Gut microbiome in association with chemotherapy-induced toxicities among patients with breast cancer.

BACKGROUND: Little research has focused on the relationship between gut microbiome and chemotherapy-induced toxicity. METHODS: This prospective study involves 301 patients with breast cancer who had prechemotherapy stool samples collected. Gut microbiome was sequenced by shotgun metagenomics; associations with chemotherapy-induced toxicities during first-line treatment by gut microbial diversity, composition, and metabolic pathways with severe (i.e., grade ≥3) hematological and gastrointestinal toxicities were evaluated via multivariable logistic regression. RESULTS: High prechemotherapy α-diversity was associated with a significantly reduced risk of both severe hematological toxicity (odds ratio [OR] = 0.94; 95% CI, 0.89-0.99; p = .048) and neutropenia (OR = 0.94; 95% CI, 0.89-0.99; p = .016). A high abundance of phylum Synergistota, class Synergistia, and order Synergistales were significantly associated with a reduced risk of severe neutropenia; conversely, enrichment of phylum Firmicutes C, class Negativicutes, phylum Firmicutes I, and class Bacilli A, order Paenibacillales were significantly associated with an increased risk of severe neutropenia (p range: 0.012-2.32 × 10-3; false discovery rate <0.1). Significant positive associations were also observed between severe nausea/vomiting and high Chao1 indexes, ß-diversity (p < .05), 20 species belonging to the family Lachnospiraceae, Oscillospiraceae, and Ruminococcaceae (p value range: 6.14 × 10-3 to 1.33 × 10-5; false discovery rate <0.1), and three metabolic pathways involved in reductive tricarboxylic acid cycle I and cycle II, and an incomplete reductive tricarboxylic acid cycle (p < .01). Conversely, a high abundance of species Odoribacter laneus and the pathway related to the L-proline biosynthesis II were inversely associated with severe nausea/vomiting. CONCLUSIONS: Our study suggests that gut microbiota may be a potential preventive target to reduce chemotherapy-induced toxicity.

Gut Microbiome of Patients With Breast Cancer in Vietnam.

PURPOSE: Gut microbiota play an important role in human health, including cancer. Cancer and its treatment, in turn, may alter the gut microbiome. To understand this complex relationship, we profiled the gut microbiome of 356 Vietnamese patients with breast cancer. MATERIALS AND METHODS: Stool samples were collected before chemotherapy, with 162 pre- and 194 postsurgery. The gut microbiome was measured by shotgun metagenomic sequencing. Associations of gut microbial diversity, taxa abundance, and gut microbiome health index (GMHI) with sociodemographic, clinical factors, and tumor characteristics were evaluated. RESULTS: Postsurgery samples were associated with significantly lower α- and ß-diversities (P < .001) and showed significant differences in the abundance of 15% of 2,864 investigated taxa (false discovery rate [FDR] <0.1) compared with presurgery samples. An unhealthy gut microbiome was prevalent among patients with breast cancer, with a mean GMHI of -0.79 and -2.81 in pre- and postsurgery stool samples, respectively. In an analysis of 162 presurgery stool samples, diagnosis delay was significantly associated with lower α-diversity, variation in ß-diversity, an increased abundance of species Enorma massiliensis, and a decreased abundance of Faecalicoccus pleomorphus. High intake of fiber was significantly associated with lower α-diversity and a higher abundance of species belonging to Bifidobacterium, Prevotella, and Bacteroides gena (FDR < 0.1). We did not find that cancer stage and subtype, menopausal status, comorbidity, antibiotic use during 3 months before stool collection, or physical activity was significantly associated with α- and ß-diversities or GMHI although a few significant differences were observed in taxa abundance. CONCLUSION: Our study revealed that diagnosis delay, high fiber intake, and breast cancer surgery, which is always followed by antibiotic prophylaxis in Vietnam, led to a less diverse and unhealthy gut microbiome among patients with breast cancer.

