Phase Angle and Body Composition As a Prognostic Factor in Acute Lymphoblastic Leukemia

Acute lymphoblastic leukaemia (ALL) is a malignant proliferation of lymphoid cells blocked at an early stage of differentiation that can invade bone marrow, blood, and extramedullary sites. Age specific incidence is highest in children aged 1-4 years, then drops sharply through childhood (5-14 years), adolescence and young adulthood (AYA) (15-39 years), reaching the lowest point between 25 years and 45 years.

Bioelectrical impedance analysis (BIA) is a method used to estimate body composition and cell membrane integrity. BIA is a useful tool as it is non-invasive, relatively inexpensive, can be performed on nearly any patient, does not expose the patient to ionizing radiation, is painless, and has both high intra and inter observer precision (coefficient of variation = 2.7%-4.0%). Phase angle (PhA) is obtained by BIA and is associated with cellular function. It is considered a reliable marker of malnutrition. PhA has been shown to predict survival in solid malignancies and hematopoietic stem cell transplant patients.

To date, no studies have evaluated the usage of PhA in ALL patients. Therefore, this retrospective study sought to establish the prognostic significance of baseline PhA and lean mass index on OS and LFS in newly diagnosed ALL patients receiving intensive chemotherapy.

Retrospective, cross-section, observational and descriptive study. The records of patients who received intensive chemotherapy from January 2019 to January 2023 were reviewed.

Statistical analysis

The qualitative variables were studied in frequencies and proportions, the quantitative variables were grouped into medians and ranges. OS and LFS were determined using Kaplan-Meier survival curves with log-Rank with a significant p <0.05 value. Statistical analysis was performed with SPSS version 25 and GraphPad Prism version 9.5.0.

Results

85 patients were included, 56.7% (48) men and 43.5% (37) women. 79 patients with ALL-B and 6 patients ALL-T. The mean age was 25 years. 68 were AYA population and 17 not-AYA. The CR was 89%, ND MRD was 57%. The chemotherapy for AYA was CALGB 10403, and not AYA was Hyper-CVAD. Relapse was documented in 38%. The mean body mass index was 26.98±5.27 kg/m ². The mean PhA was 4.547±0.9983°. The mean lean mass index was 17.8 (12.9-35.5) kg/m ². The mean fat mass index was 9.195±4.425 kg/m ². The mean OS was 86% at 1 year and OS at 3 years was 64.5%.

The results that were statistically significant in LFS compared by Kaplan Meier curves were: male vs female p=0.0344, PhA >4, p=0.0235, lean mass index ≥16, p=0.0111.

Conclusions

In conclusion, our findings suggest that in newly diagnosed ALL patients undergoing intensive induction chemotherapy, PhA may provide important prognostic information for LFS and OS. PhA is an objective, repeatable, high-precision measure in ALL patients and, unlike other prognostic factors in this population, is potentially subject to intervention. Future studies of PhA in ALL patients should address the content validity of phase angle while further exploring the promising findings of the effect of strength training and nutritional supplementation on PhA and patient outcomes.