Response to Dabrafenib Plus Trametinib in a Patient With an Uncommon Activating BRAF Mutation: A First in Non-Small Cell Lung Cancer.

Mutations in BRAF are present in 4% of non-small cell lung cancer (NSCLC), of which half are well-characterized activating variants affecting codon 600 (classified as class I). These mutations, most commonly BRAF V600E, have been associated with response to BRAF/MEK-directed small molecule kinase inhibitors. NSCLC with kinase-activating BRAF mutations occurring at other codons (class II variants) represent a substantial portion of BRAF-mutated NSCLC, but use of targeted therapy in these tumors is still under investigation. Class II mutations have been described in other tumor types and have been associated with response to BRAF/MEK-targeted agents, although optimal treatment strategies for these patients are lacking. This report presents a case of a woman with metastatic NSCLC harboring a class II BRAF p.N486_P490del variant who had a sustained clinical response to combination therapy with dabrafenib and trametinib. This first report of the use of BRAF/MEK-targeted therapy for this variant in NSCLC supports consideration of such treatment for tumors with class II BRAF variants.

Consolidation Osimertinib Versus Durvalumab Versus Observation After Concurrent Chemoradiation in Unresectable EGFR-Mutant NSCLC: A Multicenter Retrospective Cohort Study.

INTRODUCTION: Durvalumab improves survival when used as consolidation therapy after chemoradiation (CRT) in patients with stage III NSCLC. The optimal consolidation therapy for patients with EGFR-mutant (EGFRmut) stage III NSCLC remains unknown. METHODS: In this multi-institutional, international retrospective analysis across 24 institutions, we evaluated outcomes in patients with stage III EGFRmut NSCLC treated with concurrent CRT followed by consolidation therapy with osimertinib, durvalumab, or observation between 2015 and 2022. Kaplan-Meier method was used to estimate real-world progression-free survival (rwPFS, primary end point) and overall survival (secondary end point). Treatment-related adverse events (trAEs) during consolidation treatment were defined using Common Terminology Criteria for Adverse Events version 5.0. Multivariable Cox regression analysis was used. RESULTS: Of 136 patients with stage III EGFRmut NSCLC treated with definitive concurrent CRT, 56 received consolidation durvalumab, 33 received consolidation osimertinib, and 47 was on observation alone. Baseline characteristics were similar across the three cohorts. With a median follow-up of 46 months for the entire cohort, the median duration of treatment was not reached (NR) for osimertinib (interquartile range: NR-NR) and was 5.5 (interquartile range: 2.4-10.8) months with durvalumab. After adjusting for nodal status, stage III A/B/C, and age, patients treated with consolidation osimertinib had significantly longer 24-month rwPFS compared to those treated with durvalumab or in the observation cohorts (osimertinib: 86%, durvalumab: 30%, observation: 27%, p < 0.001 for both comparisons). There was no difference in rwPFS between the durvalumab and the observation cohorts. No significant difference in overall survival across the three cohorts was detected, likely due to the limited follow-up. Any-grade trAE occurred in 52% (2 [6.1%] grade ≥3) and 48% (10 [18%] grade ≥3) of patients treated with osimertinib and durvalumab, respectively. Of 45 patients who progressed on consolidation durvalumab, 37 (82%) subsequently received EGFR tyrosine kinase inhibitors. Of these, 14 (38%) patients developed trAEs including five patients with pneumonitis (14%; 2 [5.4%] grade ≥3) and five patients with diarrhea (14%; 1 [2.7%] grade ≥3). CONCLUSIONS: This study suggests that among patients with stage III unresectable NSCLC with a sensitizing EGFR mutation, consolidation osimertinib was associated with a significantly longer rwPFS compared to durvalumab or observation. No unanticipated safety signals were observed with consolidation osimertinib.

Benign Pneumatosis Intestinalis: A Case Report and Review of the Literature.

