Health and illness beliefs in adults with tuberculosis infection during the COVID-19 pandemic in the UK

Background

COVID-19 disrupted the TB prevention programme in the UK, especially for TB infection (TBI) care. We explore whether experience of the COVID-19 pandemic impacted on patients' perceptions of TBI and its treatment.

Methods

Semi-structured interviews were conducted as part of the Research to Improve Detection and Treatment of TBI (RID-TB) programme, exploring perceptual and practical barriers to TBI treatment. Nineteen people diagnosed with TBI were interviewed between August 2020 and April 2021. Recordings were transcribed and analysed using a constant comparative approach, allowing for a dynamic and iterative exploration of themes. Themes are organised using the Perceptions and Practicalities Approach.

Findings

Some participants perceived TBI as a risk factor for increased susceptibility to COVID-19, while some thought that treatment for TBI might protect against COVID-19 or mitigate its effects. Adaptations to TB services (e.g., remote follow-up) and integrated practices during the COVID-19 restrictions (e.g., medication being posted) addressed some practical barriers to TBI treatment. However, we identified beliefs about TBI and COVID-19 that are likely to act as barriers to engagement with TBI treatment, including: interpreting service delays as an indication of TBI not being serious enough for treatment and concerns about contracting COVID-19 in TB clinics.

Interpretation

COVID-19 and TBI service delays influence people's perceptions and practical barriers to TBI treatment adherence. Failure to address these beliefs may lead to people's concerns about their treatment not being fully addressed. Utilised service adaptations like remote consultations to address practical barriers may be relevant beyond COVID-19.

Funding

NIHR RID-TB Program (RP-PG-0217-20009).

1031 Exploring the Impact of Cognitive Behavioral Therapy for Insomnia (CBT-I) on Daytime Productivity in Survivors of Breast Cancer

Introduction

Post-treatment insomnia disorder and fatigue symptoms can impair work and daytime productivity in breast cancer survivors. Cognitive Behavioral Therapy for Insomnia (CBT-I) significantly improves insomnia and daytime fatigue. This feasibility study examined whether improving insomnia and fatigue using CBT-I is associated with improved work and activity productivity in breast cancer survivors.

Methods

10 survivors of early stage breast cancer participated in 7 weekly individual CBT-I sessions. The primary outcome was the Work Productivity and Activity Impairment Questionnaire-General Health (WPAIQ-GH) questionnaire. Secondary outcomes were the Insomnia Severity Index (ISI) and the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF). Assessments were conducted at baseline and post-treatment. Paired samples t-tests examined the impact of CBT-I on productivity and fatigue. Linear regression assessed whether change in fatigue was associated with change in productivity.

Results

Participants had a mean age of 50.8 (range 42-63) and the majority were diagnosed with stage II (60%) cancer. There was a significant reduction in fatigue [t(9)= 2.43, p =.04] and activity impairment due to insomnia [t(9)= 3.105, p <.05] following treatment. Insomnia affected 52% of work productivity at baseline with a non-significant decrease to 15% following treatment [t(3)= 2.25 p= .110]. Reductions in fatigue were significantly associated with reductions in activity impairment [F(1,8)= 7.25, p =.03], accounting for 47.5% of the variability.

Conclusion

Treating insomnia with CBT-I significantly improved daytime productivity, activity impairment, and fatigue. Controlled research with larger sample sizes is warranted to confirm these preliminary results.

Support

Nyissa Walsh is a trainee in the Cancer Research Training Program of the Beatrice Hunter Cancer Research Institute (BHCRI). Dr. Sheila Garland is supported by a Scotiabank New Investigator Award from BHCRI.

1045 Impact Of Pre-treatment Sleep And Menopausal Status On Sleep Quality In The 12 Months Following A Breast Cancer Diagnosis

Introduction

Sleep disturbances are a prevalent and enduring problem in women who have completed treatment for breast cancer. Less is known about whether sleep during and after cancer treatment is influenced by pre-treatment sleep quality and menopausal status. The present study aims to examine the trajectory of sleep quality in the 12 months following a cancer diagnosis and assess whether trajectory is influenced by pre-treatment sleep quality and menopausal status.

Methods

Newly-diagnosed women (N=88) with non-metastatic BCa were recruited before beginning treatment. They completed the Pittsburgh Sleep Quality Index (PSQI) before treatment and 4, 8, and 12 months later. Women with a score ≥5 on the Pittsburgh Sleep Quality Index at treatment onset were classified as poor sleepers. Menopausal status (pre- or post-menopausal) was chart abstracted. A mixed ANOVA assessed the impact of pre-treatment sleep quality and menopausal status on sleep quality trajectory.

