Identifying canonical and replicable multi-scale intrinsic connectivity networks in 100k+ resting-state fMRI datasets

Despite the known benefits of data-driven approaches, the lack of approaches for identifying functional neuroimaging patterns that capture both individual variations and inter-subject correspondence limits the clinical utility of rsfMRI and its application to single-subject analyses. Here, using rsfMRI data from over 100k individuals across private and public datasets, we identify replicable multi-spatial-scale canonical intrinsic connectivity network (ICN) templates via the use of multi-model-order independent component analysis (ICA). We also study the feasibility of estimating subject-specific ICNs via spatially constrained ICA. The results show that the subject-level ICN estimations vary as a function of the ICN itself, the data length, and the spatial resolution. In general, large-scale ICNs require less data to achieve specific levels of (within- and between-subject) spatial similarity with their templates. Importantly, increasing data length can reduce an ICN's subject-level specificity, suggesting longer scans may not always be desirable. We also find a positive linear relationship between data length and spatial smoothness (possibly due to averaging over intrinsic dynamics), suggesting studies examining optimized data length should consider spatial smoothness. Finally, consistency in spatial similarity between ICNs estimated using the full data and subsets across different data lengths suggests lower within-subject spatial similarity in shorter data is not wholly defined by lower reliability in ICN estimates, but may be an indication of meaningful brain dynamics which average out as data length increases.

A method for estimating and characterizing explicitly nonlinear dynamic functional network connectivity in resting-state fMRI data

The past 10 years have seen an explosion of approaches that focus on the study of time-resolved change in functional connectivity (FC). FC characterization among networks at a whole-brain level is frequently termed functional network connectivity (FNC). Time-resolved or dynamic functional network connectivity (dFNC) focuses on the estimation of transient, recurring, whole-brain patterns of FNC. While most approaches in this area have attempted to capture dynamic linear correlation, we are particularly interested in whether explicitly nonlinear relationships, above and beyond linear, are present and contain unique information. This study thus proposes an approach to assess explicitly nonlinear dynamic functional network connectivity (EN dFNC) derived from the relationship among independent component analysis time courses. Linear relationships were removed at each time point to evaluate, typically ignored, explicitly nonlinear dFNC using normalized mutual information (NMI). Simulations showed the proposed method estimated explicitly nonlinearity over time, even within relatively short windows of data. We then, applied our approach on 151 schizophrenia patients, and 163 healthy controls fMRI data and found three unique, highly structured, mostly long-range, functional states that also showed significant group differences. In particular, explicitly nonlinear relationships tend to be more widespread than linear ones. Results also highlighted a state with long range connections to the visual domain, which were significantly reduced in schizophrenia. Overall, this work suggests that quantifying EN dFNC may provide a complementary and potentially valuable tool for studying brain function by exposing relevant variation that is typically ignored.

Moving beyond the 'CAP' of the Iceberg: Intrinsic connectivity networks in fMRI are continuously engaging and overlapping

Resting-state functional magnetic resonance imaging is currently the mainstay of functional neuroimaging and has allowed researchers to identify intrinsic connectivity networks (aka functional networks) at different spatial scales. However, little is known about the temporal profiles of these networks and whether it is best to model them as continuous phenomena in both space and time or, rather, as a set of temporally discrete events. Both categories have been supported by series of studies with promising findings. However, a critical question is whether focusing only on time points presumed to contain isolated neural events and disregarding the rest of the data is missing important information, potentially leading to misleading conclusions. In this work, we argue that brain networks identified within the spontaneous blood oxygenation level-dependent (BOLD) signal are not limited to temporally sparse burst moments and that these event present time points (EPTs) contain valuable but incomplete information about the underlying functional patterns. We focus on the default mode and show evidence that is consistent with its continuous presence in the BOLD signal, including during the event absent time points (EATs), i.e., time points that exhibit minimum activity and are the least likely to contain an event. Moreover, our findings suggest that EPTs may not contain all the available information about their corresponding networks. We observe distinct default mode connectivity patterns obtained from all time points (AllTPs), EPTs, and EATs. We show evidence of robust relationships with schizophrenia symptoms that are both common and unique to each of the sets of time points (AllTPs, EPTs, EATs), likely related to transient patterns of connectivity. Together, these findings indicate the importance of leveraging the full temporal data in functional studies, including those using event-detection approaches.

