Imaging extrachromosomal DNA (ecDNA) in cancer

Extrachromosomal DNA (ecDNA) are circular regions of DNA that are found in many cancers. They are an important means of oncogene amplification, and correlate with treatment resistance and poor prognosis. Consequently, there is great interest in exploring and targeting ecDNA vulnerabilities as potential new therapeutic targets for cancer treatment. However, the biological significance of ecDNA and their associated regulatory control remains unclear. Light microscopy has been a central tool in the identification and characterisation of ecDNA. In this review we describe the different cellular models available to study ecDNA, and the imaging tools used to characterise ecDNA and their regulation. The insights gained from quantitative imaging are discussed in comparison with genome sequencing and computational approaches. We suggest that there is a crucial need for ongoing innovation using imaging if we are to achieve a full understanding of the dynamic regulation and organisation of ecDNA and their role in tumourigenesis.

Adult brain tumour research in 2024: Status, challenges and recommendations

In 2015, a groundswell of brain tumour patient, carer and charity activism compelled the UK Minister for Life Sciences to form a brain tumour research task and finish group. This resulted, in 2018, with the UK government pledging £20m of funding, to be paralleled with £25m from Cancer Research UK, specifically for neuro-oncology research over the subsequent 5 years. Herein, we review if and how the adult brain tumour research landscape in the United Kingdom has changed over that time and what challenges and bottlenecks remain. We have identified seven universal brain tumour research priorities and three cross-cutting themes, which span the research spectrum from bench to bedside and back again. We discuss the status, challenges and recommendations for each one, specific to the United Kingdom.

The Scottish COVID Cancer Immunity Prevalence Study: A Longitudinal Study of SARS-CoV-2 Immune Response in Patients Receiving Anti-Cancer Treatment

BACKGROUND

Cancer and anti-cancer treatment (ACT) may be risk factors for severe SARS-CoV-2 infection and limited vaccine efficacy. Long-term longitudinal studies are needed to evaluate these risks. The Scottish COVID cancer immunity prevalence (SCCAMP) study characterizes the incidence and outcomes of SARS-CoV-2 infection and vaccination in patients with solid tumors undergoing ACT. This preliminary analysis includes 766 patients recruited since May 2020.

METHODS

Patients with solid-organ cancers attending secondary care for active ACT consented to the collection of routine electronic health record data and serial blood samples over 12 months. Blood samples were tested for total SARS-CoV-2 antibody.

RESULTS

A total of 766 participants were recruited between May 28, 2020 and October 31, 2021. Most received cytotoxic chemotherapy (79%). Among the participants, 48 (6.3%) were tested positive for SARS-CoV-2 by PCR. Infection rates were unaffected by ACT, largely aligning with the local population. Mortality proportion was not higher with a recent positive SARS-CoV-2 PCR (10.4% vs 10.6%). Multivariate analysis revealed lower infection rates in vaccinated patients regardless of chemotherapy (HR 0.307 [95% CI, 0.144-0.6548]) or immunotherapy (HR 0.314 [95% CI, 0.041-2.367]) treatment. A total of 96.3% of patients successfully raised SARS-CoV-2 antibodies after >2 vaccines. This was independent of the treatment type.

CONCLUSION

This is the largest on-going longitudinal real-world dataset of patients undergoing ACT during the early stages of the COVID-19 pandemic. This preliminary analysis demonstrates that patients with solid tumors undergoing ACT have high protection from SARS-CoV-2 infection following COVID-19 vaccination. The SCCAMP study will evaluate long-term COVID-19 antibody trends, focusing on specific ACTs and patient subgroups.

PemBla: A Phase 1 study of intravesical pembrolizumab in recurrent non‐muscle‐invasive bladder cancer

Objectives

This study aimed to investigate the anti-PD-1 inhibitor pembrolizumab as a potential agent for use in non-muscle-invasive bladder cancer (NMIBC) by conducting a Phase 1 safety run-in study to assess the safety and tolerability of intravesical pembrolizumab after transurethral resection of the bladder tumour (TURBT).

