Identity Formation and General and Cancer-specific Functioning in Adolescent and Emerging Adult Survivors of Childhood Cancer: A Longitudinal Study into Directionality of Effects

BACKGROUND

Adolescent and emerging adult survivors of childhood cancer generally adjust well psychologically similar to their peers. Nevertheless, some survivors are at greater risk for developing psychological and physical difficulties. To shed light on the psychosocial functioning of adolescent and emerging adult survivors of childhood cancer, personal identity formation and its interplay with general and cancer-specific functioning need to be investigated.

PURPOSE

To examine the longitudinal associations linking identity formation to general and cancer-specific functioning in adolescent and emerging adult childhood cancer survivors using three-wave data over a 2-year period.

METHODS

Dutch-speaking survivors (at baseline: n = 125; 53% female; age range: 14-25 years) treated at the pediatric oncology department of the University Hospitals Leuven (Belgium), completed self-report questionnaires at three annual timepoints. Directionality of effects and correlated changes were examined using cross-lagged structural equation modeling.

RESULTS

Regarding general functioning, bidirectional effects occurred. Life satisfaction positively predicted identity synthesis and both life satisfaction and good physical functioning negatively predicted identity confusion over time. Identity synthesis, in turn, positively predicted life satisfaction and identity confusion negatively predicted good physical functioning over time. Regarding cancer-specific functioning, mainly unidirectional effects occurred. Post-traumatic stress symptoms negatively predicted identity synthesis and positively predicted identity confusion over time, whereas the reverse pattern of associations was found for benefit finding. Several correlated changes were found linking identity formation and psychosocial functioning as well.

CONCLUSIONS

The present study uncovered clinically meaningful pathways linking identity formation to psychosocial functioning over time in adolescents and emerging adults who survived childhood cancer.

Children´s priorities to improve the acceptability of MDR-TB treatment: qualitative data from South Africa

BACKGROUND: Multidrug-resistant TB (MDR-TB) treatment for children frequently includes unpalatable drugs with low overall acceptability. This can negatively impact children and their caregivers´ treatment experiences and is an important contributor to poor adherence, and potentially, poor treatment outcomes. Children and their caregivers´ preferences for MDR-TB treatment are not well documented. We describe children and caregivers´ priorities to inform future MDR-TB treatment regimens.METHODS: We conducted a cross-sectional qualitative study at a TB hospital in South Africa using semi-structured interviews and participatory research activities with caregivers and children routinely diagnosed and treated for MDR-TB between June and August 2018.RESULTS: We conducted 15 interviews with children and their caregivers. Children ranged from 2 to 17 years of age (median age: 8.3 years). Children and caregivers had an overall negative experience of MDR-TB treatment. Children and caregivers described how future MDR-TB drugs and regimens should prioritise sweeter flavours, fewer pills, brighter colours, and formulations that are easy to prepare and administer and dispensed in colourful, small and discrete packaging.CONCLUSIONS: MDR-TB treatment acceptability remains low, and negatively impacts children and their caregivers´ treatment experiences. Improving the overall acceptability of MDR-TB treatment requires engaging with children and their caregivers to better understand their priorities for new treatment regimens and child-friendly formulations.

Implementation of behaviour change training in practice amongst pharmacy professionals in primary care settings: Analysis using the COM-B model

BACKGROUND

The Pharmacy Integration Fund (PhIF) was established in England in 2016, with funded learning programmes or 'pathways' designed to support the development of clinical pharmacy practice in a range of settings. Despite pharmacy staff being well positioned to provide more clinical work, limited research has investigated behaviour change training targeted at widespread practice transformation.

OBJECTIVE(S)

To investigate implementation of PhIF learning in practice, using the COM-B model of behaviour change.

METHODS

An online survey distributed in February and October 2020 included questions on motivations for learning, confidence in target behaviours and impact of PhIF training on behaviour. The October 2020 survey also included questions exploring the effect of the COVID-19 pandemic. Quantitative data were analysed in SPSS. v.27 (IBM). Inferential statistics were used to compare between the pathways (Primary care pathways [PCP], Post-registration pathway [PRP] and Accuracy Checking Pharmacy Technician [ACPT] pathway). Free text comments were categorised and themed.

RESULTS

Three-hundred and eighty-three responses were received (49% PRP learners, 39% PCP learners and 12% ACPT learners). Learners generally had the capacity and opportunities to apply learning, and were strongly motivated to implement behaviours in practice, although learners based in community pharmacy (those on the PRP) were less likely to report receiving employer support. Enhanced knowledge/skills (capacity) were more commonly reported than change to patient-facing activities, leading clinical services and conducting medication reviews with patients with complex needs (clinical practice behaviours targeted by the pathways). The COVID-19 pandemic heightened barriers to implementing practice change.

CONCLUSIONS

Implementation of a range of clinical practice behaviours following at scale training appears to have been largely successful. Despite this, the community pharmacy context, where funded service opportunities may be lacking, continues to present challenges to workforce transformation plans. More work is needed to understand how training can be implemented to promote practice change for pharmacy professionals in all settings.

PRECISION: the Belgian molecular profiling program of metastatic cancer for clinical decision and treatment assignment

PRECISION is an initiative from the Belgian Society of Medical Oncology (BSMO) in collaboration with several stakeholders, encompassing four programs that aim to boost genomic and clinical knowledge with the ultimate goal to offer patients with metastatic solid tumors molecularly guided treatments. The PRECISION 1 study has led to the creation of a clinico-genomic database. The Belgian Approach for Local Laboratory Extensive Tumor Testing (BALLETT) and GeNeo studies will increase the number of patients with advanced cancer that have comprehensive genotyping of their cancer. The PRECISION 2 project consists of investigator-initiated phase II studies aiming to provide access to a targeted drug for patients whose tumors harbor actionable mutations in case the matched drug is not available through reimbursement or clinical trials in Belgium.