Results

The mean age of the sample was 60 years, 70% were classified as poor sleepers, and 72% were post-menopausal. There was a significant linear time by sleep quality interaction, F(1, 83)= 5.79, p =.02. Good sleepers experienced a greater initial worsening of sleep quality than poor sleepers. At 12 months, poor sleepers had returned to baseline levels whereas scores in good sleepers remained higher than baseline. The 3-way time x sleep quality x menopausal status and the 2-way time by menopausal status interactions were not significant.

Conclusion

Baseline sleep quality is a more powerful determinant of sleep trajectory during treatment than menopausal status. Early intervention is necessary to treat existing sleep problems and prevent the development of sleep problems in women with a history of good sleep.

Support

Dr. Garland is supported by a New Investigator Award and seed funding from the Beatrice Hunter Cancer Research Institute (BHCRI).

Introduction of standardized, cumulative quantitative measurement of blood loss into routine maternity care

Introduction: Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity in the UK. Visual estimation of blood loss is unreliable yet remains common practice. As part of a national quality improvement project to improve care during PPH, standardized, quantitative measurement of blood loss (QBL) for all deliveries was introduced into a tertiary obstetric unit in Cardiff, Wales.Methods: Retrospective analysis of 875 consecutive maternities between December 2017 and February 2018 was undertaken. Of these, 372 mothers had both pre- and post-partum hemoglobin (Hb) were recorded. Regression analyses were performed to investigate the relationship between change in Hb adjusted for red cell transfusion and QBL.Results: The correlation coefficient between QBL and adjusted change in Hb for all deliveries (n = 372) was 0.57. This corresponded to an estimated fall of adjusted change in Hb of 15.3 g/L (95% CI: 13.1, 17.6) per 1000 mL blood loss.Discussion: QBL has been shown to be reliable across all maternity settings, with reproducible results in theater and delivery rooms (on the obstetric unit and alongside midwifery-led unit). QBL is moderately correlated with adjusted change in Hb for all volumes of bleeding and gives clinicians more accurate knowledge of blood loss than visual estimation. This low-cost, low-fidelity intervention can influence the timely escalation of clinical care and therefore patient outcome.

The mobilisation of early mature CD56dim-CD16bright NK cells is blunted following a single bout of vigorous intensity exercise in Type 1 Diabetes

Type 1 diabetes (T1D) is a T cell mediated autoimmune disease that targets and destroys insulin-secreting pancreatic beta cells. Although T cell mediated, a number of other immune cells are also critically involved in coordinating the events leading to T1D. Specifically, innate subsets play an important role in the pathogenesis of T1D. NK cells are one of the first cell types to infiltrate the pancreas, causing damage and release of beta cell antigens. Previous work in our group has shown differential mobilisation of highly differentiated CD8+ T cells during vigorous intensity exercise in T1D compared to a control cohort. Here, we aimed to explore exercise-induced mobilisation of other cell types involved in T1D pathogenesis. In this study, we investigated the effects of a single bout of vigorous (80% predicted VO2max) intensity exercise on innate cell mobilisation in T1D and control participants. T1D (N=12, mean age 33.2yrs, predicted VO₂max 32.2 ml.kg.min⁻¹, BMI 25.3 kg.m⁻²) and control (N=12, mean age 29.4yrs, predicted VO2 max 38.5 ml.kg.min⁻¹, BMI 23.7 kg.m⁻² male participants completed a 30-minute bout of cycling at 80% predicted VO₂ max in a fasted state. Peripheral blood was collected at baseline, immediately post-exercise, and 1 hour post-exercise. NK cell subsets mobilised during vigorous intensity exercise in both control and T1D participants. However, mature NK cells, defined as the CD56dimCD16bright subset, displayed a lower percentage increase following vigorous intensity exercise in T1D participants (Control: 185.12%, T1D: 97.06%). This blunted mobilisation was specific to early mature NK cells (KIR+) but not later differentiated NK cells (KIR+CD57+). Myeloid lineage subsets mobilised to a similar extent in both control and T1D participants. In conclusion, vigorous exercise mobilises innate immune cells in people with T1D albeit to a different extent to those without T1D. This mobilisation of innate immune cells provides a mechanistic argument to support exercise in people with T1D where it has the potential to improve surveillance for infection and to modulate the autoimmune response to the beta cell.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2018