Patients and methods

Eligible patients had recurrent NMIBC for which adjuvant treatment post TURBT was a reasonable treatment option, Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1 and adequate end-organ function. Pembrolizumab was administered by intravesical instillation once weekly for a total of six doses. Intra-patient dose escalation was performed in three paired patient cohorts with doses starting at 50 mg and increasing through 100 mg to a maximum of 200 mg. Adverse events (AEs) were assessed using Common Terminology Criteria for Adverse Events (CTCAE) v4.03 with dose limiting toxicity (DLT) defined as a clinically significant, drug-related, Grade 4 haematological or Grade 3 or higher non-haematological toxicity occurring within 7 days of administration of the first treatment at a given dose for that patient.

Results

Six patients were treated with no DLTs seen during dose escalation. Drug-related AEs were of low grade and included dysuria and fatigue. All patients completed six doses of treatment as planned. Pharmacokinetic and pharmacodynamic assays did not detect any pembrolizumab in the serum following repeated intravesical administration, and no changes in peripheral immune cell populations were observed.

Conclusions

Administration of intravesical pembrolizumab was well tolerated and did not raise any safety concerns in patients with NMIBC following TURBT. There was no evidence of systemic absorption or systemic immune effects following intravesical administration. Further studies are required to assess whether intravesical administration has anti-tumour activity.

Oncogene expression from extrachromosomal DNA is driven by copy number amplification and does not require spatial clustering in glioblastoma stem cells

Extrachromosomal DNA (ecDNA) are frequently observed in human cancers and are responsible for high levels of oncogene expression. In glioblastoma (GBM), ecDNA copy number correlates with poor prognosis. It is hypothesized that their copy number, size, and chromatin accessibility facilitate clustering of ecDNA and colocalization with transcriptional hubs, and that this underpins their elevated transcriptional activity. Here, we use super-resolution imaging and quantitative image analysis to evaluate GBM stem cells harbouring distinct ecDNA species (EGFR, CDK4, PDGFRA). We find no evidence that ecDNA routinely cluster with one another or closely interact with transcriptional hubs. Cells with EGFR-containing ecDNA have increased EGFR transcriptional output, but transcription per gene copy is similar in ecDNA compared to the endogenous chromosomal locus. These data suggest that it is the increased copy number of oncogene-harbouring ecDNA that primarily drives high levels of oncogene transcription, rather than specific interactions of ecDNA with each other or with high concentrations of the transcriptional machinery.

Scottish COVID CAncer iMmunity Prevalence (SCCAMP): A longitudinal study of patients with cancer receiving active anti-cancer treatment during the COVID-19 pandemic

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Background: Cancer and systemic anti-cancer treatment (SACT) have been identified as possible risk factors for infection and related severe illness associated with SARS-CoV-2 virus as a consequence of immune suppression. The Scottish COVID CAncer iMmunity Prevalence (SCCAMP) study aimed to characterise the incidence and outcomes of SARS-Cov-2 infection in patients undergoing active anti-cancer treatment during the COVID-19 pandemic and their antibody response following vaccination. Methods: Eligible patients were those attending secondary care for active anti-cancer treatment for a solid tumour. Blood samples were taken for total SARS-CoV-2 antibody assay (Siemens) at baseline and after 1.5, 3, 6 and 12 months. Data on COVID-19 infection, vaccination, cancer type, treatment and outcome (patient death) was obtained from routine electronic health records. Results: The study recruited 766 eligible participants between 28th May 2020 and 31st October 2021. During the study period there were 174 deaths (22%). The median age was 63 years, and 67% were female. Most received cytotoxic chemotherapy (79%), with the remaining 14% receiving immunotherapy and 7% receiving another form of anti-cancer therapy (radiotherapy, other systemic anti-cancer treatment). 48 (6.3%) tested positive for SARS-CoV-2 by PCR during the study period. The overall infection rate matched that of the local adult general population until May 2021, after which population levels appeared higher than the study population. Antibody testing detected additional evidence of infection prior to vaccination, taking the total number to 58 (7.6%). There was no significant difference in SARS-CoV-2 PCR positive test rates based on type of anti-cancer treatment. Mortality rates were similar between those who died within 90 days of a positive SARS-CoV-2 PCR and those with no positive PCR (10.4% vs 10.6%). Death from all causes was lowest among vaccinated patients, and of the patients who had a positive SARS-CoV-2 PCR at any time, all of those who died during the study period were unvaccinated. Multivariate analysis correcting for age, gender, socioeconomic status, Charlson co-morbidity score and number of previous medications revealed that vaccination was associated with a significantly lower infection rate regardless of treatment with chemotherapy or immunotherapy with hazard ratios of 0.307 (95% CI 0.144-0.6548) or 0.314 (95% CI 0.041-2.367) in vaccinated patients respectively. Where antibody data was available, 96.3% of patients successfully raised SARS-CoV-2 antibodies at a time point after vaccination. This was unaffected by treatment type. Conclusions: SCCAMP provides real-world evidence that patients with cancer undergoing SACT have a high antibody response and protection from SARS-CoV-2 infection following COVID-19 vaccination.

