Automated Whole Slide Imaging for Label-Free Histology using Photon Absorption Remote Sensing Microscopy

: Pathologists rely on histochemical stains to impart contrast in thin translucent tissue samples, revealing tissue features necessary for identifying pathological conditions. However, the chemical labeling process is destructive and often irreversible or challenging to undo, imposing practical limits on the number of stains that can be applied to the same tissue section. Here we present an automated label-free whole slide scanner using a PARS microscope designed for imaging thin, transmissible samples.

METHODS

Peak SNR and in-focus acquisitions are achieved across entire tissue sections using the scattering signal from the PARS detection beam to measure the optimal focal plane. Whole slide images (WSI) are seamlessly stitched together using a custom contrast leveling algorithm. Identical tissue sections are subsequently H&E stained and brightfield imaged. The one-to-one WSIs from both modalities are visually and quantitatively compared.

RESULTS

PARS WSIs are presented at standard 40x magnification in malignant human breast and skin samples. We show correspondence of subcellular diagnostic details in both PARS and H&E WSIs and demonstrate virtual H&E staining of an entire PARS WSI. The one-to-one WSI from both modalities show quantitative similarity in nuclear features and structural information.

CONCLUSION

PARS WSIs are compatible with existing digital pathology tools, and samples remain suitable for histochemical, immunohistochemical, and other staining techniques.

SIGNIFICANCE

This work is a critical advance for integrating label-free optical methods into standard histopathology workflows.

Photon Absorption Remote Sensing Imaging of Breast Needle Core Biopsies Is Diagnostically Equivalent to Gold Standard H&E Histologic Assessment

Photon absorption remote sensing (PARS) is a new laser-based microscope technique that permits cellular-level resolution of unstained fresh, frozen, and fixed tissues. Our objective was to determine whether PARS could provide an image quality sufficient for the diagnostic assessment of breast cancer needle core biopsies (NCB). We PARS imaged and virtually H&E stained seven independent unstained formalin-fixed paraffin-embedded breast NCB sections. These identical tissue sections were subsequently stained with standard H&E and digitally scanned. Both the 40× PARS and H&E whole-slide images were assessed by seven breast cancer pathologists, masked to the origin of the images. A concordance analysis was performed to quantify the diagnostic performances of standard H&E and PARS virtual H&E. The PARS images were deemed to be of diagnostic quality, and pathologists were unable to distinguish the image origin, above that expected by chance. The diagnostic concordance on cancer vs. benign was high between PARS and conventional H&E (98% agreement) and there was complete agreement for within-PARS images. Similarly, agreement was substantial (kappa > 0.6) for specific cancer subtypes. PARS virtual H&E inter-rater reliability was broadly consistent with the published literature on diagnostic performance of conventional histology NCBs across all tested histologic features. PARS was able to image unstained tissues slides that were diagnostically equivalent to conventional H&E. Due to its ability to non-destructively image fixed and fresh tissues, and the suitability of the PARS output for artificial intelligence assistance in diagnosis, this technology has the potential to improve the speed and accuracy of breast cancer diagnosis.

Endothelin Receptor Blocker Reverses Breast Cancer-Induced Cardiac Remodeling

Background

Although some cancer therapies have overt and/or subclinical cardiotoxic effects that increase subsequent cardiovascular risk in breast cancer patients, we have recently shown that the breast tumor itself can also induce cardiac hypertrophy through the activation of the endothelin system to contribute to cardiovascular risk. However, the extent to which the suppression of the activation of the endothelin system could improve cardiac remodeling in breast cancer patients has yet to be investigated.

Objectives

We aimed to retrospectively assess the cardiac morphology/function in patients with breast cancer before receiving cancer chemotherapy and to investigate if the suppression of the activation of the endothelin system improves cardiac remodeling in a mouse model of breast cancer.

Methods

Our study involved 28 previously studied women with breast cancer (including 24 after tumor resection) before receiving adjuvant therapy and 17 control healthy women. In addition, we explored how the endothelin system contributed to breast cancer-induced cardiac remodeling using a mouse model of breast cancer.

Results

Our results indicate that before chemotherapy, breast cancer patients already exhibit relative cardiac remodeling and subclinical cardiac dysfunction, which was associated with the activation of the endothelin system. Importantly, our mouse data also show that the endothelin receptor blocker atrasentan significantly lessened cardiac remodeling and improved cardiac function in a preclinical model of breast cancer.

Conclusions

Although our findings should be further examined in other preclinical/clinical models, our data suggest that endothelin receptor blockers may play a role in cardiac health in individuals with breast cancer. (Understanding and Treating Heart Failure With Preserved Ejection Fraction: Novel Mechanisms, Diagnostics and Potential Therapeutics [Alberta HEART]; NCT02052804 and Multidisciplinary Team Intervention in Cardio-Oncology [TITAN]; NCT01621659).

Rationale and design of IMPACT-women: a randomised controlled trial of the effect of time-restricted eating, healthy eating and reduced sedentary behaviour on metabolic health during chemotherapy for early-stage breast cancer

Metabolic dysfunction and excess accumulation of adipose tissue are detrimental side effects from breast cancer treatment. Diet and physical activity are important treatments for metabolic abnormalities, yet patient compliance can be challenging during chemotherapy treatment. Time-restricted eating (TRE) is a feasible dietary pattern where eating is restricted to 8 h/d with water-only fasting for the remaining 16 h. The purpose of this study is to evaluate the effect of a multimodal intervention consisting of TRE, healthy eating, and reduced sedentary time during chemotherapy treatment for early-stage (I-III) breast cancer on accumulation of visceral fat (primary outcome), other fat deposition locations, metabolic syndrome and cardiovascular disease risk (secondary outcomes) compared with usual care. The study will be a two-site, two-arm, parallel-group superiority randomised control trial enrolling 130 women scheduled for chemotherapy for early-stage breast cancer. The intervention will be delivered by telephone, including 30-60-minute calls with a registered dietitian who will provide instructions on TRE, education and counselling on healthy eating, and goal setting for reducing sedentary time. The comparison group will receive usual cancer and supportive care including a single group-based nutrition class and healthy eating and physical activity guidelines. MRI, blood draws and assessment of blood pressure will be performed at baseline, after chemotherapy (primary end point), and 2-year follow-up. If our intervention is successful in attenuating the effect of chemotherapy on visceral fat accumulation and cardiometabolic dysfunction, it has the potential to reduce risk of cardiometabolic disease and related mortality among breast cancer survivors.

Does cardiac imaging surveillance strategy influence outcomes in patients with early breast cancer?

Background

Many patients with breast cancer receive therapies with the potential to cause cardiotoxicity. Echocardiography and multiple-gated acquisition (MUGA) scans are the most used modalities to assess cardiac function during treatment in high-risk patients; however, the optimal imaging strategy and the impact on outcome are unknown.

Methods

Consecutive patients with stage 0-3 breast cancer undergoing pre-treatment echocardiography or MUGA were identified from a tertiary care cancer center from 2010-2019. Demographics, medical history, imaging data and clinical events were collected from hospital charts and administrative databases. The primary outcome is a composite of all-cause death or heart failure event. Clinical and imaging predictors of outcome were evaluated on univariable and multivariable analyses.

Results

1028 patients underwent pre-treatment MUGA and 1032 underwent echocardiography. The groups were well matched for most clinical characteristics except patients undergoing MUGA were younger, had more stage 3 breast cancer and more HER2 over-expressing and triple negative cases. Routine follow-up cardiac imaging scan was obtained in 39.3% of patients with MUGA and 38.0% with echocardiography. During a median follow-up of 2448 (1489, 3160) days, there were 194 deaths, including 7 cardiovascular deaths, and 28 heart failure events with no difference in events between the MUGA and echocardiography groups. There were no imaging predictors of the primary composite outcome or cardiac events. Patients without follow-up imaging had similar adjusted risk for the composite outcome compared to those with imaging follow-up, hazard ratio 0.8 (95% confidence interval 0.5,1.3), p=0.457.

Conclusion

The selection of pretreatment echocardiography or MUGA did not influence the risk of death or heart failure in patients with early breast cancer. Many patients did not have any follow-up cardiac imaging and did not suffer worse outcomes. Cardiovascular deaths and heart failure event rates were low and the value of long-term cardiac imaging surveillance should be further evaluated.

Chemotherapy-induced weight gain in early-stage breast cancer: a prospective matched cohort study reveals associations with inflammation and gut dysbiosis

BACKGROUND

Early-stage breast cancer patients treated with chemotherapy risk the development of metabolic disease and weight gain, which can result in increased morbidity and reduced quality of life in survivorship. We aimed to analyze changes within the gastrointestinal microbiome of early-stage breast cancer patients treated with and without chemotherapy to investigate a potential relationship between dysbiosis, a systemic inflammatory response, and resultant anthropomorphic changes.

METHODS

We undertook an a priori analysis of serially collected stool and plasma samples from 40 patients with early-stage breast cancer who underwent adjuvant endocrine therapy only, adjuvant chemotherapy only, or both. Gut microbiota were assessed by metagenomic comparison of stool samples following deep sequencing. Inflammatory biomarkers were evaluated by proteomic analysis of plasma and measurement of fecal calprotectin. Body composition was investigated by dual-energy X-ray absorptiometry to determine biomass indices.

RESULTS

As opposed to treatment with endocrine therapy only, chemotherapy resulted in statistically and clinically significant weight gain and an increase in the android to gynoid ratio of fat distribution. Patients treated with chemotherapy gained an average of 0.15% total mass per month, as opposed to a significantly different loss of 0.19% in those patients who received endocrine-only therapy. Concurrently, a twofold increase in fecal calprotectin occurred after chemotherapy that is indicative of interferon-dependent inflammation and evidence of colonic inflammation. These anthropomorphic and inflammatory changes occurred in concert with a chemotherapy-dependent effect on the gut microbiome as evidenced by a reduction in both the abundance and variety of microbial species.

CONCLUSIONS

We confirm the association of chemotherapy treatment with weight gain and potential deleterious anthropometric changes and suggest that alterations of bacterial flora may contribute to these phenomena through the induction of systemic inflammation. Consequently, the gut microbiome may be a future target for intervention in preventing chemotherapy-dependent anthropometric changes.

Associations between health-related fitness and quality of life in newly diagnosed breast cancer patients

PURPOSE

Newly diagnosed breast cancer patients face substantial stress and uncertainty that may undermine their quality of life (QoL). The purpose of the present study was to examine the associations between health-related fitness (HRF) and QoL in newly diagnosed breast cancer patients from the Alberta Moving Beyond Breast Cancer Study.