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference was held in Halifax, Nova Scotia, 20-22 September 2018. Experts in radiation oncology, medical oncology, surgical oncology, and pathology who are involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics in the management of pancreatic cancer, pancreatic neuroendocrine tumours, hepatocellular cancer, and rectal and colon cancer, including ■ surgical management of pancreatic adenocarcinoma,■ adjuvant and metastatic systemic therapy options in pancreatic adenocarcinoma,■ the role of radiotherapy in the management of pancreatic adenocarcinoma,■ systemic therapy in pancreatic neuroendocrine tumours,■ updates in systemic therapy for patients with advanced hepatocellular carcinoma,■ optimum duration of adjuvant systemic therapy for colorectal cancer, and■ sequence of therapy in oligometastatic colorectal cancer.

Factors influencing surgical treatment decisions for breast cancer: a qualitative exploration of surgeon and patient perspectives

Background

The rate of mastectomy is much higher in Newfoundland and Labrador than in any other province in Canada, even for women diagnosed at an early stage. In this paper, we present qualitative data from women who have made a decision for surgical treatment and from breast surgeons in an effort to better explicate factors influencing breast cancer (bca) surgical decision-making.

Methods

The study's descriptive, qualitative design involved holding interviews with breast surgeons and holding focus groups and interviews with women who were offered the choice of breast-conserving surgery (bcs) or mastectomy (mt).

Results

Participants included 35 women and 13 surgeons. High interest in mt and increasing requests for prophylactic contralateral mt were evident. A host of factors-clinical, demographic, psychosocial, education-related, and cultural-influenced the decisions. A key factor for women was fear of recurrence and a need to "just get rid of it," but the experiences of others also influenced the decisions. Life stage and family considerations also factored prominently into women's decisions.

Conclusions

Women with early-stage bca more often chose mt and often demanded prophylactic removal of the healthy breast. Findings highlight the importance of ensuring that women at average risk are appropriately counselled about the low likelihood of a subsequent contralateral bca and the lack of survival benefit associated with prophylactic contralateral mt. Findings also revealed other areas of presurgical discussion that might help women think through their personal circumstances and values so as to encourage informed surgical decisions.

Abstract PD5-08: Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers

Understanding how standard-of-care drug treatments affect tumor intrinsic biology and microenvironment is critical for elucidating drug resistance mechanisms and developing better combination therapies as well as new therapies. To characterize the effects of neoadjuvant chemotherapy (NAC) on the genome, transcriptome and tumor infiltrating leukocytes (TILs), we have conducted whole exome and whole transcriptome sequencing of a large longitudinal breast cancer cohort consisting of 146 cases and 281 paired tumor samples. In total, 52 (38%) patients achieved pathologic complete response (pCR) while 85 patients (62%) had residual disease with standard chemotherapy regimen. Tumor biopsies were collected for each patient at three time points – pre-treatment, three weeks after the first cycle of anthracycline and cyclophosphamide (AC) and at the time of surgery after 3 more cycles of AC followed by 4 cycles of taxane or taxane plus Herceptin in case of HER2+ subtype. We detected 5,955 protein-altering somatic mutations affecting 4,414 genes in pretreatment samples and 502 acquired mutations in surgery samples affecting 477 genes including 19recurrently mutated genes such as TP53 and NOTCH1. Across all subtypes, 4,346 genes were differentially expressed (DE) following NAC treatment and significantly enriched in pathways such as cell cycle, ER signaling, PI3K/mTOR, immune and metabolism. Expression-based virtual microdissection analysis indicated that NAC treatment induced an increase in the fractions of stromal and adjacent normal tissue compartment, consistent with observed reduction in tumor cellularity. To assess the NAC induced changes in the molecular landscape of these tumors, we compared molecular features including gene expression signatures, mutation prevalence and copy number alteration between three time points while adjusting for confounding effects of molecular subtype and tumor cellularity. We found that NAC induced dynamic changes in gene expression signatures associated with proliferation and immunomodulatory treatment response. We further validated the observed pattern of change in TILs through histopathology and digital imaging analyses. In pretreatment tumors, 116 genes were DE between patients with pCR vs. those with residual disease with significant enrichment in immune/inflammatory pathways. Further, pre-treatment TIL levels were found to be significantly associated with pCR, echoing previous reports in breast cancers that implicated anti-tumor immunity in mediating the efficacy of chemotherapies. Our analyses also revealed associations between NAC response and baseline genomic attributes such as genomic alterations that affect DNA damage repair pathways. Taken together, these results suggest that NAC induced a multitude of changes on the genomic landscape and immune microenvironment of breast cancers, some of which point to combination strategies with immunomodulatory therapies and therapies that target DNA damage repair.

