Nav1.5 regulates breast tumor growth and metastatic dissemination in vivo

Voltage-gated Na+ channels (VGSCs) mediate action potential firing and regulate adhesion and migration in excitable cells. VGSCs are also expressed in cancer cells. In metastatic breast cancer (BCa) cells, the Nav1.5 α subunit potentiates migration and invasion. In addition, the VGSC-inhibiting antiepileptic drug phenytoin inhibits tumor growth and metastasis. However, the functional activity of Nav1.5 and its specific contribution to tumor progression in vivo has not been delineated. Here, we found that Nav1.5 is up-regulated at the protein level in BCa compared with matched normal breast tissue. Na+ current, reversibly blocked by tetrodotoxin, was retained in cancer cells in tumor tissue slices, thus directly confirming functional VGSC activity in vivo. Stable down-regulation of Nav1.5 expression significantly reduced tumor growth, local invasion into surrounding tissue, and metastasis to liver, lungs and spleen in an orthotopic BCa model. Nav1.5 down-regulation had no effect on cell proliferation or angiogenesis within the in tumors, but increased apoptosis. In vitro, Nav1.5 down-regulation altered cell morphology and reduced CD44 expression, suggesting that VGSC activity may regulate cellular invasion via the CD44-src-cortactin signaling axis. We conclude that Nav1.5 is functionally active in cancer cells in breast tumors, enhancing growth and metastatic dissemination. These findings support the notion that compounds targeting Nav1.5 may be useful for reducing metastasis.

The sodium channel β1 subunit mediates outgrowth of neurite-like processes on breast cancer cells and promotes tumour growth and metastasis

Voltage-gated Na⁺ channels (VGSCs) are heteromeric proteins composed of pore-forming α subunits and smaller β subunits. The β subunits are multifunctional channel modulators and are members of the immunoglobulin superfamily of cell adhesion molecules (CAMs). β1, encoded by SCN1B, is best characterized in the central nervous system (CNS), where it plays a critical role in regulating electrical excitability, neurite outgrowth and migration during development. β1 is also expressed in breast cancer (BCa) cell lines, where it regulates adhesion and migration in vitro. In the present study, we found that SCN1B mRNA/β1 protein were up-regulated in BCa specimens, compared with normal breast tissue. β1 upregulation substantially increased tumour growth and metastasis in a xenograft model of BCa. β1 over-expression also increased vascularization and reduced apoptosis in the primary tumours, and β1 over-expressing tumour cells had an elongate morphology. In vitro, β1 potentiated outgrowth of processes from BCa cells co-cultured with fibroblasts, via trans-homophilic adhesion. β1-mediated process outgrowth in BCa cells required the presence and activity of fyn kinase, and Na⁺ current, thus replicating the mechanism by which β1 regulates neurite outgrowth in CNS neurons. We conclude that when present in breast tumours, β1 enhances pathological growth and cellular dissemination. This study is the first demonstration of a functional role for β1 in tumour growth and metastasis in vivo. We propose that β1 warrants further study as a potential biomarker and targeting β1-mediated adhesion interactions may have value as a novel anti-cancer therapy.

Digital pathology for the primary diagnosis of breast histopathological specimens: an innovative validation and concordance study on digital pathology validation and training

AIM

To train and individually validate a group of breast pathologists in specialty-specific digital primary diagnosis by using a novel protocol endorsed by the Royal College of Pathologists' new guideline for digital pathology. The protocol allows early exposure to live digital reporting, in a risk-mitigated environment, and focuses on patient safety and professional development.

METHODS AND RESULTS

Three specialty breast pathologists completed training in the use of a digital microscopy system, and were exposed to a training set of 20 challenging cases, designed to help them identify personal digital diagnostic pitfalls. Following this, the three pathologists viewed a total of 694 live, entire breast cases. All primary diagnoses were made on digital slides, with immediate glass slide review and reconciliation before final case sign-out. There was complete clinical concordance between the glass and digital impression of the case in 98.8% of cases. Only 1.2% of cases had a clinically significant difference in diagnosis/prognosis on glass and digital slide reads. All pathologists elected to continue using the digital microscope as the standard for breast histopathology specimens, with deferral to glass for a limited number of clinical/histological scenarios as a safety net.