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.

Mortality Among Adults With Cancer Undergoing Chemotherapy or Immunotherapy and Infected With COVID-19

Importance

Large cohorts of patients with active cancers and COVID-19 infection are needed to provide evidence of the association of recent cancer treatment and cancer type with COVID-19 mortality.

Objective

To evaluate whether systemic anticancer treatments (SACTs), tumor subtypes, patient demographic characteristics (age and sex), and comorbidities are associated with COVID-19 mortality.

Design, Setting, and Participants

The UK Coronavirus Cancer Monitoring Project (UKCCMP) is a prospective cohort study conducted at 69 UK cancer hospitals among adult patients (≥18 years) with an active cancer and a clinical diagnosis of COVID-19. Patients registered from March 18 to August 1, 2020, were included in this analysis.

Exposures

SACT, tumor subtype, patient demographic characteristics (eg, age, sex, body mass index, race and ethnicity, smoking history), and comorbidities were investigated.

Main Outcomes and Measures

The primary end point was all-cause mortality within the primary hospitalization.

Results

Overall, 2515 of 2786 patients registered during the study period were included; 1464 (58%) were men; and the median (IQR) age was 72 (62-80) years. The mortality rate was 38% (966 patients). The data suggest an association between higher mortality in patients with hematological malignant neoplasms irrespective of recent SACT, particularly in those with acute leukemias or myelodysplastic syndrome (OR, 2.16; 95% CI, 1.30-3.60) and myeloma or plasmacytoma (OR, 1.53; 95% CI, 1.04-2.26). Lung cancer was also significantly associated with higher COVID-19-related mortality (OR, 1.58; 95% CI, 1.11-2.25). No association between higher mortality and receiving chemotherapy in the 4 weeks before COVID-19 diagnosis was observed after correcting for the crucial confounders of age, sex, and comorbidities. An association between lower mortality and receiving immunotherapy in the 4 weeks before COVID-19 diagnosis was observed (immunotherapy vs no cancer therapy: OR, 0.52; 95% CI, 0.31-0.86).

Conclusions and Relevance

The findings of this study of patients with active cancer suggest that recent SACT is not associated with inferior outcomes from COVID-19 infection. This has relevance for the care of patients with cancer requiring treatment, particularly in countries experiencing an increase in COVID-19 case numbers. Important differences in outcomes among patients with hematological and lung cancers were observed.

COVID-19 and cancer registries: learning from the first peak of the SARS-CoV-2 pandemic

The SARS-Cov-2 pandemic in 2020 has caused oncology teams around the world to adapt their practice in the aim of protecting patients. Early evidence from China indicated that patients with cancer, and particularly those who had recently received chemotherapy or surgery, were at increased risk of adverse outcomes following SARS-Cov-2 infection. Many registries of cancer patients infected with SARS-Cov-2 emerged during the first wave. We collate the evidence from these national and international studies and focus on the risk factors for patients with solid cancers and the contribution of systemic anti-cancer treatments (SACT-chemotherapy, immunotherapy, targeted and hormone therapy) to outcomes following SARS-Cov-2 infection. Patients with cancer infected with SARS-Cov-2 have a higher probability of death compared with patients without cancer. Common risk factors for mortality following COVID-19 include age, male sex, smoking history, number of comorbidities and poor performance status. Oncological features that may predict for worse outcomes include tumour stage, disease trajectory and lung cancer. Most studies did not identify an association between SACT and adverse outcomes. Recent data suggest that the timing of receipt of SACT may be associated with risk of mortality. Ongoing recruitment to these registries will enable us to provide evidence-based care.