Citation Format: Kan Z, Lal S, Ding Y, Lee JE, Lee S-H, Lee SK, Yu JH, Choi Y-l, Kim SW, Nam SJ, Kim J-Y, Ram S, Powell E, Ching K, Cho SY, Bonato V, Deng S, Park W-Y, Rejto P, Bienkowska J, Park Y-H. Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD5-08.

Eastern Canadian Colorectal Cancer Consensus Conference 2017

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference 2017 was held in St. John's, Newfoundland and Labrador, 28-30 September. Experts in radiation oncology, medical oncology, surgical oncology, and cancer genetics who are involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics in the management of gastric, rectal, and colon cancer, including ■ identification and management of hereditary gastric and colorectal cancer (crc);■ palliative systemic therapy for metastatic gastric cancer;■ optimum duration of preoperative radiation in rectal cancer-that is, short- compared with long-course radiation;■ management options for peritoneal carcinomatosis in crc;■ implications of tumour location for treatment and prognosis in crc; and■ new molecular markers in crc.

Advances in the systemic treatment of triple-negative breast cancer

Triple-negative breast cancer constitutes a heterogeneous group of malignancies that are often aggressive and associated with a poor prognosis. Molecular characterization, while not a standard of care, can further subtype triple-negative breast cancer and provide insight into prognostication and behaviour. Optimal chemotherapy regimens have yet to be established; however, there have been advances in the systemic treatment of triple-negative breast cancer in the neoadjuvant, adjuvant, and metastatic settings. In this review, we discuss evidence for the potential benefit of neoadjuvant platinum-based chemotherapy, adjuvant combination chemotherapy with weekly paclitaxel, and BRCA mutation-directed therapy in the metastatic setting. The role for adjuvant capecitabine in patients who do not achieve a pathologic complete response with neoadjuvant chemotherapy is reviewed. Future directions and data concerning novel targeted agents are reviewed, including the most recent data on parp [poly (adp-ribose) polymerase] inhibitors, antiandrogen agents, and immunotherapy.

Abstract P2-07-01: Integrative analyses of immunophenotypes and multi-omics profiles in breast cancers

The advent of immuno-oncology (IO) therapies has made it an imperative to characterize intratumoral immune microenvironment in addition to oncogenic alterations through molecular profiling of the tumor. To elucidate the baseline profiles of tumor infiltrating leukocytes (TILs) in breast cancer (BC) in the context of molecular subtypes and oncogenic alterations, we performed whole-exome sequencing (WES) and RNA-Seq of an Asian BC cohort (SMC) consisting of 178 treatment naïve primary tumors. A subset of 120 tumors was further analyzed by H&E and IHC using a panel of 8 TIL markers (CD45, CD4, CD8, CD163, PD1, PD-L1, IDO1 and FOXP3). Using expression signatures representing distinct immune cell types, we classified an expression compendium of 2,781 tumor samples, including SMC and multiple cancers from TCGA, into three immune subtypes with high, medium and low levels of TILs. Basal and HER2 subtypes show higher levels of TILs than Luminal subtypes, consistent with observed clinical responses to checkpoint blockade in clinical trials. Moreover, Asian BCs were significantly enriched in TIL-high subtype (35.3%) compared to the primarily Caucasian TCGA BC cohort (20.2%) while 50.6% of the highly immunogenic Lung adenocarcinoma was TIL-high. We then applied machine learning methods to detect and quantify TILs from H&E images of 120 SMC and 349 TCGA BC tumors. The expression signature analysis results were concordant with independently derived histology based TIL data. Taken together, our findings suggest that IO therapies may be more effective in HR negative BC subtypes and Asian BCs.