CONCLUSION

Individual training and validation for digital primary diagnosis allows pathologists to develop competence and confidence in their digital diagnostic skills, and aids safe and responsible transition from the light microscope to the digital microscope.

Predictors of pathological complete response to neoadjuvant treatment and changes to post-neoadjuvant HER2 status in HER2-positive invasive breast cancer

The response of human epidermal growth factor receptor2 (HER2)- positive breast cancer (BC) patients to anti-HER2 targeted therapy is significant. However, the response is not uniform and a proportion of HER2-positive patients do not respond. This study aims to identify predictors of response in the neoadjuvant treatment and to assess the discordance rate of HER2 status between pre- and post-treatment specimens in HER2-positive BC patients. The study group comprised 500 BC patients treated with neoadjuvant chemotherapy (NACT) and/or neoadjuvant anti-HER2 therapy and surgery who had tumours that were 3+ or 2+ with HER2 immunohistochemistry (IHC). HER2 IHC 2+ tumours were classified into five groups by fluorescence in situ hybridisation (FISH) according to the 2018 ASCO/CAP guidelines of which Groups 1, 2 and 3 were considered HER2 amplified. Pathological complete response (pCR) was more frequent in HER2 IHC 3+ tumours than in HER2 IHC 2+/HER2 amplified tumours, when either in receipt of NACT alone (38% versus 13%; p = 0.22) or neoadjuvant anti-HER2 therapy (52% versus 20%; p < 0.001). Multivariate logistic regression analysis showed that HER2 IHC 3+ and histological grade 3 were independent predictors of pCR following neoadjuvant anti-HER2 therapy. In the HER2 IHC 2+/HER2 amplified tumours or ASCO/CAP FISH Group 1 alone, ER-negativity was an independent predictor of pCR following NACT and/or neoadjuvant anti-HER2 therapy. In the current study, 22% of HER2-positive tumours became HER2-negative by IHC and FISH following neoadjuvant treatment, the majority (74%) HER2 IHC 2+/HER2 amplified tumours. Repeat HER2 testing after neoadjuvant treatment should therefore be considered.

Neoadjuvant chemotherapy with MRI monitoring for breast cancer

BACKGROUND

Neoadjuvant chemotherapy (NACT) is increasingly being offered to patients with breast cancer. No survival benefit has been demonstrated for NACT, but it may serve to reduce tumour size and improve prognosis through the attainment of a pathological complete response (pCR). The role and mode of MRI monitoring during NACT remain unclear.

METHODS

Patients managed with NACT at a UK centre over 7 years were studied using a prospectively maintained database, which also included details of MRI. Clinicopathological and radiological predictors of NACT response were analysed in a univariable setting and survival analysis was undertaken using the Kaplan-Meier method.

RESULTS

A total of 278 patients underwent surgery following NACT, of whom 200 (71·9 per cent) had residual invasive disease and 78 (28·1 per cent) achieved a pCR. Attaining a pCR improved survival significantly compared with that of patients with residual invasive disease (mean 77·1 versus 66·0 months; P = 0·004) and resulted in significantly fewer recurrences (6·0 versus 24·3 per cent; P = 0·001). The pCR rate varied significantly among molecular subgroups of breast cancer (P < 0·001): luminal A, 6 per cent; luminal B/human epidermal growth factor 2 receptor (Her2)-negative, 21 per cent; luminal B/Her2-positive, 35 per cent, Her2-positive/non-luminal, 72 per cent; and triple-negative breast cancer (TNBC), 32 per cent. High-grade disease (G3) correlated with an increased rate of pCR. A radiological response seen on the mid-treatment MRI was predictive of pCR (sensitivity 77·6 per cent, but specificity only 53·3 per cent), as was complete radiological response at final MRI (specificity 97·6 per cent, but sensitivity only 32·2 per cent).

CONCLUSION

NACT allows identification of patient subgroups within TNBC and Her2-positive cohorts with a good prognosis. MRI can be used to identify patients who are responding to treatment.

Digital pathology for primary diagnosis of screen-detected breast lesions - experimental data, validation and experience from four centres

AIM

The rate of deployment of digital pathology (DP) systems for primary diagnosis in the UK is accelerating. The flexibility and resilience of digital versus standard glass slides could be of great benefit in the NHS breast screening programme (NHSBSP). This study aims to document the safety and benefits of DP for preoperative tissue diagnosis of screen-detected breast lesions.