Resting-state thalamic dysconnectivity in schizophrenia and relationships with symptoms

BACKGROUND

Schizophrenia (SZ) is a severe neuropsychiatric disorder associated with disrupted connectivity within the thalamic-cortico-cerebellar network. Resting-state functional connectivity studies have reported thalamic hypoconnectivity with the cerebellum and prefrontal cortex as well as thalamic hyperconnectivity with sensory cortical regions in SZ patients compared with healthy comparison participants (HCs). However, fundamental questions remain regarding the clinical significance of these connectivity abnormalities.

METHOD

Resting state seed-based functional connectivity was used to investigate thalamus to whole brain connectivity using multi-site data including 183 SZ patients and 178 matched HCs. Statistical significance was based on a voxel-level FWE-corrected height threshold of p < 0.001. The relationships between positive and negative symptoms of SZ and regions of the brain demonstrating group differences in thalamic connectivity were examined.

RESULTS

HC and SZ participants both demonstrated widespread positive connectivity between the thalamus and cortical regions. Compared with HCs, SZ patients had reduced thalamic connectivity with bilateral cerebellum and anterior cingulate cortex. In contrast, SZ patients had greater thalamic connectivity with multiple sensory-motor regions, including bilateral pre- and post-central gyrus, middle/inferior occipital gyrus, and middle/superior temporal gyrus. Thalamus to middle temporal gyrus connectivity was positively correlated with hallucinations and delusions, while thalamus to cerebellar connectivity was negatively correlated with delusions and bizarre behavior.

CONCLUSIONS

Thalamic hyperconnectivity with sensory regions and hypoconnectivity with cerebellar regions in combination with their relationship to clinical features of SZ suggest that thalamic dysconnectivity may be a core neurobiological feature of SZ that underpins positive symptoms.

Decreased hemispheric connectivity and decreased intra- and inter- hemisphere asymmetry of resting state functional network connectivity in schizophrenia

Many studies have shown that schizophrenia patients have aberrant functional network connectivity (FNC) among brain regions, suggesting schizophrenia manifests with significantly diminished (in majority of the cases) connectivity. Schizophrenia is also associated with a lack of hemispheric lateralization. Hoptman et al. (2012) reported lower inter-hemispheric connectivity in schizophrenia patients compared to controls using voxel-mirrored homotopic connectivity. In this study, we merge these two points of views together using a group independent component analysis (gICA)-based approach to generate hemisphere-specific timecourses and calculate intra-hemisphere and inter-hemisphere FNC on a resting state fMRI dataset consisting of age- and gender-balanced 151 schizophrenia patients and 163 healthy controls. We analyzed the group differences between patients and healthy controls in each type of FNC measures along with age and gender effects. The results reveal that FNC in schizophrenia patients shows less hemispheric asymmetry compared to that of the healthy controls. We also found a decrease in connectivity in all FNC types such as intra-left (L_FNC), intra-right (R_FNC) and inter-hemisphere (Inter_FNC) in the schizophrenia patients relative to healthy controls, but general patterns of connectivity were preserved in patients. Analyses of age and gender effects yielded results similar to those reported in whole brain FNC studies.

Widespread white matter microstructural differences in schizophrenia across 4322 individuals: results from the ENIGMA Schizophrenia DTI Working Group

The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.

Abstract PD8-06: Multiple-gene panel testing for hereditary cancer risk reveals a racial/ethnic disparity in genetic information

Background: Multiple-gene germline sequencing panels are increasingly used to evaluate hereditary cancer risk. However, little is known about the results of such testing in racially/ethnically diverse populations.

Methods: Patients who presented to the Stanford University Clinical Cancer Genetics Program from 1/1/2013 to 12/31/2015 and underwent multiple-gene panel testing were included in the cohort (N=1,483). Information on demographics, personal and family history of cancer, and tumor characteristics was collected at time of clinic visit. Odds ratios and 95% confidence intervals were calculated for mutation status by different patient and tumor characteristics, including race/ethnicity. Results were compared using the chi-square test and considered significant if P&lt;0.05 after Bonferroni correction for multiple hypothesis testing.