Leukocyte exclusion (LE), an immunophenotype where TILs concentrate at the tumor periphery, has been linked to worse prognosis and resistance to IO therapies. Visual assessment of whole tumor IHC images identified LE patterns in 25% of SMC cases. We observed differential distribution of LE by molecular subtype and evidence for selective exclusion of immune cell subsets. Covariate analyses with clinical and molecular data while controlling for subtype as a confounder identified significant associations with tumor proliferation index, percent tumor purity and TP53 mutations. LE is also significantly associated with expression signatures of chemokine signaling, macrophages, angiogenesis and hypoxia, indicating that marked distinctions exist in both tumor intrinsic and microenvironment characteristics between TIL excluded and TIL infiltrated tumors. To validate these findings, we independently identified LE for 200 cases of TCGA BCs based on patterns of TILs extracted from H&E images and saw significant concordance of covariate relationships identified between TCGA and SMC. Our study provided a rare comprehensive resource for studying tumor associated immunity in breast cancers by generating the integrated multi-omics and IO profiles for a large cohort of primary tumors. Comparative analyses revealed that TIL activities are highly variable across different intrinsic subtypes and geographic origins of BC, with potential implications for IO therapeutic application. Correlative analyses of immunophenotypes with molecular data further yielded insights into LE's role in immune escape and identified hallmark signatures for LE indicative of causal molecular mechanisms.

Citation Format: Kan Z, Powell E, Ram S, Ching K, Ding Y, Vizcarra P, Nichols T, Hardwick J, Lee S-H, Cho SY, Choi Y-L, Yu J-H, Park YH. Integrative analyses of immunophenotypes and multi-omics profiles in breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-07-01.

Abstract GS6-06: Identifying metastatic drivers in patient-derived xenograft models of triple negative breast cancer

Metastases are responsible for the vast majority of deaths due to breast cancer. Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high rates of metastasis and poor prognosis. We are employing patient derived xenograft (PDX) models of TNBC to identify drivers of metastasis. Tumor samples are obtained from the breast tumors of patients with TNBC and engrafted immediately into the humanized mammary fat pads of immune compromised mice. Lentiviral transduction was employed to express bioluminescent and fluorescent markers in two independent PDX models of TNBC. Using these models, we demonstrated that human breast tumors are capable of completing all stages of the metastatic cascade in mice, and metastatic lesions are observed in organs normally found in patients with metastatic breast cancer including lung, liver, bone, brain, and lymph nodes. Dynamic and reversible epithelial to mesenchymal transition (EMT) was observed as tumors metastasized to lung and were re-passaged to recipient mouse mammary glands. Lung metastases were isolated using bioluminescence imaging and lung metastasis gene expression signatures were generated. Metastasis signatures from two independent PDX models were compared to identify genes that were commonly de-regulated in lung metastases relative to corresponding mammary tumors. Comprehensive gain-of-function screens were then conducted in vivo to identify functional drivers of TNBC metastasis. Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) was identified as a metastatic driver in this screen. CEACAM5 mRNA and protein levels were elevated in lung metastases relative to corresponding mammary gland tumors in mice. In addition, we demonstrated that CEACAM5 expression was upregulated in the lung metastases of breast cancer patients, and its expression inversely correlated with patient survival. Our data indicate that the metastatic function of CEACAM5 is to promote growth of breast tumors in the lung by inducing MET (mesenchymal to epithelial transition).

Citation Format: Powell E, Shao J, Picon HM, Ge Z, Echeverria GV, Peoples M, Bristow C, Cai S, Tu Y, McCoy AM, Piwnica-Worms D, Draetta G, Edwards JR, Moulder SL, Symmans WF, Heffernan TP, Liang H, Piwnica-Worms H. Identifying metastatic drivers in patient-derived xenograft models of triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS6-06.

Abstract P1-05-15: Multi-omics and immuno-oncology profiling reveal distinct molecular signatures of young Asian breast cancers

Breast cancers (BC) in younger, premenopausal patients (YBC) tend to be more aggressive with worse prognosis, higher chance of relapse and poorer response to endocrine therapies compared to breast cancers in older patients. The proportion of YBC (age ≤ 40) among BC in East Asia is estimated to be 16-32%, significantly higher than the 7% reported in Western countries. To characterize the molecular bases of Asian YBC, we have performed whole-exome sequencing (WES) and whole-transcriptome sequencing (WTS) on tumor and matched normal samples from 134 Korean BC patients consisting of 74 YBC cases (age ≤ 40) and 60 OBC cases (age > 40). We then performed comparison analyses and integrative analyses with the TCGA BC cohort consisting of 1,116 tumors from primarily Caucasian patients, also grouped by age into YBC (age ≤ 40), IBC (40 < age ≤ 60) and OBC (age > 60).

