Comparing fluorodeoxyglucose positron emission tomography with computed tomography in staging for nodal and distant metastasis in urothelial/bladder cancer

Objectives

We aim to assess the clinical value of 18F-fluorodeoxyglucose positron (18F-FDG-PET) scan in detecting nodal and distant metastasis compared with computed tomography (CT) scan in patients with urothelial carcinoma or bladder cancer, aiming to improve staging accuracy and thereby better prognosticate and determine therapy.

Methods

A retrospective review of 75 patients with invasive bladder cancer (≥T1) who were staged with both CT and 18F-FDG-PET within an 8-week interval was performed for the period between 2015 and 2020. Seventy-two per cent (54/75) had formal pelvic lymph node (LN) dissection or biopsy of lesions suspicious for metastases. FDG-PET definitions for positive sites were assessed depending on SUV Max (nodes with SUVmax >4 at any size, SUV > 2 for lymph nodes >8 mm, or any SUV if the lymph node was >10 mm on axial images). For CT scanning, enlarged LN by RECIST 1.1 criteria (>10 mm) as well as qualitative findings suggesting metastasis were considered positive. The analysis was based on the comparison of CT and 18F-FDG-PET findings to histopathology results from LN dissection or biopsies.

Results

Sensitivity, specificity, positive predictive values (PPV) and negative predictive value (NPV) of CT versus FDG-PET for detecting metastasis, in patients who underwent pelvic LN dissection or biopsy of lesions suspicious of metastases, were 46.6% (95% CI: 21%-70%) versus 60% (95% CI: 32%-84%), 100% (95% CI: 91%-100%) versus 83.78% (95% CI: 69%-94%), 100% (95% CI: 63%-100%) versus 60% (95% CI: 32%-84%), and 82.2% (95% CI: 68%-92%) versus 83.78% (95% CI: 69%-94%), respectively. 7/75 (9.3%) patients avoided cystectomy due to 18F-FDG-PET features of metastases that were not detected by CT.

Conclusion

FDG-PET may be more sensitive than CT for metastases in the staging of bladder cancer, which resulted in significant avoidance of aggressive local management in cases with occult metastasis.

The socioeconomic impact of the COVID-19 lockdown on families affected by childhood respiratory illnesses in Cape Town, South Africa

The COVID-19 pandemic impacted families globally, directly and indirectly. Children presenting with respiratory illnesses are affected by emerging health systems and socioeconomic changes in the COVID-19 era. We explored the socioeconomic impacts of the COVID-19 lockdown on families with a respiratory illness diagnosed in their child in Cape Town, South Africa. This study was nested in a prospective observational cohort of children presenting with respiratory symptoms presumptive of COVID-19. We conducted 21 semi-structured interviews to explore the socioeconomic impact of the COVID-19 pandemic on families with a child affected by respiratory illnesses. We used case descriptive analysis and thematically organised common and divergent experiences. We found that socioeconomic challenges in low-income communities were exacerbated: 1) loss of pre-COVID sources of income (loss of income, employment and working hours), 2) shrinking employment opportunities due to business closures and strict preventative measures, 3) family network dependence to cope with financial pressures, 4) impact on education, implicating additional pressures due to lack of resources for adequate home schooling and 5) caregivers' mental health and wellbeing being impacted, causing stress and anxiety due to loss of income. This study shows that the COVID-19 lockdown impacted the socioeconomic aspects of families caring for a child with a respiratory illness. Care became more complicated and adversely impacted the family's emotional well-being and health-seeking behaviour. These impacts should be more carefully considered in order to strengthen health services and global health messaging in future pandemics.

Bone mineral density fall during aromatase inhibitor treatment may predict lower breast cancer recurrence

PURPOSE

Aromatase inhibitors (AIs) are associated with reduction in bone mineral density (BMD). The use of bone strengthening agents zoledronic acid and denosumab are associated with improved breast cancer outcomes for post-menopausal patients treated with AIs. This study investigates whether change in BMD with AI therapy is associated with breast cancer recurrence.

METHODS

A cohort of patients treated at a single institution diagnosed with hormone receptor-positive breast cancer with baseline BMD and subsequent BMD test while receiving adjuvant aromatase inhibitor therapy were studied. Demographic, treatment and outcome data was obtained. Simple and multiple linear regression analysis was performed to investigate predictors of annual percent BMD change at the LS and hip. Univariate and multivariate Cox proportional hazards modelling were undertaken to investigate predictors of breast cancer recurrence.

RESULTS

353 patients eligible patients were identified. In multivariate analysis of lumbar spine BMD change, the difference between those in quartile 1, which showed the greatest reduction in BMD, and quartile 3, with substantially less reduction, was significant (HR = 3.02, 95% CI 1.15-7.90 p = 0.025). Hip BMD reduction was also not significantly associated with breast cancer recurrence. The two quartiles with the least reduction in hip BMD showing a non-significant reduced risk of recurrence relative to the quartile with the greatest (p = 0.10).

CONCLUSIONS

The findings suggest an association may exist between lumbar spine BMD change and breast cancer recurrence for patients treated with adjuvant AI. Further research is required to determine whether BMD change can be utilised as a biomarker.

Short-term outcomes of South African children with multisystem inflammatory syndrome in children: a prospective cohort study

BACKGROUND

Despite the life-threatening presentation of multisystem inflammatory syndrome in children (MIS-C), the overall prognosis is favourable in centres with access to appropriate supportive care. In this study, we investigate the short-term outcomes in children with MIS-C in Cape Town, South Africa.

METHODS

This prospective observational cohort study included children <13 years who fulfilled the WHO case definition of MIS-C and were admitted to Tygerberg Hospital in Cape Town, South Africa between 1 June 2020 and 31 October 2021. Clinical features were recorded at baseline and at follow-up at the 6-week cardiology and 3-month rheumatology-immunology clinics, respectively.

FINDINGS

Fifty-three children with a median age of 7.4 years (IQR 4.2-9.9) were included. There was a slight male predominance (30/53; 56.6%) and the majority was of mixed ancestry (28/53; 52.83%) or black African ancestry (24/53; 45.3%). Fourteen children (14/53; 26.4%) had comorbid disease. The median length of hospital stay was 8 days (IQR 6-10). All children had an echocardiogram performed at baseline of which 39 were abnormal (39/53; 73.6%). All children were discharged alive. The median days from discharge to cardiology follow-up was 39 days (IQR 33.5-41.5) and for rheumatology-immunology clinic was 70.5 days (IQR 59.5-85.0). Eleven children (11/41; 26.8%) had a persistently abnormal echocardiogram at cardiology follow-up. Systemic inflammation and organ dysfunction resolved in most.

INTERPRETATION

Although the short-term outcomes of MIS-C in our cohort were generally good, the cardiac morbidity needs further characterisation and follow-up.

A phase 1 study in healthy participants to characterize the safety and pharmacology of inclacumab, a fully human anti-P-selectin antibody, in development for treatment of sickle cell disease

PURPOSE

We evaluated the safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of intravenous (IV) inclacumab, a fully human IgG4 anti-P-selectin monoclonal antibody in development for the treatment of sickle cell disease, at doses up to and exceeding those previously tested in healthy individuals.

METHODS

In this phase 1, open-label, single-ascending-dose study, 15 healthy participants were enrolled into cohorts receiving 20 mg/kg (n = 6) or 40 mg/kg (n = 9) IV inclacumab and observed for up to 29 weeks post-dose. Safety, PK parameters, thrombin receptor-activating peptide (TRAP)-activated platelet-leukocyte aggregate (PLA) formation, P-selectin inhibition, plasma soluble P-selectin, and anti-drug antibodies were characterized.