Results: Most patients (92%) were female. Patients were 51% Non-Hispanic White (NHW), 19% Asian, 14% Hispanic, 10% Ashkenazi Jewish, 5% other, and 1% unknown. Eighty-nine genes were tested in at least one patient; panel size ranged from six to 62 genes, with a median of 25 genes. The frequency of pathogenic or likely pathogenic mutations was 15% for any panel-tested gene, 5.5% for BRCA1/2, and 5.3% for other breast cancer-associated genes; mutation frequencies were similar between NHW, Asian, Hispanic, and Ashkenazi Jewish patients. Variables significantly associated with the carriage of a pathogenic BRCA1/2 mutation included personal or family history of ovarian cancer and personal history of triple-negative breast cancer (TNBC). No variable was significantly associated with the presence of a pathogenic mutation in the other breast cancer genes. The odds ratios for carrying a BRCA1/2 mutation with personal history of ovarian cancer (4.1 [2.2-7.3]), family history of ovarian cancer (3.1 [1.9-4.9]), and TNBC relative to other breast cancer subtypes (6.0 [2.9-12.4]) did not differ significantly between NHWs and non-Whites. The frequency of variants of unknown significance (VUS) in any panel-tested gene was higher in non-Whites (36%) than in NHWs (27%) (P=2E-4), with the highest odds ratio relative to NHWs among Asians (2.0 [1.5-2.7], vs 1.3 [0.9-1.7] among Hispanics and 1.2 [0.8-1.7] among Ashkenazi Jews). The odds ratio of finding a VUS for non-Whites compared to NHWs was similar for any panel (1.5 [1.2-1.9]), for BRCA1/2 (1.3 [0.8-2.3]), and for other known breast cancer-associated genes (1.5 [1.1-1.9]).

Conclusions: In this diverse cohort tested for hereditary cancer risk with multiple-gene panels, frequencies of pathogenic mutations were similar between racial/ethnic groups. By contrast, frequencies of VUS were significantly higher among non-Whites compared to NHWs. This higher VUS rate renders multiple-gene panel testing less informative for non-White patients. Efforts toward VUS re-classification, particular among non-Whites, are urgently needed to address this genetic information disparity.

Citation Format: Caswell-Jin* JL, Gupta* T, Hall E, Petrovchich IM, Mills MA, Kingham KE, Koff R, Chun NM, Levonian P, Lebensohn AP, Ford JM, Kurian AW. Multiple-gene panel testing for hereditary cancer risk reveals a racial/ethnic disparity in genetic information [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 PD8-06.

Abstract OT2-01-16: Evaluating targets in localized and advanced breast cancer by sequencing tumor DNA at diagnosis and after progression (ELSA)

Background: Breast cancer therapy exerts strong selection pressure that shapes the evolution of the cancer. Despite the importance of these treatment-induced changes for the success of subsequent therapy, tumors have been rarely resampled and reanalyzed, with the exception of hematopoietic malignancies. The availability of next generation sequencing (NGS) has made it possible to get highly accurate sequencing that allows detection of mutations and other genetic alterations not only from tumor biopsies but also from circulating DNA fragments.

Objectives: To demonstrate the evolution of the molecular genotype of breast cancer as patients are diagnosed, treated, and upon relapse. This will be accomplished by NGS of the tumor at key time points during the natural history of the disease. The molecular profile at diagnosis will be compared to the profile at recurrence/metastasis and after treatment for metastasis. Correlation with treatment response and adverse clinical outcomes will be determined.

Study Design and Eligibility: We have initiated a prospective observational study in patients with a new diagnosis of Stage I, II and III breast cancer and an ECOG performance status of 0, 1 or 2. Patients should be medically suitable to give informed consent for a biopsy or surgical procedure. Enrollment will occur at community-based cancer centers with inclusion of under-served populations.

Methodology: Tumor samples and blood samples are collected at - initial diagnosis/definitive surgery, first local relapse, diagnosis of metastasis and at first progression after treatment for metastatic disease. Molecular genotype will be analyzed from the tumor samples and from the circulating tumor DNA (ctDNA) in blood samples at each of the time points. ctDNA will also be assessed on blood samples collected annually till the diagnosis of metastasis and then more frequently at 3-6 month intervals in patients with high risk breast cancer.

