A comparison of the efficacy of trastuzumab deruxtecan in advanced HER2-positive breast cancer: active brain metastasis versus progressive extracranial disease alone

BACKGROUND

Trastuzumab deruxtecan (T-DXd) has demonstrated efficacy in patients with brain metastasis (BM), a group historically with poor outcomes. The prevalence of BMs in patients commencing T-DXd is currently unknown. No direct comparisons have been made of the activity of T-DXd in patients with active BM versus those with extracranial progression alone. This real-world study explored the prevalence of BMs in patients commencing T-DXd, the efficacy of T-DXd in active BM versus extracranial progression alone and the safety of T-DXd.

PATIENTS AND METHODS

Patients with human epidermal growth factor receptor 2-positive advanced breast cancer treated with T-DXd between June 2021 and February 2023 at our specialist cancer hospital were identified and notes reviewed. Clinicopathological information, prior treatment, the presence or absence of central nervous system (CNS) disease, outcomes and treatment-emergent adverse events (TEAEs) were recorded.

RESULTS

Twenty-nine female patients, with a median age of 52 years (interquartile range 44-62 years), were identified; the prevalence of BM was 41%. Median number of lines of prior therapy was 2 (range 2-6). At a median follow-up of 13.8 months, median progression-free survival (PFS) for the overall population was 13.9 months [95% confidence interval (CI) 12.4 months-not estimable (NE)], 16.1 months (95% CI 15.1 months-NE) for active BMs and 12.4 months (95% CI 8.3 months-NE) for progressive extracranial disease alone. The 12-month overall survival (OS) rate was 74% (95% CI 59% to 95%) in the overall population, and 83% (95% CI 58% to 100%) and 66% (95% CI 45% to 96%) for active BMs and extracranial disease only, respectively. Most common TEAEs were fatigue, alopecia, and constipation. In nine patients (31%, including two deaths), pneumonitis occurred.

CONCLUSION

In this real-world population, we demonstrate T-DXd to be effective in patients with active BMs and those with progressive extracranial disease alone. PFS and OS were numerically longer in those with active BMs. These data demonstrate that patients with active BM treated with T-DXd have at least comparable outcomes to those with extracranial disease alone. The high rate of pneumonitis warrants further consideration.

Challenging level of rigid-body approach involving numerical elements (CHLORAINE) applied to repeated elastin peptides

Elastic proteins and derived biomaterials contain numerous tandemly repeated peptides along their sequences, ranging from a few copies to hundreds. These repetitions are responsible for their biochemical, biological and biomechanical properties. These sequences are considered to be intrinsically disordered, and the variations in their behavior are actually mainly due to their high flexibility and lack of stable secondary structures originating from their unique amino acid sequences. Consequently, the simulation of elastic proteins and large elastomeric biomaterials using classical molecular dynamics is an important challenge. Here, we propose a novel approach that allows the application of the DURABIN protocol to repeated elastin-like peptides (r-ELPs) in a simple way. Four large r-ELPs were studied to evaluate our method, which was developed for simulating extracellular matrix proteins at the mesoscopic scale. After structure clustering applied on molecular dynamic trajectories of constitutive peptides (5-mers and 6-mers), the main conformations were used as starting points to define the corresponding primitives, further used as rigid body fragments in our program. Contributions derived from electrostatic and molecular hydrophobicity potentials were tested to evaluate their influence on the interactions during simple mesoscopic simulations. The CHLORAINE approach, despite the thinner granularity due to the size of the patterns used, was included in the DURABIN protocol and emerges as a promising way to simulate elastic macromolecular systems.

P11.45.B Improved overall survival following Stereotactic Radiosurgery for brain metastases - a single institution experience

Background

Brain metastases are increasingly common due to longer survival associated with advancements in treatment. Approximately 40% of cancer patients are diagnosed with brain metastases at some point during their disease. Stereotactic radiosurgery (SRS) avoids the neuro-cognitive toxicity associated with whole brain radiotherapy and has been increasingly offered as a treatment alternative for brain metastases. Combined with developments in systemic treatments, this approach has resulted in improved overall survival (OS). This study reviewed patients treated with single fraction SRS at our institution with a primary endpoint of overall survival.

Material and Methods

A retrospective review determined overall survival for 237 patients who received single fraction SRS for 451 brain metastases from solid tumours between 1st January 2017 and 31st December 2021. Primary tumour sites were classified as breast, kidney, colorectal, melanoma, lung or other. SPSS v.27 was used for Kaplan Meier OS determination. The median follow up was 10.3 months. Cox regression analysis assessed the association between Gross Tumour Volume (GTV) and OS.