Chemotherapy-Induced Toxicities and Their Associations with Clinical and Non-Clinical Factors among Breast Cancer Patients in Vietnam.

Understanding the burden and factors related to chemotherapy-induced toxicity is important in treatment planning for breast cancer patients. We conducted a prospective study among 396 newly diagnosed and chemotherapy-treated breast cancer patients recruited in two major cancer hospitals in northern Vietnam. Toxicities were captured through medical chart reviews and patient self-reports and graded using NCI CTCAE classification. Associations for sociodemographic and clinical factors with chemotherapy-induced toxicities during first-line chemotherapy were evaluated via multivariable logistic regression. Severe (i.e., grade ≥ 3) hematological (38.6%), and gastrointestinal (12.9%) toxicities were common. A pre-existing nephrological condition was significantly associated with the risk of severe hematological toxicity with adjusted odds ratios (OR) and 95% confidence intervals (CIs) of 2.30 (1.32-4.01). Patients living in rural areas had a lower risk of severe hematological toxicity (OR = 0.48; 95% CI, 0.30-0.77). Patients diagnosed with stage II and stage III-IV had a lower risk of severe gastrointestinal toxicity with ORs and 95% CIs of 0.26 (0.12-0.59) and 0.47 (0.20-1.10), respectively. Triple-negative/basal-like subtype was associated with a higher risk of severe hematological (OR = 3.15; 95% CI, 1.56-6.34) and gastrointestinal toxicities (OR = 3.60; 95% CI, 1.45-8.95) comparing to hormone receptor (HR)-positive HER2-negative subtype. Further research investigating underlying mechanisms would facilitate the development and delivery of personalized treatment and care plans.

Racial/Ethnic Disparities in Mortality Related to Access to Care for Major Cancers in the United States.

Importance: The reasons underlying racial/ethnic mortality disparities for cancer patients remain poorly understood, especially regarding the role of access to care. Participants: Over five million patients with a primary diagnosis of lung, breast, prostate, colon/rectum, pancreas, ovary, or liver cancer during 2004-2014, were identified from the National Cancer Database. Cox proportional hazards models were applied to estimate hazard ratios (HR) and 95% confidence intervals (CI) for total mortality associated with race/ethnicity, and access to care related factors (i.e., socioeconomic status [SES], insurance, treating facility, and residential type) for each cancer. Results: Racial/ethnic disparities in total mortality were observed across seven cancers. Compared with non-Hispanic (NH)-white patients, NH-black patients with breast (HR = 1.27, 95% CI: 1.26 to 1.29), ovarian (HR = 1.20, 95% CI: 1.17 to 1.23), prostate (HR = 1.31, 95% CI: 1.30 to 1.33), colorectal (HR = 1.11, 95% CI: 1.10 to 1.12) or pancreatic (HR = 1.03, 95% CI: 1.02 to 1.05) cancers had significantly elevated mortality, while Asians (13-31%) and Hispanics (13-19%) had lower mortality for all cancers. Racial/ethnic disparities were observed across all strata of access to care related factors and modified by those factors. NH-black and NH-white disparities were most evident among patients with high SES or those with private insurance, while Hispanic/Asian versus NH-white disparities were more evident among patients with low SES or those with no/poor insurance. Conclusions and Relevance: Racial/ethnic mortality disparities for major cancers exist across all patient groups with different access to care levels. The influence of SES or insurance on mortality disparity follows different patterns for racial/ethnic minorities versus NH-whites. Impact: Our study highlights the need for racial/ethnic-specific strategies to reduce the mortality disparities for major cancers.

Association of Fruit, Vegetable, and Animal Food Intakes with Breast Cancer Risk Overall and by Molecular Subtype among Vietnamese Women.