RESULTS

Two inclacumab-related treatment-emergent adverse events were reported in 1 participant; no dose-limiting toxicities were observed. Plasma PK parameters were generally dose-proportional, with a terminal half-life of 13 to 17 days. Mean TRAP-activated PLA formation decreased within 3 h from the start of infusion, and inhibition was sustained for ~ 23 weeks. Mean P-selectin inhibition > 90% was observed up to 12 weeks post-dose. The mean ratio of free to total soluble P-selectin decreased rapidly from pre-dose to end of infusion, then increased gradually to 78% of the baseline ratio by week 29. Treatment-emergent anti-drug antibodies were observed in 2 of 15 participants (13%), without apparent impact on safety, PK, or PD.

CONCLUSIONS

Inclacumab was well tolerated, with PK as expected for a monoclonal antibody against a membrane-bound target and a long duration of PD effects after both single IV doses, supporting a prolonged dosing interval.

TRIAL REGISTRATION

ACTRN12620001156976; registered November 4, 2020.

Competencies of junior medical doctors in managing seriously ill and injured children: time to rethink our current training approach?

BACKGROUND

The correct treatment of very ill and injured children is critical, yet little is known about the competencies of South African (SA) junior doctors in managing these children.

METHODS

This survey documents SA junior doctors' reported resuscitation training opportunities, experience, skills and knowledge.

RESULTS

A total of 118 doctors (interns, medical officers and registrars) from paediatric departments affiliated with 7 medical schools, participated. Resuscitations were not rare events with 71% (84/118) reporting participation in >10 resuscitations during the preceding 2 years. Yet a third of doctors have not attended an accredited resuscitation training course within the last 2 years; 34% (12/35) medical officers and 29% (18/63) registrars, respectively, with 42% (49/118) of all participants never receiving any formal resuscitation training during employment. Feedback on performance is not standard practice with only 8% (10/118) reporting consistent debriefing after a resuscitation. Although 72% (85/118) reported their resuscitation knowledge as adequate, 56% (66/118) passed the knowledge test.

CONCLUSION

This study recognized missed learning opportunities in junior doctors' training, assessment, debriefing and knowledge which may adversely affect the quality of care in managing paediatric emergencies. This has implications for departmental and post-graduate training programmes.

Clinical Presentation and Outcome of Acute Respiratory Illnesses in South African Children During the COVID-19 Pandemic

BACKGROUND

Data from low- and middle-income countries (LMICs) show higher morbidity and mortality in children with acute respiratory illness (ARI) from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, whether SARS-CoV-2 infection is distinct from other causes of ARI in this regard is unclear. We describe clinical characteristics and outcomes of South African children with SARS-CoV-2 and non-SARS-CoV-2 ARIs.

METHODS

We performed a cross-sectional study including 0-13 years old children admitted to Tygerberg Hospital between May and December 2020 with an ARI. Routine clinical data were collected by the attending clinicians. All children underwent SARS-CoV-2 polymerase chain reaction testing. For severity of disease, the need for respiratory support and duration of support was considered. Multivariable logistic regression models were built to determine the factors associated with SARS-CoV-2 infection and severity.

RESULTS

Data for 176 children were available, 38 (22%) children were SARS-CoV-2 polymerase chain reaction positive and 138 (78%) were negative. SARS-CoV-2 positive children were more likely to be female (OR: 2.68, 95% CI: 1.18-6.07), had lower weight-for-age Z score (OR: 0.76, 95% CI: 0.63-0.93), presented more frequently with fever (OR: 3.56, 95% CI: 1.54-8.24) and less often with cough (OR: 0.27, 95% CI: 0.11-0.66). SARS-CoV-2 infection was associated with significantly longer duration of oxygen treatment (median 8 vs. 3 days; OR: 1.1, 95% CI: 1.01-1.20). Overall, 66% of children had viral coinfection, with no significant difference between the groups. In total, 18% of SARS-CoV-2 positive children were readmitted within 3 months for a respiratory reason, compared with 15% SARS-CoV-2 negative children ( P = 0.64).

CONCLUSIONS

Our data show that ARIs from SARS-CoV-2 cannot be easily differentiated, but were associated with a higher morbidity compared with ARIs from other causes. Overall outcomes were good. The long-term implications of severe SARS-CoV-2 pneumonia in young children in low- and middle-income countries require further study.

Stromal inflammation, fibrosis and cancer: An old intuition with promising potential

It is now well established that the biology of cancer is influenced by not only malignant cells but also other components of the tumour microenvironment. Chronic inflammation and fibrosis have long been postulated to be involved in carcinogenesis. Chronic inflammation can promote tumorigenesis via growth factor/cytokine-mediated cellular proliferation, apoptotic resistance, immunosuppression; and free-radical-induced oxidative deoxyribonucleic acid damage. Fibrosis could cause a perturbation in the dynamics of the tumour microenvironment, potentially damaging the genome surveillance machinery of normal epithelial cells. In this review, we will provide an in-depth discussion of various diseases characterised by inflammation and fibrosis that have been associated with an increased risk of malignancy. In particular, we will present a comprehensive overview of the impact of alterations in stromal composition on tumorigenesis, induced as a consequence of inflammation and/or fibrosis. Strategies including the application of various therapeutic agents with stromal manipulation potential and targeted cancer screening for certain inflammatory diseases which can reduce the risk of cancer will also be discussed.

Unpacking the Complexity of Epithelial Plasticity: From Master Regulator Transcription Factors to Non-Coding RNAs

Cellular plasticity in cancer enables adaptation to selective pressures and stress imposed by the tumor microenvironment. This plasticity facilitates the remodeling of cancer cell phenotype and function (such as tumor stemness, metastasis, chemo/radio resistance), and the reprogramming of the surrounding tumor microenvironment to enable immune evasion. Epithelial plasticity is one form of cellular plasticity, which is intrinsically linked with epithelial-mesenchymal transition (EMT). Traditionally, EMT has been regarded as a binary state. Yet, increasing evidence suggests that EMT involves a spectrum of quasi-epithelial and quasi-mesenchymal phenotypes governed by complex interactions between cellular metabolism, transcriptome regulation, and epigenetic mechanisms. Herein, we review the complex cross-talk between the different layers of epithelial plasticity in cancer, encompassing the core layer of transcription factors, their interacting epigenetic modifiers and non-coding RNAs, and the manipulation of cancer immunogenicity in transitioning between epithelial and mesenchymal states. In examining these factors, we provide insights into promising therapeutic avenues and potential anti-cancer targets.

Synthetic Epigenetic Reprogramming of Mesenchymal to Epithelial States Using the CRISPR/dCas9 Platform in Triple Negative Breast Cancer

Epithelial-mesenchymal transition (EMT) is a reversible transcriptional program invoked by cancer cells to drive cancer progression. Transcription factor ZEB1 is a master regulator of EMT, driving disease recurrence in poor-outcome triple negative breast cancers (TNBCs). Here, this work silences ZEB1 in TNBC models by CRISPR/dCas9-mediated epigenetic editing, resulting in highly-specific and nearly complete suppression of ZEB1 in vivo, accompanied by long-lasting tumor inhibition. Integrated "omic" changes promoted by dCas9 linked to the KRAB domain (dCas9-KRAB) enabled the discovery of a ZEB1-dependent-signature of 26 genes differentially-expressed and -methylated, including the reactivation and enhanced chromatin accessibility in cell adhesion loci, outlining epigenetic reprogramming toward a more epithelial state. In the ZEB1 locus transcriptional silencing is associated with induction of locally-spread heterochromatin, significant changes in DNA methylation at specific CpGs, gain of H3K9me3, and a near complete erasure of H3K4me3 in the ZEB1 promoter. Epigenetic shifts induced by ZEB1-silencing are enriched in a subset of human breast tumors, illuminating a clinically-relevant hybrid-like state. Thus, the synthetic epi-silencing of ZEB1 induces stable "lock-in" epigenetic reprogramming of mesenchymal tumors associated with a distinct and stable epigenetic landscape. This work outlines epigenome-engineering approaches for reversing EMT and customizable precision molecular oncology approaches for targeting poor outcome breast cancers.