METHODS

Newly diagnosed breast cancer patients with early-stage disease (n = 1458) were recruited between 2012 and 2019 in Edmonton and Calgary, Canada to complete baseline HRF and QoL assessments within 90 days of diagnosis. HRF assessments included cardiorespiratory fitness (VO_2peak treadmill test), muscular fitness (upper and lower body strength and endurance tests), and body composition (dual x-ray absorptiometry). QoL was assessed by the Medical Outcomes Study Short Form 36 (SF-36) version 2. We used logistic regression analyses to examine the associations between quartiles of HRF and poor/fair QoL (bottom 20%) after adjusting for key covariates.

RESULTS

In multivariable analysis, the least fit groups compared to the most fit groups for relative upper body strength (OR = 3.19; 95% CI = 1.98-5.14), lean mass percentage (OR = 2.31; 95% CI = 1.37-3.89), and relative VO_2peak (OR = 2.08; 95% CI = 1.21-3.57) were independently at a significantly higher risk of poor/fair physical QoL. No meaningful associations were found for mental QoL.

CONCLUSIONS

The three main components of HRF (muscular fitness, cardiorespiratory fitness, and body composition) were independently associated with physical QoL in newly diagnosed breast cancer patients. Exercise interventions designed to improve these components of HRF may optimize physical QoL and help newly diagnosed breast cancer patients better prepare for treatments and recovery.

Abstract 5662: Targeting N-myristoylation for therapy of adult acute myeloid leukemia

Two N-myristoyltransferases (NMTs) NMT1 and NMT2 catalyze the reaction. NMT1 is ubiquitous expressed and is essential for cell survival while NMT2 is more variably expressed and non-essential suggesting that their substrate specificity and activity levels differ. Historically, inhibition of myristoylation was suggested as a therapeutic anti-cancer target since NMTs expression were shown to be increased in numerous types of cancers and myristoylation was shown to be essential for proper localization and activity of some important proto-oncogenes such as Src Family Kinases (SFKs). Recently, we showed NMT2 expression is lost in numerous haematological cancer cell lines (including AML) and that these haematological cancer cell lines are exquisitely sensitive to the pan-NMT inhibitor PCLX-001. PCLX-001 recently entered human clinical trials as once daily oral therapy for relapsed/refractory B-cell Non-Hodgkin Lymphoma and advanced solid malignances. Dysregulation and oncogenic activity of SFKs occurs frequently in AML, suggesting NMT inhibition could provide therapeutic benefit in this indication. Data analysis from the TCGA transcriptome database revealed that high NMT1 and low NMT2 were associated with reduced overall and event-free survival in adult AML. Moreover, high NMT1 - but not NMT2 - expression is associated with proliferative gene sets in AML cell lines. AML cell lines treated with PCLX-001 showed a significant reduction in total protein myristoylation, reduced levels of SFK proteins and SFK phosphorylation as well as significant increases in ER stress marker BIP protein and caspase 3 cleavage. PCLX-001 induced apoptosis in AML cell lines and patient blasts at concentrations that spared a large proportion of peripheral blood lymphocytes and monocytes from healthy individuals. PCLX-001 monotherapy had dose-dependent anticancer activity in an AML MV-4-11 cell line derived xenograft (CDX) and two AML patient derived xenografts (PDXs) and produced complete remissions in subcutaneous AML CDX. In tail-vein injected PDX models, PCLX-001 treatment resulted in up to 95% reduction of human CD45+ cells in peripheral blood and bone marrow. PCLX-001 preferentially targeted AML cells inducing apoptosis and reducing leukemic burden. These findings validate NMT inhibition as a novel therapeutic strategy for AML and warrant the evaluation of PCLX-001 in clinical trials for adult AML.

Citation Format: Jay Gamma, Aishwarya Iyer, Megan Yap, Zoulika Zak, Krista Vincent, Cassidy Ekstrom, Qiang Liu, Erwan Beauchamp, Lynne Postovit, Jean Wang, John R. Mackey, Naveen Pemmaraju, Gautam Borthakur, Joseph Brandwein, Luc Berthiaume. Targeting N-myristoylation for therapy of adult acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5662.

Effect of Metformin vs Placebo on Invasive Disease-Free Survival in Patients With Breast Cancer: The MA.32 Randomized Clinical Trial

Importance

Metformin, a biguanide commonly used to treat type 2 diabetes, has been associated with potential beneficial effects across breast cancer subtypes in observational and preclinical studies.

Objective

To determine whether the administration of adjuvant metformin (vs placebo) to patients with breast cancer without diabetes improves outcomes.

Design, Setting, and Participants

MA.32, a phase 3 randomized, placebo-controlled, double-blind trial, conducted in Canada, Switzerland, US, and UK, enrolled 3649 patients with high-risk nonmetastatic breast cancer receiving standard therapy between August 2010 and March 2013, with follow-up to October 2020.

Interventions

Patients were randomized (stratified for hormone receptor [estrogen receptor and/or progesterone receptor {ER/PgR}] status, positive vs negative; body mass index, ≤30 vs >30; human epidermal growth factor receptor 2 [ERBB2, formerly HER2 or HER2/neu], positive vs negative; and any vs no chemotherapy) to 850 mg of oral metformin twice a day (n = 1824) or oral placebo twice a day (n = 1825) for 5 years.

Main Outcomes and Measures

The primary outcome was invasive disease-free survival in hormone receptor-positive breast cancer. Of the 8 secondary outcomes, overall survival, distant relapse-free survival, and breast cancer-free interval were analyzed.

Results

Of the 3649 randomized patients (mean age, 52.4 years; 3643 women [99.8%]), all (100%) were included in analyses. After a second interim analysis, futility was declared for patients who were ER/PgR-, so the primary analysis was conducted for 2533 patients who were ER/PgR+. The median duration of follow-up in the ER/PgR+ group was 96.2 months (range, 0.2-121 months). Invasive disease-free survival events occurred in 465 patients who were ER/PgR+. The incidence rates for invasive disease-free survival events were 2.78 per 100 patient-years in the metformin group vs 2.74 per 100 patient-years in the placebo group (hazard ratio [HR], 1.01; 95% CI, 0.84-1.21; P = .93), and the incidence rates for death were 1.46 per 100 patient-years in the metformin group vs 1.32 per 100 patient-years in the placebo group (HR, 1.10; 95% CI, 0.86-1.41; P = .47). Among patients who were ER/PgR-, followed up for a median of 94.1 months, incidence of invasive disease-free survival events was 3.58 vs 3.60 per 100 patient-years, respectively (HR, 1.01; 95% CI, 0.79-1.30; P = .92). None of the 3 secondary outcomes analyzed in the ER/PgR+ group had statistically significant differences. Grade 3 nonhematological toxic events occurred more frequently in patients taking metformin than in patients taking placebo (21.5% vs 17.5%, respectively, P = .003). The most common grade 3 or higher adverse events in the metformin vs placebo groups were hypertension (2.4% vs 1.9%), irregular menses (1.5% vs 1.4%), and diarrhea (1.9% vs 7.0%).

Conclusions and Relevance

Among patients with high-risk operable breast cancer without diabetes, the addition of metformin vs placebo to standard breast cancer treatment did not significantly improve invasive disease-free survival.

Trial Registration

ClinicalTrials.gov Identifier: NCT01101438.

Label-free complete absorption microscopy using second generation photoacoustic remote sensing

In the past decades, absorption modalities have emerged as powerful tools for label-free functional and structural imaging of cells and tissues. Many biomolecules present unique absorption spectra providing chromophore-specific information on properties such as chemical bonding, and sample composition. As chromophores absorb photons the absorbed energy is emitted as photons (radiative relaxation) or converted to heat and under specific conditions pressure (non-radiative relaxation). Modalities like fluorescence microscopy may capture radiative relaxation to provide contrast, while modalities like photoacoustic microscopy may leverage non-radiative heat and pressures. Here we show an all-optical non-contact total-absorption photoacoustic remote sensing (TA-PARS) microscope, which can capture both radiative and non-radiative absorption effects in a single acquisition. The TA-PARS yields an absorption metric proposed as the quantum efficiency ratio (QER), which visualizes a biomolecule’s proportional radiative and non-radiative absorption response. The TA-PARS provides label-free visualization of a range of biomolecules enabling convincing analogues to traditional histochemical staining of tissues, effectively providing label-free Hematoxylin and Eosin (H&E)-like visualizations. These findings establish an effective all-optical non-contact total-absorption microscope for label-free inspection of biological materials.

Decongestive progressive resistance exercise with an adjustable compression wrap for breast cancer-related lymphoedema (DREAM): protocol for a randomised controlled trial

INTRODUCTION

Breast cancer-related lymphoedema (BCRL) is a chronic swelling in the arm on the side of the breast cancer surgery, affecting one in five women. Recent studies in BCRL have demonstrated that resistance exercise can improve symptoms and quality of life without worsening lymphoedema. No studies have explored whether combining the principles of progressive resistance exercise training with therapeutic strategies of compression therapy and the decongestive lymphatic exercise sequence are beneficial in reducing arm lymphoedema volume. The aim of this three-arm, provincial randomised controlled trial is to determine the efficacy of a 12-week decongestive progressive resistance exercise (DRE) programme in combination with the one of two types of compression garments compared with standard care.

METHODS AND ANALYSIS

Sixty women with BCRL will be recruited and randomly assigned to one of the following three groups: (1) Standard care, (2) DRE with use of a daytime compression garment during exercise and (3) DRE with use of an adjustable compression wrap during exercise. The primary outcome is the percentage reduction in arm lymphoedema volume. Secondary outcomes include bioimpedance analysis, muscular strength, shoulder range of motion, physical activity level and health-related quality of life. Exploratory outcomes include evaluating changes in arm tissue composition using MRI and examining outcomes between the two DRE experimental groups. The primary analysis will compare changes between the groups from baseline to week 12 reflecting the end of the randomised control trial period.

ETHICS AND DISSEMINATION

The trial has received ethics approval from the Health Research Ethics Board of Alberta: Cancer Committee. The study results will be disseminated through scientific peer-reviewed publications, and presented at national and international conferences, and other media portals. The programme protocol will be shared with healthcare professionals and patient groups through clinical workshops and webinars.

TRIAL REGISTRATION NUMBER

NCT05022823.