BACKGROUND: Evidence on associations between dietary intake and risk of breast cancer subtypes is limited and inconsistent. We evaluated associations of fruit, vegetable, meat, and fish consumption with risk of breast cancer overall and by molecular subtype in the Vietnamese Breast Cancer Study (VBCS). METHOD: VBCS includes 476 incident breast cancer cases and 454 age-matched controls. Dietary habits over the past 5 years were assessed by in-person interviews using a validated food frequency questionnaire. Associations of food groups with breast cancer were evaluated via logistic regression for overall and molecular subtype with adjustment for age, education, income, family history of cancer, menopausal status, body mass index, exercise, total energy intake, and other potential dietary confounders. Odds ratio (OR) was used to approximate relative risk. RESULTS: High fruit intake was inversely associated with breast cancer risk, with adjusted ORs [95% confidence intervals (CI)] of 0.67 (95% CI, 0.47-0.95) and 0.41 (95% CI, 0.27-0.61) for second and third tertiles versus first tertile, respectively (Ptrend < 0.001). This association was stronger for triple-negative than other subtypes (Pheterogeneity < 0.001). High intake of freshwater fish was inversely associated with overall breast cancer (ORT3vsT1 = 0.63; 95% CI, 0.42-0.95; Ptrend = 0.03). An inverse association was observed between HER2-enriched subtype and red and organ meat intake (ORT3vsT1 = 0.40; 95% CI, 0.17-0.93; Ptrend = 0.04; Pheterogeneity = 0.50). CONCLUSIONS: High intakes of fruit and freshwater fish were associated with reduced breast cancer risk; association for the former was stronger for triple-negative subtype. IMPACT: Our findings suggest high intakes of fruit and freshwater fish may reduce breast cancer risk among Vietnamese women.

HIV and STI prevalence and testing history among men who have sex with men in Hanoi, Vietnam.

BACKGROUND: HIV and other sexually transmitted infections (STIs) have disproportionately affected communities of men who have sex with men (MSM). We describe HIV and STI prevalence and testing patterns among urban Vietnamese MSM. METHODS: We conducted a cross-sectional community-based study of MSM in Hanoi, Vietnam in 2016. Participants self-reported experiences of social stigma in healthcare settings and previous HIV and STI testing. STI testing included HIV, herpes simplex virus-2 (HSV-2), syphilis, gonorrhea, and chlamydia. RESULTS: 205 MSM participated in the study. STI prevalence was HIV (10%), HSV-2 (4%), syphilis (13%), gonorrhea (34%), and chlamydia (19%). More than half (55%) of participants tested positive for at least one STI. Most participants had been previously tested for HIV or another STI (72%), with 24% previously receiving a positive result. Perceived and enacted social stigma in healthcare contexts was negatively associated with previous HIV or STI testing (adjusted prevalence odds ratio (aPOR): 0.22; 95% confidence interval (CI): 0.10-0.48). DISCUSSION: High prevalence of STIs was observed among Vietnamese MSM, and perceived and enacted stigma was related to HIV and STI testing. Our findings reaffirm the importance of regular STI screening among this population as well as additional outreach to promote safe HIV and STI healthcare engagement.

Delay in the diagnosis and treatment of breast cancer in Vietnam.

BACKGROUND: Delays in diagnosis and treatment from first noticeable breast cancer symptoms are associated with poor outcomes. Understanding the reasons and barriers for patients' delay in seeking medical care is critical to mitigating the problem. METHODS: In-person surveys were conducted among 462 women, aged 18-79, with incident breast cancer cases, recruited from two cancer hospitals in North Vietnam. Delay, defined as the time interval between symptom recognition to the diagnosis and initiation of treatment equal to or exceeding 3 months, was categorized as follows: no delay (<3 months), moderate delay (3-8 months), and serious delay (≥9 months). Multivariable multinomial logistic regression was applied in data analyses. RESULTS: Over one-quarter patients (31.5%) experienced moderate delays, and close to one-fifth (17.5%) experienced serious delays. Adjusted odds ratios and 95% confidence intervals for moderate and serious delays were 5.60 (3.00-10.47) and 4.25 (2.05-8.85) for financial and physical barriers, respectively. Moderate delay was positively associated with psychological barriers (5.55 [1.75-17.57]) and lack of proper knowledge (3.15 [1.47-6.74]). The associations of barriers with delays in diagnosis and treatment appeared stronger among women living in rural areas. A lack of proper knowledge was significantly associated with delay among young women (<45 years old) and those with high incomes, while psychological barriers were significantly associated with delay among older women (≥45 years old). CONCLUSION: Delays in diagnosis and treatment are common among Vietnamese breast cancer patients and are affected by several noted barriers. Proper policy needs to be developed to address this public health issue.