Background: Pneumatosis intestinalis is the presence of gas within the walls of the intestine on imaging and has variable clinical significance, ranging from an incidental finding to a harbinger of intra-abdominal catastrophe. There are multiple mechanisms by which this radiographic finding develops, including bacterial gas production, increased intraluminal pressure within the gastrointestinal tract, mechanical disruption of the gut mucosa, and tracking of pulmonary gas along the mesenteric vasculature. Case Presentation: We present the case of a 61-year-old male veteran who had sustained a remote anoxic brain injury resulting in chronic dependence on a gastrostomy tube for enteral nutrition, found incidentally to have pneumatosis intestinalis without signs of intra-abdominal catastrophe. Conclusions: Appropriate interpretation of this finding can lead to life-saving interventions and avoid unnecessary surgical procedures.

Surgical management of aphakia.

Despite the safety and efficacy of cataract surgery, intraoperative complications can hamper the ability to place an intraocular lens in the capsular bag. With vast numbers of cataract surgeries performed daily, complications occur often enough that every ophthalmologist should be equipped with techniques to manage aphakia. Medical management of aphakia used to be commonplace but these techniques have their disadvantages including thick bulky lenses, poor cosmesis, and aniseikonia. Surgical management of aphakia overcomes these disadvantages and offers patients the possibility of a spectacle and contact lens-free lifestyle. This article reviews the various options of surgical management of aphakia and their advantages and disadvantages. Comparison of outcomes between techniques and a protocol for deciding between techniques is presented.

An estimate of rate of deviation from NCCN guideline recommendations for central nervous system imaging in trials forming basis for drug approval in first line advanced non-small cell lung cancer (NSCLC).

IMPORTANCE: It is unknown whether and to what degree trials submitted to the US FDA to support drug approval adhere to NCCN guideline-recommended care in their baseline and surveillance CNS imaging protocols. OBJECTIVE: We sought to characterize the frequency with which the trials cited in US FDA drug approvals for first line advanced NSCLC between 2015 and 2020 deviated from NCCN guideline-recommended care for baseline and surveillance CNS imaging. DESIGN, SETTING, AND PARTICIPANTS: Retrospective observational analysis using publicly available data of (1) list of trials cited by the FDA in drug approvals for first line advanced NSCLC from 2015 to 2020 (2) individual trial protocols (3) published trial data and supplementary appendices (4) archived versions of the NCCN guidelines for NSCLC from 2009 to 2018 (the years during which the trials were enrolling). MAIN OUTCOMES AND MEASURES: Estimated percentage of trials for first line advanced NSCLC leading to FDA approval which deviated from NCCN guideline-recommended care with regards to CNS baseline and surveillance imaging. RESULTS: A total of 14 studies that had been cited in FDA drug approvals for first line advanced NSCLC met our inclusion criteria between January 1, 2015 and September 30, 2020. Of these trials, 8 (57.1%) deviated from NCCN guidelines in their baseline CNS imaging requirement. The frequency of re-assessment of CNS disease was variable amongst trials as well, with 9 (64.3%) deviating from NCCN recommendations. CONCLUSIONS AND RELEVANCE: The trials supporting US FDA drug approvals in first line advanced NSCLC often have CNS imaging requirements that do not adhere to NCCN guidelines. Many trials permit alternative, substandard methods and the proportion of patients undergoing each modality is uniformly not reported. Nonstandard CNS surveillance protocols are common. To best serve patients with advanced NSCLC in the US, drug approvals by the FDA must be based on trials that mirror clinical practice and have imaging requirements consistent with current US standard of care.

Multifarious Functions of Butyrylcholinesterase in Neuroblastoma: Impact of BCHE Deletion on the Neuroblastoma Growth In Vitro and In Vivo.