PROTOCOL VERSION

12 November 2021.

ISSUE DATE

26 April 2021.

Novel, First-In-Human, Oral PCLX-001 Treatment in a Patient with Relapsed Diffuse Large B-Cell Lymphoma

Patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) have limited treatment options, particularly if they are transplantation or chimeric antigen receptor (CAR) T-cell ineligible, and novel therapeutics are needed. An 86-year-old woman with relapsed DLBCL received a novel, first-in-class small molecule inhibitor of N-myristoyltransferase (NMT) as the initial patient on a phase I dose escalation trial. Daily oral administration of 20 mg PCLX-001 tablets produced a pharmacokinetic profile suitable for single daily dosing: rapid oral absorption, followed by an apparent elimination half-life of 16 h, without systemic accumulation of drug by day 15. Pharmacodynamic tests showed no clear change in NMT1 and NMT2 levels or selected NMT substrate Lyn and HGAL protein levels in normal circulating blood mononuclear cells, suggesting a higher dose will be required for normal tissue toxicity. The patient did not experience any dose-limiting toxicities but had disease progression after 28 days of study therapy. Dose escalation continues in other patients in this first-in-human study of a new class of anticancer drug. We conclude that PCLX-001 oral monotherapy has suitable pharmacokinetic parameters for dose escalation, and that higher doses are required to achieve pharmacodynamic evidence of on-target activity in normal tissues. The current protocol is appropriately designed to achieve these ends, and the study proceeds without modification.

Incident Cardiovascular Disease Among Adults With Cancer: A Population-Based Cohort Study

Background

Patients with cancer and cancer survivors are at increased risk for incident heart failure, but there are conflicting data on the long-term risk for other cardiovascular events and how such risk may vary by cancer site.

Objectives

The aim of this study was to determine the impact of a new cancer diagnosis on the risk for fatal and nonfatal cardiovascular events.

Methods

Using administrative health care databases, a population-based retrospective cohort study was conducted among 4,519,243 adults residing in Alberta, Canada, from April 2007 to December 2018. Participants with new cancer diagnoses during the study period were compared with those without cancer with respect to risk for subsequent cardiovascular events (cardiovascular mortality, myocardial infarction, stroke, heart failure, and pulmonary embolism) using time-to-event survival models after adjusting for sociodemographic data and comorbidities.

Results

A total of 224,016 participants with new cancer diagnoses were identified, as well as 73,360 cardiovascular deaths and 470,481 nonfatal cardiovascular events during a median follow-up period of 11.8 years. After adjustment, participants with cancer had HRs of 1.33 (95% CI: 1.29-1.37) for cardiovascular mortality, 1.01 (95% CI: 0.97-1.05) for myocardial infarction, 1.44 (95% CI: 1.41-1.47) for stroke, 1.62 (95% CI: 1.59-1.65) for heart failure, and 3.43 (95% CI: 3.37-3.50) for pulmonary embolism, compared with participants without cancer. Cardiovascular risk was highest for patients with genitourinary, gastrointestinal, thoracic, nervous system and hematologic malignancies.

Conclusions

A new cancer diagnosis is independently associated with a significantly increased risk for cardiovascular death and nonfatal morbidity regardless of cancer site. These findings highlight the need for a collaborative approach to health care for patients with cancer and cancer survivors.

The Alberta moving beyond breast cancer (AMBER) cohort study: baseline description of the full cohort

Purpose

The Alberta Moving Beyond Breast Cancer (AMBER) Study is an ongoing prospective cohort study investigating how direct measures of physical activity (PA), sedentary behavior (SB), and health-related fitness (HRF) are associated with survival after breast cancer.

Methods

Women in Alberta with newly diagnosed stage I (≥ T1c) to IIIc breast cancer were recruited between 2012 and 2019. Baseline assessments were completed within 90 days of surgery. Measurements included accelerometers to measure PA and SB; a graded treadmill test with gas exchange analysis to measure cardiorespiratory fitness (VO_2peak); upper and lower body muscular strength and endurance; dual-X-ray absorptiometry to measure body composition; and questionnaires to measure self-reported PA and SB.

Results

At baseline, the 1528 participants’ mean age was 56 ± 11 years, 59% were post-menopausal, 62% had overweight/obesity, and 55% were diagnosed with stage II or III disease. Based on device measurements, study participants spent 8.9 ± 1.7 h/day sedentary, 4.4 ± 1.2 h/day in light-intensity activity, 0.9 ± 0.5 h/day in moderate-intensity activity, and 0.2 ± 0.2 h/day in vigorous-intensity activity. For those participants who reached VO_2peak, the average aerobic fitness level was 26.6 ± 6 ml/kg/min. Average body fat was 43 ± 7.1%.

Conclusion

We have established a unique cohort of breast cancer survivors with a wealth of data on PA, SB, and HRF obtained through both direct and self-reported measurements. Study participants are being followed for at least ten years to assess all outcomes after breast cancer. These data will inform clinical and public health guidelines on PA, SB, and HRF for improving breast cancer outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10552-021-01539-6.

DREAM, a possible answer to the estrogen paradox of the Women's Health Initiative Trial

Estrogen is thought to cause proliferation of all estrogen receptor positive (ER+) breast cancers. Paradoxically, in the Women's Health Initiative Trial, estrogen-only hormone replacement therapy reduced the incidence and mortality of low grade, ER+, HER2- breast cancer. We gave estradiol to 19 post-menopausal women with newly diagnosed low-grade, ER+, HER2- breast cancer in a prospective window of opportunity clinical trial and examined the changes in proliferation and gene expression before and after estradiol treatment. Ki67 decreased in 13/19 (68%) patients and 8/13 (62%) showed a decrease in Risk of Recurrence Score. We chose three prototypical estrogen responders (greatest decrease in ROR) and non-responders (no/minimal change in ROR) and applied a differential gene expression analysis to develop pre-treatment (PRESTO-30^core) and post-treatment (PRESTO-45^surg) gene expression profiles. The PRESTO-30^core predicted adjuvant benefit in a published series of tamoxifen, the partial estrogen agonist. Of the 45 genes in the PRESTO-45^surg, thirty contain the Cell cycle genes Homology Region (CHR) motif that binds the class B multi-vulva complex (MuvB) a member of the DREAM (Dimerization partner, retinoblastoma-like proteins, E2F, MuvB) complex responsible for reversible cell cycle arrest or quiescence. There was also near uniform suppression (89%) of the remaining DREAM genes consistent with estrogen induced activation of the DREAM complex to mediate cell cycle block after a short course of estrogens. To our knowledge, this is the first report to show estrogen modulation of DREAM genes and suggest involvement of DREAM pathway associated quiescence in endocrine responsive post-menopausal ER+ breast cancers.

•

WHI trial found that estrogen decreases some ER+ post-menopausal breast cancers.

•

Our prospective clinical trial confirmed an anti-proliferative effect of estradiol.

•

DREAM pathway genes were downregulated during the anti-proliferative response.

•

This suggests that estrogen may activate DREAM quiescence of ER+ breast cancers.

hENT1 Predicts Benefit from Gemcitabine in Pancreatic Cancer but Only with Low CDA mRNA

Gemcitabine or 5-fluorouracil (5-FU) based treatments can be selected for pancreatic cancer. Equilibrative nucleoside transporter 1 (hENT1) predicts adjuvant gemcitabine treatment benefit over 5-FU. Cytidine deaminase (CDA), inside or outside of the cancer cell, will deaminate gemcitabine, altering transporter affinity. ESPAC-3(v2) was a pancreatic cancer trial comparing adjuvant gemcitabine and 5-FU. Tissue microarray sections underwent in situ hybridization and immunohistochemistry. Analysis of both CDA and hENT1 was possible with 277 patients. The transcript did not correlate with protein levels for either marker. High hENT1 protein was prognostic with gemcitabine; median overall survival was 26.0 v 16.8 months (p = 0.006). Low CDA transcript was prognostic regardless of arm; 24.8 v 21.2 months with gemcitabine (p = 0.02) and 26.4 v 14.6 months with 5-FU (p = 0.02). Patients with low hENT1 protein did better with 5-FU, but only if the CDA transcript was low (median survival of 5-FU v gemcitabine; 29.3 v 18.3 months, compared with 14.2 v 14.6 with high CDA). CDA mRNA is an independent prognostic biomarker. When added to hENT1 protein status, it may also provide treatment-specific predictive information and, within the frame of a personalized treatment strategy, guide to either gemcitabine or 5FU for the individual patient.

Genome profiles of pathologist-defined cell clusters by multiregional LCM and G&T-seq in one triple-negative breast cancer patient

Pathological examination is the gold standard for cancer diagnosis, and breast tumor cells are often found in clusters. We report a case study on one triple-negative breast cancer (TNBC) patient, analyzing tumor development, metastasis, and prognosis with simultaneous DNA and RNA sequencing of pathologist-defined cell clusters from multiregional frozen sections. The cell clusters are isolated by laser capture microdissection (LCM) from primary tumor tissue, lymphatic vessels, and axillary lymph nodes. Data are reported for a total of 97 cell clusters. A combination of tumor cell-cluster clonality and phylogeny reveals 3 evolutionarily distinct pathways for this patient, each associated with a unique mRNA signature, and each correlated with disparate survival outcomes. Hub gene analysis indicates that extensive downregulation of ribosomal protein mRNA is a potential marker of poor prognosis in breast cancer.

Pathologically diverse cell clusters share genomic and transcriptomic profiles

Transcriptome-defined clones are more complex than genome-defined clones

Three distinct pathways were inferred, each with disparate survival outcomes

Lower expression of ribosomal proteins may be an indicator of poor prognosis

Rationale and design of the Diet Restriction and Exercise-induced Adaptations in Metastatic breast cancer (DREAM) study: a 2-arm, parallel-group, phase II, randomized control trial of a short-term, calorie-restricted, and ketogenic diet plus exercise during intravenous chemotherapy versus usual care

BACKGROUND

An underlying cause of solid tumor resistance to chemotherapy treatment is diminished tumor blood supply, which leads to a hypoxic microenvironment, dependence on anaerobic energy metabolism, and impaired delivery of intravenous treatments. Preclinical data suggest that dietary strategies of caloric restriction and low-carbohydrate intake can inhibit glycolysis, while acute exercise can transiently enhance blood flow to the tumor and reduce hypoxia. The Diet Restriction and Exercise-induced Adaptations in Metastatic Breast Cancer (DREAM) study will compare the effects of a short-term, 50% calorie-restricted and ketogenic diet combined with aerobic exercise performed during intravenous chemotherapy treatment to usual care on changes in tumor burden, treatment side effects, and quality of life.