Long-term diet quality is associated with gut microbiome diversity and composition among urban Chinese adults.

BACKGROUND: Few population-based studies have evaluated the influence of long-term diet on the gut microbiome, and data among Asian populations are lacking. OBJECTIVE: We examined the association of long-term diet quality, comprising 8 food groups (fruit, vegetables, dairy, fish/seafood, nuts/legumes, refined grains, red meat, and processed meat), with gut microbiome among Chinese adults. METHODS: Included were 1920 men and women, enrolled in 2 prospective cohorts (baseline 1996-2006), who remained free of cardiovascular diseases, diabetes, and cancer at stool collection (2015-2018) and had no diarrhea or antibiotic use in the last 7 d before stool collection. Microbiome was profiled by 16S rRNA sequencing. Long-term diet was assessed by repeated surveys at baseline and follow-ups (1996-2011), with intervals of 5.2 to 20.5 y between dietary surveys and stool collection. Associations of dietary variables with microbiome diversity and composition were evaluated by linear or negative binomial hurdle models, adjusting for potential confounders. False discovery rate (FDR) <0.1 was considered significant. RESULTS: The mean ± SD age at stool collection was 68 ± 1.5 y. Diet quality was positively associated with microbiome α-diversity (P = 0.03) and abundance of Firmicutes, Actinobacteria, Tenericutes, and genera/species within these phyla, including Coprococcus, Faecalibacterium/Faecalibacterium prausnitzii, Bifidobacterium / Bifidobacterium adolescentis, and order RF39 (all FDRs <0.1). Significant associations were also observed for intakes of dairy, fish/seafood, nuts/legumes, refined grains, and processed meat, including a positive association of dairy with Bifidobacterium and inverse associations of processed meat with Roseburia /Roseburia faecis. Most associations were similar, with or without adjustment for BMI and hypertension status or excluding participants with antibiotic use in the past 6 mo. CONCLUSION: Among apparently healthy Chinese adults, long-term diet quality is positively associated with fecal microbiome diversity and abundance of fiber-fermenting bacteria, although magnitudes are generally small. Future studies are needed to examine if these bacteria may mediate or modify diet-disease relations.

Tuning the Antigen Density Requirement for CAR T-cell Activity.

Insufficient reactivity against cells with low antigen density has emerged as an important cause of chimeric antigen receptor (CAR) T-cell resistance. Little is known about factors that modulate the threshold for antigen recognition. We demonstrate that CD19 CAR activity is dependent upon antigen density and that the CAR construct in axicabtagene ciloleucel (CD19-CD28ζ) outperforms that in tisagenlecleucel (CD19-4-1BBζ) against antigen-low tumors. Enhancing signal strength by including additional immunoreceptor tyrosine-based activation motifs (ITAM) in the CAR enables recognition of low-antigen-density cells, whereas ITAM deletions blunt signal and increase the antigen density threshold. Furthermore, replacement of the CD8 hinge-transmembrane (H/T) region of a 4-1BBζ CAR with a CD28-H/T lowers the threshold for CAR reactivity despite identical signaling molecules. CARs incorporating a CD28-H/T demonstrate a more stable and efficient immunologic synapse. Precise design of CARs can tune the threshold for antigen recognition and endow 4-1BBζ-CARs with enhanced capacity to recognize antigen-low targets while retaining a superior capacity for persistence. SIGNIFICANCE: Optimal CAR T-cell activity is dependent on antigen density, which is variable in many cancers, including lymphoma and solid tumors. CD28ζ-CARs outperform 4-1BBζ-CARs when antigen density is low. However, 4-1BBζ-CARs can be reengineered to enhance activity against low-antigen-density tumors while maintaining their unique capacity for persistence.This article is highlighted in the In This Issue feature, p. 627.

