Acute undifferentiated leukemia: data on incidence and outcomes from a large population-based database

Area of Science:

• Hematology
• Oncology
• Epidemiology

Background:

• Acute undifferentiated leukemia (AUL) is a rare hematologic malignancy lacking distinct myeloid or lymphoid markers.
• Limited data exists on AUL incidence, survival rates, and optimal treatment strategies in contemporary populations.

Purpose of the Study:

• To investigate the incidence, survival outcomes, and treatment patterns of AUL using a large population-based database.
• To compare AUL characteristics and prognosis with other acute leukemias, specifically acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL).

Main Methods:

• Utilized the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2016.
• Analyzed 1,888 diagnosed cases of AUL to determine incidence rates.
• Examined survival data for 1,444 AUL patients, excluding those with prior malignancies, and assessed treatment receipt (chemotherapy).

Main Results:

• AUL incidence was 1.34 per million person-years and decreased over the study period.
• AUL patients were significantly older (median age 74) than AML (65) and ALL (12) patients.
• Only 35% of AUL patients received chemotherapy, compared to 94% for ALL and 71% for AML.
• Chemotherapy significantly improved median survival for AUL patients (12 months vs. 1 month).
• Adult AUL patients had the worst overall survival (9 months) compared to ALL (27 months) and AML (13 months).
• In children, AUL survival was better than AML and similar to ALL.

Conclusions:

• AUL incidence has declined, and it predominantly affects older adults.
• AUL is associated with a poor prognosis, particularly in adults, and chemotherapy use is notably low.
• Older age and the time period of diagnosis are linked to worse outcomes in AUL.