HGG-49. Gliomatosis cerebri in children: A collaborative report from the European Society for Pediatric Oncology (SIOPE)

BACKGROUND: Gliomatosis cerebri (GC), a radiologically defined diffusely infiltrating glioma, is no longer considered a distinct entity since the 2016 WHO classification for tumors of the CNS. Due to its rarity and dismal prognosis treatment recommendations in children remain ambiguous. Using central neuroradiological review, we performed a multi-institutional, retrospective study of GC providing comprehensive radiological, clinical, and (epi)genetic characterization. RESULTS: We included 104 patients between 1-19 years. Within a median follow-up of 15.5 months (range, 2.3-138.8), 93 patients (89.4 %) had died, 4 (3.8 %) were lost to follow-up and 7 (6.8 %) were alive with stable/progressive disease. Median progression-free- (PFS) and overall survival (OS) were 8.6 months (interquartile range, 4.3-14.0) and 15.5 months (10.9-27.7), respectively. Former WHO grading correlated significantly with median OS: WHO °II: 47.8 months (25.2-55.7); WHO °III: 15.9 months (11.4-26.3); WHO °IV: 10.4 months (8.8-14.4) (p<0.001). In high-grade gliomas (HGG), radiochemotherapy showed best PFS (p=0.002). Compared to hemispheric pediatric non-GC HGG, GC phenotype was associated with decreased OS (p=0.001). Methylation-based classification and exome sequencing were possible for 49 and 45 patients, respectively. According to the 2021 WHO classification, most cases were considered as IDH-/H3-wildtype gliomas (n=37/49, 75.5 %), mostly with a pedRTK2 subtype (n=15, 30.6%), followed by pedMYCN (n=5, 10.2 %). Within the IDH-/H3-wildtype gliomas, EGFR-altered tumors (n=10) seemed overrepresented. Survival analyses revealed a better OS for IDH1-mutant tumors (n=6; 54.6 vs. 15.2 months in IDH-wildtype; p=0.015) and a worse OS for TP53-mutant tumors (n=6; p=0.001). Despite the potential overrepresentation of EGFR-altered tumors, no other specific molecular markers for GC could be identified so far. Further analyses are ongoing. CONCLUSIONS: GC in children is confirmed as a poor prognostic phenotype include various epigenetic pediatric glioma subtypes, without a proven (epi)genetic mark of its own. The relevance of overrepresented EGFR alterations has to be determined yet.

QOL-16. A 6-year longitudinal study of neurocognition in children treated for a brain tumor

Long-term neurocognitive difficulties in children treated for a brain tumor are well documented and known to be affected by treatment. However, longitudinal studies of these neurocognitive difficulties are scarce. In the present study, we investigated the impact of radiotherapy (RT) on the evolution of neurocognition between different consecutive time points after diagnosis, and throughout treatment and survivorship. This study included 69 children diagnosed with a brain tumor at the University Hospitals Leuven who completed a comprehensive neuropsychological test battery (intelligence, memory, visuomotor functioning, and QoL) on at least three consecutive time points (2-year interval). Of all patients, 40 completed the test battery at 4 time points. The first assessment was conducted at the earliest possible moment after diagnosis and before the start of any adjuvant therapy. Mean age at diagnosis and first assessment were 7.75 and 7.92 years, respectively. The most common diagnoses were pilocytic astrocytoma (n=33) and medulloblastoma (n=11). 29.0% of the children received local RT and 15.9% received craniospinal RT. A repeated measures analysis with cranial irradiation (no, focal, craniospinal) as between-subjects factor and age at diagnosis as covariate demonstrated a significant interaction effect between time and type of irradiation for both overall intelligence (p=0.007) and QoL (p=0.006) for children with three and four assessments. Children who received craniospinal irradiation demonstrated a significant decline in overall intelligence and a significant worsening of QoL. For the non-irradiated group, an improvement of QoL was observed. For processing speed, a significant time effect was found for children with three and four assessments (p<0.001), with a significant improvement for the overall group. The results of this longitudinal study demonstrated diverse longitudinal trajectories. Children who received craniospinal irradiation are most often confronted with intellectual decline and worsening of QoL.

HGG-56. Spatial mapping of the tumor micro-environment in pediatric glioma

High-grade glioma are the main cause of cancer-related death in children. The highly heterogeneous composition of the tumor cells and their interactions with the tumor micro-environment (TME), contribute substantially to the poor response to treatment and the high levels of morbidity and mortality. Here, we used high-dimensional, multiplexed immunohistochemistry to map the single-cell tissue architecture of 26 pediatric glioma samples covering 8 histologic diagnoses, allowing us to determine the spatial distribution of the various tumoral subtypes and how these interact with their local immune-microenvironment. Overall, this analysis showed that tumor grade anti-correlated with the amount of infiltrating cytotoxic T-lymphocytes (CTLs), which were typically more exhausted in the higher grade tumors. In addition, tumor associated macrophages were primarily infiltrating from the blood and presented an M2-like anti-inflammatory phenotype which became more extended with tumor grade. Using the spatial information, possible cell-cell interactions could be determined. In lower grade glioma, we observed an increased activation level of CTLs that were closely located to neighboring T-helper cells. In pediatric glioblastoma, on the other hand, CTLs, even though they were located close to a T-helper cell, could only minimally be activated, and showed more extended exhaustion when residing further away. Additionally, the activation of the CTLs was associated to the distance to the closest PD-L1 positive macrophage in pilocytic astrocytoma and desmoplastic infantile ganglioglioma. In conclusion, with the use of multiplex immunohistochemistry, we are able to study the tumor and TME of pediatric glioma in depth on a single-cell and spatial level, which allows us to further study the heterogeneous landscape of these tumors.

OTHR-39. Extraneural spreading of a diffuse leptomeningeal glioneuronal tumor in a child: patient-derived models show sensitivity to vinblastin and trametinib

Diffuse leptomeningeal glioneuronal tumors (DLGNT) are rare neoplasms of the central nervous system. We describe the generation of patient-derived models from a DLGNT that metastasized to the peritoneal cavity via a ventriculoperitoneal shunt in a child. The original tumor contained a KIAA1549:BRAF fusion with a chromosome 1p deletion and corresponded with methylation subclass DLGNT-MC-2 From a sample of ascitic fluid, metastatic tumoral cells could be extracted and expanded ex vivo into a long-term cell culture model. This patient-derived cell line (PDCL) showed mixed morphological phenotypes and expressed MAP2 and SYP. The KIAA1549:BRAF fusion was preserved and the PDCL still corresponded to the original methylation subclass DLGNT-MC-2. Whole-genome sequencing showed additional mutations potentially contributing to the malignant behavior of the tumor. Cytotoxic assays performed on the PDCL indicated high sensitivity to vinblastine and trametinib (MEK-inhibitor) and intermediate sensitivity to DRD/ClpP-modulators. The PDCL underwent viral transduction to induce GFP-fLux positivity and was intraperitoneally injected into immunocompromised mice. A mouse model could be generated, with the growth of a peritoneal tumor in a localized manner. The cells grown from the mouse tumor were again put into culture and were afterwards subjected to the same treatments as the PDCL. This confirmed a similar profile, with high sensitivity to vinblastin and trametinib and an intermediate sensitivity to the DRD/ClpP-modulators. In conclusion, we were able to generate patient-derived models from a metastatic DLGNT, which recapitulate the molecular characteristics of the original tumor. The models showed high sensitivity to vinblastin and targeted therapy with MEK-inhibition, but further studies are necessary to define the adequate treatment for this kind of tumor.