COVID-19 prevalence and mortality in patients with cancer and the effect of primary tumour subtype and patient demographics: a prospective cohort study

BACKGROUND

Patients with cancer are purported to have poor COVID-19 outcomes. However, cancer is a heterogeneous group of diseases, encompassing a spectrum of tumour subtypes. The aim of this study was to investigate COVID-19 risk according to tumour subtype and patient demographics in patients with cancer in the UK.

METHODS

We compared adult patients with cancer enrolled in the UK Coronavirus Cancer Monitoring Project (UKCCMP) cohort between March 18 and May 8, 2020, with a parallel non-COVID-19 UK cancer control population from the UK Office for National Statistics (2017 data). The primary outcome of the study was the effect of primary tumour subtype, age, and sex and on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prevalence and the case-fatality rate during hospital admission. We analysed the effect of tumour subtype and patient demographics (age and sex) on prevalence and mortality from COVID-19 using univariable and multivariable models.

FINDINGS

319 (30·6%) of 1044 patients in the UKCCMP cohort died, 295 (92·5%) of whom had a cause of death recorded as due to COVID-19. The all-cause case-fatality rate in patients with cancer after SARS-CoV-2 infection was significantly associated with increasing age, rising from 0·10 in patients aged 40-49 years to 0·48 in those aged 80 years and older. Patients with haematological malignancies (leukaemia, lymphoma, and myeloma) had a more severe COVID-19 trajectory compared with patients with solid organ tumours (odds ratio [OR] 1·57, 95% CI 1·15-2·15; p<0·0043). Compared with the rest of the UKCCMP cohort, patients with leukaemia showed a significantly increased case-fatality rate (2·25, 1·13-4·57; p=0·023). After correction for age and sex, patients with haematological malignancies who had recent chemotherapy had an increased risk of death during COVID-19-associated hospital admission (OR 2·09, 95% CI 1·09-4·08; p=0·028).

INTERPRETATION

Patients with cancer with different tumour types have differing susceptibility to SARS-CoV-2 infection and COVID-19 phenotypes. We generated individualised risk tables for patients with cancer, considering age, sex, and tumour subtype. Our results could be useful to assist physicians in informed risk-benefit discussions to explain COVID-19 risk and enable an evidenced-based approach to national social isolation policies.

FUNDING

University of Birmingham and University of Oxford.

Immune checkpoint blockade: releasing the breaks or a protective barrier to COVID-19 severe acute respiratory syndrome?

The rapid emergence of COVID-19 has sent shockwaves through healthcare systems globally, with cancer patients at increased risk. The interplay of the virus and host immune system has been implicated in the development of ARDS. Immunotherapy agents have the potential to adversely potentiate this phenomenon, requiring careful real-world observation.

COVID-19 mortality in patients with cancer on chemotherapy or other anticancer treatments: a prospective cohort study

BACKGROUND

Individuals with cancer, particularly those who are receiving systemic anticancer treatments, have been postulated to be at increased risk of mortality from COVID-19. This conjecture has considerable effect on the treatment of patients with cancer and data from large, multicentre studies to support this assumption are scarce because of the contingencies of the pandemic. We aimed to describe the clinical and demographic characteristics and COVID-19 outcomes in patients with cancer.

METHODS

In this prospective observational study, all patients with active cancer and presenting to our network of cancer centres were eligible for enrolment into the UK Coronavirus Cancer Monitoring Project (UKCCMP). The UKCCMP is the first COVID-19 clinical registry that enables near real-time reports to frontline doctors about the effects of COVID-19 on patients with cancer. Eligible patients tested positive for severe acute respiratory syndrome coronavirus 2 on RT-PCR assay from a nose or throat swab. We excluded patients with a radiological or clinical diagnosis of COVID-19, without a positive RT-PCR test. The primary endpoint was all-cause mortality, or discharge from hospital, as assessed by the reporting sites during the patient hospital admission.