METHODS AND RESULTS

Concordance data for glass and digital slides of the same cases from four sites were subjected to detailed concordance-discordance analysis. A literature review of DP in the primary diagnosis of breast lesions is presented, making this the most comprehensive synthesis of digital breast cancer histopathological diagnostic data to date. Detailed concordance analysis of experimental data from two histopathology departments reveals clinical concordance rates for breast biopsies of 96% (216 of 225) and 99.6% (249 of 250). Data from direct comparison validation studies in two histopathology departments, utilising the protocol recommended by the Royal College of Pathologists, found concordance rates for breast histology cases of 99.4% (180 of 181) and 99.0% (887 of 896). An intraobserver variation study for glass versus digital slides for difficult cases from the NHSBSP yielded a kappa statistic of 0.80, indicating excellent agreement. Discordances encountered in the studies most frequently concerned discrepancies in grading attributable to mitotic count-scoring and identification of weddelite.

CONCLUSIONS

The experience of four histopathology laboratories and our review of pre-existing literature suggests that DP is safe for the primary diagnosis of NHSBSP breast histology specimens, and does not increase the risk of misclassification.

Interobserver variation in the diagnosis of fibroepithelial lesions of the breast: a multicentre audit by digital pathology

Aim

Fibroepithelial lesions (FELs) of the breast span a morphological continuum including lesions where distinction between cellular fibroadenoma (FA) and benign phyllodes tumour (PT) is difficult. The distinction is clinically important with FAs managed conservatively while equivocal lesions and PTs are managed with surgery. We sought to audit core biopsy diagnoses of equivocal FELs by digital pathology and to investigate whether digital point counting is useful in clarifying FEL diagnoses.

Method

Scanned slide images from cores and subsequent excisions of 69 equivocal FELs were examined in a multicentre audit by eight pathologists to determine the agreement and accuracy of core needle biopsy (CNB) diagnoses and by digital point counting of stromal cellularity and expansion to determine if classification could be improved.

Results

Interobserver variation was high on CNB with a unanimous diagnosis from all pathologists in only eight cases of FA, diagnoses of both FA and PT on the same CNB in 15 and a ‘weak’ mean kappa agreement between pathologists (k=0.36). ‘Moderate’ agreement was observed on CNBs among breast specialists (k=0.44) and on excision samples (k=0.49). Up to 23% of lesions confidently diagnosed as FA on CNB were PT on excision and up to 30% of lesions confidently diagnosed as PT on CNB were FA on excision. Digital point counting did not aid in the classification of FELs.

Conclusion

Accurate and reproducible diagnosis of equivocal FELs is difficult, particularly on CNB, resulting in poor interobserver agreement and suboptimal accuracy. Given the diagnostic difficulty, and surgical implications, equivocal FELs should be reported in consultation with experienced breast pathologists as a small number of benign FAs can be selected out from equivocal lesions.

Concordance of HER2-low scoring in breast carcinoma among expert pathologists in the United Kingdom and the republic of Ireland -on behalf of the UK national coordinating committee for breast pathology

BACKGROUND

Recent clinical evidence showed that breast cancer with low HER2 expression levels responded to trastuzumab deruxtecan therapy. The HER2-low cancers comprise immunohistochemistry (IHC) score 1+ and 2+ ISH non-amplified tumours, currently classified as HER2 negative. Little data exists on the reproducibility of pathologists reporting of HER2-low cancer.

PATIENT AND METHODS

Sixteen expert pathologists of the UK National Coordinating Committee for Breast Pathology scored 50 digitally scanned HER2 IHC slides. The overall level of agreement, Fleiss multiple-rater kappa statistics and Cohen's Kappa were calculated. Cases with low concordance were re-scored by the same pathologists after a washout period.