The physiological functions of butyrylcholinesterase (BChE) and its role in malignancy remain unexplained. Our studies in children newly diagnosed with neuroblastoma indicated that BChE expressions is proportional to MYCN amplification suggesting that pathogenesis of high-risk disease may be related to the persistent expression of abnormally high levels of tumor-associated BChE. BChE-deficient neuroblastoma cells (KO [knockout]) were produced from MYCN -amplified BE(2)-C cells (WT [wild-type]) by the CRISPR-Cas9 targeted disruption of the BCHE locus. KO cells have no detectable BChE activity. The compensatory acetylcholinesterase activity was not detected. The average population doubling time of KO cells is 47.0±2.4 hours, >2× longer than WT cells. Reduced proliferation rates of KO cells were accompanied by the loss of N-Myc protein and a significant deactivation of tyrosine kinase receptors associated with the aggressive neuroblastoma phenotype including Ros1, TrkB, and Ltk. Tumorigenicity of WT and KO cells in male mice was essentially identical. In contrast, KO xenografts in female mice were very small (0.37±0.10 g), ~3× smaller compared with WT xenografts (1.11±0.30 g). Unexpectedly, KO xenografts produced changes in plasma BChE similarly to WT tumors but lesser in magnitude. The disruption of BCHE locus in MYCN -amplified neuroblastoma cells decelerates proliferation and produces neuroblastoma cells that are less aggressive in female mice.

Use of Second-line Immunotherapy in Control Arms of Randomized Clinical Trials in Kidney Cancer: A Systematic Review.

Importance: Immunotherapy (anti-programmed death ligand 1 antibodies) is associated with improved survival rates in advanced kidney cell carcinoma (KCC) after progression on first-line tyrosine kinase inhibitor (TKI) treatment. It is unknown whether and to what degree patients in the control arm receive postprotocol immunotherapy in trials comparing combination immunotherapy regimens with TKI in first-line advanced KCC. Objective: To characterize the proportion of patients in the control arm who received postprotocol immunotherapy in trials comparing combination immunotherapy regimens with TKI in first-line advanced KCC. Evidence Review: A search of PubMed was conducted to identify randomized clinical trials of combination immunotherapy compared with TKI in first-line advanced KCC between January 1, 2015, and February 28, 2021. Combination immunotherapy was defined as an anti-programmed death ligand 1 agent and an additional agent. Search terms included renal cell cancer and first-line and were filtered by the type clinical trial. All English-language trials of combination immunotherapy compared with a TKI were included. The trials and their protocols and supplements were analyzed to determine the proportion of patients in the control arm receiving postprotocol immunotherapy. Findings: A total of 106 articles met search criteria and were screened. A total of 6 trials and 3 published updates of trial results were included in the systematic review. Of 2565 patients assigned to control arm groups, 2069 (81%) were no longer on TKI at last data cutoff. Of patients in the control arm who discontinued TKI, 932 (45%) received postprotocol immunotherapy. Of patients in the control arm receiving any type of postprotocol therapy, 66.4% received immunotherapy. Conclusions and Relevance: This systematic review found that the proportion of patients in the control arm receiving postprotocol immunotherapy is low in randomized clinical trials of first-line combination immunotherapy regimens for advanced KCC. Appropriate use of postprotocol therapy is essential to answering the question of whether a combination or sequential treatment strategy with immunotherapy is superior.

Post-intensive care syndrome following cardiothoracic critical care: Feasibility of a complex intervention.

OBJECTIVES: To describe the long-term outcomes of cardiac intensive care unit patients and their primary caregivers, and to explore the feasibility of implementing a complex intervention, designed to support problems associated with post-intensive care syndrome and post-intensive care syndrome-family, in the year following discharge from the cardiac intensive care unit. DESIGN: A complex multidisciplinary rehabilitation programme, delivered as a quality improvement initiative, in a single centre in the West of Scotland. Outcomes were measured using surveys of health related quality of life, self efficacy, anxiety, depression, pain, caregiver strain, and insomnia. PARTICIPANTS: Patients and their caregivers were invited to participate 12 weeks after hospital discharge. Twenty-seven patients and 23 caregivers attended the programme. RESULTS: Over 90% of patients had problems in at least one quality of life domain at baseline, 41% of patients had symptoms of anxiety and 22% had symptoms of depression. During the baseline visit, caregiver strain was present in 20% of caregivers, 57% had symptoms of anxiety, and 35% had symptoms of depression. Improvements in outcomes were seen in both patients and caregivers at 1-year follow-up. The programme was implemented, and iterative learning obtained about the content and the operationalization of the service, in order to understand feasibility. CONCLUSION: This small-scale quality improvement project has demonstrated that this complex multidisciplinary rehabilitation programme is feasible and has positive implications for patients following discharge from the cardiac intensive care unit, and their caregivers.

