Thymic epithelial tumour radiotherapy in the UK: A survey of current clinical practice

Significant variation in treatment centre setup and radiotherapy practice for thymic epithelial tumours (TET) was identified through a comprehensive survey of current UK Clinical (Radiation) Oncology practice. Multi-centre collaboration and wider TET specific multidisciplinary team meetings are needed and will be essential for developing expertise in TET radiotherapy.

Immune-related adverse events in checkpoint blockade: Observations from human tissue and therapeutic considerations

Checkpoint inhibitors (CPIs) are monoclonal antibodies which, by disrupting interactions of immune checkpoint molecules with their ligands, block regulatory immune signals otherwise exploited by cancers. Despite revolutionary clinical benefits, CPI use is associated with an array of immune-related adverse events (irAEs) that mirror spontaneous autoreactivity. Severe irAEs necessitate pausing or stopping of CPI therapy and use of corticosteroids and/or other immunomodulatory interventions. Despite increasingly widespread CPI use, irAE pathobiology remains poorly understood; its elucidation may point to targeted mitigation strategies and uncover predictive biomarkers for irAE onset in patients, whilst casting new light on mechanisms of spontaneous immune-mediated disease. This review focuses on common CPI-induced irAEs of the gut, skin and synovial joints, and how these compare to immune-mediated diseases such as ulcerative colitis, vitiligo and inflammatory arthritis. We review current understanding of the immunological changes reported following CPI therapy at the level of peripheral blood and tissue. Many studies highlight dysregulation of cytokines in irAE-affected tissue, particularly IFNγ and TNF. IrAE-affected tissues are also predominantly infiltrated by T-cells, with low B-cell infiltration. Whilst there is variability between studies, patients treated with anti-programmed cell death-1 (PD-1)/PDL-1 therapies seem to exhibit CD8+ T-cell dominance, with CD4+ T-cells dominating in those treated with anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) monotherapy. Interestingly, CD8+CXCR3+ T-cells have been reported to be elevated in gastrointestinal, dermatological and musculoskeletal -irAE affected tissues. These findings may highlight potential opportunities for therapeutic development or re-deployment of existing therapies to prevent and/or improve the outcome of irAEs.

The association of pre-existing autoimmune disease and immune-related adverse events secondary to immune checkpoint inhibition therapy in a UK multicenter cohort

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Background: Pre-existing autoimmune disease (AID) potentially increases the propensity for the development of immune related adverse events (irAE) in response to oncological immune checkpoint inhibitors (ICIs) is biologically plausible and clinically observed. However, due to consistent clinical trial exclusion of those with pre-existing AID, the impact on the frequency and severity of irAEs is uncertain. Here we analyse this relationship in a large, real-world, UK multi-centre cohort. Methods: A retrospective analysis of 2049 patients treated with ICIs over a two year period was undertaken across 12 National Health Service centres by the UK National Oncology Trainees Collaborative for Healthcare Research (NOTCH). Patients received ICIs as standard of care for malignant melanoma, non-small cell lung cancer and renal cell carcinoma. The presence of pre-existing AIDs was assessed and classified as either autoantibody driven or autoinflammatory then correlated with clinically significant irAEs (i.e. ≥grade 2 or all-grade endocrinopathies). Statistical analyses included T-test, Mann-Whitney and Chi-squared. For overall survival (OS) Kaplan-Meier and log-rank tests were utilised. Results: Pre-existing AID were present in 13% (n = 257) of the overall cohort. Pre-existing endocrinopathies (30%; n = 76) were most common followed by rheumatological AIDs (18%; n = 46). In the pre-existing AID cohort there was a female predominance (48% vs 39%; p = 0.006) but no difference in smoking history (p = 0.074) or ethnicity (p = 0.12). There was no difference in ICI treatment between those with and without pre-existing AID (p = 0.2800). IrAEs occurred in 45% (n = 117) patients with pre-existing AID vs 33% (n = 583) without (p£0.001). The median time to onset of irAEs was similar. IrAEs with an increased incidence in the pre-existing AID cohort were colitis (p = < 0.001), arthralgia (p = 0.008) and dermatological irAEs (p = 0.014). There was no difference in the incidence of irAEs in patients with autoantibody driven vs autoinflammatory pre-existing AID (44.0 % vs 44.8%, p = 0.905). In the overall cohort, those with pre-existing AIDs had a median OS of 20.4 months (95% CI: 19.4-21.7) vs 14.1 months (95% CI: 12.8-16.3) in those without pre-existing AID (p = 0.004). Conclusions: This large multi-centre ICI-treated cohort demonstrates that pre-existing AID is a predisposing factor for the development of irAEs, however the incidence is lower than previously quoted. The pathological basis of pre-existing AID did not differentially affect irAE manifestation. Patients with pre-existing AID had improved OS compared to those without which has not been observed in previously reported studies. ICI treatment should be considered in those with pre-existing AID but further studies are needed to determine how best to optimise outcomes whilst mitigating the impact of irAEs.