RESULTS

Absolute agreement was achieved in 6% of cases, all of which scored 3+. Poor agreement was found in 5/50 (10%) of cases. This was due to heterogeneous HER2 expression, cytoplasmic staining and low expression spanning the 10% cut-off value. Highest concordance (86%) was achieved when scores were clustered as 0 versus others. Improvement in kappa of overall agreement was achieved when scores 1+ and 2+ were combined. Inter-observer agreement was moderate to substantial in the whole cohort but fair to moderate in the HER2-low group. Similarly, consensus-observer agreement was substantial to almost perfect in the whole cohort and moderate to substantial in the HER2-low group.

CONCLUSION

HER2-low breast cancer suffers from lower concordance among expert pathologists. While most cases can reproducibly be classified, a small proportion (10%) remained challenging. Refining the criteria for reporting and consensus scoring will help select appropriate patients for targeted therapy.

Adding value to rare tissue samples donated to biobanks: characterisation of breast tissue and primary cell cultures obtained from a female-to-male transgender patient

Biobanks provide a window of opportunity to store and add value to material from rare cases allowing their future use in biomedical research. One such example is the opportunityto obtain good quality tissue from patients undergoing gender re-assignment. Following patient agreement to donate tissue samples to our biobank we catalogued the histological appearance, defined the expression of the hormone receptors ERα, PR, AR and the proliferation marker Ki67, and generated and characterised primary cell cultures in a female to male (FTM) transgender patient referred to our unit for surgery. Immunohistochemistry was performed for ERα, PR and AR and the proliferation marker Ki67. Hormone receptor expression was confined to epithelial cells lining the breast ducts. Ki67 immunoreactivity was sparse indicating little proliferation of luminal epithelium, consistent with normal mammary gland. Cultures of epithelial cells and fibroblasts were derived from surplus tissue. The latter lacked expression of epithelial markers and hormone receptors but exhibited expression of vimentin. Culture of the former on Matrigel saw an outgrowth of more rounded "epithelial-like" cells. Immunofluoresence characterisation showed a mixed phenotype with expression of vimentin and both myoepithelial and luminal epithelial markers. Sporadic weak ERα expression and moderate PR expression was seen. In summary, as well as routinely collecting tissue and blood samples, we have characterised and stored tissue and cells from a FTM transgender patient, adding value to this resource which,available from the Breast Cancer Campaign Tissue Bank for those interested in further studying the biology of FTM transgender tissue.

Parasitic infection of the male breast

Breast lumps are commonly seen in clinical practice, yet deeper exploration of this particular case presented an unusual diagnostic challenge.

The frequency and clinical significance of centromere enumeration probe 17 alterations in HER2 immunohistochemistry-equivocal invasive breast cancer

Background and aims

Chromosome 17 alterations affect the assessment of HER2 gene amplification in breast cancer (BC), but its clinical significance remains unclear. This study aimed to identify the prevalence of centromere enumeration probe 17 (CEP17) alterations, and its correlation with response to neoadjuvant therapy (NAT) in BC patients with human epidermal growth factor receptor 2 (HER2) immunohistochemistry‐equivocal score.

Methods and results

A large BC cohort (n = 6049) with HER2 immunohistochemistry score 2+ and florescent in‐situ hybridisation (FISH) results was included to assess the prevalence of CEP17 alterations. Another cohort (n = 885) with available clinicopathological data was used to evaluate the effect of CEP17 in the setting of NAT. HER2‐amplified tumours with monosomy 17 (CEP17 copy number < 1.5 per nucleus), normal 17 (CEP17 1.5–< 3.0) and polysomy 17 (CEP17 ≥ 3.0) were observed in 16, 59 and 25%, respectively, compared with 3, 74 and 23%, respectively, in HER2‐non‐amplified tumours. There was no significant relationship between CEP17 alterations and pathological complete response (pCR) rate in both HER2‐amplified and HER2‐non‐amplified tumours. The independent predictors of pCR were oestrogen (ER) negativity in HER2‐amplified tumours [ER negative versus positive; odds ratio (OR) = 11.80; 95% confidence interval (CI) = 1.37–102.00; P = 0.02], and histological grade 3 in HER2 non‐amplified tumours (3 versus 1, 2; OR = 5.54; 95% CI = 1.61–19.00; P = 0.007).

Conclusion

The impacts of CEP17 alterations are not as strong as those of HER2/CEP17 ratio and HER2 copy number. The hormonal receptors status and tumour histological grade are more useful to identify BC patients with a HER2 immunohistochemistry‐equivocal score who would benefit from NAT.