Somatic mutation prevalence analysis identified 7 significantly mutated genes and the same top three genes – TP53, GATA3 and PIK3CA – were reported by the TCGA BC study. To identify differentially expressed (DE) genes and pathways in YBCs vs. OBCs, we performed logistic regression analyses while controlling for the confounding effects of tumor purity and stage. We were surprised to see a significant overlap in DE pathways between a comparison of adjacent normal tissues in younger vs. older TCGA cohorts and a comparison of YBC vs. OBC tumors, indicating that normal tissue compartment could contribute to observed differences between bulk tumors. To separately examine molecular signatures from tumor, stroma and normal compartments, we used non-negative matrix factorization (NMF) analyses to virtually dissect bulk tumor expression data and identified 14 factors including 3 factors associated with normal tissues, 1 factor associated with stroma and 1 factor associated with tumor infiltrating lymphocytes (TIL). Integrative analyses of tumor associated factors and DE pathways revealed that estrogen response, endocrine therapy resistance, and oxidative phosphorylation pathways are up-regulated in YBCs compared to OBCs while cell cycle and proliferation pathways are up-regulated in Asian OBCs. Interestingly, many immune and inflammation pathways correlated with the TIL factor were significantly upregulated in OBCs vs. YBCs. Using gene expression signatures representing distinct immune cell types, we classified our cohort into four subtypes of varying TIL activities and observed significant enrichment of the TIL-high subtype in OBCs compared to YBCs. These observations were confirmed by IHC analyses of four TIL markers (CD45, CD4, CD8 and CD163) in 120 tumors.

To our knowledge, this is the first large-scale multi-omics study of Asian breast cancer and would significantly contribute to the compendium of molecular data available for studying young breast cancers. The major landmarks in the molecular landscape looked similar across BCs of different ethnicities and ages, however, we have identified a number of distinguishing molecular characteristics associated with Asian YBC. The sources for some signatures were further traced to non-tumor intrinsic compartments, indicating that tumor microenvironment may play potentially important roles in driving the carcinogenesis of young breast cancers.

Citation Format: Kan Z, Ding Y, Cho S, Lee S-H, Powell E, Jung HH, Chung W, Deng S, Choi Y-l, Kim J, Park W-Y, Vizcarra P, Fernandez-Banet J, Nichols T, Ram S, Lee SK, Kim SW, Lee JE, Ching KA, Kim J-Y, Ahn JS, Im Y-H, Nam SJ, Park YH. Multi-omics and immuno-oncology profiling reveal distinct molecular signatures of young Asian breast cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-15.

Abstract P6-01-08: Identifying metastatic drivers in patient derived xenograft models of triple negative breast cancer

Metastases are responsible for the vast majority of deaths due to breast cancer. Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high rates of metastasis and poor response to chemotherapy. We are using patient derived xenograft (PDX) models of TNBC to identify drivers of TNBC metastasis. Using these models, we demonstrated that human breast tumors are capable of completing all stages of the metastatic cascade in mice, and metastatic lesions are observed in organs normally found in patients with metastatic breast cancer including lung, liver, bone, brain and lymph nodes. Lentiviral transduction was employed to express both bioluminescent and fluorescent proteins in three distinct PDX models of TNBC. In this way, metastatic lesions can be isolated using bioluminescent imaging and circulating tumor cells (CTCs) are isolated by flow cytometry. A lung metastasis gene expression signature was generated and comprehensive gain-of-function screens are being conducted in vivo to validate this signature and identify functional drivers of TNBC metastasis.

Citation Format: Powell E, Shao J, Tieu T, Peoples M, Bristow C, Manyam G, Cai S, Tu Y, Edwards JR, Heffernan TP, Piwnica-Worms D, Liang H, Piwnica-Worms H. Identifying metastatic drivers in patient derived xenograft models of triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-01-08.

Phosphorylation of serine 367 of FOXC2 by p38 regulates ZEB1 and breast cancer metastasis, without impacting primary tumor growth