Results

In this patient cohort, 60% (N=142) were female and 40% (N=95) were male, with a median age of 63 [32-85]. 63.7% (N = 151) had a solitary metastasis. Patients received a single fraction of 15, 17.5 or 20 Gy (prescribed to 80% isodose) dependent on the planning target volume (PTV) size and whether it was initial treatment or re-treatment. 71% of all patients were alive at 6 months with median OS of 12.0 months [10.6-13.4]. Primary tumour site significantly affected OS (Log rank, Chi squared 15.656, p0.008) with breast cancer patients (N=58) surviving longest with a median OS 16.0 months [13.6-18.4] followed by melanoma median OS 15.0 months [7.6-22.4], kidney cancer patients (N = 24) median OS 12.0 months [8.3-15.7] and lung patients (N=87) median OS 10.0 months [8.9-11.3]. The lowest median OS was for colorectal patients at 7.0 months [1.4-12.6]. However, considering the small sample size, N = 15, more data is needed to confirm the significance. The larger the GTV volume the lower the survival time (Chi squared 8.692, p 0.003).

Conclusion

71% of patients had an OS of 6.0 months or more with a median of 12.0 months. As expected, primary tumour site has a significant impact on OS, with breast cancer patients living longest. In addition, increasing GTV size is associated with significantly worse survival. Given the improved survival for these patients, the avoidance of neuro cognitive decline remains of paramount importance and outcomes for these patients need to be reported in future work.

OP0054 REDUCING THE BURDEN OF LOW BACK PAIN: RESULTS FROM A NEW MICROSIMULATION MODEL

Background

Low back pain (LBP) has been the leading cause of disability worldwide for the past 30 years. In 2019, LBP was responsible for 64 million years lived with disability (YLDs) [1].

Objectives

The purpose of the present study was to project and compare the impact of three strategies for reducing the population health burden of LBP: weight loss, ergonomic interventions, and an exercise program.

Methods

We have developed a microsimulation model of LBP in Canada using a novel simulation platform, SimYouLate. The initial population was derived from Cycle 1 (2001) of the Canadian Community Health Survey (CCHS). We modeled an open population 20 years of age and older. Key variables included age, sex, education, body mass index (BMI), type of work, having a back problem, pain level in persons with back problems, and exercise. The effects of interventions on the risk of LBP were obtained from the CCHS for the effect of BMI, the Global Burden of Disease Study for occupational risks, and a published meta-analysis for the effect of exercise. All interventions lasted from 2021 to 2040. Strength of the interventions varied over a wide range. YLDs were defined as LBP prevalence multiplied by disability weight. The population health impact of the interventions was calculated as a difference in YLDs between the base-case scenario and each intervention scenario and expressed as YLDs averted per intervention unit and as % of total LBP-related YLDs.

Results

In the base-case scenario, LBP in 2020 was responsible for 424,900 YLDs in Canada and the amount increased to 460,312 YLDs in 2040. The effects of the interventions on YLDs were as follows: 27,993 (95% CI 23,373, 32,614) YLDs averted over 20 years per 0.1 unit change in log-transformed BMI (10.5% change in BMI) among overweight and obese individuals, 19,416 (16,275, 22,557) YLDs averted per 1% reduction in the proportion of workers exposed to occupational risks, and 26,058 (22,455, 29,661) YLDs averted per 1% increase in the proportion of eligible patients with back problems participating in the exercise program. Table 1 shows the intervention impact as % of total LBP-related YLDs and Figure 1 shows YLD-equivalence between the interventions. A one unit reduction in BMI per year among the overweight and obese individuals would be approximately equivalent in terms of disability reduction to an effective ergonomic intervention in 35% of at-risk workers and an exercise intervention in 27% of eligible patients with back problems over the same period (Figure 1).

Table 1.

YLDs averted between 2021 and 2040 as % of total LBP-related YLDs, according to intervention type and level, in persons aged 20+ in Canada

InterventionEffect (%)95% LCL95% UCLReduction in BMI per year0.11.4-1.44.10.34.82.27.30.56.33.98.81.08.56.011.03.011.99.414.45.013.510.916.0Reduction in occupational exposure20%5.21.98.540%9.56.412.760%13.810.616.980%18.114.821.4100%22.418.825.9Increase in exercise participation20%6.62.810.440%12.48.716.060%18.114.521.780%23.920.127.6100%29.625.533.7

LCL: lower confidence limit. UCL: upper confidence limit.

Figure 1.

Equivalence between BMI, ergonomic and exercise interventions in terms of their impact on YLDs. Each point represents a specific number of YLDs averted. Values on the y-axis show reduction in % of workers at risk and increase in % exercising that are required to achieve the same reduction in YLDs as the corresponding reduction in BMI shown on the x-axis.

Conclusion

This is the first population-based microsimulation study to compare currently available preventive strategies in LBP in terms of YLDs averted and to provide measures of equivalence between these strategies.