METHODS

Fifty patients with measurable metastases and primary breast cancer starting a new line of intravenous chemotherapy will be randomly assigned to usual care or the combined diet and exercise intervention. Participants assigned to the intervention group will be provided with food consisting of 50% of measured calorie needs with 80% of calories from fat and ≤ 10% from carbohydrates for 48-72 h prior to each chemotherapy treatment and will perform 30-60 min of moderate-intensity cycle ergometer exercise during each chemotherapy infusion, for up to six treatment cycles. The diet and exercise durations will be adapted for each chemotherapy protocol. Tumor burden will be assessed by change in target lesion size using axial computed tomography (primary outcome) and magnetic resonance imaging (MRI)-derived apparent diffusion coefficient (secondary outcome) after up to six treatments. Tertiary outcomes will include quantitative MRI markers of treatment toxicity to the heart, thigh skeletal muscle, and liver, and patient-reported symptoms and quality of life. Exploratory outcome measures include progression-free and overall survival.

DISCUSSION

The DREAM study will test a novel, short-term diet and exercise intervention that is targeted to mechanisms of tumor resistance to chemotherapy. A reduction in lesion size is likely to translate to improved cancer outcomes including disease progression and overall survival. Furthermore, a lifestyle intervention may empower patients with metastatic breast cancer by actively engaging them to play a key role in their treatment.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03795493 , registered 7 January, 2019.

Nighttime compression supports improved self-management of breast cancer-related lymphedema: A multicenter randomized controlled trial

BACKGROUND

Lymphedema is a prevalent long-term effect of breast cancer treatment associated with reduced quality of life. This study examined the efficacy of nighttime compression as a self-management strategy for women with chronic breast cancer-related lymphedema.

METHODS

Th authors conducted a parallel 3-arm, multicenter, randomized trial. Women were recruited from 3 centers in Canada and randomized to group 1 (daytime compression garment alone [standard care]), group 2 (daytime compression garment plus nighttime compression bandaging), or group 3 (daytime compression garment plus the use of a nighttime compression system garment). The primary outcome was the change in excess arm volume from the baseline to 12 weeks. Participants from all groups used a nighttime compression system garment from weeks 13 to 24.

RESULTS

One hundred twenty women were enrolled, 118 completed the randomized trial, and 114 completed the 24-week follow-up. The rates of adherence to nighttime compression were 95% ± 15% and 96% ± 11% in the compression bandaging and nighttime compression system groups, respectively. After the intervention, the addition of nighttime compression was found to be superior to standard care for both absolute milliliter reductions (P = .006) and percentage reductions (P = .002) in excess arm lymphedema volume. Significant within-group changes were seen for quality of life across all groups; however, no between-group differences were found (P > .05).

CONCLUSIONS

The trial demonstrated a significant improvement in arm lymphedema volume from the addition of nighttime compression whether through the application of compression bandaging or through the use of a nighttime compression system garment.

LAY SUMMARY

Lymphedema is swelling that occurs in the arm on the side of the surgery for breast cancer. Lymphedema occurs in approximately 21% of women. Lymphedema tends to worsen over time and can result in recurrent infections in the arm, functional impairment, and pain. Currently, treatment consists of intensive treatments to reduce the swelling followed by regular use of a compression sleeve during the day. This study examined and found a benefit from the addition of nighttime compression (whether through self-applied compression bandaging or through the use of a nighttime compression system garment) to the use of a daytime compression sleeve.

Exercise and health-related fitness predictors of chemotherapy completion in breast cancer patients: pooled analysis of two multicenter trials

PURPOSE

Achieving a higher chemotherapy completion rate is associated with better outcomes in breast cancer patients. We examined the role of exercise and health-related fitness variables in predicting chemotherapy completion in early stage breast cancer patients.

METHODS

We pooled data from two large, multicenter, exercise trials that obtained baseline (pre-chemotherapy) measures of exercise and health-related fitness in 543 breast cancer patients initiating adjuvant chemotherapy. Assessments included body composition, cardiovascular fitness, muscular strength, patient-reported physical functioning, and self-reported exercise behavior. Chemotherapy completion was assessed as the average relative dose intensity (RDI) for the originally planned regimen. We used logistic regression analyses with a two-sided p value of < 0.05 to estimate the associations between the predictors and an RDI of ≥ 85%.

RESULTS

Overall, 432 of 543 (79.6%) breast cancer patients received an RDI of ≥ 85%. In logistic regression analyses adjusted for significant covariates, patients in the highest 20% vs. lowest 80% of absolute VO_2peak were significantly more likely to complete ≥ 85% RDI (89.0% vs. 77.2%; OR_adj 2.06, 95% CI 1.07-3.96, p = 0.031). Moreover, patients in the highest 80% vs. lowest 20% of absolute chest strength were significantly more likely to complete ≥ 85% RDI (81.5% vs. 71.4%; OR_adj 1.80, 95% CI 1.09-2.98, p = 0.021).

CONCLUSIONS

In these exploratory analyses, higher baseline (pre-chemotherapy) cardiovascular fitness and muscular strength were associated with higher rates of chemotherapy completion in early stage breast cancer patients. Aerobic and/or strength training interventions that increase cardiovascular fitness and muscular strength prior to chemotherapy for breast cancer may improve treatment tolerability and outcomes.

CLINICAL TRIAL REGISTRATION

START: NCT00115713, June 24, 2005; CARE: NCT00249015, November 7, 2005 ( http://clinicaltrials.gov ).

Uridine Glucuronosyltransferase 2B7 Polymorphism-Based Pharmacogenetic Dosing of Epirubicin in FEC Chemotherapy for Early-Stage Breast Cancer

BACKGROUND

Epirubicin is metabolized by uridine glucuronosyltransferase 2B7 (UGT2B7). Patients homozygous for the minor allele (CC) in the UGT2B7 -161 promoter polymorphism have lower clearance and significantly higher rates of leukopenia compared to wild-type homozygote (TT) or heterozygote (CT) patients. This study was designed to determine if TT and CT genotype patients could tolerate a higher epirubicin dose compared to CC genotype patients.

PATIENTS AND METHODS

We studied women with histologically confirmed non-metastatic, invasive breast cancer who were scheduled to receive at least three cycles of FE₁₀₀C in the (neo)adjuvant setting. Patients received standard-dose FE₁₀₀C during the first 21-day cycle. Based on genotype, the epirubicin dose was escalated in the second and third cycles to 115 and 130 mg/m² or to 120 and 140 mg/m² for CT and TT genotype patients, respectively. The main outcome measurements were myelosuppression and dose-limiting toxicity. These were analyzed for relationships with the three genotypes.

RESULTS

Forty-five patients were enrolled (10 CC, 21 CT, and 14 TT genotypes) and received 100 mg/m² of epirubicin in the first cycle. Twelve and 10 TT patients were dose escalated at the second and third cycles, respectively; 16 CT patients were dose escalated at the second and third cycles. Leukopenia, but not febrile neutropenia, was genotype and dose dependent and increased in patients with CT and TT genotypes as their dose was increased. However, the third-cycle leukopenia rates were comparable to patients with the CC genotype receiving standard-dose epirubicin.

CONCLUSION

Pharmacogenetically guided epirubicin dosing is well tolerated and allowed dose escalation without increased toxicity.

Cardiac and Cardiometabolic Phenotyping of Trastuzumab-Mediated Cardiotoxicity: a Secondary Analysis of the MANTICORE trial

AIMS

An improved understanding of the pathophysiology of trastuzumab-mediated cardiotoxicity is required to improve outcomes of patients with HER2-positive breast cancer. We aimed to characterize the cardiac and cardiometabolic phenotype of trastuzumab-mediated toxicity and potential interactions with cardiac pharmacotherapy.

METHODS AND RESULTS

This study was an analysis of serial magnetic resonance imaging (MRI) and circulating biomarker data acquired from patients with HER2-positive early stage breast cancer participating in a randomized-controlled clinical trial for the pharmaco-prevention of trastuzumab-associated cardiotoxicity. Circulating biomarkers (B-type natriuretic peptide, troponin I, MMP-2 and -9, GDF-15, neuregulin-1 and IGF-1) and MRI of cardiac structure and function and abdominal fat distribution were acquired prior to trastuzumab, post-cycle 4 and post-cycle 17. Ninety-four participants (51±8 years) completed the study with 30 on placebo, 33 on perindopril, and 31 on bisoprolol. Post-cycle 4, global longitudinal strain (GLS) deteriorated from baseline in both placebo (+2.0±2.7%, p = 0.002) and perindopril (+0.9±2.5%, p = 0.04), but not with bisoprolol (-0.2±2.1%, p = 0.55). In all groups combined, extracellular volume fraction and GDF-15 increased post-cycle 4 (+1.3±4.4%, p = 0.004; +130±150%, p ≤ 0.001, respectively). However, no significant change in troponin I was detected throughout trastuzumab. In all groups combined, visceral and intermuscular fat volume increased post-cycle 4 (+7±17%, p = 0.02, +8±23%, p = 0.02, respectively), while muscle volume and IGF-1 decreased from post-cycle 4 to 17 (-2±10%, p = 0.008, -18±28%, p < 0.001, respectively).

CONCLUSION

Trastuzumab results in impaired cardiac function and early myocardial inflammation. Trastuzumab is also associated with deleterious changes to the cardiometabolic phenotype which may contribute to the increased cardiovascular risk in this population.

Aerobic Fitness Is Related to Myocardial Fibrosis Post-Anthracycline Therapy

PURPOSE

We evaluated the impact of anthracyclines on left ventricular function and myocardial tissue characteristics using cardiovascular magnetic resonance (CMR) imaging to determine their relationship with V˙O2peak.

METHODS

Women with breast cancer who had not yet received treatment (No-AT, n = 16) and had received anthracycline treatment ~1 yr earlier (Post-AT, n = 16) and controls without cancer (CON, n = 16) performed a maximal exercise test and a comprehensive 3T CMR examination, including native myocardial T1 mapping, where elevated T1 times are indicative of myocardial fibrosis. ANOVA and linear regression were used to compare CMR variables between groups and to determine associations with V˙O2peak. Subgroup analysis was performed by categorizing participants as "fit" or "unfit" based on whether their V˙O2peak value was greater or less than 100% of reference value for age, respectively.