Fatty Acid Mediators in the Tumor Microenvironment.

Patients with cancer frequently overexpress inflammatory cytokines with an associated neutrophilia both of which may be downregulated by diets with high omega-3 polyunsaturated fatty acids (ω-3 PUFA). The anti-inflammatory activity of dietary ω-3 PUFA has been suggested to have anticancer properties and to improve survival of cancer patients. Currently, the majority of dietary research efforts do not differentiate between obesity and dietary fatty acid consumption as mediators of inflammatory cell expansion and tumor microenvironmental infiltration, initiation, and progression. In this chapter, we discuss the relationships between dietary lipids, inflammation, neoplasia and strategies to regulate these relationships. We posit that dietary composition, notably the ratio of ω-3 vs. ω-6 PUFA, regulates tumor initiation and progression and the frequency and sites of metastasis that, together, impact overall survival (OS). We focus on three broad topics: first, the role of dietary lipids in chronic inflammation and tumor initiation, progression, and regression; second, lipid mediators linking inflammation and cancer; and third, dietary lipid regulation of murine and human tumor initiation, progression, and metastasis.

Alpha-Particle Therapy for Multifocal Osteosarcoma: A Hypothesis.

Osteosarcoma (OST) is the most common bone tumor in children and adolescents with a second peak of incidence in elderly adults usually diagnosed as secondary tumors in Paget's disease or irradiated bone. Subjects with metastatic disease or whose disease relapses after the initial therapy have a poor prognosis. Moreover, multifocal OST contains tumor-initiating cells that are resistant to chemotherapy. The use of aggressive therapies in an attempt to eradicate these cells can have long-term negative consequences in these vulnerable patient populations. 227Th-labeled molecular probes based on ligands to OST-associated receptors such as IGF-1R (insulin-like growth factor receptor 1), HER2 (human epidermal growth factor receptor 2), and PSMA (prostate-specific membrane antigen) are expected to detect and treat osseous and nonosseous sites of multifocal OST. Published reports indicate that 227Th has limited myelotoxicity, can be stably chelated to its carriers and, as it decays at targeted sites, 227Th produces 223Ra that is subsequently incorporated into the areas of increased osteoblastic activity, that is, osseous metastatic lesions. Linear energy transfer of α particles emitted by 227Th and its daughter 223Ra is within the range of the optimum relative biological effectiveness. The radiotoxicity of α particles is virtually independent of the phase in the cell cycle, oxygenation, and the dose rate. For these reasons, even resistant OST cells remain susceptible to killing by high-energy α particles, which can also kill adjacent quiescent OST cells or cells with low expression of targeted receptors. Systemic side effects are minimized by the limited range of these intense radiations. Quantitative single-photon emission computed tomography of 227Th and 223Ra is feasible. Additionally, the availability of radionuclide pairs, for example, 89Zr for positron emission tomography and 227Th for therapy, establish a strong basis for the theranostic use of 227Th in the individualized treatment of multifocal OST.

Effects of novel pyrrolomycin MP1 in MYCN amplified chemoresistant neuroblastoma cell lines alone and combined with temsirolimus.