Association of Computed Tomography Measures of Muscle and Adipose Tissue and Progressive Changes throughout Treatment with Clinical Endpoints in Patients with Advanced Lung Cancer Treated with Immune Checkpoint Inhibitors

To investigate the association between skeletal muscle mass and adiposity measures with disease-free progression (DFS) and overall survival (OS) in patients with advanced lung cancer receiving immunotherapy, we retrospectively analysed 97 patients (age: 67.5 ± 10.2 years) with lung cancer who were treated with immunotherapy between March 2014 and June 2019. From computed tomography scans, we assessed the radiological measures of skeletal muscle mass, and intramuscular, subcutaneous and visceral adipose tissue at the third lumbar vertebra. Patients were divided into two groups based on specific or median values at baseline and changes throughout treatment. A total number of 96 patients (99.0%) had disease progression (median of 11.3 months) and died (median of 15.4 months) during follow-up. Increases of 10% in intramuscular adipose tissue were significantly associated with DFS (HR: 0.60, 95% CI: 0.38 to 0.95) and OS (HR: 0.60, 95% CI: 0.37 to 0.95), while increases of 10% in subcutaneous adipose tissue were associated with DFS (HR: 0.59, 95% CI: 0.36 to 0.95). These results indicate that, although muscle mass and visceral adipose tissue were not associated with DFS or OS, changes in intramuscular and subcutaneous adipose tissue can predict immunotherapy clinical outcomes in patients with advanced lung cancer.

Palbociclib plus letrozole as treatment for postmenopausal women with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer for whom letrozole therapy is deemed appropriate: An expanded access study in Australia and India

AIM

Palbociclib was approved in the United States in 2015 to treat estrogen receptor-positive/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). This study evaluated outcomes and safety in patients treated with palbociclib in Australia and India with hormone receptor-positive (HR+)/HER2- ABC before palbociclib became commercially available.

METHODS

Postmenopausal women (≥18 years) with HR+/HER2- ABC who were appropriate candidates for letrozole therapy received palbociclib 125 mg once daily for 21 days followed by 7 days off, and letrozole 2.5 mg once daily (continuous). Safety, tumor response, and patient-reported outcomes (Australian cohort) were evaluated.

RESULTS

In total, 252 patients received palbociclib plus letrozole (Australia, n = 152; India, n = 100). More patients in the Australian versus Indian cohort had received prior chemotherapy (advanced/metastatic setting: 45.9% vs. 32.0%), endocrine therapy (advanced/metastatic setting: 63.2% vs. 54.3%), and advanced/metastatic therapies (61.8% vs. 31.0%). The most frequently reported all-grade palbociclib-related treatment-emergent adverse events were neutropenia (66.7%), fatigue (35.3%), and stomatitis (26.6%); grade 3/4 neutropenia was reported as palbociclib-related in 62.7% of patients. Febrile neutropenia was reported in six patients (2.4%). Eight patients (3.2%) discontinued because of an adverse event. The objective response rate was 19.4% (95% CI, 14.7%-24.9%) overall and 2.3% in Australian patients with ≥2 lines of prior therapy for metastatic disease. Patient-reported quality of life scores were maintained throughout the study.

CONCLUSIONS

In an expanded access setting in Australia and India, palbociclib plus letrozole was well tolerated in patients with HR+/HER2- ABC, with a safety profile consistent with previous reports.

SARS-CoV-2 in children and their accompanying caregivers: Implications for testing strategies in resource limited hospitals

Background

Identification of SARS-CoV-2 infected individuals is imperative to prevent hospital transmission, but symptom-based screening may fail to identify asymptomatic/mildly symptomatic infectious children and their caregivers.

Methods

A COVID-19 period prevalence study was conducted between 13 and 26 August 2020 at Tygerberg Hospital, testing all children and their accompanying asymptomatic caregivers after initial symptom screening. One nasopharyngeal swab was submitted for SARS-CoV-2 using real-time reverse-transcription polymerase chain reaction (rRT-PCR). An additional Respiratory Viral 16-multiplex rRT-PCR test was simultaneously done in children presenting with symptoms compatible with possible SARS-CoV-2 infection.

Results

SARS-Co-V 2 RT-PCR tests from 196 children and 116 caregivers were included in the analysis. The SARS-CoV-2 period prevalence in children was 5.6% (11/196) versus 15.5% (18/116) in asymptomatic caregivers (p<0.01). Presenting symptoms did not correlate with SARS-CoV-2 test positivity; children without typical symptoms of SARS-CoV-2 were more likely to be positive than those with typical symptoms (10.2% [10/99] vs 1% [1/97]; p<0.01). Children with typical symptoms (97/196; 49.5%) mainly presented with acute respiratory (68/97; 70.1%), fever (17/97; 17.5%), or gastro-intestinal complaints (12/97; 12.4%); Human Rhinovirus (23/81; 28.4%) and Respiratory Syncytial Virus (18/81; 22.2%) were frequently identified in this group. Children-caregiver pairs' SARS-CoV-2 tests were discordant in 83.3%; 15/18 infected caregivers' children tested negative. Symptom-based COVID-19 screening alone would have missed 90% of the positive children and 100% of asymptomatic but positive caregivers.

Conclusion

Given the poor correlation between SARS-CoV-2 symptoms and RT-PCR test positivity, universal testing of children and their accompanying caregivers should be considered for emergency and inpatient paediatric admissions during high COVID-19 community transmission periods. Universal PPE and optimising ventilation is likely the most effective way to control transmission of respiratory viral infections, including SARS-CoV-2, where universal testing is not feasible. In these settings, repeated point prevalence studies may be useful to inform local testing and cohorting strategies.

Thoracic ultrasound for TB diagnosis in adults and children

Thoracic ultrasound is an appealing alternative to chest radiography for the diagnosis of TB. Based on research experience conducting thoracic ultrasound for adults and children in South Africa, three key considerations for potential scale-up were identified. First, thoracic ultrasound requires a comprehensive training programme for novice users; artificial intelligence may be used to simplify training and interpretation. Second, a robust ultrasound device is needed with good subpleural resolution and a probe suitable for children. Third, comprehensive scanning of the lungs is time-intensive, and shorter scanning protocols may be more feasible in clinical practice.

Assessment of Clinical Outcomes Among Children and Adolescents Hospitalized With COVID-19 in 6 Sub-Saharan African Countries

IMPORTANCE

Little is known about COVID-19 outcomes among children and adolescents in sub-Saharan Africa, where preexisting comorbidities are prevalent.

OBJECTIVE

To assess the clinical outcomes and factors associated with outcomes among children and adolescents hospitalized with COVID-19 in 6 countries in sub-Saharan Africa.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was a retrospective record review of data from 25 hospitals in the Democratic Republic of the Congo, Ghana, Kenya, Nigeria, South Africa, and Uganda from March 1 to December 31, 2020, and included 469 hospitalized patients aged 0 to 19 years with SARS-CoV-2 infection.

EXPOSURES

Age, sex, preexisting comorbidities, and region of residence.

MAIN OUTCOMES AND MEASURES

An ordinal primary outcome scale was used comprising 5 categories: (1) hospitalization without oxygen supplementation, (2) hospitalization with oxygen supplementation, (3) ICU admission, (4) invasive mechanical ventilation, and (5) death. The secondary outcome was length of hospital stay.

