to males (45.1%). The median age at diagnosis for cases treated in the public setting was 52.5 years (range 18-74), while in the private setting it was 61 years (range 19-89) with a statistically significant difference between them (p<.001). Also, the Charlson Comorbidity Index (CCI) of patients from private centers was higher than those from public centes (median CCI 4,0 versus 1,0). The ELN risk group was classified as good in 23.8% (n=55), intermediate in 42.4% (n=98), high in 31.6% (n=73), and unknown in 2.2% (n=5). Patients from the public setting had a higher proportion of cases classified as intermediate risk (50.5% versus 35.9%), which is possibly associated with its lower availability of NGS panels, potentially resulting in a higher proportion of patients classified as AML not otherwise specified. Regarding the preferred treatment protocol, anthracyclines and cytarabine represented the majority of prescribed treatments in the public setting (94.4% of treated patients), whereas in the private setting they represented 47.8% of treatments, 9.8% of them also receiving gemtuzumab-ozogamicin and 5.4% receiving FLT3 inhibitors. Venetoclax-based treatment with hypomethylating agents accounted for 45.2% of treatments in the private setting. The early mortality rate for patients treated in the public context was 26.8% compared to 9.8% in private settings, with an odds ratio for death of 3.37 (p=0.002). With a median follow-up of 19 months, the median OS for patients treated in the public system was 7.0 months (95% CI, 5.06 - 8.93) compared to 22 months in the private system (95% CI, 10.82 - 33.17), with a statistically significant difference between the two (p<.001). The median PFS in public services was 6 months (95% CI, 4.5-7.5) compared to 17 months (95% CI, 12.1 – 21.8) in private (p<.001). In multivariate analysis, being treated in a public center was associated with a HR for death of 4,5 (CI 95%, 2,2-9,23, p<.001).

Conclusions:

The difference in early mortality, OS, and PFS reflects the profound disparity between the support offered to AML patients in the public and private settings. Even at older ages and higher comorbidity index, patients treated in private services had better clinical outcomes. The study provided an initial analysis of the epidemiological profile of patients with AML in Brazil and the most commonly used treatments in each setting.