eHealth supported multi-months dispensing of antiretroviral therapy: a mixed-methods preference assessment in rural Lesotho.

BACKGROUND: Multi-month dispensing (MMD) of antiretroviral therapy (ART) represents one approach of differentiated service delivery (DSD) aiming to improve quality and cost-effectiveness for HIV services in resource-limited settings. However, reduction in clinic visits for people living with HIV (PLWH) should go along with out-of-clinic care tailored to PLWH`s preferences and comorbidities to maintain quality of care. eHealth supported MMD offers a potential solution. METHODS: Between October 2019 and January 2020 we assessed preferences on an eHealth supported MMD package among adult PLWH attending routine ART care at a rural clinic in Lesotho using a mixed-methods approach. Participants reported their preferences among different refill and eHealth options. They were invited to test automated text messages (SMS) informing about their viral load results, an automated tuberculosis symptoms screening call and telemedical support by an expert nurse. Telemedical service comprised a call-back option if participants required any additional support and adherence counselling for closer follow-up of participants with unsuppressed viral loads. After 6 weeks, participants were followed-up to assess perception of the chosen eHealth support using a qualitative approach. RESULTS: Among 112 participants (median age = 43 years; 74% female), 83/112 (75%) preferred MMD for 6-12 months (median = 9 months, IQR = [5, 12]). Neither sex, age, employment, costs and time for travel to clinic, nor the duration of taking ART correlated with the MMD preference. All 17 participants attending routine viral load measurement wished to receive the result via SMS. Fifteen (19.2%) participants requested a telemedical nurse call-back during the study period. All participants with recent unsuppressed viral load (N = 13) requested telemedical adherence counselling for closer follow-up. Among 78 participants followed-up, 76 (97%) would appreciate having the call-back option in future. Seventy-five participants (67%) received and evaluated the automated symptomatic tuberculosis screening call, overall 71 (95%) appreciated it. CONCLUSIONS: The great majority of PLWH in this study preferred 6-12 months MMD and appreciated the additional eHealth support, including viral load results via SMS, telemedical nurse consultations and automated tuberculosis symptom screening calls. eHealth supported MMD packages appear to be a promising approach for DSD models and should be assessed for clinical endpoints and cost-effectiveness in larger studies.

An In Vivo CRISPR Screen Identifies Stepwise Genetic Dependencies of Metastatic Progression.

Blood-borne metastasis of breast cancer involves a series of tightly regulated sequential steps, including the growth of a primary tumor lesion, intravasation of circulating tumor cells (CTC), and adaptation in various distant metastatic sites. The genes orchestrating each of these steps are poorly understood in physiologically relevant contexts, owing to the rarity of experimental models that faithfully recapitulate the biology, growth kinetics, and tropism of human breast cancer. Here, we conducted an in vivo loss-of-function CRISPR screen in newly derived CTC xenografts, unique in their ability to spontaneously mirror the human disease, and identified specific genetic dependencies for each step of the metastatic process. Validation experiments revealed sensitivities to inhibitors that are already available, such as PLK1 inhibitors, to prevent CTC intravasation. Together, these findings present a new tool to reclassify driver genes involved in the spread of human cancer, providing insights into the biology of metastasis and paving the way to test targeted treatment approaches. SIGNIFICANCE: A loss-of-function CRISPR screen in human CTC-derived xenografts identifies genes critical for individual steps of the metastatic cascade, suggesting novel drivers and treatment opportunities for metastatic breast cancers.

Hypoxia Triggers the Intravasation of Clustered Circulating Tumor Cells.