References

[1]Hartvigsen J, Hancock MJ, Kongsted A, et al. What low back pain is and why we need to pay attention. Lancet 2018;391(10137):2356-2367.

Acknowledgements

The study was supported by a grant from the Canadian Institutes for Health Research (FRN 142440).

Disclosure of Interests

None declared.

Factors Affecting Trends in Societal Indicators of Ageing Well in Hong Kong: Policies, Politics and Pandemics

OBJECTIVES

To document the trend in a quality of life indicator for the older Hong Kong population as an assessment of the impact of age friendly city policies, political conflicts and the covid-19 pandemic.

DESIGN

Random telephone survey and collection of government data over four years (2017-2020).

SETTING

Community living older people.

PARTICIPANTS

People aged 50 years and over.

MEASUREMENTS

The Hong Kong Quality of Life Index covering four domains of in income security, health status, capability and enabling environment.

RESULTS

From 2017-9, improvements were seen in various domains in parallel with the adoption of the World Health Organization's Age Friendly City concept by government policy together with a territory wide initiative supported by a major philanthropic organization. However scores of all domains dropped markedly as a result of political conflicts as well as the onset of the pandemic.

CONCLUSION

The documentation of the trend in HKEQOL shows that while it may be used as a macro indicator that is able to reflect policies affecting the well-being of older people, it is also able to reflect the impact of societal unrest and pandemics, and that the latter may override the effect of existing ageing policies. It also follows that during social unrest and pandemics, specific policies targeting older people may be needed to maintain well-being.

Adjuvant management of locally advanced oral squamous cell carcinoma - real-world challenges and opportunities

Patients with locally advanced oral squamous cell cancer (LAOSCC) are treated with adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) following surgical ablation. This depends on the pathological risk factors and aims to reduce the risk of local recurrence and improve survival. Delivery of these aggressive treatments is, however, challenging particularly following major surgery. To inform the adaptations necessary to deliver gold-standard therapy, we aimed to describe real-world delivery of multimodality treatment in LAOSCC, in a UK population with high levels of disease incidence and low socioeconomic status. Patients with LAOSCC (T1-4 N1-3/T3-4 N0) who were treated between October 2014 and October 2016 and had a minimum follow up of 24 months were included. They were identified using the Somerset Cancer Register and data were collected through retrospective case note review. Approval was obtained from the audit departments at the relevant NHS institutions, and data were analysed using IBM SPSS Statistics for Windows version 24 (IBM Corp). The analysis included 129 patients with 82% having an initial performance status (PS) of 0-1. The most frequent change in PS was a one point drop (46%). Twenty of the 93 eligible patients (22%) underwent adjuvant CRT. A total of 37 (40%) began adjuvant CRT/RT within 42 days, and 79 (85%) within 56 days. A delay in initiating adjuvant therapy was associated with higher rates of complications and a longer postoperative hospital stay. Concordance between imaging and pathological nodal staging was poor (cK 0.223). PS frequently declines after complex surgical procedures and long postoperative recovery periods, leading to difficulties providing adjuvant treatments within the national guidance of 42 days. Frequent deviation from planned adjuvant therapies highlights the need for improved treatment strategies.

0574 Prevalence and Characteristics of Rapid Eye Movement Obstructive Sleep Apnoea (REM OSA) in a Multi-Ethnic OSA Cohort

Introduction

Recent studies have shown that REM OSA is associated with increased incidence of hypertension and insulin resistance. However, there is a lack of Asian data on REM OSA. Our study aimed to examine the prevalence and characteristics of REM OSA in a multi-ethnic OSA cohort.

Methods

This was a retrospective observational study of all patients who underwent an overnight diagnostic polysomnography at a Singapore tertiary hospital from 1st August 2017 to 31st August 2018. All patients with a diagnosis of OSA (Apnoea Hypopnea Index (AHI) ≥5) were included in the study. REM OSA is defined as an overall AHI≥5, REM AHI/Non REM (NREM) AHI>2, NREM AHI<15 and at least 15 minutes of REM sleep.

Results

457 OSA subjects were included in the analysis. 19% (87/457) had REM OSA. Univariate analysis showed that REM OSA was more prevalent among female OSA than male OSA [34/115 (29.6%) versus 53/342 (15.5%) respectively, p<0.001]. Compared to non REM OSA, REM OSA had milder OSA severity [mean AHI 12.74±4.71 versus 45.34±28.38, p<0.001] and lower prevalence of hypertension [21/87 (24.1%) versus 138/370(37.3%), p=0.02]. No differences were found between both groups for age (p=0.273), ethnicity (p=0.615), Body Mass Index (p=0.336), diabetes mellitus (p=0.245) and Epworth Sleepiness Scale (0.06). Gender and OSA severity differences between both groups remained statistically significant in multivariate analysis (higher prevalence of REM OSA in female, p=0.043 and milder disease severity in REM OSA, p=0.006).