Metastatic competence is contingent upon the aberrant activation of a latent embryonic program, known as the epithelial-mesenchymal transition (EMT), which bestows stem cell properties as well as migratory and invasive capabilities upon differentiated tumor cells. We recently identified the transcription factor FOXC2 as a downstream effector of multiple EMT programs, independent of the EMT-inducing stimulus, and as a key player linking EMT, stem cell traits and metastatic competence in breast cancer. As such, FOXC2 could serve as a potential therapeutic target to attenuate metastasis. However, as FOXC2 is a transcription factor, it is difficult to target by conventional means such as small-molecule inhibitors. Herein, we identify the serine/threonine-specific kinase p38 as a druggable upstream regulator of FOXC2 stability and function that elicits phosphorylation of FOXC2 at serine 367 (S367). Using an orthotopic syngeneic mouse tumor model, we make the striking observation that inhibition of p38-FOXC2 signaling selectively attenuates metastasis without impacting primary tumor growth. In this model, circulating tumor cell numbers are significantly reduced in mice treated with the p38 inhibitor SB203580, relative to vehicle-treated counterparts. Accordingly, genetic or pharmacological inhibition of p38 decreases FOXC2 protein levels, reverts the EMT phenotype and compromises stem cell attributes in vitro. We also identify the EMT-regulator ZEB1-known to directly repress E-cadherin/CDH1-as a downstream target of FOXC2, critically dependent on its activation by p38. Consistent with the notion that activation of the p38-FOXC2 signaling axis represents a critical juncture in the acquisition of metastatic competence, the phosphomimetic FOXC2(S367E) mutant is refractory to p38 inhibition both in vitro and in vivo, whereas the non-phosphorylatable FOXC2(S367A) mutant fails to elicit EMT and upregulate ZEB1. Collectively, our data demonstrate that FOXC2 regulates EMT, stem cell traits, ZEB1 expression and metastasis in a p38-dependent manner, and attest to the potential utility of p38 inhibitors as antimetastatic agents.

CCR5-Δ32 genotype does not improve predictive value of IL28B polymorphisms for treatment response in chronic HCV infection

IL28B polymorphisms strongly predict spontaneous and treatment-induced clearance of hepatitis C virus (HCV) infection. A recent study proposed a 32-base pair deletion in the CC-chemokine receptor 5 (CCR5) gene (CCR5-Δ32) interacting with the IL28B polymorphisms to influence spontaneous HCV clearance. The aim of this study was to clarify the role of CCR5-Δ32 in treatment-induced clearance of chronic hepatitis C (CHC). A cross-sectional cohort of 813 Caucasian patients with CHC genotype 1 (365 responders and 448 non-responders) who had received standard of care dual therapy with interferon (IFN)-α and ribavirin (RBV) was genotyped for the CCR5-Δ32 and IL28B polymorphisms to examine their interaction with respect to treatment response. CCR5-Δ32 did not influence treatment-induced recovery to IFN-α/RBV in CHC, and did not improve prediction of sustained virological response in the context of the IL28B polymorphisms in a multivariate model. CCR5-Δ32 homozygotes were significantly more frequent in those with CHC than healthy controls in the European cohorts (2.9% vs 0.4%, P<0.0001), but not in Australians of European ancestry. In conclusion, CCR5-Δ32 does not influence treatment response in the context of IL28B polymorphisms. Although CCR5-Δ32 may affect viral clearance within closely controlled geographical and genetic environments, we found no effect in larger cohorts treated with dual therapy.

Biomarker analysis in a phase III study of pemetrexed-carboplatin versus etoposide-carboplatin in chemonaive patients with extensive-stage small-cell lung cancer

BACKGROUND

Clinical results of a randomized phase III trial comparing pemetrexed-carboplatin (PC) with etoposide-carboplatin (EC) in chemonaive patients with extensive-stage disease small-cell lung cancer (ED-SCLC) resulted in trial closure for futility; biomarker analyses using immunohistochemistry (IHC) and single-nucleotide polymorphisms (SNPs) are described herein.

PATIENTS AND METHODS

Thymidylate synthase (TS), excision repair cross complementing-1 (ERCC1), glycinamide ribonucleotide formyltransferase (GARFT), and folylpolyglutamate synthetase (FPGS) were investigated using IHC (n=395). SNPs were genotyped for TS, FPGS, γ-glutamyl hydrolase (GGH), methylenetetrahydrofolate reductase (MTHFR), folate receptor-α FR-α, and solute carrier 19A1 (SLC19A1; n=611).

RESULTS

None of the IHC biomarkers (folate pathway or ERCC1) were found to be predictive or prognostic in this setting. rs2838952 (adjacent to SLC19A1) had significant treatment-independent association with overall survival (OS; hazard ratio 0.590, P=0.01). Nine GGH-associated SNPs interacted with rs3788205 (SLC19A1) for OS on the PC arm. rs12379987 (FPGS) interacted with treatment for OS (interaction P=0.036).

CONCLUSION

Potential ERCC1 and folate pathway IHC biomarkers failed to predict outcome in either study arm in ED-SCLC. SNPs in regions including FPGS and SLC19A1 and interacting SNPs in GGH and SLC19A1 were associated with differences in OS; however, none of these SNPs predicted for greater survival with PC over EC.