Abstract P1-08-28: Real world use of OncotypeDx testing in the management of breast cancer. The North East England experience

OncotypeDx testing is now routinely used to help decide management of hormone positive HER2 negative breast cancer. We have reviewed adjuvant treatment and long-term outcomes of breast cancer patients in those who had a genomic OncotypeDx study performed by the oncology team based at the Northern Centre for Cancer Care (NCCC) in Newcastle Upon Tyne over a 10 year period between 2011-2021. Guidance on the use of chemotherapy according to age and recurrence score changed from July 2018, which has been factored in to our review. We also reviewed the other clinicopathological features that could affect outcomes, including tumour size, grade, nodal status , Nottingham Prognostic index and the presence or absence of in situ disease and lymphovascular invasion. The notes of 908 patients who underwent a total of 974 oncotype Dx scores were reviewed to assess:1.Were the management decisions in line with the guidance on recurrence scores in use at that time?2.What were the outcomes for these patients (we have assessed disease free and overall survival for those who have completed 3 years or more of follow up)?3.For patients who relapsed, would a different decision have been made if current guidelines are applied?. 508 tumours had a low recurrence score (18 or less) and would typically be advised that chemotherapy would not be of benefit. 198 tumours scored in the intermediate group and a decision about chemotherapy currently would be made on the basis of their age. 268 tumours had a high recurrence score of 25 or greater and current advice would advocate chemotherapy in this group. The cut off figures for oncotype score groups have changed with previous ‘intermediate’ recurrence score figures from 18-30, and the ‘high’ score category above 30. 232 tumours of the 974 were node positive (80 with micrometastases, 148 with 1-3 nodes, and 4 had more than 4 involved nodes). In the 255 records evaluated thus far for patient outcome, only 22 relapses have occurred, with 9 local recurrences and 13 distant recurrences. Only two patients in the low recurrence score group evaluated so far (n=147) received chemotherapy and there were 6 patients with recurrences in this group; 4 were local and 3 distant. In the high recurrence score group (n=99 )85 patients received chemotherapy and 14 patients did not, of whom 5 were due to patient choice. Seven patients have so far relapsed (2 local & 5 distant recurrences). In the intermediate group 15 patients received chemotherapy of the total group evaluated to date(n=73). Six patients in the intermediate group have relapsed (2 local & 4 distant recurrences). Under modern guidelines, only two further patients in this group would have been offered chemotherapy. 25 of the patients in the intermediate group were 55 years or above and 4 of these received chemotherapy - under current UK guidance these patients would avoid chemotherapy. Whilst the aim is to share results from the complete dataset in our poster, early results from this study confirm the benefit of OncotypeDx testing in the real world management of patients with breast cancer. AcknowledgementsMark Verrill, NicCresti, Daniella Lee, Radha Todd, Helen Turnbull, Kathryn Wright, NajibahMahtab, Ed Hallam, Sarah Reynia

Citation Format: Abigail Gault, Jayshree Veeratterapillay, Wendy Taylor. Real world use of OncotypeDx testing in the management of breast cancer. The North East England experience [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-28.

Key findings from the UKCCMP cohort of 877 patients with haematological malignancy and COVID-19: disease control as an important factor relative to recent chemotherapy or anti-CD20 therapy

Patients with haematological malignancies have a high risk of severe infection and death from SARS-CoV-2. In this prospective observational study, we investigated the impact of cancer type, disease activity, and treatment in 877 unvaccinated UK patients with SARS-CoV-2 infection and active haematological cancer. The primary end-point was all-cause mortality. In a multivariate analysis adjusted for age, sex and comorbidities, the highest mortality was in patients with acute leukaemia [odds ratio (OR) = 1·73, 95% confidence interval (CI) 1·1-2·72, P = 0·017] and myeloma (OR 1·3, 95% CI 0·96-1·76, P = 0·08). Having uncontrolled cancer (newly diagnosed awaiting treatment as well as relapsed or progressive disease) was associated with increased mortality risk (OR = 2·45, 95% CI 1·09-5·5, P = 0·03), as was receiving second or beyond line of treatment (OR = 1·7, 95% CI 1·08-2·67, P = 0·023). We found no association between recent cytotoxic chemotherapy or anti-CD19/anti-CD20 treatment and increased risk of death within the limitations of the cohort size. Therefore, disease control is an important factor predicting mortality in the context of SARS-CoV-2 infection alongside the possible risks of therapies such as cytotoxic treatment or anti-CD19/anti-CD20 treatments.