Conclusion

REM OSA was common in our OSA cohort and had higher prevalence in female and milder disease severity compared to non REM OSA. However, we did not find an increased prevalence of hypertension or diabetes mellitus in REM OSA. Further population-based study on REM OSA is needed to understand this phenotype better.

Support

NIL

Three-year longitudinal cognitive functioning in patients recently diagnosed with bipolar disorder

OBJECTIVE

The longitudinal course of neuropsychological functioning after the first manic episode in bipolar disorder is unknown. The present study evaluated cognitive change in bipolar disorder in the first 3 years after the initial manic episode.

METHODS

Ninety-one newly diagnosed patients with bipolar disorder and 61 demographically similar healthy participants received a neuropsychological evaluation assessing multiple cognitive domains at baseline, 1-year, and 3-year time points. Patients also received clinical assessments including mood ratings at all time points.

RESULTS

Patients showed deficits in all domains at baseline, but similar longitudinal trajectories across time relative to healthy participants in most cognitive domains. For processing speed, patients showed more gains than controls from baseline to 1 year, but these gains stabilized thereafter. Patients with alcohol/substance abuse showed an initial delay but subsequent recovery in executive functioning. Patients who discontinued antipsychotic treatment showed better cognitive outcomes in verbal memory.

CONCLUSION

Appropriately treated patients with bipolar disorder showed favorable cognitive outcome in the first 3 years after experiencing an initial manic episode, arguing against cognitive neuroprogression at this stage of the illness. Discontinuation of antipsychotic treatment may be associated with better cognitive outcomes, but clarification of the role of antipsychotics on cognitive functioning requires further investigation.

IRF4-induced upregulation of lncRNA SOX2-OT promotes cell proliferation and metastasis in cholangiocarcinoma by regulating SOX2 and PI3K/AKT signaling

OBJECTIVE

The aim of this study was to investigate the role of lncRNA SOX2-OT in the proliferation and metastasis of cholangiocarcinoma (CCA) and its underlying mechanisms.

PATIENTS AND METHODS

A total of 82 patients with CCA underwent surgery in our hospital were enrolled in this study. Five CCA cell lines (HuH-28, QBC939, HuCCT1, CCLP1, RBE) were used. The ability of proliferation and metastasis of CCA cells were detected by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, colony formation assay, and transwell assay, respectively. Additionally, in vivo tumor metastasis assay was done. Furthermore, the Kaplan Meier method was used to validate the prognostic importance of SOX2-OT for patients with cholangiocarcinoma. Besides, the protein and mRNA expression of CCA cells were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot, respectively.

RESULTS

The expression level of lncRNA SOX2-OT was significantly upregulated in cholangiocarcinoma tissues. Functional assays were further conducted to prove the oncogenic role of SOX2-OT on the proliferation and metastasis of cholangiocarcinoma cells. Furthermore, mechanism investigations manifested that transcription factor IRF4 upregulates SOX2-OT by promoting the transcriptional activity of SOX2-OT. SOX2-OT could positively regulate the nearby gene SOX2. SOX2-OT suppressed the nuclear transcription of PTEN, thereby activating PI3K/AKT signaling.

CONCLUSIONS

lncRNA SOX2-OT upregulated by IRF4 promotes cell proliferation and metastasis in cholangiocarcinoma via upregulating SOX2 and activating PI3K/AKT signaling pathway.

The application of a haemorrhage assessment tool in evaluating control of bleeding in a pilot trauma haemorrhage trial

OBJECTIVES

To determine whether it was feasible to use a haemorrhage assessment tool (HAT) within a trauma trial and whether the data obtained could differentiate patients who had achieved haemostasis.

BACKGROUND

Major haemorrhage is one of the leading causes of death worldwide, affecting 40% of trauma patients. Clinical trials evaluating haemostatic interventions often use transfusion outcomes as a primary endpoint. Transfusion is highly dependent on local practice, limiting its reliability as a robust, transferable endpoint.

METHODS

A five-point HAT questionnaire was applied to participants enrolled into the EFIT-1 trial. This RCT evaluated the feasibility of administering a 6 g fibrinogen concentrate to patients with severe trauma haemorrhage.

RESULTS

Of participants, 98% completed a HAT; 75% participants had 'achieved haemostasis' at the time of tool completion, as determined by clinical acumen alone. HAT scores were able to differentiate which participants required transfusion after 3 h. Of participants, 56% were transfused red blood cells when they scored 0-2, compared to 17% with HAT scores between 3 and 5.

CONCLUSION

This study has confirmed the feasibility of using a HAT during the emergency care of patients suffering trauma haemorrhage, and future studies should be conducted to determine its value as an endpoint in haemostasis studies.