Automated H&E whole slide image surrogate Ki67 index prediction and prognostic value across breast cancer subtypes

e12518

Background: Despite its purported prognostic significance in breast cancer, Ki67 index assessment remains poorly standardized and features high discordance rates amongst pathologists. Moreover, its clinical utility is presently confined to low stage, ER+/HER2- tumors in determining the advisability of adjuvant chemotherapy. Unfortunately, established cut-offs limit its utility to tumors with either high or low Ki67 index extremes. While Ki67 is a marker of actively dividing cells, it fails to capture the detail of cell cycle phase and dynamics which could be informative in terms of prognosis and tumor sensitivity to specific therapies (e.g. CDK4/6 inhibitors). This study therefore developed two novel indices as surrogates of (i) Ki67 index and (ii) quiescent cell population load (QPL). Methods: Breast cancer (comprising evenly distributed hormone receptor/HER2 status cases) H&E slides ( n = 79 cases/108 slides) were digitized on an Aperio DT3 scanner, and used to extract surrogate Ki67 and QPL indices. Sections were also stained for Ki67 by immunohistochemistry (IHC) using a clinically validated assay and digitized. Whole slide image (WSI) tumor Ki67 counts were performed on QuPath and used to validate the surrogate Ki67 index (Cohen’s kappa score). Indices (i) and (ii) were related to progression free survival (PFS). Survival analyses were performed using Kaplan-Meier (KM; with median cut-off) and Cox Proportional Hazards (as a continuous variable) models. Results: The surrogate Ki67 index showed good concordance with IHC scores (kappa = 0.76; 95%CI 0.61-0.91; P< 0.00001). However, this surrogate index performed better as a prognostic indicator of PFS compared to conventional Ki67 IHC (KM P = 0.048; HR = 1.35, P = 0.015 vs. KM P = 0.70; HR = 1.23, P = 0.08). Prognostically, the QPL index outperformed both Ki67 indices (KM P = 0.03; HR = 3.22, P = 0.001). Conclusions: We have developed two novel surrogate indices of Ki67 and QPL that can be readily automated to analyze H&E breast cancer WSIs. Our results show that both outperformed conventional Ki67 IHC evaluation in terms of prognostication, applied across molecular subtypes, improved informativeness of mid-range Ki67 index calls, and could potentially have predictive merit in selecting patients for cell cycle targeted therapies such as CDK4/6 inhibitors.

Abstract 1972: The sodium channel auxiliary subunit SCN1B promotes breast tumor growth and metastasis

Voltage-gated Na+ channels (VGSCs) are heteromeric proteins composed of pore-forming α subunits and smaller β subunits. The β subunits are multifunctional channel modulators and are members of the immunoglobulin superfamily of cell adhesion molecules (CAMs). β1, encoded by SCN1B, is best characterized in the central nervous system (CNS), where it plays a critical role in regulating electrical excitability, neurite outgrowth and migration during development. β1 is also expressed in breast cancer cell lines, where it regulates adhesion and migration in vitro. Using the Oncomine database, we found that SCN1B mRNA was up-regulated in breast cancer, compared with normal breast. Similarly, β1 protein was up-regulated in a cohort of breast cancer tissue specimens compared with surrounding normal tissue. Over-expression of β1 in MDA-MB-231 cells substantially increased tumor growth and metastasis from orthotopic xenografts in immune-deficient mice. β1 had no effect on the density of Ki67-positive cycling cells in the primary tumors. However, β1 increased the density of CD31-positive vessel structures and reduced the density of apoptotic cells expressing activated caspase-3. β1-expressing MDA-MB-231 cells had an elongate morphology in tumors in vivo and in 2D culture in vitro. β1 potentiated the outgrowth of processes from MDA-MB-231 cells and MCF-7 cells co-cultured with fibroblasts, via trans-homophilic adhesion. Both the src family tyrosine kinase inhibitor PP2 and siRNA targeting fyn kinase blocked β1-mediated process extension in breast cancer cells. Thus, β1-mediated process outgrowth in breast cancer cells requires the presence and activity of fyn kinase. This recapitulates the mechanism by which β1 regulates neurite outgrowth in CNS neurons. We conclude that when present in breast tumors, β1 drives pathological growth and cellular dissemination by recapitulating its well-defined role in CNS ontogeny. This study is the first demonstration of a functional role for β1 as a CAM in tumor growth and metastasis. We propose that targeting β1-mediated adhesion interactions may have potential as a novel anti-cancer therapy.