RESULTS

Left ventricular end-diastolic volume, ejection fraction, and mass were similar between groups. Post-AT, T1 times were elevated (1534 ± 32 vs 1503 ± 28 ms, P < 0.01), and V˙O2peak was reduced (23.1 ± 7.5 vs 29.5 ± 7.7 mL·kg-1⋅min-1, P = 0.02) compared with CON. In No-AT, T1 times and V˙O2peak were similar to CON. In the Post-AT group, T1 time was associated with V˙O2peak (R2 = 64%), whereas in the absence of anthracyclines (i.e., No-AT and CON groups), T1 time was not associated with V˙O2peak. Regardless of group, all fit women had similar T1 times, whereas unfit women Post-AT had higher T1 than unfit CON (1546 ± 22 vs 1500 ± 33 ms, P < 0.01).

CONCLUSIONS

After anthracycline chemotherapy, an elevated T1 time suggesting greater extent of myocardial fibrosis, was associated with lower V˙O2peak. However, those who were fit did not have evidence of myocardial fibrosis after anthracycline treatment.

N-myristoyltransferase proteins in breast cancer: prognostic relevance and validation as a new drug target

Purpose

N-myristoyltransferases 1 and 2 (NMT1 and NMT2) catalyze the addition of 14-carbon fatty acids to the N-terminus of proteins. Myristoylation regulates numerous membrane-bound signal transduction pathways important in cancer biology and the pan-NMT inhibitor PCLX-001 is approaching clinical development as a cancer therapy. The tissue distribution, relative abundances, and prognostic value of the two human NMTs remain poorly understood.

Methods

We generated and validated mutually exclusive monoclonal antibodies (mAbs) specific to human NMT1 and NMT2. These mAbs were used to perform immunohistochemical analysis of the abundance and distribution of NMT1 and NMT2 in normal breast epithelial samples and a large cohort of primary breast adenocarcinomas from the BCIRG001 clinical trial (n = 706).

Results

NMT1 protein was readily quantified in normal and most transformed breast epithelial tissue and was associated with higher overall histologic grade, higher Ki67, and lower hormone receptor expression. While NMT2 protein was readily detected in normal breast epithelial tissue, it was undetectable in the majority of breast cancers. Detectable NMT2 protein correlated with significantly poorer overall survival (hazard ratio 1.36; P = 0.029) and worse biological features including younger age, higher histologic grade, lower hormone receptor expression, higher Ki67, and p53 positivity. Treatment of cultured breast cancer cells with PCLX-001 reduced cell viability in vitro. Daily oral administration of PCLX-001 to immunodeficient mice bearing human MDA-MB-231 breast cancer xenografts produced significant dose-dependent tumor growth inhibition in vivo.

Conclusions

These results support further evaluation of NMT immunohistochemistry for patient selection and clinical trials of NMT inhibition in breast cancer patients.

Supplementary Information

The online version of this article (10.1007/s10549-020-06037-y) contains supplementary material, which is available to authorized users.

Histopathology for Mohs micrographic surgery with photoacoustic remote sensing microscopy

Mohs micrographic surgery (MMS) is a precise oncological technique where layers of tissue are resected and examined with intraoperative histopathology to minimize the removal of normal tissue while completely excising the cancer. To achieve intraoperative pathology, the tissue is frozen, sectioned and stained over a 20- to 60-minute period, then analyzed by the MMS surgeon. Surgery is continued one layer at a time until no cancerous cells remain, meaning MMS can take several hours to complete. Ideally, it would be desirable to circumvent or augment frozen sectioning methods and directly visualize subcellular morphology on the unprocessed excised tissues. Employing photoacoustic remote sensing (PARS) microscopy, we present a non-contact label-free reflection-mode method of performing such visualizations in frozen sections of human skin. PARS leverages endogenous optical absorption contrast within cell nuclei to provide visualizations reminiscent of histochemical staining techniques. Presented here, is the first true one to one comparison between PARS microscopy and standard histopathological imaging in human tissues. We demonstrate the ability of PARS microscopy to provide large grossing scans (>1 cm2, sufficient to visualize entire MMS sections) and regional scans with subcellular lateral resolution (300 nm).

Targeting N-myristoylation for therapy of B-cell lymphomas

Myristoylation, the N-terminal modification of proteins with the fatty acid myristate, is critical for membrane targeting and cell signaling. Because cancer cells often have increased N-myristoyltransferase (NMT) expression, NMTs were proposed as anti-cancer targets. To systematically investigate this, we performed robotic cancer cell line screens and discovered a marked sensitivity of hematological cancer cell lines, including B-cell lymphomas, to the potent pan-NMT inhibitor PCLX-001. PCLX-001 treatment impacts the global myristoylation of lymphoma cell proteins and inhibits early B-cell receptor (BCR) signaling events critical for survival. In addition to abrogating myristoylation of Src family kinases, PCLX-001 also promotes their degradation and, unexpectedly, that of numerous non-myristoylated BCR effectors including c-Myc, NFκB and P-ERK, leading to cancer cell death in vitro and in xenograft models. Because some treated lymphoma patients experience relapse and die, targeting B-cell lymphomas with a NMT inhibitor potentially provides an additional much needed treatment option for lymphoma.

Improving maximal safe brain tumor resection with photoacoustic remote sensing microscopy

Malignant brain tumors are among the deadliest neoplasms with the lowest survival rates of any cancer type. In considering surgical tumor resection, suboptimal extent of resection is linked to poor clinical outcomes and lower overall survival rates. Currently available tools for intraoperative histopathological assessment require an average of 20 min processing and are of limited diagnostic quality for guiding surgeries. Consequently, there is an unaddressed need for a rapid imaging technique to guide maximal resection of brain tumors. Working towards this goal, presented here is an all optical non-contact label-free reflection mode photoacoustic remote sensing (PARS) microscope. By using a tunable excitation laser, PARS takes advantage of the endogenous optical absorption peaks of DNA and cytoplasm to achieve virtual contrast analogous to standard hematoxylin and eosin (H&E) staining. In conjunction, a fast 266 nm excitation is used to generate large grossing scans and rapidly assess small fields in real-time with hematoxylin-like contrast. Images obtained using this technique show comparable quality and contrast to the current standard for histopathological assessment of brain tissues. Using the proposed method, rapid, high-throughput, histological-like imaging was achieved in unstained brain tissues, indicating PARS’ utility for intraoperative guidance to improve extent of surgical resection.

All-optical label-free human breast tissue block histology using photoacoustic remote sensing

The direct imaging of tissue preserved in formalin-fixed paraffin-embedded (FFPE) blocks remains a challenge. There are presently millions of tissues preserved as FFPE blocks whose assessment via bright-field microscopes requires them to be sectioned and subsequently stained. These processes are laborious, resource-intensive, and time consuming. In this Letter, we utilize an ultraviolet laser with photoacoustic remote sensing to provide a novel method that enables direct label-free pathological assessment of FFPE blocks. We demonstrate the efficacy of this technique by imaging human breast tissue, highlighting salient features such as ducts, adipocytes, and ductal hyperplasia. This direct imaging of FFPE blocks facilitates pathological assessment much earlier in the histopathological workflow, saving valuable time in clinical and research settings. The presented non-contact label-free reflection-mode device enables augmentation of existing histopathological workflows and aims to expand the arsenal of imaging technologies available to clinicians.

Abstract 1782: N-myristoyltransferase proteins in breast cancer: Prognostic relevance and validation as a new drug target

N-myristoyltransferases (NMTs) catalyze the addition of 14-carbon fatty acids to the N-terminus of proteins. This activity regulates numerous membrane-bound signal transduction pathways important in cancer biology, and the pan-NMT inhibitor PCLX-001 is in clinical development as a cancer therapy. The physiologic distribution and relative contributions of the two human NMTs, NMT1 and NMT2, remain poorly understood as previous studies used polyclonal antibodies with potential cross-reactivity. We generated and validated mutually exclusive monoclonal antibodies (mAbs) specific to the human isotypes of NMT1 and NMT2. These mAbs were used to perform an immunohistochemical (IHC) analysis of the abundance and distribution of NMT1 and NMT2 in normal human breast epithelial samples and a large (n=703) cohort of primary breast adenocarcinomas from the BCIRG001 study. While NMT1 protein was readily identifiable in most normal and transformed breast epithelial tissue, NMT1 abundance was associated with higher overall histologic grade, higher Ki67, and lower hormone expression. While NMT2 protein was readily detected in normal breast epithelial tissue, NMT2 protein was undetectable in the majority of malignant breast cancers, but detectable NMT2 protein correlated with significantly poorer overall survival outcomes (hazard ratio for death 1.36; p &lt; 0.029) and significantly worse biological features including younger age, higher histologic grade, lower hormone receptor expression, higher Ki67, and p53 positivity. NMT status was unrelated to HER2 status. NMT1 and NMT2 protein abundances were positively correlated with each other. Treatment of cultured breast cancer cells with the pan-NMT inhibitor PCLX-001 reduced cell viability in vitro. Daily oral administration of PCLX-001 to immunodeficient mice bearing human MDA-MB-231 breast cancer xenografts induced significant dose-dependent tumor growth inhibition in vivo. These results support the further evaluation of NMT immunohistochemistry for selection of patients for NMT inhibitor therapy, and clinical trials of NMT inhibition in breast cancer patients.

Citation Format: John R. Mackey, Justine Lai, Utkarsh Chauhan, Wei-Feng Dong, Darryl Glubrect, Sunita Ghosh, Gilbert Bigras, Raymond Lai, Luc G. Berthiaume. N-myristoyltransferase proteins in breast cancer: Prognostic relevance and validation as a new drug target [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1782.