RESULTS

Among 469 hospitalized children and adolescents, the median age was 5.9 years (IQR, 1.6-11.1 years); 245 patients (52.4%) were male, and 115 (24.5%) had comorbidities. A total of 39 patients (8.3%) were from central Africa, 172 (36.7%) from eastern Africa, 208 (44.3%) from southern Africa, and 50 (10.7%) from western Africa. Eighteen patients had suspected (n = 6) or confirmed (n = 12) multisystem inflammatory syndrome in children. Thirty-nine patients (8.3%) died, including 22 of 69 patients (31.9%) who required intensive care unit admission and 4 of 18 patients (22.2%) with suspected or confirmed multisystem inflammatory syndrome in children. Among 468 patients, 418 (89.3%) were discharged, and 16 (3.4%) remained hospitalized. The likelihood of outcomes with higher vs lower severity among children younger than 1 year expressed as adjusted odds ratio (aOR) was 4.89 (95% CI, 1.44-16.61) times higher than that of adolescents aged 15 to 19 years. The presence of hypertension (aOR, 5.91; 95% CI, 1.89-18.50), chronic lung disease (aOR, 2.97; 95% CI, 1.65-5.37), or a hematological disorder (aOR, 3.10; 95% CI, 1.04-9.24) was associated with severe outcomes. Age younger than 1 year (adjusted subdistribution hazard ratio [asHR], 0.48; 95% CI, 0.27-0.87), the presence of 1 comorbidity (asHR, 0.54; 95% CI, 0.40-0.72), and the presence of 2 or more comorbidities (asHR, 0.26; 95% CI, 0.18-0.38) were associated with reduced rates of hospital discharge.

CONCLUSIONS AND RELEVANCE

In this cohort study of children and adolescents hospitalized with COVID-19 in sub-Saharan Africa, high rates of morbidity and mortality were observed among infants and patients with noncommunicable disease comorbidities, suggesting that COVID-19 vaccination and therapeutic interventions are needed for young populations in this region.

Abstract P5-05-03: Adipocyte associated methionine domain containing (AAMDC): A nuclear envelope protein with predictive and prognostic potential in luminal breast cancer

Background Estrogen receptor (ER) positive breast cancers (BCs) are less likely to relapse than other types, due to a lower propensity to disseminate and to sensitivity to anti-estrogen drugs in the adjuvant setting. However, combined analysis of DNA mutation and mRNA expression profiles in BC identifies a number of Integrative Clusters (IntClus), one of which, IntClus2, is characterized by ER positivity but high relpase and mortality. A hallmark of IntClus2 tumours is an amplification of chromosome 11, at the center of which lies the gene for the protein AAMDC. Pre-clinical research shows this protein to drive proliferation, migration, colony formation, switching between glucose and lipid metabolism, folate metabolism and anti-estrogen resistance. We postulated that resultant clinical behaviours could include; high relapse and mortality, anti-estrogen resistance, an interaction with the protective effect on relapse from statins and sensitivity to fluorouracil (FU)-based therapies. Methods The retrospective study cohort comprised 1766 ER positive early BC patients treated 1994-2014. Patient and tumour demographic, statin prescription and treatment data were collated. Primary tumour tissue was available with AAMDC expression data on 419 patients. On noting nuclear (N), cytoplasmic (C) and nuclear envelope (NE) expression, separate intensity scores were attributed to each localization. Intensity score cut-points were based on providing statistically useable sub-group sizes for comparison. Results No significant correlations between BC biology and patterns of AAMDC expression were seen. Cytoplasmic AAMDC weakly linked to some aggressive features, including high grade, luminal B sub-type and progesterone receptor negativity, although less lymph node spread. In contrast, nuclear AAMDC associated with some less aggressive features, being less in high grade and luminal B cancers. Nuclear envelope AAMDC was rarer in the HER2 positive sub-type without other correlates. A trend to higher distant relapse was seen for NE +ive BCs (20 v 14%, p=0.09). Overall mortality was statistically higher for NE expression (54 v 44% mortality, p=0.04) and cytoplasmic expression (56 v 47% mortality, p=0.04) and a trend to lower mortality for nuclear expression (46 v 54%, p=0.06). Looking at combinatorial expression, BC deaths were significantly lower in the nuclear +ive/NE -ive phenotype (4.7%) than the nuclear -ive/NE -ive (19.5%, p=0.013), nuclear -ive/NE +ive (17.6%, p=0.017) or nuclear +ive/NE +ive phenotypes (19.3%, p=0.011).Considering the effects of statins on early BC outcome, overall our patients on statins had notably lower BC return rates (HR 0.31, p=0.004). Considering interactions with AAMDC, in high-risk NE +ive cancers statin protection was high (HR for relapse 0.33, p=0.032), compared to no protection in already low risk NE -ive tumours (HR 0.90, p=0.41). The hypothesis that AAMDC confers sensitivity to FU-based agents was confirmed with a correlation observed for longer responses to FU-based chemotherapy for increasing NE AAMDC expression (R=0.334), whereas no link was seen for other agents or other AAMDC expression sub-locations. The mean times on FU-based therapy for low, moderate and high NE expression were 2.0, 5.7 and 12.2 months respectively (p=0.02). This work indicates that AAMDC expression can BC affect outcome, identifying nuclear envelope located AAMDC as both associating with higher mortality and correlating with superior protection from statins as well as response to FU-based chemotherapies. This could guide metastatic chemotherapy selection for affected patients, implies NE positive BCs might preferentially benefit from adjuvant statins and suggests that AAMDC and NE-associated AAMDC partners may be future therapeutic targets.

Citation Format: Indunil Weerasena, Lisa Spalding, Benjamin F Dessauvagie, Emily Golden, Eleanor Woodward, Pilar Blancafort, Andrew Redfern. Adipocyte associated methionine domain containing (AAMDC): A nuclear envelope protein with predictive and prognostic potential in luminal breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-05-03.

Phase 1 clinical trial evaluating safety, exposure and pharmacodynamics of BTK inhibitor tolebrutinib (PRN2246, SAR442168)

Bruton’s tyrosine kinase (BTK), expressed in B cells and cells of innate immunity, including microglia, is an essential signaling element downstream of the B‐cell receptor and Fc‐receptors. Tolebrutinib (PRN2246, SAR442168) is a potent BTK inhibitor that covalently binds the kinase, resulting in durable inhibition with the potential to target inflammation in the periphery and central nervous system (CNS). Tolebrutinib crosses the blood‐brain barrier and potently inhibits BTK in microglial cells isolated from the CNS. A first‐in‐human randomized, double‐blind, placebo‐controlled study of tolebrutinib was conducted. The trial design consisted of five single ascending dose arms with oral administration of a single dose of 5, 15, 30, 60, and 120 mg (n = 6 per arm, n = 2 placebo), five multiple ascending dose arms with oral administration of 7.5, 15, 30, 60, and 90 mg (n = 8 per arm, n = 2 placebo) over 10 days, and one arm (n = 4) in which cerebral spinal fluid (CSF) exposure was measured 2 h after a single 120 mg dose. Tolebrutinib was well‐tolerated in the study and all treatment‐related treatment emergent adverse events were mild. Tolebrutinib was rapidly absorbed following oral administration with a rapid half‐life of ~ 2 h. Peripheral BTK occupancy was assessed at various timepoints by an enzyme‐linked immunosorbent assay‐based readout using an irreversible probe. Assessments demonstrated extensive and prolonged peripheral BTK occupancy at steady‐state with once daily doses as low as 7.5 mg. Further, CSF exposure was demonstrated 2 h after administration at 120 mg.