FINDINGS

From March 18, to April 26, 2020, we analysed 800 patients with a diagnosis of cancer and symptomatic COVID-19. 412 (52%) patients had a mild COVID-19 disease course. 226 (28%) patients died and risk of death was significantly associated with advancing patient age (odds ratio 9·42 [95% CI 6·56-10·02]; p<0·0001), being male (1·67 [1·19-2·34]; p=0·003), and the presence of other comorbidities such as hypertension (1·95 [1·36-2·80]; p<0·001) and cardiovascular disease (2·32 [1·47-3·64]). 281 (35%) patients had received cytotoxic chemotherapy within 4 weeks before testing positive for COVID-19. After adjusting for age, gender, and comorbidities, chemotherapy in the past 4 weeks had no significant effect on mortality from COVID-19 disease, when compared with patients with cancer who had not received recent chemotherapy (1·18 [0·81-1·72]; p=0·380). We found no significant effect on mortality for patients with immunotherapy, hormonal therapy, targeted therapy, radiotherapy use within the past 4 weeks.

INTERPRETATION

Mortality from COVID-19 in cancer patients appears to be principally driven by age, gender, and comorbidities. We are not able to identify evidence that cancer patients on cytotoxic chemotherapy or other anticancer treatment are at an increased risk of mortality from COVID-19 disease compared with those not on active treatment.

FUNDING

University of Birmingham, University of Oxford.

Case report of oxalate nephropathy in a patient with pancreatic metastases from renal carcinoma

BACKGROUND

Patients with metastatic renal carcinoma frequently have pre-existing renal impairment and not infrequently develop worsening renal function as a complication of their treatment. The presence of pancreatic metastases in patients with metastatic renal carcinoma, often confers a more favourable prognosis and as a consequence this patient group may be exposed to such treatments for more prolonged periods of time. However, the development of renal failure may also be a consequence of the cancer itself rather than its treatment.

CASE PRESENTATION

We present an 84-year-old patient receiving the tyrosine kinase inhibitor (TKI) pazopanib for metastatic renal carcinoma who developed oxalate nephropathy as a consequence of pancreatic exocrine insufficiency resulting from pancreatic metastases.

CONCLUSIONS

This case demonstrates the importance of investigating unexpected toxicities and highlights the potential consequences of pancreatic insufficiency and its sequelae in patients with pancreatic metastases.

A phase I study to assess the safety and tolerability of intravesical pembrolizumab in recurrent non-muscle invasive bladder cancer (NMIBC)

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Background: Intravesical BCG has been the mainstay of therapy following TURBT for intermediate risk NMIBC for many years and is thought to act through activation of non-specific local immunity. With the recent success of checkpoint inhibitor treatment in metastatic bladder cancer, we sought to investigate the anti-PD1 inhibitor pembrolizumab as a potential agent for use in patients with intermediate risk NMIBC in a phase I/II study. The primary aim of the phase I safety run-in was to assess the safety and tolerability of intravesical pembrolizumab after TURBT in patients with intermediate risk NMIBC. Methods: Eligible patients had recurrent NMIBC for which adjuvant treatment post TURBT was a reasonable treatment option, ECOG PS 0-1 and adequate end organ function. Pembrolizumab was administered by intravesical instillation once weekly for a total of 6 doses. Intra-patient dose escalation was performed in three paired patient cohorts with doses starting at 50mg and increasing through 100mg to a maximum of 200mg. Adverse events (AEs) were assessed using CTCAE v4.03 with dose limiting toxicity (DLT) defined as a clinically significant, drug related, grade 4 haematological or ≥ grade 3 non-haematological toxicity occurring within 7 days of administration of the first treatment at a given dose for that patient. Results: In the first 4 patients treated, no DLTs were seen during dose escalation. Drug-related AEs included Grade 1 dysuria, fatigue and nausea. Grade 1-2 urinary tract infections, Grade 1 cystitis and Grade 3 urosepsis (SAE) were observed but assessed as probably not related to pembrolizumab. Recruitment of a final cohort of two patients at repeated doses of 200mg is ongoing to confirm safety and tolerability of this dose. Conclusions: Administration of intravesical pembrolizumab was safe and well tolerated in patients with NMIBC following TURBT. A randomised, parallel group, phase II marker-lesion study to assess the safety, efficacy and tolerability of either intravesical pembrolizumab or intravenous pembrolizumab in a larger cohort of patients with intermediate risk recurrent NMIBC is planned. Clinical trial information: NCT03167151.