Abstract 5156: Targeting N-myristoylation in B-cell lymphomas as a therapeutic strategy

Myristoylation is the N-terminal modification of proteins with the fatty acid myristate. This process is mediated by two ubiquitously expressed N-myristoyltransferases, NMT1 and NMT2, and is critical for membrane targeting and cell signaling. Because NMT expression is increased in some cancers, we used three robotic screens to evaluate the potential of the potent pan-NMT inhibitor PCLX-001 on 300 cancer cell lines spanning the spectrum of human cancers. We discovered a marked increase in the sensitivity of hematological cancer cell lines, including B-cell lymphomas, to myristoylation inhibition. PCLX-001 consistently reduced both lymphoma cell proliferation and viability at concentrations lower than those needed to inhibit the growth of or to kill benign immortalized B cells. In lymphoma cell lines, PCLX-001 treatment inhibited early B-cell receptor (BCR) signaling events by disrupting membrane targeting of several myristoylated Src family kinases and promoted their ubiquitin-mediated degradation. Unexpectedly, PCLX-001 also promoted the degradation of non-myristoylated transcriptional activators P-ERK, c-Myc, NFκB and CREB downstream in the BCR signaling cascade, leading to loss of survival signals and apoptosis. Furthermore, compared to clinically approved drugs dasatinib and ibrutinib, PCLX-001 was more potent in vitro at inhibiting B-cell signaling, had a wider breadth of efficacy, and had greater selectivity thus sparing normal B cells. PCLX-001 treatment reduced tumor size in a time and concentration dependent manner in three B-cell lymphoma xenograft models and resulted in complete disease regression in two of these models, including an R-CHOP refractory lymphoma patient-derived xenograft. To investigate the potential mechanisms responsible for the sensitivity of hematological cancers to PCLX-001, we examined the NMT expression levels in cancer cells using publically available databases. Contrary to the reported NMT overexpression in some cancers, we found that hematological cancer cell lines and tumors both display significant reduction in NMT2 expression. The decreased NMT2 expression is significantly correlated with lower EC50 and poorer patient prognosis. Using the CRISPR-based genetic alteration Cancer Dependency Map, we discovered that cancer cells are highly dependent on functional NMT1, and that NMT1 dependency increases with low NMT2 expression. PCLX-001 treatment may mimic the effect of genetic alteration of NMT1 in hematological cancer cells low in NMT2 by pharmacologically inhibiting the remaining NMT1 in these cells. This results in an effect reminiscent of synthetic lethality since the vast majority of normal cells express both NMTs and PCLX-001 selectively kills NMT2-deficient cancer cells while sparing normal cells. Our findings support the ongoing development and eventual clinical trials of PCLX-001 as a therapy for hematological cancers.

Citation Format: Erwan Beauchamp, Megan C. Yap, Maneka A. Perinpanayagam, Jay M. Gamma, Krista M. Vincent, Raymond Lai, Wei-Feng Dong, Manikandan Lakshmanan, Anandhkumar Raju, Vinay Tergaonkar, Soo Yong Tan, Soon Thye Lim, Lynne Postovit, Kevin D. Read, David W. Gray, Paul G. Wyatt, John R. Mackey, Luc G. Berthiaume. Targeting N-myristoylation in B-cell lymphomas as a therapeutic strategy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5156.

Breast cancer diagnosis is associated with relative left ventricular hypertrophy and elevated endothelin-1 signaling

BACKGROUND

The survival rates of women with breast cancer have improved significantly over the last four decades due to advances in breast cancer early diagnosis and therapy. However, breast cancer survivors have an increased risk of cardiovascular complications following chemotherapy. While this increased risk of later occurring structural cardiac remodeling and/or dysfunction has largely been attributed to the cardiotoxic effects of breast cancer therapies, the effect of the breast tumor itself on the heart prior to cancer treatment has been largely overlooked. Thus, the objectives of this study were to assess the cardiac phenotype in breast cancer patients prior to cancer chemotherapy and to determine the effects of human breast cancer cells on cardiomyocytes.

METHODS

We investigated left ventricular (LV) function and structure using cardiac magnetic resonance imaging in women with breast cancer prior to systemic therapy and a control cohort of women with comparable baseline factors. In addition, we explored how breast cancer cells communicate with the cardiomyocytes using cultured human cardiac and breast cancer cells.

RESULTS

Our results indicate that even prior to full cancer treatment, breast cancer patients already exhibit relative LV hypertrophy (LVH). We further demonstrate that breast cancer cells likely contribute to cardiomyocyte hypertrophy through the secretion of soluble factors and that at least one of these factors is endothelin-1.

CONCLUSION

Overall, the findings of this study suggest that breast cancer cells play a greater role in inducing structural cardiac remodeling than previously appreciated and that tumor-derived endothelin-1 may play a pivotal role in this process.

Towards virtual biopsies of gastrointestinal tissues using photoacoustic remote sensing microscopy

Gastrointestinal (GI) tissue biopsies provide critical diagnostic information for a wide variety of conditions such as neoplastic diseases (colorectal, small bowel and stomach cancers) and non-neoplastic diseases (inflammatory disorders, infection, celiac disease). Endoscopic biopsies collect small tissue samples that require resource intensive processing to permit histopathological analysis. Unfortunately, the sparsely collected biopsy samples may fail to capture the pathologic condition because selection of biopsy sites relies on macroscopic superficial tissue features and clinician judgement. Here, we present the first all-optical non-contact label-free non-interferometric photoacoustic microscopy system capable of performing "virtual biopsies". A modular photoacoustic remote sensing (PARS™) architecture is used facilitating imaging of unprocessed tissues providing information similar to conventional histopathological staining techniques. Prospectively this would allow gastroenterologists to assess subcellular tissue morphology in situ when selecting biopsy location. Tested on preserved unstained human and freshly resected murine tissues, the presented PARS microscope rapidly retrieves images of similar area to current biopsies, while maintaining comparable quality to the current standard for histopathological analysis. Additionally, results show the first label free assessment of subsurface cellular morphology in FFPE GI tissue blocks. Clinically relevant features are recovered including cellular details such as lamina propria within colon tissue and cell nuclear structure in resected smooth muscle. Constructed with a modular architecture, this system facilitates the future development of compact imaging heads. The modular PARS system overcomes many of the challenges with imaging unstained thick tissue in situ, representing a significant milestone in the development of a clinical microscope providing virtual biopsy capabilities.

Fine-mapping of a novel premenopausal breast cancer susceptibility locus at Chr4q31.22 in Caucasian women and validation in African and Chinese women

We previously identified a novel breast cancer susceptibility variant on chromosome 4q31.22 locus (rs1429142) conferring risk among women of European ancestry. Here, we report replication of findings, validation of the variant in diverse populations and fine-mapping of the associated locus in Caucasian population. The SNP rs1429142 (C/T, minor allele frequency 18%) showed association for the overall breast cancer risk in Stages 1-4 (n = 4,331 cases/4271 controls; p = 4.35 × 10^-8 ; odds ratio, OR_C-allele ,1.25), and an elevated risk among premenopausal women (n = 1,503 cases/4271 controls; p = 5.81 × 10^-10 ; OR_C-allele 1.40) in European populations. SNP rs1429142 was associated with premenopausal breast cancer risk in women of African (T/C; p-value 1.45 × 10^-02 ; OR_C-allele 1.2) but not from Chinese ancestry. Fine-mapping of the locus revealed several potential causal variants which are present within a single association signal, revealed from the conditional regression analysis. Functional annotation of the potential causal variants revealed three putative SNPs rs1366691, rs1429139 and rs7667633 with active enhancer functions inferred based on histone marks, DNase hypersensitive sites in breast cell line data. These putative variants were bound by transcription factors (C-FOS, STAT1/3 and POL2/3) with known roles in inflammatory pathways. Furthermore, Hi-C data revealed several short-range interactions in the fine-mapped locus harboring the putative variants. The fine mapped locus was predicted to be within a single topologically associated domain, potentially facilitating enhancer-promoter interactions possibly leading to the regulation of nearby genes.

Patterns and predictors of exercise behavior during 24 months of follow-up after a supervised exercise program during breast cancer chemotherapy

Background

Understanding the longer-term exercise behavior of patients with breast cancer after chemotherapy is important to promote sustained exercise. The purpose of the current study was to report the longer-term patterns and predictors of exercise behavior in patients with breast cancer who exercised during chemotherapy.

Methods

In the Combined Aerobic and Resistance Exercise (CARE) Trial, 301 patients with breast cancer were randomized to three different exercise prescriptions during chemotherapy. Exercise behaviors after chemotherapy were self-reported at 6-, 12-, and 24-month follow-up. Exercise patterns were identified by categorizing patients according to which exercise guideline they were meeting (neither, aerobic only, resistance only, or combined) at each of the three follow-up timepoints (64 possible patterns). Predictors of longer-term exercise behavior included physical fitness, patient-reported outcomes, and motivational variables from the theory of planned behavior assessed at postintervention (postchemotherapy). Univariate and multivariate stepwise multinomial logistic regression and linear regression were used for statistical analyses.

Results

A total of 264 (88%) participants completed all three follow-up exercise behavior assessments and exhibited 50 different exercise patterns. Postintervention aerobic fitness was the most consistent predictor of longer-term exercise behavior at all three timepoints. For example, higher aerobic fitness (per 1 ml/kg/min) predicted better adherence to the “aerobic only” (OR = 1.09; p = 0.005) and “combined” (OR = 1.12; p < 0.001) guidelines compared to “neither” guideline at 6-month follow-up. Additionally, higher postintervention muscular strength (per 1 kg) was associated with better adherence to the “resistance only” (OR = 1.07; p = 0.025) and “combined” (OR = 1.08; p < 0.001) guidelines compared to “neither” guideline at 24-month follow-up. Finally, lower perceived difficulty (per 1 scale point) was associated with better adherence to the “combined” (OR = 0.62; p = 0.010) and “aerobic only” (OR = 0.58; p = 0.002) guideline compared to the “neither” guideline at the 24-month follow-up.

Conclusions

Our study is the first to show that the longer-term exercise patterns of patients with breast cancer who exercised during chemotherapy are diverse and predicted by physical fitness and motivational variables after chemotherapy. Our novel implications are that improving physical fitness during chemotherapy and applying motivational counseling after chemotherapy may improve longer-term exercise behavior in patients with breast cancer.

Trial registration

(NCT00249015).

Seroprevalence of Human Betaretrovirus Surface Protein Antibodies in Patients with Breast Cancer and Liver Disease

Mouse mammary tumor virus (MMTV) is a betaretrovirus that plays a causal role in the development of breast cancer and lymphoma in mice. Closely related sequences that share 91-99% nucleotide identity with MMTV have been repeatedly found in humans with neoplastic and inflammatory diseases. Evidence for infection with a betaretrovirus has been found in patients with breast cancer and primary biliary cholangitis and referred to as the human mammary tumor virus and the human betaretrovirus (HBRV), respectively. Using the gold standard technique of demonstrating retroviral infection, HBRV proviral integrations have been detected in cholangiocytes, lymph nodes, and liver of patients with primary biliary cholangitis. However, the scientific biomedical community has not embraced the hypothesis that MMTV like betaretroviruses may infect humans because reports of viral detection have been inconsistent and robust diagnostic assays are lacking. Specifically, prior serological assays using MMTV proteins have produced divergent results in human disease. Accordingly, a partial HBRV surface (Su) construct was transfected into HEK293 to create an ELISA. The secreted HBRV gp52 Su protein was then used to screen for serological responses in patients with breast cancer and liver disease. A greater proportion of breast cancer patients (n = 98) were found to have serological reactivity to HBRV Su as compared to age- and sex-matched control subjects (10.2% versus 2.0%, P=0.017, OR = 5.6 [1.25-26.3]). Similarly, the frequency of HBRV Su reactivity was higher in patients with primary biliary cholangitis (n  =  156) as compared to blood donors (11.5% vs. 3.1%, P=0.0024, OR = 4.09 [1.66-10.1]). While the sensitivity of the HBRV Su ELISA was limited, the assay was highly specific for serologic detection in patients with breast cancer or primary biliary cholangitis, respectively (98.0% [93.1%-99.7%] and 97.0% [93.4%-98.6%]). Additional assays will be required to link immune response to betaretrovirus infection and either breast cancer or primary biliary cholangitis.