Fine Needle Aspiration Biopsy of Peripheral Lymph Nodes in Children: Practical Experience in a Tertiary Hospital

BACKGROUND

Peripheral lymphadenopathy occurs often in children; fine needle aspiration biopsy (FNAB) is a commonly performed diagnostic procedure. We describe FNAB use and outcome for peripheral lymphadenopathy in children in a routine clinical setting.

METHODS

A retrospective study done at Tygerberg Hospital, Cape Town of children (<13 years) who had an FNAB for lymphadenopathy from July 2012 to June 2014. Demographic, clinical, treatment and follow-up data were retrieved from patient folders; FNAB and special investigation results were obtained from the laboratory database.

RESULTS

Of the 173 children, the median age was 37 (interquartile range 13-75) months; 20 (11.5%) were HIV positive. Most FNABs were done in the neck (131; 76%) and axillary areas (34; 20%). FNAB provided a result in 165 (95%) cases; in 8 (5%) children FNAB was insufficient for diagnosis. Mycobacterial aetiology was diagnosed in 84 (49%); 49 (58%) were culture-confirmed (37 Mycobacterium tuberculosis, 10 Mycobacterium bovis BCG, 1 both and 1 non-tuberculous mycobacterium). Reactive lymphadenopathy was diagnosed in 56 (32%), neoplastic disease in 6 (3.5%) and other pathology in 19 (11%) cases. Additional special investigations changed FNAB diagnosis or led to an additional diagnosis in 8 (5%) children. Overall, 70/84 (83%) with mycobacterial aetiology and all neoplastic disease cases received the correct treatment. Follow-up appointments were arranged in 144 (83%) patients.

CONCLUSIONS

In a high tuberculosis burden area, a single FNAB provided a diagnosis in most cases in a routine referral setting; FNAB remains a safe and useful investigation. Follow-up of children to initiate appropriate treatment could improve.

LAY SUMMARY

Large swollen lymph nodes, especially in the neck, are a common finding in children. Fine needle aspiration biopsy (FNAB) is a commonly used diagnostic procedure and we looked at how well this procedure works in everyday hospital practice. We identified all children <13 years of age over a 2-year period (2012-2014) who had an FNAB done at Tygerberg Hospital, Cape Town, South Africa, and looked how well this procedure performed and what the doctors did with these children. We found 173 children who had an FNAB done. They were generally young children of around 3 years old. With a single FNAB, we could make a diagnosis in 95% of these children. About half of the children had tuberculosis or complications of a BCG vaccine (both caused by mycobacteria), only 4% had a malignancy of some kind, about a third had reactive lymph nodes (usually other mainly local infectious causes) and the rest had other pathology like abscesses. All malignancies and >80% of the mycobacterial pathology cases were correctly managed; the latter could definitely improve.

Clinical Experience With Severe Acute Respiratory Syndrome Coronavirus 2-Related Illness in Children: Hospital Experience in Cape Town, South Africa

BACKGROUND

Children seem relatively protected from serious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease, but little is known about children living in settings with high tuberculosis and human immunodeficiency virus (HIV) burden. This study reflects clinical data on South African children with SARS-CoV-2.

METHODS

We collected clinical data of children aged <13 years with laboratory-confirmed SARS-CoV-2 presenting to Tygerberg Hospital, Cape Town, between 17 April and 24 July 2020.

RESULTS

One hundred fifty-nine children (median age, 48.0 months [interquartile range {IQR}, 12.0-106.0 months]) were included. Hospitalized children (n = 62), with a median age of 13.5 months (IQR, 1.8-43.5 months) were younger than children not admitted (n = 97; median age, 81.0 months [IQR, 34.5-120.5 months]; P < .01.). Thirty-three of 159 (20.8%) children had preexisting medical conditions. Fifty-one of 62 (82.3%) hospitalized children were symptomatic; lower respiratory tract infection was diagnosed in 21 of 51 (41.2%) children, and in 11 of 16 (68.8%) children <3 months of age. Respiratory support was required in 25 of 51 (49.0%) children; 13 of these (52.0%) were <3 months of age. One child was HIV infected and 11 of 51 (21.2%) were HIV exposed but uninfected, and 7 of 51 (13.7%) children had a recent or new diagnosis of tuberculosis.

CONCLUSIONS

Children <1 year of age hospitalized with SARS-CoV-2 in Cape Town frequently required respiratory support. Access to oxygen may be limited in some low- and middle-income countries, which could potentially drive morbidity and mortality. HIV infection was uncommon but a relationship between HIV exposure, tuberculosis, and SARS-CoV-2 should be explored.

A phase I open label dose-escalation study to evaluate the tolerability, safety and immunological efficacy of sub-urothelial durvalumab injection in adults with muscle-invasive or high-risk non-muscle-invasive bladder cancer (SUBDUE-1, SUB-urothelial DUrvalumab injection-1 study): clinical trial protocol

OBJECTIVES

This article presents the clinical trial protocol for a phase I open label dose-escalation study to evaluate the tolerability, safety and immunological efficacy of sub-urothelial durvalumab injection in adults with muscle-invasive or high-risk non-muscle-invasive bladder cancer (NMIBC), the SUB-urothelial DUrvalumab injection-1 study (SUBDUE-1). The primary objectives of this study are to assess the safety of sub-urothelial injection of durvalumab using patient reported outcome measures and observed local or systemic adverse events. The secondary objectives are to examine the local immunological efficacy of sub-urothelial administration of durvalumab.

PATIENTS AND METHODS

The SUBDUE-1 trial will include adult patients with either high-risk NMIBC or MIBC, who are scheduled for radical cystectomy or who have refused or are unsuitable for systemic neoadjuvant chemotherapy. Three fixed total dose levels of durvalumab (25, 75, 150 mg) will be studied to identify a dose suitable to be taken forward into phase II trials. The primary endpoint is to evaluate the safety and tolerability of the trial intervention in terms of the incidence and severity of adverse events and the potential establishment of dose-limiting toxicities. The secondary efficacy endpoints include rates of pT0 status at resection, lymph node status, as well as the change in distribution of tumour-infiltrating lymphocytes and tumour-activated macrophages between pre- and post-injection bladder biopsies. Translational studies will focus on bladder tumour molecular sub-typing, immune infiltrate characterisation, and immune checkpoint protein expression relative to efficacy end-points.

OUTCOME AND SIGNIFICANCE

If proven safe and effective, this novel strategy comprising sub-urothelial durvalumab injections aimed at promoting an anti-tumour immune reaction, will provide additional treatment options for reducing tumour recurrence and progression in treatment-naïve patients with high-risk NMIBC or in patients with bacille Calmette-Guérin-refractory NMIBC. Local administration of durvalumab may be associated with a reduced rate of immunological side-effects and lower costs when compared to systemic delivery.

Measuring and Modelling the Epithelial- Mesenchymal Hybrid State in Cancer: Clinical Implications

The epithelial-mesenchymal (E/M) hybrid state has emerged as an important mediator of elements of cancer progression, facilitated by epithelial mesenchymal plasticity (EMP). We review here evidence for the presence, prognostic significance, and therapeutic potential of the E/M hybrid state in carcinoma. We further assess modelling predictions and validation studies to demonstrate stabilised E/M hybrid states along the spectrum of EMP, as well as computational approaches for characterising and quantifying EMP phenotypes, with particular attention to the emerging realm of single-cell approaches through RNA sequencing and protein-based techniques.

How much time do doctors spend providing care to each child in the ED? A time and motion study

BACKGROUND

The total time per patient doctors spend providing care in emergency departments (EDs) has implications for the development of evidence-based ED staffing models. We sought to measure the total time taken by doctors to assess and manage individual paediatric patients presenting to two EDs in the Western Cape, South Africa and to compare these averages to the estimated benchmarks used regionally to calculate ED staffing allocations.