Statistical Design/Size of study sample: Formal sample size calculations are not required for this study as by design, it is based on participation. There is no discrete endpoint that can be powered by sample size calculation for this study. We are screening all patients who are diagnosed with breast cancer at our facility. The proposed enrollment is 300 patients per year. The study launched in December 2015 at 4 of our community-based cancer centers. Current enrollments is 46 patients.

Citation Format: Gaba AG, Powell SF, Jennifer WL, Megan LL, Chun-Hung C, Lora BJ, Ford JM. Evaluating targets in localized and advanced breast cancer by sequencing tumor DNA at diagnosis and after progression (ELSA) [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 OT2-01-16.

Abstract PD7-01: Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer

Background: Emerging evidence demonstrates the effectiveness of targeted gene sequencing panels as a practical method for the diagnosis of inherited susceptibility to breast cancer. Sequencing of multiple high and moderate risk genes simultaneously accelerates the discovery of deleterious mutations (DM) or variants of unknown significance (VUS). However, a consequence of Multiplex Gene Panel (MGP) testing is the discovery of unexpected DMs in high or moderate risk genes other than BRCA1 or BRCA2 (BRCA1/2). The overall clinical utility and incremental gain of information conferred by MGP testing in hereditary cancer risk assessment is still unknown.

Methods: We are conducting a multicenter prospective cohort study of patients undergoing cancer-risk assessment using a 25 gene sequencing panel, which includes APC, ATM, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, SMAD4, STK11, and TP53. Patients were recruited from August 2014 to June 2015 at three medical centers. Patients are enrolled if they meet standard criteria for genetic testing or are predicted to have a ≥ 2.5% probability of inherited susceptibility to cancer calculated by validated risk prediction models. We present a planned interim analysis after enrolling 500 of 2000 total participants.

Results: HCP testing was performed for 332 patients referred for clinical suspicion of hereditary breast and ovarian cancer (HBOC). In this cohort, 96.7% were female (n=321) and the mean age was 50 years (standard deviation, SD=12.2); race/ethnicity was 43.1% Hispanic (n=143), 37% Non-Hispanic White (n=123), 4.2% Black (n=14), 10.5% Asian (n=35), and 1.8% other (n=6). Among this cohort, 37 tested positive for one deleterious mutation (DM) (11.1%: 95% confidence interval (CI), 8.2% to 15%) and 118 patients carried at least one variant of uncertain significance (VUS) (35.5%: 95% CI, 30.6% to 69%). Excluding BRCA1 or BRCA2, 14 patients (4.3%: 95% CI, 2.6% to 7.2%) have a DM in ATM (n=3), CHEK2 (n=2), MSH6 (n=1), MUTYH (n=3), PALB2 (n=1), PMS2 (n=1), RAD51C (n=2), and TP53 (n=2). In a patient with an unexpected PMS2 mutation, enhanced cancer surveillance based on Lynch Syndrome guidelines was recommended. Among 160 patients with a history of invasive breast cancer or breast DCIS, 19 patients carried a DM (11.8 %: 95 CI, 7.7% to 17.8%).

Conclusion: In this multicenter prospective cohort study among a diverse group of participants undergoing 25-gene MGP testing, 11.1% of participants tested positive for a DM. Among participants testing negative for BRCA1 and BRCA2, MGP testing identified DMs in 4.3% of participants prompting clinically appropriate risk reduction recommendations and enhanced cancer surveillance. Ongoing recruitment and long-term follow-up are in progress.

Citation Format: Idos GE, Kurian AW, Mcdonnell KJ, Ricker CN, Sturgeon DY, Culver JO, Lowstuter K, Hartman A-R, Allen B, Teeter C-R, Kingham KE, Koff R, Lebensohn A, Chun NM, Mills MA, Petrovchich I, Hong C, Ladabaum U, Ford JM, Gruber SB. Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD7-01.