QOL-08. Visual memory and potential clinical risk factors in long-term survivors of a childhood brain tumor

A brain tumor treatment has previously been associated with long-term neurocognitive sequelae. However, clinical profiles differ between certain patient subgroups. We investigated the impact of tumor location, radiotherapy (RT), and age at diagnosis in childhood brain tumor survivors on long-term cognitive outcomes. Adult survivors (n=32) of pediatric brain tumors (n=11 infratentorial, n=21 supratentorial; 14 astrocytomas, 3 craniopharyngiomas, 2 ependymomas, 2 germinomas, 1 hemangioblastomas, 4 medulloblastomas, 6 nervus opticus gliomas) participated in this neuropsychological study (n=11 RT) (16.8-35.1 years old, >2years after treatment, mean age at diagnosis = 9.2 years, 50% male). An extensive neurocognitive test battery was used to assess intelligence scales (n=5), verbal and visual memory (n=2), and language (n=3). In order to investigate the effects of tumor location (infra- versus supratentorial), RT (yes vs. no), and age at diagnosis on the cognitive scores, a multivariate ANCOVA model was tested including the main effects and interaction between age and RT. Of all included scales, only visual memory was significantly associated with the risk factors. More specifically, patients who received RT (F=10.3, p=.004) and were younger at diagnosis (F=6.9, p=.014) scored worse on this task. Furthermore, the interaction effect between these factors was also significant (F=8.8, p=.006). These findings suggest that younger patients could be more vulnerable to the radiotoxic effects to visual memory outcomes. Tumor location (supra- vs. infratentorial) was not significantly associated with any outcome. In this study, only visual memory appeared to be associated with the risk factors of interest. Both radiotherapy and age at radiotherapy, as well as their interaction, could be risk factors for altered neurodevelopmental patterns of brain areas associated with visual memory.

Better detection of reduced motor functioning in brain tumor survivors based on objective motor assessments: an incentive for improved standardized follow-up

Long-term sequelae are well-known in childhood brain tumor survivors, but motor functioning remains poorly described. This cross-sectional study aimed to assess objective motor functioning, patient-specific risk factors, and parental perceptions. Fifty-two childhood brain tumor patients (pilocytic astrocytoma, medulloblastoma, and other types) who were at least 6 months out of treatment were evaluated. Mean age at testing was 11.7 years. Objective motor functioning was assessed with the Movement Assessment Battery for Children (MABC-2-NL) and/or Bruininks-Oseretsky test of motor proficiency (BOT-2). Functional walking capacity was assessed with the 6-min walk test (6MWT). Parent-reported motor functioning was addressed using the ABILHAND-Kids, ABILOCO-Kids questionnaires, and a standardized anamnesis. Patients showed impaired motor functioning in all domains (p < 0.001). Regarding risk factors, younger age at diagnosis (< 5 year) was significantly associated with lower scores on body coordination (p = 0.006). Adjuvant treatment resulted in lower scores for fine manual control of the BOT-2 (p = 0.024) and balance of MABC-2-NL (p = 0.036). Finally, questionnaires revealed an underestimation of motor problems as perceived by the parents. In conclusion, many children who are in follow-up for a brain tumor show impaired motor functioning on multiple aspects, with younger age at diagnosis and adjuvant treatment as specific risk factors. Based on the questionnaires and anamnesis, motor problems appear to be underestimated by the parents.  Conclusion: These findings point to the need for timely prospective screening of motor functioning. Based on a screening assessment, adequate rehabilitation programs can be applied in childhood brain tumor survivors, aiming to reduce the adverse impact on their daily lives, both for functional activities and cardiovascular fitness. What is Known: • A pediatric brain tumor and its treatment are associated with potential long-term motor sequelae. • Test assessments could enable us to objectify motor functioning of these patients. What is New: • Pediatric brain tumors survivors show lower motor performance compared to the norm, which is often underestimated by parents. • Younger age at diagnosis and adjuvant treatment could be specific risk factors.

PATH-21. THE SINGLE-CELL PATHOLOGY LANDSCAPE OF PEDIATRIC GLIOMA

High-grade glioma are the main cause of cancer-related death in children. Despite extensive research, their prognosis remains poor with very few treatment options. This can be attributed to the highly heterogeneous and plastic nature of glioma tumor cells and their interactions with the microenvironment, although quantitative data are still largely missing. Here, we used high-dimensional, multiplexed immunohistochemistry to map the spatial, single-cell tissue architecture of 31 pediatric glioma samples covering 9 histologic diagnoses. This novel approach allowed us to map the spatial distribution of the various tumoral subtypes, which typically occur in specific tumoral niches, and how these interact with their local immune-microenvironment. Finally, by aligning these findings to the clinical data of the patients and comparing these to adult glioblastoma, we are now able to more precisely describe the heterogeneous landscape of pediatric glioma at single-cell resolution.

Brain network hubs and cognitive performance of survivors of childhood infratentorial tumors

BACKGROUND

Childhood infratentorial tumor patients frequently suffer from long-term cognitive deficits. As each constituent of their treatment can lead to neurotoxicity, cascade effects can lead to profound reorganization of the underlying brain network, the so-called 'connectome'. However, to date, few studies have assessed the relationship between brain network topology, the functional role of network hubs (i.e. highly connected regions), and neurocognitive outcomes in adult survivors of childhood infratentorial tumors.

METHODS

In this cross-sectional study, childhood infratentorial tumor survivors (n = 21: pilocytic astrocytoma (n = 8), ependymoma (n = 1) and medulloblastoma (n = 12)) and healthy controls (n = 21) were recruited. Using multishell diffusion-weighted MRI, microstructural organization and topology of supratentorial white matter was investigated; using a voxel-based approach, a fixel-based analysis, and a graph theoretical approach. In addition, neurocognitive subscales of the WAIS-IV intelligence test, and their relationship with nodal strength and network efficiency metrics were assessed.

RESULTS

Similar to earlier studies, we observed widespread decreases in fractional anisotropy (FA) in patients compared to controls, based on voxel-based analyses. In addition, the fixel-based analyses dissociated macro- from microstructural changes, which were encountered in in infratentorial versus supratentorial brain areas, respectively. Finally, regional reorganization (i.e. differences in local efficiency) occurred mainly in hubs, which suggests a specific vulnerability of these areas. These hubs were not only mostly affected, but also most strongly correlated with the intelligence subscales.

CONCLUSION

This study suggests that network hubs are functionally important for intellectual outcomes in infratentorial tumor survivors. Furthermore, these regions could be the primary targets of treatment toxicity. Validation of this specific hypothesis in larger samples is required.