METHODS

We conducted a cross-sectional, observational study applying time and motion methodology, using convenience sampling. Data were collected over a 5-week period from 11 December 2015 to 18 January 2016 at Khayelitsha District Hospital Emergency Centre and Tygerberg Hospital Paediatric Emergency and Ambulatory Unit. We assessed total doctor time for each patient stratified by acuity level using the South African Triage Scale.

RESULTS

Care was observed for a total of 100 patients. Median age was 21 months (IQR 8-55). Median total doctor time per patient (95% CI) was 31 (22 to 38), 39 (31 to 63), 48 (32 to 63) and 96 (66 to 122) min for triage categories green, yellow, orange and red, respectively. Median timing was significantly higher than the estimated local benchmark for the lowest acuity 'green' triage category (31 min (22 to 38) vs 15 min; p=0.001) and the highest acuity 'red' category (96 min (66 to 122) vs 50 min; p=0.002).

CONCLUSION

Doctor time per patient increased with increasing acuity of triage category and exceeded estimated benchmarks for the highest and lowest acuities. The distinctive methodology can easily be extended to other settings and populations.

Incorporation of eribulin in the systemic treatment of metastatic breast cancer patients in Australia

PURPOSE

Review of utilization and efficacy of eribulin in Australian metastatic breast cancer (MBC) patients.

METHODS

Retrospective review of consecutive MBC patients treated with eribulin in tertiary Australian BC centers. Key inclusion criteria included eribulin administration in nonclinical trial setting from October 2014 onwards, known duration of MBC systemic treatments administered and known follow-up date after eribulin. Cox regression model was used to assess survival.

RESULTS

Study population comprised 266 patients from eight centers treated between October 2014 and May 2018. Median age at time of MBC diagnosis was 54 years with 18% of patients having de novo MBC. Seventy-six percent had hormone receptor positive (HRp) disease, 19% triple negative (TN) and 5% HER2-positive. CNS involvement was present in 36% of patients. Eribulin was most frequently given as third-line chemotherapy (36%), with no prior anthracycline exposure in 14% of total population. Eribulin was given more frequently as ≤third-line chemotherapy than > third-line in patients with TN disease, ≥ two metastatic sites or CNS disease. Median overall survival (OS) from eribulin administration was 9.2 (95% CI [8.0, 10.3]) months.

CONCLUSION

Similar efficacy was demonstrated for eribulin when given in the first-line to beyond the fifth line of chemotherapy in all subtypes of MBC.

Infants 21-90 days presenting with a possible serious bacterial infection - are evaluation algorithms from high income countries applicable in the South African public health sector?

BACKGROUND

Young infants with a possible serious bacterial infection (SBI) are a very common presentation to emergency centres (ECs). It is often difficult to distinguish clinically between self-limiting viral infections and an SBI. Available evaluation algorithms to assist clinicians are mostly from high-income countries. Data to inform clinical practice in low- and middle-income countries are lacking.

OBJECTIVES

To determine the period prevalence of SBI and invasive bacterial infection (IBI) and describe current practice in the assessment and management of young infants aged 21-90 days presenting with a possible SBI to a Paediatric Emergency centre (PEC) in Cape Town, South Africa.

METHODS

A retrospective cross-sectional review of infants 21-90 days old presenting to the Tygerberg Hospital PED between 1 January 2016 and 31 May 2016.

RESULTS

A total of 248 infants 21-90 days were included in the study. Sixty-two patients (25%, 95% CI 20-30) had an SBI and 13 (5.2%, 95% CI 3-8) had an IBI. One hundred and sixty-five infants had a possible SBI based on WHO IMCI criteria. The sensitivity of the WHO IMCI criteria in detecting SBI was 82.3% (95% CI 70.5-90.8) and the specificity 38.7% (95% CI 31.7-46.1). More than half (51.2%) of the infants received antibiotics within the 48 h prior to presentation, of which 33.5% included intramuscular injection of Ceftriaxone. Only 20 (8.0%) patients in this age group were discharged home after initial evaluation. A significant relationship was noted between fever and the risk of SBI (p-value 0.010) and IBI (p-value 0.009). There also appeared to be a significant relationship between nutritional status and IBI (p-value 0.013).

CONCLUSION

Period prevalence of SBI and IBI was higher compared to that published in the literature. Validated evaluation algorithms to stratify risk of SBI are needed to assist clinicians in diagnosing and managing infants appropriately in low- and middle-income settings.

Abstract PS6-58: The impact of baseline modified glasgow prognostic score (mGPS) on survival outcomes in in indigenous and non-indigenous patients with advanced breast cancer patients of Western Australia

Introduction: The modified Glasgow prognostic score (mGPS) is known to be useful in prognostication of multiple cancers. The mGPS, which integrates albumin and C-reactive protein, could assist as a possible prognostic marker in breast cancer. Indigenous women have inferior breast cancer survival to non-Indigenous women and may also have a differing inflammatory environment. Here, we examine the utility and impact of baseline mGPS on survival outcomes in women with metastatic breast cancer by Indigenous status.

Methods: We retrospectively collected data from the Western Australian Cancer Registry and electronic records for patients diagnosed with breast cancer between 2001 and 2016 with confirmed metastatic disease. Overall survival (OS) were measured from the date of diagnosis until death. mGPS comprised scores of one point given for CRP &gt; 10 mg/L and/or albumin &lt; 3.5 g/dL, therefore having a value of 0 to 2.

Results: Of 152 patients with metastatic breast cancer, 89 patients had all relevant data available and were included with a median follow up of 120 months. The median age was 55.3 years. Baseline mGPS was 0 in 46.6 %, 1 in 34.8 % and 2 in 18.6 %.

Median OS across Indigenous and non-Indigenous patients combined was significantly worse moving from the mGPS-0 group through mGPS-1 to mGPS 2, 50.0 v 30.0 v 8.0 months respectively (p&lt;0.0001). Looking at the groups separately, both cohorts separately demonstrated inferior median OS in mGPS-2 compared to mGPS-1 patients, 9 v 32 months (p=0.02) for Indigenous patients, and 2.0 vs 25.0 months for non_Indigenous patients (p=0.001).

The correlation between mGPS and the neutrophil-to-lymphocyte ratio (NLR) was weak with a Pearson correlation R-value of 0.184 (p=0.085)

Conclusion: The study shows that the mGPS is an independent prognostic factor in advanced-stage disease. A higher baseline mGPS score was associated with worse survival in Indigenous and non-Indigenous patients. A larger prospective study is needed to validate the results, inclusive of assessing links between mGPS and OS in different breast cancer sub-types.

Citation Format: Azim Khan, Hilary Martin, Lisa Spalding, Andrew Redfern. The impact of baseline modified glasgow prognostic score (mGPS) on survival outcomes in in indigenous and non-indigenous patients with advanced breast cancer patients of Western Australia [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-58.

The Critical Need for Pooled Data on Coronavirus Disease 2019 in African Children: An AFREhealth Call for Action Through Multicountry Research Collaboration

Globally, there are prevailing knowledge gaps in the epidemiology, clinical manifestations, and outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among children and adolescents; and these gaps are especially wide in African countries. The availability of robust age-disaggregated data is a critical first step in improving knowledge on disease burden and manifestations of coronavirus disease 2019 (COVID-19) among children. Furthermore, it is essential to improve understanding of SARS-CoV-2 interactions with comorbidities and coinfections such as human immunodeficiency virus (HIV), tuberculosis, malaria, sickle cell disease, and malnutrition, which are highly prevalent among children in sub-Saharan Africa. The African Forum for Research and Education in Health (AFREhealth) COVID-19 Research Collaboration on Children and Adolescents is conducting studies across Western, Central, Eastern, and Southern Africa to address existing knowledge gaps. This consortium is expected to generate key evidence to inform clinical practice and public health policy-making for COVID-19 while concurrently addressing other major diseases affecting children in African countries.