Circulating tumor cells (CTCs) are shed from solid cancers in the form of single or clustered cells, and the latter display an extraordinary ability to initiate metastasis. Yet, the biological phenomena that trigger the shedding of CTC clusters from a primary cancerous lesion are poorly understood. Here, when dynamically labeling breast cancer cells along cancer progression, we observe that the majority of CTC clusters are undergoing hypoxia, while single CTCs are largely normoxic. Strikingly, we find that vascular endothelial growth factor (VEGF) targeting leads to primary tumor shrinkage, but it increases intra-tumor hypoxia, resulting in a higher CTC cluster shedding rate and metastasis formation. Conversely, pro-angiogenic treatment increases primary tumor size, yet it dramatically suppresses the formation of CTC clusters and metastasis. Thus, intra-tumor hypoxia leads to the formation of clustered CTCs with high metastatic ability, and a pro-angiogenic therapy suppresses metastasis formation through prevention of CTC cluster generation.

PEBRA trial - effect of a peer-educator coordinated preference-based ART service delivery model on viral suppression among adolescents and young adults living with HIV: protocol of a cluster-randomized clinical trial in rural Lesotho.

BACKGROUND: Despite tremendous progress in controlling the HIV epidemic in sub-Saharan Africa, HIV-related mortality continues to increase among adolescents and young people living with HIV (AYPLHIV). Globally, sub-Saharan Africa accounts for 85% of the AYPLHIV. Overall outcomes along the HIV care cascade are worse among AYPLHIV as compared to all other age groups due to various challenges in accessing and adhering to antiretroviral therapy (ART). New, innovative multicomponent packages of differentiated service delivery (DSD) models, are required to address the specific needs of AYPLHIV. This study aims to evaluate the feasibility and effectiveness of a multicomponent DSD model (PEBRA model) designed for AYPLHIV and coordinated by a peer-educator. METHODS: PEBRA (Peer-Educator Based Refill of ART) is a cluster randomized, open-label, superiority trial conducted at 20 health facilities in three districts of Lesotho, Southern Africa. The clusters (health facilities) are randomly assigned to either the PEBRA model or standard of care in a 1:1 ratio, stratified by district. AYPLHIV aged 15-24 years old in care and on ART at one of the clusters are eligible. In the PEBRA model, a peer-educator coordinates the antiretroviral therapy (ART) services - such as medication pick-up, SMS notifications and support options - according to the preferences of the AYPLHIV. The peer-educator delivers this personalized model using a tablet-based application called PEBRApp. The control clusters continue to offer standard of care: ART services coordinated by the nurse. The primary endpoint is viral suppression at 12 months. Secondary endpoints include self-reported adherence to ART, quality of life, satisfaction with care and engagement in care. The target sample size is 300 AYPLHIV. Statistical analyses are conducted and reported in line with CONSORT guidelines for cluster randomized trials. DISCUSSION: The PEBRA trial will provide evidence on the feasibility and effectiveness of an inclusive, holistic and preference-based DSD model for AYPLHIV that is coordinated by a peer-educator. Many countries in SSA have an existing peer-educator program. If proven effective, the PEBRA model and PEBRApp have the potential to be scaled up to similar settings. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03969030. Registered on 31 May 2019. More information: www.pebra.info.

Neutrophils escort circulating tumour cells to enable cell cycle progression.

A better understanding of the features that define the interaction between cancer cells and immune cells is important for the development of new cancer therapies1. However, focus is often given to interactions that occur within the primary tumour and its microenvironment, whereas the role of immune cells during cancer dissemination in patients remains largely uncharacterized2,3. Circulating tumour cells (CTCs) are precursors of metastasis in several types of cancer4-6, and are occasionally found within the bloodstream in association with non-malignant cells such as white blood cells (WBCs)7,8. The identity and function of these CTC-associated WBCs, as well as the molecular features that define the interaction between WBCs and CTCs, are unknown. Here we isolate and characterize individual CTC-associated WBCs, as well as corresponding cancer cells within each CTC-WBC cluster, from patients with breast cancer and from mouse models. We use single-cell RNA sequencing to show that in the majority of these cases, CTCs were associated with neutrophils. When comparing the transcriptome profiles of CTCs associated with neutrophils against those of CTCs alone, we detect a number of differentially expressed genes that outline cell cycle progression, leading to more efficient metastasis formation. Further, we identify cell-cell junction and cytokine-receptor pairs that define CTC-neutrophil clusters, representing key vulnerabilities of the metastatic process. Thus, the association between neutrophils and CTCs drives cell cycle progression within the bloodstream and expands the metastatic potential of CTCs, providing a rationale for targeting this interaction in treatment of breast cancer.