Therapeutic implications of improved molecular diagnostics for rare CNS-embryonal tumor entities: results of an international, retrospective study

BACKGROUND

Only few data are available on treatment-associated behavior of distinct rare CNS-embryonal tumor entities previously treated as "CNS-primitive neuroectodermal tumors" (CNS-PNET). Respective data on specific entities, including CNS neuroblastoma, FOXR2 activated (CNS NB-FOXR2), and embryonal tumor with multi-layered rosettes (ETMR) are needed for development of differentiated treatment strategies.

METHODS

Within this retrospective, international study, tumor samples of clinically well-annotated patients with the original diagnosis of CNS-PNET were analyzed using DNA methylation arrays (n=307). Additional cases (n=66) with DNA methylation pattern of CNS NB-FOXR2 were included irrespective of initial histological diagnosis. Pooled clinical data (n=292) were descriptively analyzed.

RESULTS

DNA methylation profiling of "CNS-PNET" classified 58(19%) cases as ETMR, 57(19%) as HGG, 36(12%) as CNS NB-FOXR2, and 89(29%) cases were classified into 18 other entities. Sixty-seven (22%) cases did not show DNA methylation patterns similar to established CNS tumor reference classes. Best treatment results were achieved for CNS NB-FOXR2 patients (5-year PFS: 63%±7%, OS: 85%±5%, n=63), with 35/42 progression-free survivors after upfront craniospinal irradiation (CSI) and chemotherapy. The worst outcome was seen for ETMR and HGG patients with 5-year PFS of 18%±6% and 22%±7%, and 5-year OS of 24%±6% and 25%±7%, respectively.

CONCLUSION

The historically reported poor outcome of CNS-PNET patients becomes highly variable when tumors are molecularly classified based on DNA methylation profiling. Patients with CNS NB-FOXR2 responded well to current treatments and a standard-risk-CSI based regimen may be prospectively evaluated. The poor outcome of ETMR across applied treatment strategies substantiates the necessity for evaluation of novel treatments.

Retrospective study of diffuse intrinsic pontine glioma in the Belgian population: a 25 year experience

INTRODUCTION

Diffuse intrinsic pontine glioma is a rare disease with a high mortality. Our primary aim was to determine the incidence of this disease in Belgium. Secondly, we wanted to compare the treatment approach of Belgian pediatric oncology centres, to investigate possibilities for improvement.

METHODS

We retrospectively collected and analysed data on DIPG-patients diagnosed between 1994 and 2018 and recorded in the Belgian Cancer Registry. We included patients ≤ 18 years who were followed in one of the eight Belgian pediatric oncology centres.

RESULTS

We included 100 patients. Files were complete in 87 patients. We observed an increase in diagnoses with an incidence of 3.1 per 1,000,000 persons (aged 0-≤ 18) per year over the last 5 years compared to an overall incidence of 1.8. Biopsy was performed at diagnosis in 51.7% of patients. In one fifth this was study-related. Mutation analysis was known in eight patients, of which six showed the H3 K27M-mutation. 58.8% of patients received chemotherapy, without a significant survival benefit. 12.6% of patients were included in a clinical trial. Biopsy rate and the use of chemotherapy differed widely between centres. Mean OS and PFS were 10.49 and 4.87 months respectively. We observed an improved survival over time.

CONCLUSIONS

Over the past 25 years, we observed an increase of new DIPG-diagnoses. Outcome in our cohort is comparable with literature findings. We demonstrate an important heterogeneity in treatment approach between different centres and limited inclusion in clinical trials. Therefore, collaboration between centres and inclusion of patients in clinical trials is much needed.

Cross-sector pre-registration pharmacist placements in general practice in England: lessons from a national evaluation

Introduction

In 2019/2020, the Pharmacy Integration Fund commissioned delivery of cross-sector pre-registration pharmacist training incorporating 3–6 month placements in general practice (GP). GP placements were managed by Health Education England (HEE) and organised as one (or more) blocks, or as spilt weeks/days across base sector (hospital/community) and GP. Trainees had a pharmacist tutor at base and in GP.

Aim

to evaluate the implementation of cross-sector pre-registration pharmacy placements in GP in England, and to identify barriers and enablers of a successful placement.

Methods

A qualitative approach was taken, with case study sites purposively sampled for maximum variation: pharmacy base (hospital/community), number of pre-registration pharmacist trainees in base doing GP placement, length of GP placement, organisation of GP placement and geographical location. With consent, trainees and tutors identified as meeting sampling criteria were emailed invitation letters and participant information sheets. Where the trainee and their tutor(s) agreed to participate, semi-structured telephone interviews were conducted January - July 2020. Questions developed from literature(1, 2) and the HEE handbook were tailored to understanding trainees’ and tutors’ views on the implementation of pre-registration pharmacist placements in GP, including benefits, unintended consequences and impacts. Thematic analysis across sites was undertaken with a focus on exploring inter and intra group themes.

Results

Thirty-four interviews were completed in 11 study sites (5 GP/hospital; 6 GP/community pharmacy). Trainees and tutors considered GP placements had been successful. Contributing factors were: placement planning (induction, contingency arrangements for cover should GP tutor be unavailable); tutors working together (good communication and collaboration); GP tutor support (regular contact, reflection; identifying learning needs; opportunities for learning); integration of GP placements within training year (specific learning/training activities at base during GP placement); and GP tutors having backing of their organisation to supervise effectively. A lack of these impacted negatively. Trainees completed a wide spectrum of activities and gradually moved from administrative to clinical tasks. They built up confidence to undertake patient-facing activities, with more direct supervision at the beginning moving to indirect supervision using debriefing. Thirteen weeks in GP was considered an appropriate minimum duration by all trainees and tutors; those based in community felt that 26 weeks in GP provided more opportunities for clinical and consultation skills learning. Cross-sector experience facilitated a better understanding of patient pathways and the importance of holistic patient care. All trainees considered working in GP in future but highlighted the lack of a cross-sector GP foundation programme. Base tutors felt the time commitment was comparable to single sector placements. Base and GP tutors felt that a clear set of competencies for GP placements and a broader governance framework would ensure standards and consistency.

Conclusion

This is the first national evaluation of cross-sector pre-registration pharmacists in general practice placements in England. Sampling as case studies enabled data triangulation and generated a multi-faceted understanding on factors impacting GP placements. A key limitation was the volunteer bias associated with recruitment. Key attributes of a successful pre-registration cross-sector training experience are highlighted and can inform policy reforms including change from pre-registration to foundation year training.

References

1. Gray N. Review of Experience of Pre-registration Pharmacist Placements in the General Practice Setting – Final Report. 2019.

2. Jee SD, Schafheutle EI, Noyce PR. Is pharmacist pre-registration training equitable and robust? Higher Education, Skills and Work-Based Learning. 2019;9(3):347–58.

