Abstract Topic: 2. Acute lymphoblastic leukemia - Clinical
Background: Acute lymphoblastic leukemia (ALL) is the second most common acute leukemia in adults. In Ecuador, there are no survival studies of patients ≥15 years of age, whence, this is the first report.
Aims: To describe clinical, and demographic characteristics, as well as overall survival associated to management and results.
Methods: The medical records of 255 patients with acute lymphoblastic leukemia (ALL) over 15 years of age, diagnosed between January/2015 and December/2022, in 4 reference centers in Ecuador, were reviewed. It was defined as 1) high risk: age ≥ 35 years and/or leukocytes ≥ 30,000/mm3 and/or infiltration of the Central Nervous System (CNS) at debut; and 2) if none of these factors were present, it was classified as standard risk. Overall survival (OS), disease-free survival (DFS), and treatment-related mortality were evaluated.
Results: 255 patients with ALL were evaluated. The demographic and clinical characteristics of the patients at diagnosis are summarized in Table 1. Complete hematological response (CHR) was achieved in 143/178 (80.3%), reaching negative minimal residual disease (MRD) <0.01% in 65/144 (45.1%) patients. 61/234 patients (26.1%) died during the induction phase and 24/234 patients (10.25%) during the consolidation phase, reaching a chemotherapy-related mortality of 36.3%. In addition, 8/107 (7.4%) patients considered as high risk who achieved CHR received hematopoietic stem cell transplantation (HSCT). OS for all patients with ALL at 5 years was 20%, with a median of 8 months (IQ 1 – 23 months). Median OS for patients who receiving intensive chemotherapy in the high-risk and standard-risk groups were 9 months (IQ 2-29 months) and 12 months (IQ 3-96 months), respectively, with no significant difference (p =0.83), showed in Figure 1. The 5-year OS of patients who presented the BCR:ABL fusion gene (n:22) were 36.1%, in those who received HSCT was 54.6% (median not reached), and for patients with T-cell ALL (n:12) was 14.9%.
Summary/Conclusion: The OS rates reported in this cohort are considerably low compared to cohorts in the literature, probably related to high early mortality rates (related to treatment or early relapse); and the reduced number of patients who received HPCT.
Table 1. Clinical demographic data of patients with acute lymphoblastic leukemia.
| Variable | n | (%) | |
|---|---|---|---|
| 255 | (100) | ||
| Age in years | Mean 38,3 (± 17,8 SD) | ||
| Sex | |||
| Female | 124 | (48,6) | |
| Male | 131 | (51,4) | |
| Lineage | |||
| ALL-B | 242 | (94,9) | |
| ALL-T | 12 | (4,7) | |
| Ambiguous lineage | 1 | (0,4) | |
| BCR::ABL Fusión | 159 | (100) | |
| Negative | 137 | (86,2) | |
| Positive | 22 | (13,8) | |
| KMT2A rearrangement | 70 | (100) | |
| Negative | 64 | (91,4) | |
| Positive | 6 | (8,6) | |
| CNS infiltration | 219 | (100) | |
| No | 159 | (72,2) | |
| Yes | 60 | (27,3) | |
| Risk stratification | 254 | (100) | |
| Standard | 62 | (24,4) | |
| High | 192 | (75,6) | |
| Therapy with asparaginase | 234 | (100) | |
| No | 54 | (21,2) | |
| Yes | 180 | (70,6) |
SD Standard deviation; ALL Acute lymphoblastic leukemia; CNS central nervous system.
Figure 1. Kaplan Meier curve of ALL patients with intensive chemotherapy according at-risk group. Overall survival at 5 years of the high risk group was 23.4% and of the standard risk group was 16.9%.
Keywords: Treatment-related mortality, Survival, Acute lymphoblastic leukemia, Mortality