BACKGROUND: The activity of MP1, a pyrrolomycin, was studied in MYCN amplified neuroblastoma (NB) alone and combined with temsirolimus (TEM). METHODS: Activity of MP1 was tested in MYCN amplified (BE-2c, IMR) and non amplified (SKN-AS) NB cells. The effect of MP1 on MYCN, MCL-1, cleaved PARP, LC3II/LC3I, bcl-2, BAX, and BRD-4 were determined by western blot and RNAseq. The effect of MP1 on metabolism, mitochondrial morphology, and cell cycle was determined. Toxicology and efficacy of MP1 plus TEM were evaluated. RESULTS: The IC50 of MP1 was 0.096 µM in BE-2c cells compared to 0.89 µM in IMR, and >50 µM in SKN-AS. The IC50 of MP1 plus TEM in BE-2c cells was 0.023 µM. MP1 inhibited metabolism leading to quiescence and produced a decline in cell cycle S-phase. Electron microscopy showed cristae loss and rounding up of mitochondria. Gene and protein expression for MYCN and MCL-1 declined while LCII and cleaved PARP increased. Protein expression of BAX, bcl-2, and BRD-4 were not significantly changed after MP1 treatment. The in-vivo concentrations of MP1 in blood and tumor were sufficient to produce the biologic effects seen in-vitro. MP1 plus TEM produced a complete response in 3 out of 5 tumor bearing mice. In a second mouse study, the combination of MP1 and TEM slowed tumor growth compared to control. CONCLUSIONS: MP1 has a potent inhibitory effect on the viability of MYCN amplified NB. Inhibition of metabolism by MP1 induced quiescence and autophagy with a favorable toxicology and drug distribution profile. When combined with TEM anti-tumor activity was potentiated in-vitro and in-vivo.

Surface nano-modification by ion beam-assisted deposition alters the expression of osteogenic genes in osteoblasts.

Biomaterials with enhanced biocompatibility are favored in implant studies to improve the outcomes of total joint replacement surgeries. This study tested the hypothesis that nano-structured surfaces for orthopedic applications, produced by the ion beam-assisted deposition method, would enhance osteointegration by altering the expression of bone-associated genes in osteoblasts. The ion beam-assisted deposition technique was employed to deposit nano-films on glass or titanium substrates. The effects of the ion beam-assisted deposition produced surfaces on the human osteosarcoma cell line SAOS-2 at the molecular level were investigated by assays of adhesion, proliferation, differentiation, and apoptosis on coated surfaces versus uncoated cobalt-chrome, as the control. Ion beam-assisted deposition nano-coatings enhanced bone-associated gene expression at initial cell adhesion, proliferation, and differentiation compared to cobalt-chrome surfaces as assessed by polymerase chain reaction techniques. Increased cell proliferation was observed using a nuclear cell proliferation-associated antigen. Moreover, enhanced cell differentiation was determined by alkaline phosphatase activity, an indicator of bone formation. In addition, programmed cell death assessed by annexin V staining and flow cytometry was lower on nano-surfaces compared to cobalt-chrome surfaces. Overall, the results indicate that nano-coated surfaces produced by the ion beam-assisted deposition technique for use on implants were superior to orthopedic grade cobalt-chrome in supporting bone cell adhesion, proliferation, and differentiation and reducing apoptosis. Thus, surface properties altered by the ion beam-assisted deposition technique should enhance bone formation and increase the biocompatibility of bone cell-associated surfaces.

A Cross-Sectional Study of Return to Work Rate Following Heart Transplantation and the Contributing Role of Illness Perceptions.