Exercise Intolerance in Anthracycline-Treated Breast Cancer Survivors: The Role of Skeletal Muscle Bioenergetics, Oxygenation, and Composition

BACKGROUND

Peak oxygen consumption (VO₂ ) is reduced in women with a history of breast cancer (BC). We measured leg blood flow, oxygenation, bioenergetics, and muscle composition in women with BC treated with anthracycline chemotherapy (n = 16, mean age: 56 years) and age- and body mass index-matched controls (n = 16).

MATERIALS AND METHODS

Whole-body peak VO₂ was measured during cycle exercise. ³¹ Phosphorus magnetic resonance (MR) spectroscopy was used to measure muscle bioenergetics during and after incremental to maximal plantar flexion exercise (PFE). MR imaging was used to measure lower leg blood flow, venous oxygen saturation (S_v O₂ ), and VO₂ during submaximal PFE, and abdominal, thigh, and lower leg intermuscular fat (IMF) and skeletal muscle (SM).

RESULTS

Whole-body peak VO₂ was significantly lower in BC survivors versus controls (23.1 ± 7.5 vs. 29.5 ± 7.7 mL/kg/minute). Muscle bioenergetics and mitochondrial oxidative capacity were not different between groups. No group differences were found during submaximal PFE for lower leg blood flow, S_v O₂ , or VO₂ . The IMF-to-SM ratio was higher in the thigh and lower leg in BC survivors (0.36 ± 0.19 vs. 0.22 ± 0.07, p = .01; 0.10 ± 0.06 vs. 0.06 ± 0.02, p = .03, respectively) and were inversely related to whole-body peak VO₂ (r = -0.71, p = .002; r = -0.68, p = .003, respectively)_. In the lower leg, IMF-to-SM ratio was inversely related to VO₂ and O₂ extraction during PFE.

CONCLUSION

SM bioenergetics and oxidative capacity in response to PFE are not impaired following anthracycline treatment. Abnormal SM composition (increased thigh and lower leg IMF-to-SM ratio) may be an important contributor to reduced peak VO₂ during whole-body exercise among anthracycline-treated BC survivors.

IMPLICATIONS FOR PRACTICE

Peak oxygen consumption (peak VO₂ ) is reduced in breast cancer (BC) survivors and is prognostic of increased risk of cardiovascular disease-related and all-cause mortality. Results of this study demonstrated that in the presence of deficits in peak VO₂ 1 year after anthracycline therapy, skeletal muscle bioenergetics and oxygenation are not impaired. Rather, body composition deterioration (e.g., increased ratio of intermuscular fat to skeletal muscle) may contribute to reduced exercise tolerance in anthracycline BC survivors. This finding points to the importance of lifestyle interventions including caloric restriction and exercise training to restore body composition and cardiovascular health in the BC survivorship setting.

Development and validation of a compact on-person storage device (SMHeartCard) for emergency access to acetylsalicylic acid and nitroglycerin

BACKGROUND

Guidelines recommend that patients with coronary artery disease (CAD) carry and immediately use acetylsalicylic acid (ASA) and sublingually administered nitroglycerin at the onset of chest pain; however, compliance with these recommendations is poor. We designed and tested a compact on-person storage device for these medications.

METHODS

We designed an airtight, light-proof and chemically inert holder to carry four 81-mg ASA tablets and three 0.3-mg Nitrostat (nitroglycerin, Pfizer) tablets. After establishing the temperatures ranges in wallets and pockets, we tested nitroglycerin dissolution and release of the stored Nitrostat tablets across a range of relevant temperatures and a variety of tablet enclosure systems.

RESULTS

Microcalorimeter thermal conduction studies as well as dissolution and release testing showed that nitroglycerin tablets were stable at temperatures ranging from -20°C to 60°C for 1 week. In testing up to 24 weeks, 0.3-mg Nitrostat tablets enclosed completely in polytetrafluoroethylene (PTFE) performed similarly to those stored in the manufacturer's borosilicate glass packaging across a wide range of temperatures relevant to on-person carriage. Real-world on-person testing for 24 weeks confirmed these results. Non-PTFE enclosures performed poorly.

INTERPRETATION

The PTFE enclosure with a PTFE-coated cap liner maintained long-term performance of 0.3-mg Nitrostat tablets under laboratory and real-world conditions. This storage device is now commercially available as the SMHeartCard to improve compliance and provide immediate access to emergency cardiac medications.

Assessment of ERBB2/HER2 Status in HER2-Equivocal Breast Cancers by FISH and 2013/2014 ASCO-CAP Guidelines

Importance

The 2013/2014 American Society of Clinical Oncology and College of American Pathologists (ASCO-CAP) guidelines for HER2 testing by fluorescence in situ hybridization (FISH) designated an "equivocal" category (average HER2 copies per tumor cell ≥4-6 with HER2/CEP17 ratio <2.0) to be resolved as negative or positive by assessments with alternative control probes. Approximately 4% to 12% of all invasive breast cancers are characterized as HER2-equivocal based on FISH.

Objective

To evaluate the following hypotheses: (1) genetic loci used as alternative controls are heterozygously deleted in a substantial proportion of breast cancers; (2) use of these loci for assessment of HER2 by FISH leads to false-positive assessments; and (3) these HER2 false-positive breast cancer patients have outcomes that do not differ from clinical outcomes for patients with HER2-negative breast cancer.

Design, Setting, and Participants

We retrospectively assessed the use of chromosome 17 p-arm and q-arm alternative control genomic sites (TP53, D17S122, SMS, RARA, TOP2A), as recommended by the 2013/2014 ASCO-CAP guidelines for HER2 testing, in patients whose data were available through Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and whose tissues were available through the Breast Cancer International Research Group clinical trials. We used data from an international cohort database of invasive breast cancers (1980 participants) and international clinical trial of adjuvant chemotherapy in invasive, node-positive breast cancer patients.

Main Outcomes and Measures

The primary objectives were to (1) assess frequency of heterozygous deletions in chromosome 17 genomic sites used as FISH internal controls for evaluation of HER2 status among HER2-equivocal cancers; (2) characterize impact of using deleted sites for determination of HER2-to-internal-control-gene ratios; (3) assess HER2 protein expression in each subgroup; and (4) compare clinical outcomes for each subgroup.

Results

Of the 1980 patients in METABRIC,1915 patients were fully evaluated. In addition, 100 HER2-equivocal breast cancers by FISH and 100 comparator FISH-negative breast cancers from the BCIRG-005 trial were analyzed. Heterozygous deletions, particularly in specific p-arm sites, were common in both HER2-amplified and HER2-not-amplified breast cancers. Use of alternative control probes from these regions to assess HER2 by FISH in HER2-equivocal as well as HER2-not-amplified breast cancers resulted in high rates of false-positive ratios (HER2-to-alternative control ratio ≥2.0) owing to heterozygous deletions of control p-arm genomic sites used in ratio denominators. Misclassification of HER2 status was observed not only in breast cancers with ASCO-CAP equivocal status but also in breast cancers with an average of fewer than 4.0 HER2 copies per tumor cell when using alternative control probes.

Conclusions and Relevance

The indiscriminate use of alternative control probes to calculate HER2 FISH ratios in HER2-equivocal breast cancers may lead to false-positive interpretations of HER2 status resulting from unrecognized heterozygous deletions in 1 or more of these alternative control genomic sites and incorrect HER2 ratio determinations.

Predictive and Prognostic Properties of Human Equilibrative Nucleoside Transporter 1 Expression in Gemcitabine-Treated Pancreatobiliary Cancer: A Meta-Analysis

Purpose

Gemcitabine, the primary drug for the treatment of pancreatobiliary cancer (PBC), requires human equilibrative nucleoside transporter 1 (hENT1) to enter cells. High tumoral hENT1 expression has been linked with improved survival among patients with PBC treated with gemcitabine; however, this finding has been inconsistent, and studies used different expression assays.

Methods

Databases were reviewed for studies that examined hENT1 and clinical outcome in PBC. Of 307 publications, 34 studies were found that used immunohistochemistry (IHC) with one of eight anti–hENT1 antibody assays. Five studies were excluded for redundancy, and 29 studies underwent detailed review.

Results

On average, 51% of tumor samples had high hENT1 expression (range, 7% to 92%). Among studies that examined hENT1 expression and overall survival (OS), 58% (15 of 26 studies) showed an association between high tumoral hENT1 and improved OS for gemcitabine-treated patients. Among 10D7G2 antibody studies, 88% (seven of eight studies) demonstrated this association. Studies with other antibodies—in particular, SP120 (two of nine studies)—were less consistent. The ability to detect an association between improved OS and high hENT1 was antibody dependent (χ2 P = .0237). An association between high tumoral hENT1 expression and improved disease-free/progression-free survival (DFS/PFS) was demonstrated in 71% of studies (15 of 21 studies). Pooled hazard ratio (HR) analyses of all antibody studies demonstrated a link between high hENT1 tumor expression and improved OS (HR, 0.674; 95% CI, 0.509 to 0.893; P = .006) and DFS/PFS (HR, 0.740; 95% CI, 0.517 to 0.1.059; P = .10). This signal was stronger among studies that used the 10D7G2 antibody in comparison to those in which another antibody was used, with HRs of 0.488 (95% CI, 0.396 to 0.602; P < .001) and 0.410 (95% CI, 0.280 to 0.599; P < .001), respectively.

Conclusion

High tumoral hENT1 expression on IHC with 10D7G2 is a strong and reproducible prognostic marker for improved outcome among gemcitabine-treated patients with PBC.