QOL-18. A LONGITUDINAL STUDY OF NEUROCOGNITION IN CHILDREN TREATED FOR A BRAIN TUMOR

It is well known that neurocognition in children treated for a brain tumor can be affected. However, studies on the trajectory of these neurocognitive problems are scarce. In the present study we investigated the evolution of neurocognition between timepoints of diagnosis, 2, 4 and 6 years later. A total of 53 children diagnosed with a brain tumor were recruited in this study, of which all completed a comprehensive neuropsychological test battery at three successive timepoints and 30 at 4 timepoints. The first assessment was conducted as soon as possible after diagnosis and before initiation of chemo- and/or radiotherapy. Mean age at diagnosis was 8.06 years. The most common diagnoses were pilocytic astrocytoma (n=28) and medulloblastoma (n=10). 24.5% and 18.9% of these patient groups received focal or craniospinal irradiation, respectively. A repeated measures analysis with cranial irradiation (no, focal, craniospinal) as between-subjects factor demonstrated a significant interaction effect between time and type of irradiation for overall intelligence (p=0.02) for children with three assessments. The same interaction effect was found for overall intelligence and processing speed for children with four assessments (p=.005 and p=.002, respectively). The group who received craniospinal irradiation demonstrated the most pronounced decline. Interestingly, no main time effect or interaction effect was found for general memory functioning. Our results demonstrate that not all neurocognitive functions in children treated for a brain tumor decline after treatment. Overall IQ and processing speed are the most vulnerable outcomes in our cohort, especially for the children treated with craniospinal irradiation.

QOL-07. CORTICAL VOLUME AND THICKNESS IN ADULT SURVIVORS OF CHILDHOOD POSTERIOR FOSSA TUMORS

PURPOSE

A brain tumor treatment including cranial radiotherapy has previously been associated with long-term neurocognitive sequelae. Since underlying neurological mechanisms remain inconclusive, we investigated cortical features in childhood posterior fossa tumor survivors.

METHODS

T1-weighted MRI (MPRAGE, resolution=.98x.98x1.2mm) was acquired to investigate the cortical structure in adult survivors of childhood infratentorial tumors (n=19, 15males) (16.4–34.8 years old, >2years after treatment). These scans were compared to age- and gender- matched controls. Supratentorial cortical volume and thickness were investigated using voxel-based morphometry (VBM) and surface-based morphometry (SBM), respectively. We compared patients and controls, irradiated (n=13) versus non-irradiated patients, and investigated the age at radiotherapy (peak level: p<.001).

RESULTS

Lower GM volumes were encountered in multiple brain areas of patients compared to controls, with the largest clusters in the right and left occipital fusiform gyri. Irradiated patients showed lower GM volumes then non-irradiated patients in the superior and middle frontal gyri, the right supramarginal gyrus and precuneus. Age at radiotherapy was associated with GM volume in the inferior frontal gyrus. SBM yielded larger cortical thickness in patients in the left precuneus, inferior temporal and fusiform gyrus. The opposite effect was only marginally significant, in the left temporal lingual gyrus. Age at radiotherapy was not associated with cortical thickness, but radiotherapy was associated with lower thickness of the left pars opercularis.

CONCLUSION

Widespread differences in cortical volumes and thickness were observed in posterior fossa tumor survivors. Both radiotherapy and age at radiotherapy could be suggested as risk factors for long-term cortical development.

QOL-19. PARENT-REPORTED COGNITIVE PROBLEMS AND DIRECT ASSESSMENT OF COGNITION IN CHILDREN TREATED FOR A BRAIN TUMOR

The Pediatric Perceived Cognitive Function (PedsPCF) item bank is a short parent and self-reported cognitive screening questionnaire developed in the context of pediatric oncology. The PedsPCF demonstrated satisfactory psychometric properties and the scores of the PedsPCF are found to be associated with clinical outcomes. Today little research is available to evaluate whether the PedsPCF is correlated with direct assessments of neurocognitive domains. The aim of the current study is to investigate whether important cognitive domains, such as different aspects of intelligence, memory, visuomotor integration can predict the PedsPCF score. We obtained 100 PedsPCF filled in by parents from children treated for a brain tumor. All these children completed a comprehensive neuropsychological battery. Mean age at diagnosis was 7.47 years and mean age at completion of PedsPCF and testing 13.84. The most common diagnoses were pilocytic astrocytoma (n=43) and medulloblastoma (n=14). A linear regression model with verbal comprehension, perceptual reasoning, processing speed, visuomotor integration as predictors for overall PedsPCF score was significant (p.005), but the overall model fit was limited (adjusted R2: 14%). Visuomotor integration and processing speed were significant predictors (beta = 0.56 and -0.29). Our results are in line with the overall finding that the correlation between questionnaires assessing quality of survival and direct assessments of cognition are low. For clinical practice these results are important as the PedsPCF can’t be used to replace direct cognitive assessments or vice versa.

Left heart Impella-device to bridge acute mitral regurgitation to MitraClip-procedure: a novel implementation of percutaneous mechanical circulatory support

Background

Acute mitral regurgitation (MR) is an emergency, often requiring urgent surgery. Severe acute MR presenting with hemodynamic collapse is usually caused by papillary muscle rupture or dysfunction after acute myocardial infarction (AMI) or chordal rupture, resulting in flail mitral leaflet(s). Preoperative stabilization is complex due to concomitant hemodynamic collapse and hypoxic respiratory failure. Finding the right balance between both preload and inotropic support is challenging. When patients are too sick for immediate surgical intervention, mechanical circulatory support can be considered because of its ability to both unload and reduce of cardiac work while increasing coronary perfusion and cardiac output. Nevertheless, even after initial stabilization, surgical risk remains high in critically ill acute severe MR patients and transcatheter treatments such as MitraClip are increasingly being explored.

Methods

Between August 2017 and September 2019, patients presenting with acute severe mitral regurgitation and considered too ill for immediate surgical intervention (EURO-II score &gt;11.2% plus pulmonary oedema necessitating mechanical ventilation and/or hemodynamic instability), were selected for an Impella-assisted LV unloading technique as bridge to MitraClip-procedure. Five patients were selected for the combined left Impella/MitraClip-procedure in two tertiary cardiac ICUs.