Modulation of Target Antigen Density Improves CAR T-cell Functionality and Persistence.

PURPOSE: Chimeric antigen receptor T-cell (CART) therapy targeting CD22 induces remission in 70% of patients with relapsed/refractory acute lymphoblastic leukemia (ALL). However, the majority of post-CD22 CART remissions are short and associated with reduction in CD22 expression. We evaluate the implications of low antigen density on the activity of CD22 CART and propose mechanisms to overcome antigen escape. EXPERIMENTAL DESIGN: Using ALL cell lines with variable CD22 expression, we evaluate the cytokine profile, cytotoxicity, and in vivo CART functionality in the setting of low CD22 expression. We develop a high-affinity CD22 chimeric antigen receptor (CAR) as an approach to improve CAR sensitivity. We also assess Bryostatin1, a therapeutically relevant agent, to upregulate CD22 and improve CAR functionality. RESULTS: We demonstrate that low CD22 expression negatively impacts in vitro and in vivo CD22 CART functionality and impairs in vivo CART persistence. Moreover, low antigen expression on leukemic cells increases naïve phenotype of persisting CART. Increasing CAR affinity does not improve response to low-antigen leukemia. Bryostatin1 upregulates CD22 on leukemia and lymphoma cell lines for 1 week following single-dose exposure, and improves CART functionality and in vivo persistence. While Bryostatin1 attenuates IFNγ production by CART, overall in vitro and in vivo CART cytotoxicity is not adversely affected. Finally, administration of Bryostain1 with CD22 CAR results in longer duration of in vivo response. CONCLUSIONS: We demonstrate that target antigen modulation is a promising strategy to improve CD22 CAR efficacy and remission durability in patients with leukemia and lymphoma.See related commentary by Guedan and Delgado, p. 5188.

A prospective "test-and-treat" demonstration project among people who inject drugs in Vietnam.

INTRODUCTION: Modelling suggests that early diagnosis and immediate antiretroviral therapy (ART) among key populations would have a substantial impact in reducing HIV transmission and mortality in Vietnam. An implementation research project of "test-and-treat" among people who inject drugs (PWID) was developed to inform effective roll-out of such interventions. METHODS: "Test-and-treat" was offered to PWID in two high burden provinces, Thai Nguyen and Thanh Hoa. The interventions comprised the offer of biannual HIV testing and immediate ART, irrespective of CD4 count. PWID were enrolled between April 2014 and July 2015 and followed up for 12 months, and retention, HIV viral load (VL) and risk behaviours were assessed. Retention in care of this prospective cohort was compared with the retention among men enrolled in care in the preceding period (April 2012 to March 2013) at the same clinics when ART was initiated at CD4 cell count ≤350 cells/mm3 . RESULTS: In total, 287 HIV positive PWID started immediate ART. The majority (98%) were men; median age was 34; and median (interquartile range) CD4 count was 199 (50 to 402) cells/mm3 . After 12 months, 238 participants (83%) were retained on ART, and 205 achieved viral suppression (<1000 copies/mL) (92% among those in whom VL was measured, 71% overall). Baseline CD4 count ≤100 cells/mm3 and history of imprisonment were associated with lower retention and viral suppression, while engagement in methadone maintenance was associated with higher retention. Retention in care was higher in the "test-and-treat" cohort (83%) compared with men enrolled in care in the preceding period (78%), primarily because lost-to-follow-up during pre-ART care was eliminated. No decline in consistent condom use and clean needle use was observed. CONCLUSIONS: Early ART initiation resulted in successful treatment outcomes among PWID, with no observed increase in self-reported risk behaviours, suggesting feasibility and potential effectiveness of "test-and-treat" approach. The results also call for differentiated care for PWID, including promoting early diagnosis and engagement in methadone maintenance therapy while enhancing care for those with advanced HIV disease and history of imprisonment.