Reduced prevalence of impaired glucose tolerance and no change in prevalence of diabetes despite increasing BMI among Aboriginal people from a group of remote homeland communities

OBJECTIVE

To examine trends in glucose tolerance and coronary risk among Aboriginal people from a group of homeland communities in central Australia during a 7-year follow-up period.

RESEARCH DESIGN AND METHODS

Community-based screenings of adult volunteers were performed in 1988 (n = 437; 93% response rate) and in 1995 (n = 424; 85% response rate). A health promotion intervention program commenced after the 1988 survey that focused on the benefits of exercise and appropriate diet.

RESULTS

Mean (95% CI) BMI increased significantly from 22.8 kg/m2 (22.3-23.2) to 24.2 kg/m2 (23.8-24.7) during the follow-up period (P < 0.001). This increase was similar for men and women and across all age-groups. The increase in BMI was greater among subjects residing adjacent to a store compared with those residing in communities located far from a store (P < 0.001). Decreases were evident in the prevalence of impaired glucose tolerance (IGT) (from 22.5 to 10.1% among women, P < 0.001; from 12.2 to 6.5% among men, P = 0.074) and hypercholesterolemia (from 36.7 to 25.8% among women, P < 0.01; from 52.4 to 44.0% among men, P = 0.147), but no change was evident in the prevalence of diabetes. Smoking remained rare among women (<4%) and decreased among men (from 52.9 to 40.8%, P < 0.05).

CONCLUSIONS

The trends in glucose intolerance were clearly better than have been observed in other Aboriginal communities. The institution of an intervention program corresponded with reductions in the prevalence of IGT, hypercholesterolemia, and smoking. The prevalence of diabetes remained unaltered despite a significant increase in mean BMI, possibly because of the promotion of increased physical activity levels.

Abnormal glucose tolerance and other coronary heart disease risk factors in an isolated aboriginal community in central Australia

OBJECTIVE

To determine the age- and sex-specific prevalence of diabetes, impaired glucose tolerance (IGT), and coronary heart disease risk factors in a remote central Australian Aboriginal community maintaining some degree of traditional lifestyle, living in homeland communities on their ancestral land.

RESEARCH DESIGN AND METHODS

A cross-sectional survey of 437 subjects > or = 15 years of age (189 men, 248 women), representing 80% of the adult population residing in the community at the time of the survey, was performed and the following parameters measured: BMI, glucose tolerance, circulating insulin and lipids, and blood pressure.

RESULTS

The mean BMI for this population was 22.9 +/- 4.8 kg/m2. The prevalence of diabetes in the age group of 15-34 years (103 men and 140 women) was 2 and 6% for men and women, respectively. In the 35-years-and-older age group (86 men and 108 women), diabetes prevalence was 19 and 13% for men and women, respectively. Over half the diabetic subjects did not exhibit fasting hyperglycemia. IGT occurred in 8 and 15% of younger men and women, respectively, and in 17 and 32% of older men and women, respectively. Smoking was common among men (53% current smokers) but rare among women (2% current smokers). The prevalence of hypercholesterolemia, hypertriglyceridemia, hypertension, and overweight rose with increasing degrees of glucose intolerance. The two communities adjacent to the only store in the area had a higher prevalence of abnormal glucose tolerance than did the more remote homeland communities (odds ratio for abnormal glucose tolerance: 2.92; 95% CI 1.51-5.63).

CONCLUSIONS

Despite their relative leanness, this Aboriginal population exhibited relatively high prevalences of IGT and diabetes without fasting hyperglycemia. The data suggest a protective effect of a decentralized mode of living, as opposed to a more urbanized lifestyle, on the occurrence of glucose intolerance. Abnormal lipid profiles (particularly high triglycerides and low HDL cholesterol) and the high prevalence of smoking in men indicated a high-risk profile for coronary heart disease in this population.