Results

The mean age was 72 years. The cause of MR was ischemic in 20% and all patients presented in cardiogenic shock state, necessitating mechanical ventilation. The overall cardiac operative risk assessment (Euro-II) score predicted a 35% chance of in-hospital mortality. Cardiac output was severely impaired (mean LVOT VTI 8.2 cm). All patients were on inotropic support and supported by an Impella-CP pVAD (mean flow 2.5 Liter per minute; mean 6.3 days of support). In all cases, we managed to reduce the LVEDP below 15 mmHg using the combination of medical therapy (afterload reduction, inotropes), mechanical ventilation and pVAD-therapy. The MR was significantly reduced by a MitraClip-procedure in each Impella supported patient. The overall survival at discharge was 80%. One patient with late referral and multiple organ failure at presentation deceased due to refractory cardiogenic shock. Overall, severe MR was reduced to grade 1+ and all four patients survived 6 months after discharge with only one readmission for decompensated heart failure.

Conclusions

A combined strategy of Impella and MitraClip appears to be a novel, feasible alternative for patients presenting with acute, severe MR unable to proceed to a corrective surgical procedure at presentation due to severe left ventricular forward flow failure. In these cases, the early initiation of pVAD-support may reduce the risk of development of irreversible end- organ damage and dysfunction. Exploration in a larger, randomised population is warranted to investigate this strategy further.

Funding Acknowledgement

Type of funding source: None

Prevalence of leukoencephalopathy and its potential cognitive sequelae in cancer patients

Due to the rising use of chemotherapy treatment in cancer patients and growing survival rates, therapy-induced neurotoxic side effects are increasingly reported. Given the ambiguity about the prevalence and severity of leukoencephalopathy, one of such toxic side effects, in non-central nervous system (CNS) cancer patients, we performed a systematic literature search using the PubMed/Medline database to summarize existing literature regarding leukoencephalopathy epidemiology in non-CNS cancer patients and its potential cognitive sequelae. The search was based on the following terms: ('MRI' OR 'T2-weighted MRI' OR 'FLAIR') AND ('cancer' OR 'tumour' OR 'leukaemia' OR 'neoplasms') AND ('chemotherapy' OR 'radiotherapy') AND ('posterior reversible encephalopathy' OR 'leukoencephalopathy' OR 'cerebral ischaemia' OR 'stroke'). Thirty-two studies discussing the occurrence of leukoencephalopathy in cancer patients were included, of which the majority investigated Acute Lymphoblastic Leukaemia (ALL) patients (n = 22).Regularly scanned ALL patients showed a prevalence of leukoencephalopathy between 17 - 87%, and 15 - 83% of patients presented with leukoencephalopathy when only scanned after a CNS event. When diagnosed with posterior reversible encephalopathy syndrome, 100% of patients showed leukoencephalopathy because its diagnosis is based in part on observable lesions. An increased prevalence was observed in ALL patients treated with higher doses of methotrexate (5 g/m² MTX, 42 - 87%) when compared to lower doses (< 5 g/m², 32 - 67%). By contrast, in breast cancer patients, white matter lesions were mainly detected in case of neurological symptoms, but not (yet) clearly associated with chemotherapy administration. However, chemotherapy treatment was associated with more infratentorial microbleeds in breast cancer patients . Up to 50% of other (neurologically asymptomatic) solid tumour patients presented white matter lesions, even years after treatment. When cognitive data were investigated, lesioned patients showed lower scores on neurocognitive tests in 50% of studies, years after ending therapy.In conclusion, leukoencephalopathy is well-documented for ALL patients (with a focus on methotrexate), but there is a lack of knowledge for other intravenous chemotherapeutics, other oncological populations, wider age ranges and possible risk factors (e.g. history of CNS event). Furthermore, the long-term neuropsychological impact and potential risk for neurodegenerative processes due to leukoencephalopathy remains inconclusive. Hence, large international databanks, epidemiological and prospective case-control studies are necessary to stratify risk groups for CNS-related side effects.

Differences in clinical characteristics and reported quality of life of men and women undergoing cardiac resynchronization therapy

Aims

Response to cardiac resynchronization therapy (CRT) is known to be associated with a number of clinical characteristics, including QRS duration and morphology, gender, height, and the aetiology of heart failure (HF). We assessed the relation of gender and baseline characteristics with QRS duration and Kansas City Cardiomyopathy Questionnaire.

Methods and results

AdaptResponse is a global randomized trial. The trial enrolled CRT‐indicated patients with New York Heart Association classes II–IV HF, left bundle branch block (QRS ≥ 140 ms in men, ≥130 ms in women), and baseline PR interval ≤200 ms. In total, 3620 patients were randomized, including 1569 women (43.3%) approaching the actual proportion of women in the HF population. Women were older and more often New York Heart Association class III or IV than men (55.6% vs. 48.7%), had less frequent ischaemic cardiomyopathy (21.2% vs. 39.5%), and had a 5.1 ms shorter QRS duration than men. Women were more often depressed (18.5% vs. 9.7%), had a significantly lower Kansas City Cardiomyopathy Questionnaire score, and had differences in medication prescriptions.

Conclusions

AdaptResponse is the largest randomized CRT trial and enrolled more women than any other landmark CRT trial. Women differed from men with regard to baseline characteristics and quality of life. Whether these differences translate into clinical outcome differences will be examined further in the AdaptResponse trial.

Social competence in newly diagnosed pediatric brain tumor patients

Brain tumors (BTs) are a common pediatric malignancy. Improved treatment has resulted in higher survival rates. There is, however, increasing concern about adverse effects of the disease and its treatment, including effects on social competence (i.e. effective social functioning in everyday life). The aim of this study is to examine multiple levels of social competence (i.e. social skills and social adjustment) in newly diagnosed pediatric BT patients. Thirty newly diagnosed BT patients aged 5-12 years were assessed shortly after diagnosis with a neuropsychological test battery focusing on social competence, including tests for IQ, social skills (i.e. social-affective and executive functioning) and social adjustment (rated by parents and teachers). Their performance was compared to 95 healthy controls who completed the same assessment. Patients and healthy controls were largely comparable with regard to demographic and environmental factors and did not differ on measures of IQ, social skills and social adjustment. Furthermore, age was found to have a positive significant effect on social skills independent of group. Shortly after diagnosis, pediatric BT patients did not perform different from healthy controls on IQ and measures of social skills and social adjustment. This is an encouraging finding. However, because of potentially neurotoxic adjuvant therapy and the ongoing development of social skills, longitudinal follow-up studies are needed to investigate long-term outcome regarding social competence in BT survivors.