Abstract OT2-05-04: The Talazoparib Beyond BRCA (TBB) trial: A phase II clinical trial of talazoparib (BMN 673) in BRCA1 and BRCA2 wild-type patients with (i) advanced triple-negative breast cancer (TNBC) and homologous recombination deficiency (HRD) as assessed by myriad genetics HRD assay, and (ii) advanced HER2-negative breast cancer (BC) with either a germline or somatic mutation in homologous recombination (HR) pathway genes

Background: Poly-ADP-ribose polymerase (PARP) inhibition induces synthetic lethality in tumor cells bearing deleterious mutations in the genes BRCA1/2. Talazoparib (BMN 673) is a novel, dual-mechanism PARP inhibitor that potently inhibits the PARP enzyme and effectively traps PARP on DNA. Talazoparib has shown promising single-agent anti-tumor efficacy in several BRCA1/2 mutation-associated advanced cancers. The efficacy of PARP inhibition in BRCA1/2 wild-type TNBC with HR defects and in breast tumors with mutations in other non-BRCA1/2 HR pathway genes is currently unknown.

Trial Design & Eligibility: This Phase 2 trial (TBB) explores the activity of single agent talazoparib in BRCA1/2 wild-type BC patients using an optimal Simon two-stage design. Eligible subjects will be assigned to one of two parallel cohorts: 1) Cohort A: Subjects (n=29) with advanced TNBC with underlying HR defects as assessed by the HRD assay and, 2) Cohort B: Subjects (n=29) with advanced HER2-negative BC with a somatic or germline deleterious mutation in a non-BRCA1/2 HR pathway gene. Gene mutations of interest are: PTEN, PALB2, CHEK2, ATM, NBN, BARD1, BRIP1, RAD50, RAD51C, RAD51D, MRE11, ATR, Fanconi anemia complementation group of genes (FANCA, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCL). Other key eligibility criteria include metastatic disease treated with at least one prior line of chemotherapy, no deleterious BRCA1/2 mutation, and no prior platinum exposure. In cohort A, TNBC patients must have a HRD score of ≥ 42. Eligible patients will receive oral talazoparib (1.0 mg/day, 28-day cycles) until disease progression or unacceptable toxicity.

Endpoints & Statistical Plan: The primary endpoint is objective response rate (ORR). Secondary endpoints include clinical benefit rate (CBR), progression free survival (PFS), and safety. In this study, we have set a null hypothesis of ≤ 5% objective response rate and alternative response rate of ≥ 20% based on RECIST 1.1. Interim analysis will be performed after accrual of 10 patients in each cohort. If at least one out of the 10 patients responds, then we will accrue 19 additional patients for a total of 29 patients in each cohort. At least four patients have to respond out of the 29 patients in each cohort to declare statistical significance at a one-sided 5% level with 80% power or better.

This trial is enrolling patients at Stanford University in California (NCT 02401347).

Citation Format: Afghahi A, Chang P-J, Ford JM, Telli ML. The Talazoparib Beyond BRCA (TBB) trial: A phase II clinical trial of talazoparib (BMN 673) in BRCA1 and BRCA2 wild-type patients with (i) advanced triple-negative breast cancer (TNBC) and homologous recombination deficiency (HRD) as assessed by myriad genetics HRD assay, and (ii) advanced HER2-negative breast cancer (BC) with either a germline or somatic mutation in homologous recombination (HR) pathway genes. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-05-04.

Abstract P2-09-07: The patient experience in a prospective trial of multiplex gene panel testing for cancer risk

Background: Multiplex gene sequencing panels (MGP) are increasingly used for assessment of hereditary breast cancer risk. Compared to testing for BRCA1 and BRCA2 (BRCA1/2) only, testing more genes increases the likelihood of identifying a deleterious mutation (DM) and/or a variant of uncertain significance (VUS), which might cause distress, uncertainty or regret about testing. Little is known about the patient experience of MGP testing.

Methods: We conducted a prospective study of MGP testing, using a panel of 25 genes: APC, ATM, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, SMAD4, STK11, and TP53. Participants were enrolled at three medical centers and were eligible if they met standard genetic testing guidelines or if they had a ≥2.5% probability of a DM in any gene on the panel, as calculated by predictive models (e.g. IBIS, Penn II, MMRPro). Participants were surveyed about their experiences with MGP testing including distress and uncertainty at baseline (before test results disclosure) and three months later. The 25-item Multidimensional Impact of Cancer Risk Assessment (MICRA) scale measured distress, uncertainty and positive experiences at three months after testing. We present a planned interim analysis after enrolling 500 of 2000 total participants.