Pharmacogenomic analysis from a phase III study of pemetrexed plus carboplatin (PC) versus etoposide plus carboplatin (EC) in chemonaive patients (pts) with extensive-stage disease small cell lung cancer (ED-SCLC)

8030

Background: We have reported results of a randomized phase III trial in chemonaive patients with ED-SCLC comparing PC to EC. Study enrollment was closed for futility but pharmacogenomic endpoints were not reported. Here we report the results of immunohistochemistry (IHC) analysis from tumor tissues and single nucleotide polymorphism (SNP) analysis of selected genes implicated in pemetrexed, carboplatin, or etoposide activity. Methods: Proteins studied by validated IHC on Benchmark XT were thymidylate synthase (TS), excision repair cross complementing-1 (ERCC1), glycinamide ribonucleotide formyl transferase (GARFT), and folylpolyglutamate synthetase (FPGS). SNP data from whole blood were genotyped by massArray mass spectrometry from 611 samples. One hundred fifty-eight SNPs were genotyped for TS, FPGS, γ-glutamyl hydrolase (GGH), methylene tetrahydrofolate reductase (MTHFR), folate receptor- α (FR-α), solute carrier 19A1 (SLC19A1) and adjacent regions. Allele frequency and Hardy-Weinberg equilibrium were calculated for each SNP. Results: Of 408 tissue samples (from 908 enrolled pts) available for IHC, 336 samples were assayed for > 1 assay target. The IHC analyses showed improved OS in the EC arm relative to the PC arm for patients with low TSnuclear (12.9 vs 7.5 month, p < 0.001, interaction p value = 0.017). There was no differential treatment effect within the PC arm for low vs. high TS. High vs low ERCC1 levels did not predict outcome following C exposure. GARFT was not associated with outcome by treatment. SNP rs2838952 (adjacent to SLC19A1) was significant for improved OS (HR = 0.590, p = 0.01) in both study arms. SNP rs12379987 (FPGS) was significantly associated with treatment for OS (interaction p value = 0.036). Exploratory analyses found associations between additional SNPs and PFS within and across treatments. Conclusions: Pharmacogenomic analyses of tumor samples show that low TSnuclear expression correlates with OS in the EC arm. Two germline SNPs in regions including FPGS and SLC19A1 were associated with better OS. Further analysis of these pharmacogenomic results is ongoing.

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Pharmacodynamic (PD) evaluation of LY2181308 in patients with metastatic malignancies

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Background: Survivin is an inhibitor of apoptosis and its overexpression in cancer has been associated with poor survival. LY2181308 (LY), a novel modified antisense oligonucleotide is a specific inhibitor of survivin. The safety and PK profile of LY from this first-in-human study was presented at ASCO 2008. We now present the PD data from this trial. Methods: Patients with advanced or metastatic malignancies who had failed previous anti-tumor treatments were enrolled. Three consecutive IV loading doses given over 3 hours were followed by weekly maintenance doses. Pre- and post-dosing biopsies were mandated to test for evidence of modification of the target at doses where a PD effect was expected. Biopsies were taken 48 hours after the last loading dose by CT-guided fine needle biopsy. Tumor tissue was paraffin-embedded for immunohistochemistry (IHC) and survivin gene expression. Given the finite amount of biopsy material, the quantification of survivin protein was prioritized. In addition, at one site, pre- and post-dosing endobronchial sampling was conducted in NSCLC patients, with the aim of quantifying levels of native survivin protein, and assessing changes in cell cycle profile in freshly isolated tumor cells using FACS analysis. Results: Out of the 34 patients enrolled, 22 patients had a pre- and posttreatment biopsy. Results from IHC indicated that survivin expression was reduced in the nucleus and cytoplasm in 11/17 and 5/14 evaluable pairs, respectively. LY was detected in neoplastic and non-neoplastic tumor cells in 5/16 and 15/16 evaluable pairs respectively. Gene expression analysis indicated a reduction in survivin expression by 20% to 50% in 11/15 evaluable pairs. Analysis of the fresh tumor material from endobronchial sampling revealed that 2 out of 3 patients with NSCLC had a near-complete elimination of survivin-positive cells accompanied by an increase in the fraction of cells with a sub-G1 DNA content, consistent with cell death. Conclusions: In this study, we were able to demonstrate the presence of the ASO in tumor tissue and confirm a reduction in survivin protein and gene expression. These findings demonstrate the proof of principle of antitumor activity of LY and provide the rationale for phase II studies.

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