BACKGROUND: Social rehabilitation, including return to work (RTW), is a key indicator of transplant success. However, little is known regarding the RTW rate following heart transplantation or the factors influencing this. The objective of this study was to examine RTW among heart transplant recipients and identify associated predictors. METHODS: Attendees of the post-heart transplant clinic based at the Golden Jubilee National Hospital, Scotland, were invited to respond to a mailed survey comprising a demographic form, an employment history questionnaire, and a modified Brief Illness Perception Questionnaire. Frequency distributions, χ test, and stepwise regression were used to examine employment history and associated factors. RESULTS: Sixty percent of transplant recipients reported working 12 mo prior to transplant compared with 50% of recipients at 1-y post-transplant. Forty-four percent of all working-age recipients were currently employed, a relatively median rate compared with those found in previous studies. Univariate analysis revealed "receipt of benefits," "time off work pre-heart transplant," "employment 12 mo pre-heart transplant," "employment at listing," "perceived work ability," "discharge age," "illness consequences," "illness concern," and "emotional representation" as predictors of RTW. Logistic regression modeling revealed "time off work pre-heart transplant" and "perceived work ability" to have the most significant influence on RTW, explaining 62% of the variance in outcome. CONCLUSIONS: Psychological and demographic variables influence RTW after heart transplant. Knowledge and understanding of these variables facilitate the design of interventions and services to help promote RTW and social rehabilitation. Study limitations are discussed, and suggestions for similar research and the outpatient clinic are provided.

Immune regulation and anti-cancer activity by lipid inflammatory mediators.

Rodent and clinical studies have documented that myeloid cell infiltration of tumors is associated with poor outcomes, neutrophilia and lymphocytopenia. This contrasts with increased lymphocyte infiltration of tumors, which is correlated with improved outcomes. Lifestyle parameters, such as obesity and diets with high levels of saturated fat and/or omega (ω)-6 polyunsaturated fatty acids (PUFAs), can influence these inflammatory parameters, including an increase in extramedullary myelopoiesis (EMM). While tumor secretion of growth factors (GFs) and chemokines regulate tumor-immune-cell crosstalk, lifestyle choices also contribute to inflammation, abnormal pathology and leukocyte infiltration of tumors. A relationship between obesity and high-fat diets (notably saturated fats in Western diets) and inflammation, tumor incidence, metastasis and poor outcomes is generally accepted. However, the mechanisms of dietary promotion of an inflammatory microenvironment and targeted drugs to inhibit the clinical sequelae are poorly understood. Thus, modifications of obesity and dietary fat may provide preventative or therapeutic approaches to control tumor-associated inflammation and disease progression. Currently, the majority of basic and clinical research does not differentiate between obesity and fatty acid consumption as mediators of inflammatory and neoplastic processes. In this review, we discuss the relationships between dietary PUFAs, inflammation and neoplasia and experimental strategies to improve our understanding of these relationships. We conclude that dietary composition, notably the ratio of ω-3 vs ω-6 PUFA regulates tumor growth and the frequency and sites of metastasis that together, impact overall survival (OS) in mice.

Long-chain omega-3 polyunsaturated fatty acids decrease mammary tumor growth, multiorgan metastasis and enhance survival.