Analysis of the neuronal promoter of the rat aromatic L-amino acid decarboxylase gene

The rat aromatic L-amino acid decarboxylase (AADC) gene contains alternative promoters directing expression of neuronal and nonneuronal mRNAs that differ only in their 5' untranslated regions (UTRs). We have analyzed the expression of the neuronal promoter of the AADC gene in cells synthesizing catecholamines and serotonin, as well as in non-AADC-expressing cells. We demonstrate the use of the neuronal-specific UTR in individual dopamine-, norepinephrine-, and serotonin-containing neurons. Transfection analyses show that the rat AADC neuronal promoter, containing 2,400 bp upstream of the transcription start site and including the 68-bp untranslated exon 2, can activate transcription from a reporter gene in both catecholaminergic and serotonergic cell lines. These analyses identified several positive and negative cis-active elements within this region. Unexpectedly, we observed that this promoter, when removed from its native context within the AADC gene, can also direct expression of a reporter gene in cells that do not normally express AADC mRNA. These results suggest that tissue-specific expression of the neuronal promoter may not be controlled by cis-active elements within the first 2,400 bp of the promoter. Additional information may be required to restrict neuronal promoter expression to appropriate cell types. This regulatory information could reside elsewhere within the promoter, within introns, or may be provided by interactions between the two AADC promoters.

Molecular cloning and expression of early T cell costimulatory molecule-1 and its characterization as B7-2 molecule

The interaction of T cell CD28/CTLA-4 receptors with B7-1 activation Ag on APC represents an important costimulatory pathway in T cell activation. However, it is now evident that this costimulatory pathway is neither unique nor universal for the activation of T cells. Our previous study indicated that a 60-kDa membrane protein, recognized by mAb 2D10, was expressed before B7 by activated murine B cells. This molecule was critically involved in activation of T cells in response to auto- and alloantigens. In the present study, we report on the isolation of a cDNA for this early T cell costimulatory molecule (ETC-1). ETC-1, like B7-1, is a member of the Ig supergene family and is composed of 303 amino acids. Nucleic acid sequence comparison indicated that ETC-1 is identical to the B7-2 molecule. When expressed in Chinese hamster ovary cells, ETC-1 showed profound T cell costimulatory activity as demonstrated by its ability to enhance CD4 T cell proliferation in response to Con A or anti-CD3 stimulation. Furthermore, ETC-1 also bound to both CD28-Ig and CTLA4-Ig fusion proteins. These results strongly support the notion that the interaction of ETC-1/B7-2 with CD28 or CTLA-4 receptors represents an alternative T cell costimulatory pathway.

Molecular cloning and expression of early T cell costimulatory molecule-1 and its characterization as B7-2 molecule

The interaction of T cell CD28/CTLA-4 receptors with B7-1 activation Ag on APC represents an important costimulatory pathway in T cell activation. However, it is now evident that this costimulatory pathway is neither unique nor universal for the activation of T cells. Our previous study indicated that a 60-kDa membrane protein, recognized by mAb 2D10, was expressed before B7 by activated murine B cells. This molecule was critically involved in activation of T cells in response to auto- and alloantigens. In the present study, we report on the isolation of a cDNA for this early T cell costimulatory molecule (ETC-1). ETC-1, like B7-1, is a member of the Ig supergene family and is composed of 303 amino acids. Nucleic acid sequence comparison indicated that ETC-1 is identical to the B7-2 molecule. When expressed in Chinese hamster ovary cells, ETC-1 showed profound T cell costimulatory activity as demonstrated by its ability to enhance CD4 T cell proliferation in response to Con A or anti-CD3 stimulation. Furthermore, ETC-1 also bound to both CD28-Ig and CTLA4-Ig fusion proteins. These results strongly support the notion that the interaction of ETC-1/B7-2 with CD28 or CTLA-4 receptors represents an alternative T cell costimulatory pathway.

Monoclonal antibody 2D10 recognizes a novel T cell costimulatory molecule on activated murine B lymphocytes

We have developed a panel of rat mAbs against dibutyryl cAMP-activated 5C2 cells. In this panel, one mAb, 1G10, recognized murine B7. Another mAb designated 2D10 did not bind to murine B7 but could recognize a surface molecule expressed only on dibutyryl cAMP-activated 5C2 mouse B lymphoma cells or on LPS-stimulated splenic B cells. This new molecule is referred to as early T cell costimulatory molecule-1 (ETC-1). From both activated 5C2 cells and splenic B cells, mAb 2D10 immunoprecipitated a 59- to 60-kDa protein, which was different from the 47- to 55-kDa murine B7 protein precipitated from the same cell populations. FACS analysis showed that, in contrast to B7, the expression of ETC-1 on 5C2 cells was induced by lower concentrations of dibutyryl cAMP and displayed a faster kinetics. LPS-stimulated splenic B cells expressed relatively low levels of B7 and much higher levels of ETC-1. Importantly, in an Ag presentation assay using activated 5C2 cells as APC, the secretion of IL-2 by C8A3 T hybrids was partially inhibited by mAb 2D10 alone and completely blocked by combination use of mAbs 2D10 and 1G10 in a dose-dependent and synergistic fashion. In a one-way primary MLR, mAb 2D10 alone at 0.1 to 1 microgram/ml inhibited T cell proliferation by 19 to 56%. However, an additive blocking effect (up to 76%) was observed when two mAbs were added in combination. Thus, our data have demonstrated that a novel T cell costimulatory molecule is present on activated murine B cells, which, in cooperation with B7, may play a critical role in optimal T cell activation.