Abiraterone acetate in combination with prednisone in the treatment of metastatic hormone-sensitive prostate cancer: clinical evidence and experience

More than a million men worldwide are diagnosed with prostate cancer every year. After androgen deprivation therapy (ADT), chemotherapy has been the only subsequent intervention to improve survival in the metastatic setting but has limitations for patients who may not tolerate its toxicity profile or are not candidates on the basis of comorbidities. Novel anti-androgens such as abiraterone acetate have shown promise for such patients. This review draws on clinical evidence and experience to identify abiraterone as a well-tolerated, effective alternative to docetaxel. In the castration-resistant setting, studies demonstrated a survival benefit over placebo, prompting further trials in the hormone-naïve population. More recently the STAMPEDE and LATITUDE studies suggest abiraterone has comparable survival outcomes to docetaxel in the castration-sensitive setting, with evidence in favour of its quality of life profile. Available comparisons with docetaxel are limited, but those available suggest they have comparable efficacy. However, the significant cost compared with docetaxel is a major barrier in resource-rationed healthcare settings. Overall, abiraterone is an effective alternative to chemotherapy for men with castration-sensitive prostate cancer, but this should be balanced with the significantly greater cost.

Challenges to DNA replication in hypoxic conditions

The term hypoxia refers to any condition where insufficient oxygen is available and therefore encompasses a range of actual oxygen concentrations. The regions of tumours adjacent to necrotic areas are at almost anoxic levels and are known to be extremely therapy resistant (radiobiological hypoxia). The biological response to radiobiological hypoxia includes the rapid accumulation of replication stress and subsequent DNA damage response, including both ATR- and ATM-mediated signalling, despite the absence of detectable DNA damage. The causes and consequences of hypoxia-induced replication stress will be discussed.

Whole-genome sequencing identifies homozygous BRCA2 deletion guiding treatment in dedifferentiated prostate cancer

Whole-genome sequencing (WGS) has transformed the understanding of the genetic drivers of cancer and is increasingly being used in cancer medicine to identify personalized therapies. Here we describe a case in which the application of WGS identified a tumoral BRCA2 deletion in a patient with aggressive dedifferentiated prostate cancer that was repeat-biopsied after disease progression. This would not have been detected by standard BRCA testing, and it led to additional treatment with a maintenance poly ADP ribose polymerase (PARP) inhibitor following platinum-based chemotherapy. This case demonstrates that repeat biopsy upon disease progression and application of WGS to tumor samples has meaningful clinical utility and the potential to transform outcomes in patients with cancer.

Abstract LB-290: Oncometabolites induce a BRCAness state that can be exploited by PARP inhibitors