Bayesian strategy selection identifies optimal solutions to complex problems using an example from GP prescribing

Complex health problems require multi-strategy, multi-target interventions. We present a method that uses machine learning techniques to choose optimal interventions from a set of possible interventions within a case study aiming to increase General Practitioner (GP) discussions of physical activity (PA) with their patients. Interventions were developed based on a causal loop diagram with 26 GPs across 13 clinics in Geelong, Australia. GPs prioritised eight from more than 80 potential interventions to increase GP discussion of PA with patients. Following a 2-week baseline, a multi-arm bandit algorithm was used to assign optimal strategies to GP clinics with the target outcome being GP PA discussion rates. The algorithm was updated weekly and the process iterated until the more promising strategies emerged (a duration of seven weeks). The top three performing strategies were continued for 3 weeks to improve the power of the hypothesis test of effectiveness for each strategy compared to baseline. GPs recorded a total of 11,176 conversations about PA. GPs identified 15 factors affecting GP PA discussion rates with patients including GP skills and awareness, fragmentation of care and fear of adverse outcomes. The two most effective strategies were correctly identified within seven weeks of the algorithm-based assignment of strategies. These were clinic reception staff providing PA information to patients at check in and PA screening questionnaires completed in the waiting room. This study demonstrates an efficient way to test and identify optimal strategies from multiple possible solutions.

Long-term leukoencephalopathy and neurocognitive functioning in childhood sarcoma patients treated with high-dose intravenous chemotherapy

PURPOSE

Knowledge is limited regarding the prevalence and persistence of chemotherapy-induced leukoencephalopathy in childhood sarcoma patients. This study explored the presence, clinical relevance, and potential risk factors of leukoencephalopathy in childhood bone and soft tissue sarcoma survivors, treated with intravenous chemotherapy.

METHODS

We acquired cross-sectional neurocognitive data in adult survivors (n = 34) (median age at diagnosis [AaD] = 13.32 years, age range = 16-35 years) and healthy age-matched controls (n = 34). Additionally, magnetic resonance imaging included T2-weighted FLAIR (leukoencephalopathy Fazekas rating), multiexponential T2 relaxation (MET2), and multishell diffusion MRI to estimate myelin integrity-related metrics and fluid movement restrictions. Finally, chemotherapy subgroups (methotrexate, alkylating agents, or combination), AaD, and Apoε and MTHFRC677T polymorphisms were explored as potential risk factors for leukoencephalopathy.

RESULTS

At the group level, quality of life, working memory, processing speed, and visual memory were significantly lower in patients compared to controls. Furthermore, long-term leukoencephalopathy was observed in 27.2% of the childhood sarcoma survivors, which was related to attentional processing speed. Lesions were related to diffusion-derived, but not to myelin-sensitive metrics. A significant interaction effect between AaD and chemotherapy group demonstrated more lesions in case of high-dose methotrexate (HD-MTX) (F = 3.434, P = .047). However, patients treated with alkylating agents (without HD-MTX) also showed lesions in younger patients. Genetic predictors were nonsignificant.

CONCLUSION AND IMPLICATION

This study suggests long-term leukoencephalopathy with possibly underlying changes in vasculature, inflammation, or axonal injury, but not necessarily long-term demyelination. Such lesions could affect processing speed, and as such long-term daily life functioning of these patients.

Diagnostics and treatment of diffuse intrinsic pontine glioma: where do we stand?

Introduction

Diffuse intrinsic pontine glioma (DIPG) is a rare clinically, neuro-radiologically, and molecularly defined malignancy of the brainstem with a median overall survival of approximately 11 months. Our aim is to evaluate the current tendency for its treatment in Europe in order to develop (inter)national consensus guidelines.

Methods

Healthcare professionals specialized in DIPG were asked to fill in an online survey with questions regarding usual treatment strategies at diagnosis and at disease progression in their countries and/or their centers, respectively.

Results

Seventy-four healthcare professionals responded to the survey, of which 87.8% were pediatric oncologists. Only 13.5% of the respondents biopsy all of their patients, 41.9% biopsy their patients infrequently. More than half of the respondents (54.1%) treated their patients with radiotherapy only at diagnosis, whereas 44.6% preferred radiotherapy combined with chemotherapy. When the disease progresses, treatment strategies became even more diverse, and the tendency for no treatment increased from 1.4% at diagnosis to 77.0% after second progression. 36.5% of the healthcare professionals treat children younger than 3 years differently than older children at diagnosis. This percentage decreased, when the disease progresses. Most of the participants (51.4%) included less than 25% of their patients in clinical trials.

Conclusion

This survey demonstrates a large heterogeneity of treatment regimens, especially at disease progression. We emphasize the need for international consensus guidelines for the treatment of DIPG, possible by more collaborative clinical trials.

Electronic supplementary material

The online version of this article (10.1007/s11060-019-03287-9) contains supplementary material, which is available to authorized users.

A-58 Rare Case of Klinefelter Syndrome with 13/14 Balanced Translocation and Absence Epilepsy: Impact of Combined Genotypes on Cognitive Neuropsychological Phenotype

Objective

Klinefelter syndrome (KS) and Robertsonian translocation of 13/14 [rob t(13;14)] are the most common sex-chromosome disorder and chromosome rearrangement, respectively (Engels et al., 2008; Skakkebæk, Wallentin, & Gravholt, 2015). Both are associated with increased risk of cognitive/intellectual disability (ID). A case of KS and de novo (i.e., unbalanced) rob t(13;14) was previously reported (Gül & Şayli, 1994). A case of KS with balanced rob t(13;14) and well-controlled generalized absence epilepsy will be presented with consideration for pediatric neuropsychological practice.

Method

Neuropsychological evaluation of a 12-year-old, right-handed boy diagnosed with comorbid KS, rob t(13;14), and generalized absence epilepsy. Particular attention was given to language given his KS diagnosis. The patient is in a 12:1:1 self-contained classroom with speech-language therapy and social skills groups in place. The patient’s mother is confirmed to have rob t(13;14), whereas paternal contribution is unknown.

Results

Adolescent with a history of language difficulties, especially comprehension. Recent school-based WISC-V FSIQ was in the extremely low range (SS = 53), with weaker verbal comprehension and working memory. Academic achievement was globally very low. Expressive and receptive language, visual perception and motor coordination were extremely low to low average. Verbal list learning and visual attention were near average to average.

Conclusions

This case contributes to the very limited body of pediatric neuropsychological data on the combined genotype of KS with rob t(13;14) and absence epilepsy. Both the KS and rob t(13;14) cognitive phenotypes have been characterized as highly variable, with the comorbidity a likely increased risk for ID.

B-32 The Use of Repeat Neuropsychological Assessment to Guide Treatment of Possible Normal Pressure Hydrocephalus in a Complex Case

Objective

Normal Pressure Hydrocephalus (NPH) is a condition that is characterized by the buildup of cerebrospinal fluid (CSF) in the brain that can cause urinary incontinence, gait disturbance, and cognitive impairment. NPH can be progressive but may be managed or reversed with shunt placement. External Lumbar Drainage (ELD) trials in determining if shunt placement is appropriate are common, but the role of repeat neuropsychological assessments during ELD procedures is not well documented in the literature. Repeat, pre-, peri and post- ELD trial, assessment in a complex case of possible NPH is presented.