Honeybee venom and melittin suppress growth factor receptor activation in HER2-enriched and triple-negative breast cancer

Despite decades of study, the molecular mechanisms and selectivity of the biomolecular components of honeybee (Apis mellifera) venom as anticancer agents remain largely unknown. Here, we demonstrate that honeybee venom and its major component melittin potently induce cell death, particularly in the aggressive triple-negative and HER2-enriched breast cancer subtypes. Honeybee venom and melittin suppress the activation of EGFR and HER2 by interfering with the phosphorylation of these receptors in the plasma membrane of breast carcinoma cells. Mutational studies reveal that a positively charged C-terminal melittin sequence mediates plasma membrane interaction and anticancer activity. Engineering of an RGD motif further enhances targeting of melittin to malignant cells with minimal toxicity to normal cells. Lastly, administration of melittin enhances the effect of docetaxel in suppressing breast tumor growth in an allograft model. Our work unveils a molecular mechanism underpinning the anticancer selectivity of melittin, and outlines treatment strategies to target aggressive breast cancers.

Risk-Stratification of Children Presenting to Ambulatory Paediatrics with First-Onset Seizures: Should We Order an Urgent CT Brain?

INTRODUCTION

A computed tomography (CT) brain scan is an often-utilised emergency department imaging modality to detect emergent intra-cranial pathology in a child with a first seizure. Identifying children at low risk of having a clinically significant intra-cranial abnormality could prevent unnecessary radiation exposure and contrast/sedation-related risks.

OBJECTIVES

To identify clinical variables which could predict clinically significant CT brain abnormalities and use recursive partitioning analysis to define a low-risk group of children in whom emergent CT brain can be deferred.

METHODS

Retrospective cross-sectional review of 468 children who underwent emergent CT brain after presenting to a low- and middle-income paediatric emergency department following first seizure.

RESULTS

In total 133/468 (28.4%) of CT brain scans had clinically significant abnormalities. Failure to return to neurological baseline and focal neurological deficit persisting >36 h had statistical significance in a multiple regression analysis. Recursive partitioning analysis, applied to a subgroup without suspected tuberculous meningitis (n = 414), classified 153 children aged between 6 months and 5 years, who had a normal neurological baseline, had returned to baseline post-seizure, and were not in status epilepticus, as non-clinically significant scans and 98% were correctly classified.

CONCLUSION

Our study re-inforces the American Academy of Neurology recommendation that children with persistent post-ictal abnormal neurological status and/or post-ictal focal deficit be prioritised for emergent CT brain. Having excluded children with suspected tuberculous meningitis, the remaining subgroup aged 6 months to 5 years presenting with a non-status first seizure, normal neurological baseline and return to baseline post-seizure, are at very low risk of having a clinically significant CT brain abnormality.

Controversies around epithelial-mesenchymal plasticity in cancer metastasis

Experimental evidence accumulated over decades has implicated epithelial-mesenchymal plasticity (EMP), which collectively encompasses epithelial-mesenchymal transition and the reverse process of mesenchymal-epithelial transition, in tumour metastasis, cancer stem cell generation and maintenance, and therapeutic resistance. However, the dynamic nature of EMP processes, the apparent need to reverse mesenchymal changes for the development of macrometastases and the likelihood that only minor cancer cell subpopulations exhibit EMP at any one time have made such evidence difficult to accrue in the clinical setting. In this Perspectives article, we outline the existing preclinical and clinical evidence for EMP and reflect on recent controversies, including the failure of initial lineage-tracing experiments to confirm a major role for EMP in dissemination, and discuss accumulating data suggesting that epithelial features and/or a hybrid epithelial-mesenchymal phenotype are important in metastasis. We also highlight strategies to address the complexities of therapeutically targeting the EMP process that give consideration to its spatially and temporally divergent roles in metastasis, with the view that this will yield a potent and broad class of therapeutic agents.

Measuring height and weight as part of routine mammographic screening for breast cancer

Objectives

Body mass index is a strong predictor of post-menopausal breast cancer risk and (negatively) confounds the association between mammographic breast density and breast cancer risk; however, height and weight are not typically measured as part of routine mammographic screening. This study piloted voluntary height and weight measurement within the BreastScreen Western Australia (WA) programme, and assessed trial participation.

Methods

From February 2016 to January 2018, 204,429 women attending BreastScreen WA were invited to have their height and weight measured and recorded as part of their routine screening mammogram. Descriptive data analysis was used to assess pilot participation rates by available screening data.

Results

Of the 204,429 patients who attended BreastScreen WA during the pilot, 76.35% (156,072) agreed to have their height and weight measured. Pilot participation rates were significantly lower in those patients with disabilities (RR: 0.626; 95% CI: 0.600, 0.653), those who spoke a language other than English at home (RR: 0.876; 95% CI: 0.867, 0.885), and those who identified as Aboriginal and Torres Strait Islander (RR: 0.829; 95% CI: 0.807, 0.852). Pilot participation decreased over time from 88.9% in the first three months to 55.5% in the last month, due to lessening of support from BreastScreen staff.

Conclusion

Measuring height and weight at the time of routine mammographic screening is feasible, although logistical issues, particularly the added time/effort required of support staff, should be considered. BreastScreen WA has since decided to collect voluntary self-reported height and weight data as routine screening policy.

Hypoxia as a signal for prison breakout in cancer

PURPOSE OF REVIEW

We discuss recent discoveries in hypoxic cellular pathophysiology and explore the interplay between hypoxic malignant cells and other stromal elements. This review will provide an update on the effects of hypoxia on cancer outcomes and therapeutic resistance.

RECENT FINDINGS

Hypoxia has been discovered to be a key driver for tumor progression, both because of impacts on tumor cells and separately on the wider tumor microenvironment. The latter effects occur via epithelial mesenchymal transition, autophagy and metabolic switching. Through epithelial mesenchymal transition, hypoxia both drives metastasis and renders key target tissues receptive to metastasis. Autophagy is a double-edged sword which requires greater understanding to ascertain when it is a threat. Metabolic switching allows tumor cells to access hypoxic survival mechanisms even under normoxic conditions.Every element of the malignant stroma contributes to hypoxia-driven progression. Exosomal transfer of molecules from hypoxic tumor cells to target stromal cell types and the importance of microRNAs in intercellular communication have emerged as key themes.Antiangiogenic resistance can be caused by hypoxia-driven vasculogenic mimicry. Beyond this, hypoxia contributes to resistance to virtually all oncological treatment modalities.

SUMMARY

Recent advances have moved us closer to being able to exploit hypoxic mechanisms to overcome hypoxia-driven progression and therapy failure.

The association between mammographic density and breast cancer risk in Western Australian Aboriginal women

PURPOSE

Mammographic density is an established breast cancer risk factor within many ethnically different populations. The distribution of mammographic density has been shown to be significantly lower in Western Australian Aboriginal women compared to age- and screening location-matched non-Aboriginal women. Whether mammographic density is a predictor of breast cancer risk in Aboriginal women is unknown.

METHODS

We measured mammographic density from 103 Aboriginal breast cancer cases and 327 Aboriginal controls, 341 non-Aboriginal cases, and 333 non-Aboriginal controls selected from the BreastScreen Western Australia database using the Cumulus software program. Logistic regression was used to examine the associations of percentage dense area and absolute dense area with breast cancer risk for Aboriginal and non-Aboriginal women separately, adjusting for covariates.