Citation Format: Michaela Nelson, Rebecca Millican-Slater, Lorna C. Forrest, William J. Brackenbury. The sodium channel auxiliary subunit SCN1B promotes breast tumor growth and metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1972. doi:10.1158/1538-7445.AM2014-1972

Abstract P3-05-48: Prediction of disease recurrence in low risk Oncotype Dx breast cancers from digital H&E-stained whole slide images of pre-treatment resections alone

Background Breast cancer patients with estrogen receptor (ER)+/HER2- (and usually node-negative) tumors can avail themselves of Oncotype DX Breast Recurrence Score (ODXRS) testing to predict their risk of distant recurrence within 9 years and, consequently, putative chemotherapy benefit. However, ODXRS testing requires sufficient tumour availability and specimen shipping, which imposes time and financial burdens to testing which have to be met by healthcare systems. The advent of digital pathology offers a potential avenue for exploring computer-aided diagnostic solutions which may overcome these hurdles by extracting the requisite information from hematoxylin and eosin (H&E)-stained tissue whole slide images (WSIs) alone. In turn, this technology could significantly reduce diagnostic turnaround times and cost, and improve accessibility and test reproducibility, thereby enabling healthcare systems to run more efficiently and offer patients more timely results. Ideally, such a platform should incorporate a measure of the underlying tumor biology to provide a fully explainable, white box solution, and may offer further insights into the identification of early recurrence events. Aims The aim of this study was to establish whether our computer-aided solution’s (Q-Plasia OncoReader Breast, QPORB) digital biomarker representing G1/S cell cycle deformations extracted from H&E WSIs was prognostic for disease-free survival (DFS) and could predict disease recurrence, particularly in the setting of low risk ODXRS breast cancers. Methods Primary breast cancer resection/excision specimens (n=70 cases) sent for ODXRS testing from St James’s University Hospital, UK (2016-2019) were collected. Anonymised diagnostic glass slides (n=198 slides) of H&E-stained tumors were scanned at x20 magnification on an Aperio AT2 scanner. In parallel, relevant clinical and histological data were collected from pathology reports and electronic patient records, including both ODXRS and recurrence events during follow-up. The QPORB recurrence scale (QPORB-RS), which combines statistical physics and tumor biology to identify image-based malignant cell cycle deformation, extracts prognostic information from WSIs. The contribution of potential confounders (age, stage, grade, lesion size, Nottingham prognostic index and Charlson score) were accounted for. Results The QPORB-RS was prognostic for DFS for patients with predominantly node-negative (including node micro-metastases) HR+/HER2- tumors over a median follow-up period of 5 years (P=0.02; dichotomized Kaplan Meyer with median cut-off). The QPORB-RS concurred with ODXRS’s high vs. low recurrence risk in 73% (19/26) and 61% (27/44) of cases, respectively, with an overall agreement of 66% (46/70). Moreover, the QPORB-RS identified all 5 patients who had recurrences (with ODXRS of 6, 9, 10, 21 and 26, and ages of 55, 66, 42, 35 and 50 years, respectively) as being high risk in the subset of those given a low (including historically intermediate) ODXRS and who did not receive chemotherapy. Conclusion The QPORB-RS is a good prognostic test of risk of disease recurrence in breast cancer patients with predominantly node-negative (including node micro-metastases) HR+/HER2- tumors within a median 5-year follow-up period. Our efforts are now focussed on extending this cohort and establishing the prognostic value of the QPORB-RS across all breast carcinomas, regardless of molecular subtype, stage/node positivity and menopausal status.

Citation Format: Satabhisa Mukhopadhyay, Tathagata Dasgupta, Elizabeth Walsh, Rebecca Millican-Slater, Andrew hanby, Joanne Stephenson, Craig A. Bunnell, Nicolas M. Orsi. Prediction of disease recurrence in low risk Oncotype Dx breast cancers from digital H&E-stained whole slide images of pre-treatment resections alone [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-48.