Chromophore selective multi-wavelength photoacoustic remote sensing of unstained human tissues

Identifying positive surgical margins after resection of cancer often triggers re-excision and adjuvant treatments. Incomplete initial resections result in poorer patient outcomes, psychological and financial stress to the patient and increased healthcare costs. Surgical margins are typically assessed post-operatively using time consuming and expensive slide-based histopathology tissue analysis. Currently, a real-time non-contact virtual histology-like intraoperative margin assessment tool is not available. To address this need, we have developed a non-contact multi-wavelength reflection-mode, photoacoustic remote sensing (PARS) microscope demonstrating chromophore selective contrast in human tissues. We show the capabilities of multi-wavelength PARS microscopy utilizing both 266 nm and 532 nm excitation wavelengths and a 1310 nm detection wavelength. Cell nuclei and hemoglobin were visualized at the cellular scale without the addition of exogenous contrast agents. These works provide a critical step towards a virtual histology tool to provide intraoperative histology-like information in living tissue.

Upregulation of Myt1 Promotes Acquired Resistance of Cancer Cells to Wee1 Inhibition

Adavosertib (also known as AZD1775 or MK1775) is a small-molecule inhibitor of the protein kinase Wee1, with single-agent activity in multiple solid tumors, including sarcoma, glioblastoma, and head and neck cancer. Adavosertib also shows promising results in combination with genotoxic agents such as ionizing radiation or chemotherapy. Previous studies have investigated molecular mechanisms of primary resistance to Wee1 inhibition. Here, we investigated mechanisms of acquired resistance to Wee1 inhibition, focusing on the role of the Wee1-related kinase Myt1. Myt1 and Wee1 kinases were both capable of phosphorylating and inhibiting Cdk1/cyclin B, the key enzymatic complex required for mitosis, demonstrating their functional redundancy. Ectopic activation of Cdk1 induced aberrant mitosis and cell death by mitotic catastrophe. Cancer cells with intrinsic adavosertib resistance had higher levels of Myt1 compared with sensitive cells. Furthermore, cancer cells that acquired resistance following short-term adavosertib treatment had higher levels of Myt1 compared with mock-treated cells. Downregulating Myt1 enhanced ectopic Cdk1 activity and restored sensitivity to adavosertib. These data demonstrate that upregulating Myt1 is a mechanism by which cancer cells acquire resistance to adavosertib. SIGNIFICANCE: Myt1 is a candidate predictive biomarker of acquired resistance to the Wee1 kinase inhibitor adavosertib.

Comparing docosahexaenoic acid (DHA) concomitant with neoadjuvant chemotherapy versus neoadjuvant chemotherapy alone in the treatment of breast cancer (DHA WIN): protocol of a double-blind, phase II, randomised controlled trial

INTRODUCTION

Neoadjuvant chemotherapy for breast cancer treatment is prescribed to facilitate surgery and provide confirmation of drug-sensitive disease, and the achievement of pathological complete response (pCR) predicts improved long-term outcomes. Docosahexaenoic acid (DHA) has been shown to reduce tumour growth in preclinical models when combined with chemotherapy and is known to beneficially modulate systemic immune function. The purpose of this trial is to investigate the benefit of DHA supplementation in combination with neoadjuvant chemotherapy in patients with breast cancer.

METHODS AND ANALYSIS

This is a double-blind, phase II, randomised controlled trial of 52 women prescribed neoadjuvant chemotherapy to test if DHA supplementation enhances chemotherapy efficacy. The DHA supplementation group will take 4.4 g/day DHA orally, and the placebo group will take an equal fat supplement of vegetable oil. The primary outcome will be change in Ki67 labelling index from prechemotherapy core needle biopsy to definitive surgical specimen. The secondary endpoints include assessment of (1) DHA plasma phospholipid content; (2) systemic immune cell types, plasma cytokines and inflammatory markers; (3) tumour markers for apoptosis and tumour infiltrating lymphocytes; (4) rate of pCR in breast and in axillary nodes; (5) frequency of grade 3 and 4 chemotherapy-associated toxicities; and (6) patient-perceived quality of life. The trial has 81% power to detect a significant between-group difference in Ki67 index with a two-sided t-test of less than 0.0497, and accounts for 10% dropout rate.

ETHICS AND DISSEMINATION

This study has full approval from the Health Research Ethics Board of Alberta - Cancer Committee (Protocol #: HREBA.CC-18-0381). We expect to present the findings of this study to the scientific community in peer-reviewed journals and at conferences. The results of this study will provide evidence for supplementing with DHA during neoadjuvant chemotherapy treatment for breast cancer.

TRIAL REGISTRATION NUMBER

NCT03831178.

Community-based exercise for health promotion and secondary cancer prevention in Canada: protocol for a hybrid effectiveness-implementation study

INTRODUCTION

Cancer care has expanded from a disease-focused, survival-oriented model to an approach that now considers how survivors can live well in the aftermath of intensive therapy, where they may deal with significant changes to their bodies, mental health or emotional well-being. Research evidence supports the benefit of exercise during and following cancer treatments for cancer-related symptoms, physical functioning and fitness, and health-related quality of life. To move this efficacy evidence into practice, we designed and launched a 5-year study to evaluate the relative benefit from implementing a clinic-to-community-based cancer and exercise model of care.

METHODS AND ANALYSIS

A hybrid effectiveness and implementation trial design is being used to evaluate the effectiveness of delivery of community-based exercise and to collect data on implementation of the programme. The study opened in January 2017, with estimated completion by January 2022. The programme will be delivered in seven cities across the province of Alberta, Canada, with sites including three academic institutions, six YMCA locations, Wellspring Edmonton and Calgary, and six municipal fitness centres. Participants are adult cancer survivors (n=2500) from all tumour groups and stages and at any time point along their cancer treatment trajectory, up to 3 years post treatment completion. Survivors take part in a minimum of 60 min of mild-to-moderate intensity full body exercise twice weekly for a 12-week period. The primary effectiveness outcome is the proportion of participants meeting or exceeding 150 min of moderate intensity exercise per week at 1-year follow-up. The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework will be utilised to capture individual-level and organizational-level impact of the exercise programme at 12 and 24 weeks and 1-year follow-up. The cohort of survivors participating in the study will allow for long-term (>5-year) evaluation of rates of cancer recurrence and secondary cancers beyond the funding period.

ETHICS AND DISSEMINATION

The study was approved by the Health Research Ethics Board of Alberta. The study is funded by Alberta Innovates and the Alberta Cancer Foundation. The study will help to answer critical questions on the effectiveness of cancer-specific community-based exercise programming in both the short-term and the long-term. Collectively, the findings will help to inform the acceptability, adoption, feasibility, reach and sustainability of community-based exercise.

TRIAL REGISTRATION NUMBER

NCT02984163; Pre-results.

Abstract 3046: Targeting N-myristoylation in B cell lymphomas as a therapeutic strategy

Treatment of aggressive lymphoma is toxic, expensive, and a substantial proportion of patients relapse and die. There is an urgent need for more effective treatments. Myristoylation is required for biological activity of &gt;200 intracellular proteins. N-myristoyltransferases (NMTs) transfer the fatty acid myristate to N-terminal glycine residue; there are two isoforms, NMT1 and 2. Since they are critical to intracellular signaling, NMTs are potential anti-cancer targets. We tested a novel potent pan-NMT inhibitor, PCLX-001, in B cell lymphoma cell lines. In vitro assays included cell viability, immunoblotting, and metabolic labeling of lymphoma cell lines. Immunohistochemistry was performed on formalin fixed paraffin embedded lymphoma specimens from patients. In vivo experiments included cell line derived murine xenografts and a patient derived mouse xenograft treated with increasing concentrations of PCLX-001. PCLX-001 selectively killed lymphoma cells, while sparing normal cells in vitro and in 3 mouse xenograft models, eradicating tumors in two of these models including a patient-derived xenograft from a R-CHOP refractory lymphoma patient. While NMT2 is overexpressed in some cancers, loss of NMT2 expression is common in numerous cancers and occurs at the highest prevalence in lymphomas, where it is independently linked to a worse prognosis. This NMT2 suppression occurred through epigenetic mechanisms and may account for lymphoma sensitivity to NMT inhibition. The global myristoylation of lymphoma cell proteins, including that of the protein tyrosine kinase oncogene Src, is profoundly inhibited by PCLX-001. Loss of Src myristoylation is accompanied by loss of Src activity and may account for loss of prosurvival signals causing lymphoma cell death. Targeting NMT2 deficient B cell lymphoma with a pan-NMT inhibitor suppresses the residual NMT1 function provides a novel, selective, and effective therapeutic strategy.

Citation Format: John R. Mackey, Erwan Beauchamp, Megan C. Yap, Aishwarya Iyer, Maneka A. Perinpanayagam, Krista M. Vincent, Abass M. Al-Momany, Ryan J. Heit, Jacky Y. Sim, Raymond Lai, Wei-feng Dong, Manikandan Lakshmanan, Anandhkumar Raju, Vinay Tergaonkar, Soo Yong Tan, Soon Thye Lim, Lynne M. Postovit, Kevin D. Read, David W. Gray, Paul G. Wyatt, Luc G. Berthiaume. Targeting N-myristoylation in B cell lymphomas as a therapeutic strategy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3046.

Effects of exercise dose and type during breast cancer chemotherapy on longer-term patient-reported outcomes and health-related fitness: A randomized controlled trial

The Combined Aerobic and Resistance Exercise (CARE) Trial compared different types and doses of exercise performed during breast cancer chemotherapy. Here, we report the longer-term follow-up of patient-reported outcomes, health-related fitness and exercise behavior at 6, 12 and 24 months postintervention. A multicenter trial in Canada randomized 301 breast cancer patients initiating chemotherapy to thrice weekly, supervised exercise consisting of a standard dose of 25-30 min of aerobic exercise (STAN; n = 96), a higher dose of 50-60 min of aerobic exercise (HIGH; n = 101) or a combined dose of 50-60 min of aerobic and resistance exercise (COMB; n = 104) performed for the duration of chemotherapy (median of 17 weeks). Primary outcomes were patient-reported outcomes including quality of life, cancer-related symptoms and psychosocial outcomes. Secondary outcomes were objective health-related fitness (assessed at 12 months only) and self-reported exercise behavior. A total of 269 (89.4%) participants completed patient-reported outcomes at all three follow-up time points and 263 (87.4%) completed the health-related fitness assessment at 12-month follow-up. COMB was significantly superior to (i) STAN for sleep quality at 6-month follow-up (p = 0.027); (ii) HIGH for upper body muscular endurance at 12-month follow-up (p = 0.020); and (iii) HIGH for meeting the resistance exercise guideline at 6-month follow-up (p = 0.006). Moreover, self-reported meeting of the combined exercise guideline during follow-up was significantly associated with better patient-reported outcomes and health-related fitness. Performing combined exercise during and after breast cancer chemotherapy may result in better longer-term patient-reported outcomes and health-related fitness compared to performing aerobic exercise alone.