Circulating Tumor Cell Clustering Shapes DNA Methylation to Enable Metastasis Seeding.

The ability of circulating tumor cells (CTCs) to form clusters has been linked to increased metastatic potential. Yet biological features and vulnerabilities of CTC clusters remain largely unknown. Here, we profile the DNA methylation landscape of single CTCs and CTC clusters from breast cancer patients and mouse models on a genome-wide scale. We find that binding sites for stemness- and proliferation-associated transcription factors are specifically hypomethylated in CTC clusters, including binding sites for OCT4, NANOG, SOX2, and SIN3A, paralleling embryonic stem cell biology. Among 2,486 FDA-approved compounds, we identify Na+/K+ ATPase inhibitors that enable the dissociation of CTC clusters into single cells, leading to DNA methylation remodeling at critical sites and metastasis suppression. Thus, our results link CTC clustering to specific changes in DNA methylation that promote stemness and metastasis and point to cluster-targeting compounds to suppress the spread of cancer.

Denosumab treatment is associated with the absence of circulating tumor cells in patients with breast cancer.

BACKGROUND: The presence of circulating tumor cells (CTCs) in patients with breast cancer correlates to a bad prognosis. Yet, CTCs are detectable in only a minority of patients with progressive breast cancer, and factors that influence the abundance of CTCs remain elusive. METHODS: We conducted CTC isolation and enumeration in a selected group of 73 consecutive patients characterized by progressive invasive breast cancer, high tumor load and treatment discontinuation at the time of CTC isolation. CTCs were quantified with the Parsortix microfluidic device. Clinicopathological variables, blood counts at the time of CTC isolation and detailed treatment history prior to blood sampling were evaluated for each patient. RESULTS: Among 73 patients, we detected at least one CTC per 7.5 ml of blood in 34 (46%). Of these, 22 (65%) had single CTCs only, whereas 12 (35%) featured both single CTCs and CTC clusters. Treatment with the monoclonal antibody denosumab correlated with the absence of CTCs, both when considering all patients and when considering only those with bone metastasis. We also found that low red blood cell count was associated with the presence of CTCs, whereas high CA 15-3 tumor marker, high mean corpuscular volume, high white blood cell count and high mean platelet volume associated specifically with CTC clusters. CONCLUSIONS: In addition to blood count correlatives to single and clustered CTCs, we found that denosumab treatment associates with most patients lacking CTCs from their peripheral circulation. Prospective studies will be needed to validate the involvement of denosumab in the prevention of CTC generation.

Detection of circulating tumour cell clusters in human glioblastoma.

Human glioblastoma (GBM) is a highly aggressive, invasive and hypervascularised malignant brain cancer. Individual circulating tumour cells (CTCs) are sporadically found in GBM patients, yet it is unclear whether multicellular CTC clusters are generated in this disease and whether they can bypass the physical hurdle of the blood-brain barrier.  Here, we assessed CTC presence and composition at multiple time points in 13 patients with progressing GBM during an open-label phase 1/2a study with the microtubule inhibitor BAL101553. We observe CTC clusters ranging from 2 to 23 cells and present at multiple sampling time points in a GBM patient with pleomorphism and extensive necrosis, throughout disease progression. Exome sequencing of GBM CTC clusters highlights variants in 58 cancer-associated genes including ATM, PMS2, POLE, APC, XPO1, TFRC, JAK2, ERBB4 and ALK. Together, our findings represent the first evidence of the presence of CTC clusters in GBM.