Acute Myeloid Leukemia in Adolescents and Young Adults (AYA): The MD Anderson Cancer Center (MDACC) Experience

Background: Acute myeloid leukemia (AML) is a heterogeneous group of hematopoietic neoplasms demonstrating clonal proliferation of myeloid precursors and is typically a disease of older adults. In acute lymphoblastic leukemia (ALL) adolescent and young adult (AYA) patients (pts) have a distinct outcome, possibly influenced by type of therapy (i.e., usually better with more intensive regimens). There is little information about outcome of AML in AYA.

Aims: To define the characteristics and outcome of AYA pts with AML treated at MDACC.

Methods: We retrospectively analyzed the data of all pts with AML treated at MDACC from 1965 to 2008. Those aged 16 to 21 years were defined as AYA.

Results: Among 3934 adult pts seen during this period, 163 (4%) were AYA. The median age was 19 yrs. These included 27 (17%) pts with Core Binding Factor (CBF)-AML [inv(16), t (8:21)]and 19 pts (12%) with acute promyelocytic leukemia (APL). Among other evaluable pts, 50% had diploid cytogenetics, 39% miscellaneous changes, and 11% 5-and/or 7- abnormalities. Antecedent hematologic disorders were present in 33 (20%) and AML was a secondary malignancy in 6%. Among 20 evaluable pts, FLT3 ITD was documented in 4 and mutation in 2. CR rates were 89% for CBF AML, 79% for APL, and 75% for all others. The median survival for the total group was 88 weeks (wks) with 36% alive at 3 yrs, and median CR duration of 67 wks (30% CR at 3 yrs). Outcome is better for pts with CBF leukemias (3-yr survival 56%, CR duration 49%) and APL (3-yr survival 51%, CR duration 36%) compared to other AML (3-yr survival 28%, CR duration 24%). CR rates have improved from 71% in 1965–84, to 85% in 1985–94 and 83% after 1994. Similarly, overall survival (OS) has increased during the same time periods (3-yr survival 18%, 44%, and 53%, respectively) together with CR duration (3-yr CR duration 21%, 32% and 39%, respectively) as early mortality has decreased (11%, 8%, and 4%, respectively). To compare outcome with older adults, we focused on those with diploid cytogenetics (Table 1):

Conclusion: The outcome of AYA pts with AML is significantly better than that of older adults with AML. Despite these improvements over time, there is still significant room for improvement in this area, particularly among those with AML other than CBF and APL. Exploration of new treatment options is needed in this patient population.