2-Hydroxyglutarate (2HG) exists as two enantiomers, R-2HG and S-2HG, and both are implicated in tumor progression via their inhibitory effects on α-ketoglutarate (αKG)-dependent dioxygenases. The former is an oncometabolite that is induced by the neomorphic activity conferred by isocitrate dehydrogenase-1 and -2 (IDH1/2) mutations, while the latter is produced under pathologic process such as hypoxia. Recurring IDH1/2 mutations were first identified gliomas and acute myeloid leukemia (AML), and subsequently they were found in multiple other tumor types. Many IDH1/2-mutant tumors are known to be chemo- and radiosensitive, although the mechanisms underlying this enhanced sensitivity have been elusive. Here, we report that IDH1/2 mutations induce a homologous recombination (HR) defect which renders tumor cells exquisitely sensitive to Poly (ADP-Ribose) polymerase (PARP) inhibitors. Remarkably, this “BRCAness” phenotype can be completely reversed by small molecule mutant IDH1/2 inhibitors, and it can be entirely recapitulated by treatment with either 2HG enantiomer in cells with intact IDH1/2. We performed a comprehensive series of studies directly implicate two αKG-dependent dioxygenases, KDM4A and KDM4B, as key mediators of the observed phenotype. In addition, we demonstrate that 2HG-induced HR suppression cannot be explained by mutant IDH1/2-associated alterations in NAD+ levels. We have demonstrated IDH1/2-dependent PARP inhibitor sensitivity in a range of clinically relevant models, including primary patient-derived glioma cells and AML bone marrow cultures in vitro, as well as genetically-matched tumor xenografts in vivo. Finally, we have extended these findings to several structurally related and clinically relevant oncometabolites. We demonstrate profound synthetic lethality with PARP inhibitors in tumors which produce these other oncometabolites, and our data suggest a similar mechanism of action via which HR is suppressed. Small molecule inhibition of oncogenic kinases is a pillar of precision medicine in modern oncology, and this approach has been extrapolated to treat IDH1/2-mutant and other oncometabolite-producing cancers with small molecule inhibitors which block the neomorphic activity of the mutant proteins. The findings present here directly challenge this therapeutic strategy, and they instead provide a novel approach to treat these tumors oncometabolite-producing tumors with DNA repair inhibitors. Furthermore, our results uncover an unexpected link between oncometabolites, altered DNA repair and genetic instability. We previously reported that hypoxia suppresses HR, driving genetic instability and conferring a BRCAness phenotype in hypoxic tumor cells. It is tempting to speculate that the findings reported here provide a novel commonality between hypoxia and IDH1/2 mutations as mediating a “hit-and-run” mechanism for genetic instability and tumor progression through 2HG, but at the same time bestowing a vulnerability to PARP inhibition that can be therapeutically exploited. Based on these findings, we are planning a multi-center Phase II trial testing the efficacy of olaparib for the treatment of recurrent IDH1/2-mutant tumors, and we anticipate this trial will be open for enrollment later this year.

Citation Format: Parker Sulkowski, Christopher Corso, Nathaniel Robinson, Susan Scanlon, Karin Purshouse, Hanwen Bai, Yanfeng Liu, Ranjini Sundaram, Denise Hegan, Nathan Fons, Gregory Breuer, Yuanbin Song, Ketu Mishra, Henk De Feyter, Robin de Graaf, Yulia Surovtseva, Maureen Kachman, Stephanie Halene, Murat Gunel, Peter Glazer, Ranjit S. Bindra. Oncometabolites induce a BRCAness state that can be exploited by PARP inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-290. doi:10.1158/1538-7445.AM2017-LB-290

The BET inhibitor JQ1 selectively impairs tumour response to hypoxia and downregulates CA9 and angiogenesis in triple negative breast cancer

The availability of bromodomain and extra-terminal inhibitors (BETi) has enabled translational epigenetic studies in cancer. BET proteins regulate transcription by selectively recognizing acetylated lysine residues on chromatin. BETi compete with this process leading to both downregulation and upregulation of gene expression. Hypoxia enables progression of triple negative breast cancer (TNBC), the most aggressive form of breast cancer, partly by driving metabolic adaptation, angiogenesis and metastasis through upregulation of hypoxia-regulated genes (for example, carbonic anhydrase 9 (CA9) and vascular endothelial growth factor A (VEGF-A). Responses to hypoxia can be mediated epigenetically, thus we investigated whether BETi JQ1 could impair the TNBC response induced by hypoxia and exert anti-tumour effects. JQ1 significantly modulated 44% of hypoxia-induced genes, of which two-thirds were downregulated including CA9 and VEGF-A. JQ1 prevented HIF binding to the hypoxia response element in CA9 promoter, but did not alter HIF expression or activity, suggesting some HIF targets are BET-dependent. JQ1 reduced TNBC growth in vitro and in vivo and inhibited xenograft vascularization. These findings identify that BETi dually targets angiogenesis and the hypoxic response, an effective combination at reducing tumour growth in preclinical studies.

Abstract P2-02-03: The Collagen Receptor Endo180: A Metastatic Plasma Marker In Breast Cancer Modulated By Bisphosphonate Treatment

Purpose: To establish whether the collagen remodelling receptor, Endo180, should be given consideration as a useful plasma marker in metastatic breast cancer.