Epidemiological studies show a reduced risk of breast cancer (BC) in women consuming high levels of long-chain (LC) omega-3 (ω-3) fatty acids (FAs) compared with women who consumed low levels. However, the regulatory and mechanistic roles of dietary ω-6 and LC-ω-3 FAs on tumor progression, metastasis and survival are poorly understood. Female BALB/c mice (10-week old) were pair-fed with a diet containing ω-3 or an isocaloric, isolipidic ω-6 diet for 16 weeks prior to the orthotopic implantation of 4T1 mammary tumor cells. Major outcomes studied included: mammary tumor growth, survival analysis, and metastases analyses in multiple organs including pulmonary, hepatic, bone, cardiac, renal, ovarian, and contralateral MG (CMG). The dietary regulation of the tumor microenvironment was evaluated in mice autopsied on day-35 post tumor injection. In mice fed the ω-3 containing diet, there was a significant delay in tumor initiation and prolonged survival relative to the ω-6 diet-fed group. The tumor size on day 35 post tumor injection in the ω-3 group was 50% smaller and the frequencies of pulmonary and bone metastases were significantly lower relative to the ω-6 group. Similarly, the incidence/frequencies and/or size of cardiac, renal, ovarian metastases were significantly lower in mice fed the ω-3 diet. The analyses of the tumor microenvironment showed that tumors in the ω-3 group had significantly lower numbers of proliferating tumor cells (Ki67+)/high power field (HPF), and higher numbers of apoptotic tumor cells (TUNEL+)/HPF, lower neo-vascularization (CD31+ vessels/HPF), infiltration by neutrophil elastase+ cells, and macrophages (F4/80+) relative to the tumors from the ω-6 group. Further, in tumors from the ω-3 diet-fed mice, T-cell infiltration was 102% higher resulting in a neutrophil to T-lymphocyte ratio (NLR) that was 76% lower (p < 0.05). Direct correlations were observed between NLR with tumor size and T-cell infiltration with the number of apoptotic tumor cells. qRT-PCR analysis revealed that tumor IL10 mRNA levels were significantly higher (six-fold) in the tumors from mice fed the ω-3 diet and inversely correlated with the tumor size. Our data suggest that dietary LC-ω-3FAs modulates the mammary tumor microenvironment slowing tumor growth, and reducing metastases to both common and less preferential organs resulting in prolonged survival. The surrogate analyses undertaken support a mechanism of action by dietary LC-ω-3FAs that includes, but is not limited to decreased infiltration by myeloid cells (neutrophils and macrophages), an increase in CD3+ lymphocyte infiltration and IL10 associated anti-inflammatory activity.

Unforeseen challenges of living with an LVAD.

BACKGROUND: The implantable left ventricular assist device (LVAD) is being used more commonly, and is associated with improved outcomes physically but can be related to psychological distress. KEY POINTS: A 28-year-old male of Asian ethnicity who received LVAD implantation for advanced heart failure. Incidents are described wherein the external battery pack for his LVAD was misidentified as an explosive device, and he a security threat. These impacted on the patient's psychological wellbeing. These difficulties were ameliorated after successful heart transplant. CONCLUSIONS: Similar incidents could occur, as rates of hate crimes and support for racial profiling increase. Thus, this report calls for greater recognition of the challenge of living with the LVAD by clinicians, leading to better patient education and increased access to psychological therapy. There is also an avenue for national bodies to develop greater awareness of LVAD and improve access to psychological support.

Long-Chain Omega-3 Polyunsaturated Fatty Acids Modulate Mammary Gland Composition and Inflammation.

Studies in rodents have shown that dietary modifications as mammary glands (MG) develop, regulates susceptibility to mammary tumor initiation. However, the effects of dietary PUFA composition on MGs in adult life, remains poorly understood. This study investigated morphological alterations and inflammatory microenvironments in the MGs of adult mice fed isocaloric and isolipidic liquid diets with varying compositions of omega (ω)-6 and long-chain (Lc)-ω3FA that were pair-fed. Despite similar consumption levels of the diets, mice fed the ω-3 diet had significantly lower body-weight gains, and abdominal-fat and mammary fat pad (MFP) weights. Fatty acid analysis showed significantly higher levels of Lc-ω-3FAs in the MFPs of mice on the ω-3 diet, while in the MFPs from the ω-6 group, Lc-ω-3FAs were undetectable. Our study revealed that MGs from ω-3 group had a significantly lower ductal end-point density, branching density, an absence of ductal sprouts, a thinner ductal stroma, fewer proliferating epithelial cells and a lower transcription levels of estrogen receptor 1 and amphiregulin. An analysis of the MFP and abdominal-fat showed significantly smaller adipocytes in the ω-3 group, which was accompanied by lower transcription levels of leptin, IGF1, and IGF1R. Further, MFPs from the ω-3 group had significantly decreased numbers and sizes of crown-like-structures (CLS), F4/80+ macrophages and decreased expression of proinflammatory mediators including Ptgs2, IL6, CCL2, TNFα, NFκB, and IFNγ. Together, these results support dietary Lc-ω-3FA regulation of MG structure and density and adipose tissue inflammation with the potential for dietary Lc-ω-3FA to decrease the risk of mammary gland tumor formation.