RESULTS

Both percentage density and absolute dense area were strongly predictive of risk in Aboriginal women with odds per adjusted standard deviation (OPERAS) of 1.36 (95% CI 1.09, 1.69) and 1.36 (95% CI 1.08, 1.71), respectively. For non-Aboriginal women, the OPERAS were 1.22 (95% CI 1.03, 1.46) and 1.26 (95% CI 1.05, 1.50), respectively.

CONCLUSIONS

Whilst mean mammographic density for Aboriginal women is lower than non-Aboriginal women, density measures are still higher in Aboriginal women with breast cancer compared to Aboriginal women without breast cancer. Thus, mammographic density strongly predicts breast cancer risk in Aboriginal women. Future efforts to predict breast cancer risk using mammographic density or standardize risk-associated mammographic density measures should take into account Aboriginal status when applicable.

The distribution and determinants of mammographic density measures in Western Australian aboriginal women

Background

Mammographic density (MD) is an established risk factor for breast cancer. There are significant ethnic differences in MD measures which are consistent with those for corresponding breast cancer risk. This is the first study investigating the distribution and determinants of MD measures within Aboriginal women of Western Australia (WA).

Methods

Epidemiological data and mammographic images were obtained from 628 Aboriginal women and 624 age-, year of screen-, and screening location-matched non-Aboriginal women randomly selected from the BreastScreen Western Australia database. Women were cancer free at the time of their mammogram between 1989 and 2014. MD was measured using the Cumulus software. Kolmogorov-Smirnov tests were used to compare distributions of absolute dense area (DA), precent dense area (PDA), non-dense area (NDA) and total breast area between Aboriginal and non-Aboriginal women. General linear regression was used to estimate the determinants of MD, adjusting for age, NDA, hormone therapy use, family history, measures of socio-economic status and remoteness of residence for Aboriginal and non-Aboriginal women separately.

Results

Aboriginal women were found to have lower DA and PDA and higher NDA than non-Aboriginal women. Age (p <  0.001) was negatively associated and several socio-economic indices (p <  0.001) were positively associated with DA and PDA in Aboriginal and non-Aboriginal women. Remoteness of residence was associated with both mammographic measures but for non-Aboriginal women only.

Conclusions

Aboriginal women have, on average, less MD than non-Aboriginal women but the factors associated with MD are similar for both sample populations. Since reduced MD is associated with improved sensitivity of mammography, this study suggests that mammographic screening is a particularly good test for Australian Indigenous women, a population that suffers from high breast cancer mortality.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1113-4) contains supplementary material, which is available to authorized users.

Abstract P5-08-05: The interplay between stromal density, epithelial mesenchymal transition and chemoresistance in breast cancer

Epithelial Mesenchymal Transition (EMT) refers to the transition of cells from a more differentiated epithelial phenotype to a less differentiated mesenchymal phenotype, a process that may be triggered by a range of therapeutic interventions including cytotoxic treatment, and which we have previously linked to poor breast cancer (BrCa) outcome after neoadjuvant chemotherapy (NAC)1. Mammographic breast density (MBD)represents the white radiographic appearance of epithelial and stromal breast tissue on a mammogram. High MBD in patients being treated for BrCa also associates with chemoresistance, correlating with lower pathological complete response rates (pCR)2. Linking these two stimuli, EMT can also be induced by artificial high-density stroma, where it also leads to chemoresistance in vitro3.

Here we set out to validate the link between poor outcome after NAC and EMT in a larger validatory patient cohort, and to ascertain the molecular drivers through which EMT is triggered in this setting. Further we look to confirm the association of high MBD with poor chemoresponse in the same cohort, and to assess whether this chemoresistance is mediated through EMT with the same drivers.

In a pilot cohort of 50 NAC-treated locally advanced BrCas with a pCR rate of 20%, pre-NAC biopsies and post-NAC surgical specimens were analysed for expression changes in a panel of EMT-related markers across treatment using 230 Nanostring assays. This included the EMT-driving transcription factors TWIST 1 and 2, SNAIL 1, 2 and 3 and ZEB 1 and 2, which were correlated with risk of relapse. Snail-3 showed significantly greater induction in relapsers compared to non-relapsers (OR=1.8, p=0.04) with a borderline significantly greater induction of TWIST-1 (OR=2.4, p=0.08) in relapsers in addition.

In a subsequent 240-patient validation cohort with a pCR rate of 18%, contralateral cranio-caudal view mammograms from the time of diagnosis have been collated and digitized with MBD assessment employing Cumulus software ongoing. Percent breast density will be assessed both as a continuous variable and by quartiles. Immunohistochemistry on pre- and post-operative tissue sections with pan-cytokeratin-vimentin co-staining to identify EMT and staining for SNAIL-3 and TWIST-1 is also in progress.

Associations between MBD, EMT before and after chemotherapy, pCR and relapse-free survival will be presented. The role of Snail-3 and TWIST-1 in the interplay between MBD, EMT and outcome is being explored and will be reported.

Citation Format: Agarwal V, Spalding LJ, Blick T, Dobrovic A, Thompson EW, Redfern A. The interplay between stromal density, epithelial mesenchymal transition and chemoresistance in breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-08-05.

Hormone receptor positive, HER2 negative metastatic breast cancer: Impact of CDK4/6 inhibitors on the current treatment paradigm

Resistance to endocrine therapy is a significant therapeutic challenge in the treatment of women with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer. Cyclin-dependent kinase (CDK)4/6 inhibitors in combination with endocrine therapy have been shown to improve progression free survival, overall response rate and clinical benefit rate in women with HR+ HER2- metastatic breast cancer compared with endocrine therapy alone. This review examines the clinical evidence to support the use of CDK4/6 inhibitors in first and second line settings. Practical guidance is provided for the use of CDK4/6 inhibitors, including tolerability data, monitoring requirements and management of key toxicities for each of the available agents.

Emerging data and future directions for CDK4/6 inhibitor treatment of patients with hormone receptor positive HER2-non-amplified metastatic breast cancer

Cyclin-dependent kinase (CDK4/6) inhibitors in combination with endocrine therapy are currently the optimal first line treatment for hormone receptor (HR) positive, human epidermal growth factor receptor 2 (HER2) non-amplified metastatic breast cancer (MBC). However, not all patients benefit from this treatment and all patients will inevitably progress. Identifying therapeutic strategies in this setting is therefore of immediate clinical importance. We present an overview of the mechanisms of resistance to CDK4/6 inhibitors and review potential biomarkers that may guide therapy selection. We also discuss the use of CDK4/6 inhibitors in the context of non-HR-positive/HER2-non-amplified breast cancer and in combination with therapies other than endocrine therapy.

Mammographic density: a potential monitoring biomarker for adjuvant and preventative breast cancer endocrine therapies

Increased mammographic density (MD) has been shown beyond doubt to be a marker for increased breast cancer risk, though the underpinning pathobiology is yet to be fully elucidated. Estrogenic activity exerts a strong influence over MD, which consequently has been observed to change predictably in response to tamoxifen anti-estrogen therapy, although results for other selective estrogen receptor modulators and aromatase inhibitors are less consistent. In both primary and secondary prevention settings, tamoxifen-associated MD changes correlate with successful modulation of risk or outcome, particularly among pre-menopausal women; an observation that supports the potential use of MD change as a surrogate marker where short-term MD changes reflect longer-term anti-estrogen efficacy. Here we summarize endocrine therapy-induced MD changes and attendant outcomes and discuss both the need for outcome surrogates in such therapy, as well as make a case for MD as such a monitoring marker. We then discuss the process and steps required to validate and introduce MD into practice as a predictor or surrogate for endocrine therapy efficacy in preventive and adjuvant breast cancer treatment settings.