Patients and Methods: Analysis of MCF-7 and MDA-MB-231 cell conditioned medium validated the anti-human (39.10) monoclonal antibody as suitable for the detection of soluble Endo180 in plasma. Eighty-seven breast cancer patients with early primary, locally advanced and metastatic disease were included in the study. Correlations between Endo180, CA 15–3 antigen (MUC1; mucin 1) and bisphosphonate treatment were investigated.

Results: Endo180 was elevated in metastatic compared to early breast cancer (P &lt;.0001) and was able to differentiate locoregional disease and visceral and/or osseous metastasis (P = .0005). In combination CA 15–3 antigen (cut-off: 28 U/mL) and Endo180 (relative plasma level cut-off range: 0.95–1.65) had sensitivity of 94–97% and specificity of 52–68%. Endo180 levels were significantly higher in patients who were treatment naive (2.17 ± 0.82, N = 13) compared to those previously (1.82 ± 0.33, N = 5) or currently (1.37 ± 0.74, N = 24) receiving bisphosphonates (P = .011). In the bisphosphonate naive setting (N = 57) the combination of Endo180 (relative plasma level cut-off range: 0.95–1.65) and CA 15–3 antigen (cut-off: 28 U/mL) had a sensitivity of 87–92% and specificity of 72–79%.

Conclusion: Endo180 is a plasma marker with high sensitivity in metastatic breast cancer that can be modulated by bisphosphonate treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-02-03.

Can healthy lifestyle modify risk factors for dementia? Findings from a pilot community-based survey in Chennai (India) and Newcastle (UK)

BACKGROUND

Currently there are no effective treatments available for dementia. Attention has turned to defining preventive strategies and identifying modifying effects of lifestyle, including physical activity, diet, alcohol intake and smoking, in reducing cognitive decline and overt memory problems in the elderly.

METHODS

In this study, we addressed the modifying aspects of various components of lifestyle in two ageing samples and explored the possible effects that exercise, diet and spiritual and religious beliefs have upon physical and mental health. A total of 251 subjects (128 in Chennai, India, and 123 in Newcastle, UK) filled in a questionnaire regarding their lifestyle habits. Data were analysed with χ² analysis.

RESULTS

Our findings highlight that spiritual and religious beliefs promoted good physical and mental health and were negatively associated with risk factors for dementia, such as high blood pressure, high cholesterol level and diabetes. Lifelong diet and physical activity also contributed to better overall well-being in both samples.

CONCLUSIONS

Our study suggests substantial lifestyle variations between two urban populations in Chennai, India, and Newcastle-upon-Tyne, UK. Further detailed work is required to identify the lifestyle components that have the greatest impact on modifying the known risk factors for dementia.

Can healthy lifestyle modify risk factors for dementia? findings from a pilot population-based survey

Introduction

Aspects of lifestyle are a key component to successful ageing and reducing the risk of cognitive impairment. Many developing countries, including India, currently have a much lower rate of dementia in people of the same age in the UK (Alzheimer’s Disease International 2008), in contrast to the higher prevalence rates of cardiovascular risk factors (reviewed in Misra and Kurana, 2009).

Objectives

Compare lifestyle choices in a developed and a developing country, that show contrasting dementia prevalence rates.

Aims

Identify protective factors that may reduce dementia prevalence.

Methods

A total of 251 participants at public meetings (123 in Newcastle and 128 in Chennai) on ageing completed a questionnaire voluntarily regarding their lifestyle, health status, 4-item GDS, and their subjective perception of their mental and physical health. The two groups had similar sociodemographic characteristics.

Results

Diabetes was three times more prevalent in the Chennai group (p = 0.001) but a significantly higher proportion of the Chennai population reported receiving treatment for diabetes (p = 0.012). Vegeterian diet was more frequent in the Chennai cohort (p = 0.000), as well as curry consumption (p = 0.000). The Newcastle group consumed more alcohol (p = 0.000) and practiced exercise less often (p = 0.005). Not surprinsingly, 95% of the Indian is religious, in contrast to 59.7% of the English (p = 0.000).

Conclusions

Type of diet, curry and alcohol consumption, and religious or spiritual beliefs, were the most significantly different, and may therefore confer protective advantages for dementia. Other explanations could be a higher proportion of uncontrolled diabetes and inactive people in the Newcastle sample.