The use of technology to find sexual health information online among men who have sex with men in Hanoi, Vietnam, 2016.

In an era where mobile phones and computers are ubiquitous, technology-based interventions to reduce HIV and other sexually transmitted infections (STIs) have great potential to reach high-risk groups, including men who have sex with men (MSM). This study aimed to examine technology usage to find sexual health information online among MSM in Hanoi, Vietnam. A cross-sectional study of 205 MSM in Hanoi was conducted from February to May 2016. Overall, 50.7% of participants reported having used a smartphone, computer, or tablet to find HIV/STI testing locations in the past year, and 75.1% reported having used such devices to find other HIV/STI information online. Unemployment (adjusted prevalence ratio [aPR]: 1.13, 95%CI: 1.00-1.28) and having been tested for HIV (aPR: 1.27, 95%CI: 1.07-1.51) were significantly associated with using technology to find online sexual health information. MSM who had ever exchanged sex for money or drugs (aPR: 0.80; 95%CI: 0.68-0.94) were less likely to use technology to find sexual health information online. Technology is a promising platform for HIV/STI prevention programs among MSM, with the potential to reach different subgroups. Further efforts to develop technology-based interventions tailored to the needs of the MSM communities in Hanoi and to encourage MSM who were not currently seeking sexual health information and testing services online to do so are necessary.

Tumor Antigen and Receptor Densities Regulate Efficacy of a Chimeric Antigen Receptor Targeting Anaplastic Lymphoma Kinase.

We explored the utility of targeting anaplastic lymphoma kinase (ALK), a cell surface receptor overexpressed on pediatric solid tumors, using chimeric antigen receptor (CAR)-based immunotherapy. T cells expressing a CAR incorporating the single-chain variable fragment sequence of the ALK48 mAb linked to a 4-1BB-CD3ζ signaling domain lysed ALK-expressing tumor lines and produced interferon-gamma upon antigen stimulation but had limited anti-tumor efficacy in two xenograft models of human neuroblastoma. Further exploration demonstrated that cytokine production was highly dependent upon ALK target density and that target density of ALK on neuroblastoma cell lines was insufficient for maximal activation of CAR T cells. In addition, ALK CAR T cells demonstrated rapid and complete antigen-induced loss of receptor from the T cell surface via internalization. Using a model that simultaneously modulated antigen density and CAR expression, we demonstrated that CAR functionality is regulated by target antigen and CAR density and that low expression of either contributes to limited anti-tumor efficacy of the ALK CAR. These data suggest that stoichiometric relationships between CAR receptors and target antigens may significantly impact the anti-tumor efficacy of CAR T cells and that manipulation of these parameters could allow precise tuning of CAR T cell activity.

CD19 CAR immune pressure induces B-precursor acute lymphoblastic leukaemia lineage switch exposing inherent leukaemic plasticity.

Adoptive immunotherapy using chimeric antigen receptor (CAR) expressing T cells targeting the CD19 B lineage receptor has demonstrated marked success in relapsed pre-B-cell acute lymphoblastic leukaemia (ALL). Persisting CAR-T cells generate sustained pressure against CD19 that may drive unique mechanisms of resistance. Pre-B ALL originates from a committed pre-B cell or an earlier progenitor, with potential to reprogram into other hematopoietic lineages. Here we report changes in lineage markers including myeloid conversion in patients following CD19 CAR therapy. Using murine ALL models we study the long-term effects of CD19 CAR-T cells and demonstrate partial or complete lineage switch as a consistent mechanism of CAR resistance depending on the underlying genetic oncogenic driver. Deletion of Pax5 or Ebf1 recapitulates lineage reprogramming occurring during CD19 CAR pressure. Our findings establish lineage switch as a mechanism of CAR resistance exposing inherent plasticity in genetic subtypes of pre-B-cell ALL.