Monoclonal antibody 2D10 recognizes a novel T cell costimulatory molecule on activated murine B lymphocytes

We have developed a panel of rat mAbs against dibutyryl cAMP-activated 5C2 cells. In this panel, one mAb, 1G10, recognized murine B7. Another mAb designated 2D10 did not bind to murine B7 but could recognize a surface molecule expressed only on dibutyryl cAMP-activated 5C2 mouse B lymphoma cells or on LPS-stimulated splenic B cells. This new molecule is referred to as early T cell costimulatory molecule-1 (ETC-1). From both activated 5C2 cells and splenic B cells, mAb 2D10 immunoprecipitated a 59- to 60-kDa protein, which was different from the 47- to 55-kDa murine B7 protein precipitated from the same cell populations. FACS analysis showed that, in contrast to B7, the expression of ETC-1 on 5C2 cells was induced by lower concentrations of dibutyryl cAMP and displayed a faster kinetics. LPS-stimulated splenic B cells expressed relatively low levels of B7 and much higher levels of ETC-1. Importantly, in an Ag presentation assay using activated 5C2 cells as APC, the secretion of IL-2 by C8A3 T hybrids was partially inhibited by mAb 2D10 alone and completely blocked by combination use of mAbs 2D10 and 1G10 in a dose-dependent and synergistic fashion. In a one-way primary MLR, mAb 2D10 alone at 0.1 to 1 microgram/ml inhibited T cell proliferation by 19 to 56%. However, an additive blocking effect (up to 76%) was observed when two mAbs were added in combination. Thus, our data have demonstrated that a novel T cell costimulatory molecule is present on activated murine B cells, which, in cooperation with B7, may play a critical role in optimal T cell activation.

Expression and functional analysis of murine B7 delineated by a novel monoclonal antibody

The B cell surface molecule designated B7 has been shown to be expressed by activated human B cells and monocytes and to be a ligand for the CD28 and CTLA-4 molecules on T cells. B7/CD28 interactions can provide a second signal to T cells (in addition to occupancy of the T cell antigen receptor) that is needed for T cell activation. COS cells transfected with the mouse homologue of B7 have been demonstrated to provide a stimulatory signal to murine and human T cells. In this report we describe a rat anti-mouse B7 mAb designated 1G10. Scatchard and/or FACS analyses utilizing 1G10 demonstrated that B7 was not expressed on resting splenic T cells or B cells, but could be induced at high levels on B cells cocultured with a syngeneic I-Ak-restricted autoreactive T cell hybridoma. Furthermore, activation of B cells with dibutyryl-cAMP (db-cAMP), a second messenger for class II MHC signaling, or with LPS induced the expression of B7 and the two agents showed additive effects. In contrast to B cells, freshly isolated mouse peritoneal macrophages constitutively expressed B7. Antibody-blocking experiments indicated that anti-B7 antibody partially inhibited T cell proliferative responses to primary antigenic stimulation but had no effect on the responses of previously activated T cells to antigenic restimulation.

Signalling through the MHC class II cytoplasmic domain is required for antigen presentation and induces B7 expression

Class II major histocompatibility complex (MHC) molecules function as antigen-presenting elements as well as signal transducers on B lymphocytes. We previously reported that a B lymphoma cell transfectant, 5C2, expressing genetically engineered I-Ak molecules with truncated cytoplasmic domains was severely impaired in both antigen presentation and in anti-Ia-induced intracytoplasmic signalling. These two functions could be restored by preculturing 5C2 cells with cyclic AMP analogues. Here we demonstrate that impaired signal transduction by truncated class II molecules results in a deficiency in induction of the newly defined B-cell accessory molecule B7 (ref. 8), which can be reversed by restoration of B7 expression. These data imply that contact of the T-cell antigen receptor with MHC/antigen ligand results in signal transmission through the class II cytoplasmic domain. This signal, which can be mimicked by dibutyryl cAMP, induces expression of B7, resulting in effective antigen presentation. The fact that crosslinking of surface class II MHC also induces B7 expression on normal resting human B cells supports this contention.