Examining the efficacy of treatments for arm lymphedema in breast cancer survivors: an overview of systematic reviews with meta-analyses

Background

Lymphedema affects one in six breast cancer survivors making it a global healthcare challenge. There is considerable debate about the efficacy of different treatments for lymphedema. We aimed to summarize the current evidence for treatments for lymphedema in breast cancer survivors.

Methods

In this overview of systematic reviews with meta-analyses (SRMAs), five databases were searched for SRMAs of randomised controlled trials (RCTs) reporting effects of medications, surgery, exercise, laser therapy, acupuncture, kinesio taping, or complex decongestive physiotherapy (CDP) for breast cancer-related lymphedema published from database inception up to March 7, 2023. Data extraction was performed for the SRMAs and RCTs, and SRMAs were appraised with AMSTAR2. Random effects meta-analyses of the RCTs provided estimates of the pooled effects sizes (Hedges' g) for each treatment modality. This study is registered with PROSPERO, CRD42020184813.

Findings

1569 studies were identified by the search and eighteen SRMAs with 51 RCTs were included, investigating manual lymphatic drainage (MLD), compression pump, exercise, kinesio taping, laser, and acupuncture. Overall, the methodological quality of the SRMAs was low. SRMAs reached different conclusions for all treatment modalities, except for kinesio taping where the two SRMAs found no effect. The analysis of 40 RCTs with 1970 participants revealed a small effect across all interventions compared to any control (g = 0.20, p = 0.047, I2 = 0.79), corresponding to volume reductions of 119.7 ml (95% CI 135-104) and 88.0 ml (95% CI 99-77) in the intervention and control groups, respectively, and a small effect of exercise (g = 0.26, p = 0.022, I2 = 0.44). The between-group differences in volume reduction were small and did not reach statistical significance for any one treatment modality.

Interpretation

Based on the available data, there is no evidence of superiority of any one treatment on volume reduction nor any solid research refuting these treatments. Thus, definitive conclusions to inform clinical practice about the efficacy of these treatments cannot be drawn. Due to poor-quality evidence, more research is needed to untangle the efficacy of each treatment component for different stages of lymphedema.

Funding

Danish Cancer Society.

GCN5 acetylates and regulates the stability of the oncoprotein E2A-PBX1 in acute lymphoblastic leukemia

The t(1;19) translocation in pediatric pre-B-cell acute lymphoblastic leukemia (ALL) fuses the genes, which encode the transcriptional activator E2A and homeobox pre-B-cell leukemia transcription factor 1 (PBX1), resulting in expression of the chimeric transcription factor E2A-PBX1. E2A-PBX1 can promote cell transformation both in vitro and in vivo; however, the mechanisms by which E2A-PBX1 contributes to malignancy merit further investigation. In the current work we report, for the first time, a physical and functional interaction between the SPT3-TAFII31-GCN5L acetylase (STAGA) complex and E2A-PBX1. STAGA, and its acetyltransferase subunit GCN5, directly interacted with the E2A portion of E2A-PBX1. GCN5 acetylated E2A-PBX1 and increased the stability of E2A-PBX1 protein in cells. Moreover, the GCN5 inhibitor α-methylene-γ-butyrolactone 3 (MB-3) decreased E2A-PBX1 acetylation and E2A-PBX1 protein levels in leukemic cells, indicating that GCN5 inhibitors have potential value as therapeutic agents for ALL. In addition, we show that the E3 ubiquitin ligase HDM2 potentiates the degradation of E2A-PBX1. We suggest that dynamic regulation of E2A-PBX1 protein levels in vivo has a fundamental role in ALL.

Development of cellular absorptive tracers for quantitative characterization of microbial mass in flow systems

We report a new cellular absorptive tracer (CAT) method for simple, nondestructive characterization of bacterial mass in flow systems. Results show that adsorption of a CAT molecule into the cellular mass results in its slowdown during flow, which is an accurate quantitative measurement of biomass quantity and distribution. No such methods are currently available for quantitative characterization of cell mass.