Method

33-year-old Hispanic English-Speaking female with cognitive/memory complaints following intraventricular hemorrhage (IVH) secondary to vasculopathy was initially seen for post IVH outpatient neuropsychological evaluation. MRI showed enlarged ventricles/communicating hydrocephalus and workup for NPH was initiated. Repeat inpatient evaluations were completed during the ELD trial, with annual outpatient neuropsychological follow-up.

Results

Gait evaluation was inconclusive. Inpatient testing demonstrated minor improvement immediately following ELD opening, but performances were variable across the 4 days of re-evaluation. Shunt placement was rejected due to neuropsychological findings. Outpatient follow-up of patient over several years has demonstrated mild improvement and not evidence of cognitive decline since ELD trial.

Conclusions

Assessment of cognitive functioning in outpatient and inpatient settings before, during, and for several years following ELD testing was beneficial to ascertain the decision not to place a shunt. Repeat neuropsychological assessment in inpatient and outpatient settings provided crucial information for guiding treatment decisions.

A-34 An Atypical Case of Primary Progressive Aphasia: Implications for Differentiating the Semantic Variant

Objective

Primary progressive aphasia is a neurodegenerative condition consisting of three primary variants. The semantic variant (svPPA) is typically associated with anomia and word-finding issues paired with fluent speech, although other symptoms can arise over time including non-verbal deficits and behavioral changes. A complex case of svPPA with evidence of robust impairment across multiple domains in the presence of notable psychosocial and medical factors is presented.

Method

Sixty-year-old woman with complaints of worsening memory and language changes in the context of marked behavioral disinhibition, deterioration of daily functioning, and indication of delusions was seen for outpatient neuropsychological evaluation. Medical history includes severe depression, anxiety, hypertension, and rheumatic heart disease. CT scan was significant for frontal and temporal atrophy and chronic right cerebellar infarct.

Results

Neuropsychological evaluation revealed uniformly extremely low scores. Presentation was notable for inappropriate behaviors, and expressive and receptive language difficulties. Significant confusion and functional impairment were evident. Her time awareness varied and she at some moments spoke about events from 20-30 years ago as if they were recent. Global language impairment was evident on formal testing and clearly moderated all other performances, including tasks of memory which were impaired. Notable weakness in visual-spatial processing and executive function were also present.

Conclusions

Complex medical and psychosocial history, and atypical decline patterns complicated the diagnosis of a patient with profound progressive expressive language impairment. SvPPA is offered as the diagnosis.

Abstract GS3-02: PALLET: A neoadjuvant study to compare the clinical and antiproliferative effects of letrozole with and without palbociclib

Background: CDK4/6 inhibitors, such as palbociclib, are used to treat ER+ metastatic breast cancer in combination with endocrine therapy with trials ongoing in patients with primary disease. No biomarkers exist to identify those who do/do not benefit from added CDK4/6 inhibition. PALLET is an investigator-initiated/led phase II randomized trial collaboration between UK and NSABP investigators evaluating the biological and clinical effects of palbociclib with letrozole combination as neoadjuvant therapy.

Methods: Postmenopausal women with ER+ primary breast cancer and tumors &gt;2.0cm (ultrasound) were randomized to one of 4 treatment groups (3:2:2:2 ratio): Group A: letrozole (2.5mg/d) for 14 weeks; Group B: letrozole for 2 weeks followed by letrozole + palbociclib to 14 weeks; Group C: palbociclib for 2 weeks followed by letrozole + palbociclib to 14 weeks; Group D: letrozole + palbociclib for 14 weeks. Palbociclib was given 125mg/d PO on a 21 days on, 7 days off schedule. Post-14 week treatment was at the discretion of the treating clinician including letrozole until surgery. Core-cut biopsies were taken at baseline, 2 weeks and 14 weeks. Co-primary endpoints for letrozole alone vs palbociclib groups (Group A vs Groups B+C+D) were: (i) change in Ki67 (IHC) between baseline and 14 weeks (log-fold change, Mann-Whitney test); (ii) clinical response (ultrasound) after 14 weeks (4 group, ordinal, Mann-Whitney test). Complete cell-cycle arrest (CCCA) (Ki67≤2.7%) was analyzed using a logistic regression model adjusting for recruitment region. Pre-specified exploratory biomarkers included c-PARP (apoptosis).

Results: 307 patients were recruited between 27 Feb 2015 and 08 Mar 2018; 103 were randomized to letrozole alone and 204 to letrozole + palbociclib. 279 (90.9%) patients were evaluable for 14 week clinical response. Clinical response was not significantly different between letrozole vs letrozole + palbociclib groups [(p=0.20; CR+PR 49.5% (46/93) vs 54.3% (101/186) and PD 5.4% (5/93) vs 3.2% (6/186)] nor was the small proportion of patients with pathological CR (1/87, 1.1% vs 6/180, 3.3%; p=0.43). 190 (61.9%) patients were evaluable for 14 week change in Ki67. The median log-fold change in Ki67 was greater with letrozole + palbociclib vs letrozole alone (-4.1 vs -2.2; p&lt;0.001) corresponding to a geometric mean change of -97.4% vs -88.5%. Similarly, a greater proportion of patients who received letrozole + palbociclib achieved CCCA (90% vs 59%, p&lt;0.001). 146 (47.6%) patients were evaluable for c-PARP and the log-fold change (suppression) was greater with letrozole + palbociclib vs letrozole alone (-0.80 vs -0.42; p=0.003) corresponding to a geometric mean change of -56.8% vs -31.4%. Other biomarkers of response / resistance are being evaluated. A higher proportion of patients had a grade ≥3 toxicity on letrozole + palbociclib than letrozole alone (49.8% vs 17.0%; p&lt;0.001) mainly due to asymptomatic neutropenia.

Conclusion: Adding palbociclib to letrozole markedly enhanced the suppression of malignant cell proliferation as assessed by Ki67 but did not substantially increase the clinical response of primary ER+ breast cancer over a 14-week period. Concurrent reductions in cell death may have reduced the speed of tumor shrinkage.

Citation Format: Dowsett M, Jacobs S, Johnston S, Bliss J, Wheatley D, Holcombe C, Stein R, McIntosh S, Barry P, Dolling D, Snowdon C, Perry S, Batten L, Dodson A, Martins V, Modi A, Cornman C, Puhalla S, Wolmark N, Julian T, Pogue-Geile K, Robidoux A, Provencher L, Boileau JF, Shalaby I, Thirlwell M, Fisher K, Huang Bartlett C, Koehler M, Osborne K, Rimawi M. PALLET: A neoadjuvant study to compare the clinical and antiproliferative effects of letrozole with and without palbociclib [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 GS3-02.