Results: Of 500 participants, 332 (66%) were referred for suspicion of hereditary breast/ovarian cancer syndrome. Of these 332, 97% were female, 79% were white, 43% were Hispanic and 33% were Spanish-speaking only; for 25%, high school was their highest level of education. A total of 48% had breast cancer, 5% had ovarian cancer, and 7% had another cancer: 11% had a DM and 35% had VUS in one or more genes. At study entry most participants thought about cancer rarely or not at all (69%, 95% confidence interval (CI) 58%-77%), and few (7%, CI 3%-14%) had thoughts of cancer that affected their daily lives; results were unchanged three months later, after genetic results disclosure (Chi-squared test, p-value &gt;0.1). MICRA scores at three months were low for distress (mean score 2 out of a possible 30) and uncertainty (mean score 7 out of 45), and high for positive testing experiences (mean score 9 out of 15). Most (82%, CI 72%-88%) participants wanted to know all of their MGP results even if the clinical relevance was not fully understood, and most (87%, CI 79%-93%) never regretted learning their MGP results.

Conclusions: Among diverse participants of a prospective, multi-center MGP testing trial, cancer- and genetic testing-related distress were low at entry and remained low three months later. These results provide no evidence for an increase in distress or uncertainty after MGP. Longer-term follow-up in a larger cohort is underway.

Citation Format: Kurian AW, Idos G, McDonnell K, Ricker C, Sturgeon D, Culver J, Lowstuter K, Hartman A-R, Allen B, Rowe-Teeter C, Kingham KE, Koff RB, Lebensohn A, Chun NM, Petrovchich IM, Mills MA, Hong C, Ladabaum U, Ford JM, Gruber SB. The patient experience in a prospective trial of multiplex gene panel testing for cancer risk. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-07.

Abstract P2-09-20: Evaluation on the mutation screening by next-generation sequencing in hereditary breast and ovarian cancer: Implementation of recurrent mutation panel

Background: Hereditary disposition accounts for 10-15% in breast cancers and 20-25% in ovarian cancers, in which 5-10% of women have genomic alteration in breast cancer predisposition genes, BRCA1 and BRCA2, while the rest are likely due to less penetrant genes. In specific ethnicities such as Ashkenazi Jewish, three founder mutations have been identified which covers 95 % of all the BRCA mutations identified in this race. These genes are screened prior to the gold standard Sanger Sequencing in order to reduce cost. Sanger Sequencing, however, still has the limitation on the necessity of laborious processing and results interpretation. Moreover, it limits the number of genes that can be analyzed in one setting. With the use of next-generation sequencing (NGS), identification of hereditary breast and ovarian cancer (HBOC) syndrome associated genes, other than BRCA, can be sequenced at the same time but yet a faster turnover time. This allows more timely targeted risk-reducing strategies and interventions to be implemented for mutation positive carriers and their family members.

Methods: In this study cohort, 948 high-risk breast/ovarian patients who met the HBOC selection criteria were recruited for mutation screening by our NGS pipeline. With the inclusion of 90 Sanger-validated known mutation cases, the performance of the NGS pipeline were proven to be comparable to Sanger sequencing. PTEN and TP53, other than BRCA1 and BRCA2, a 4 gene sequencing panel were included in the mutation screening for high-risk patients.

Results: The prevalence of BRCA1/BRCA2 germline mutations was 7.28% in our Chinese cohort and 47.8% of the mutation were recurrent mutations. Based on this finding, we further adopted a new workflow by screening the recurrent mutations including founder mutations from Chinese cohort prior to NGS for those who tested negative. In a testing cohort of 343 cases, the recurrent mutation pick-up rate was 3.5%, this implicated a more cost-effective method for mutation screening in the clinical setting. Moreover, the frequencies of PTEN and TP53 were 0.21% and 0.53% respectively in our population with breast and ovarian cases.

Conclusion: Taken together, our data demonstrated a strategic upfront screening for recurrent mutations in Chinese population which is highly applicable in most of the diagnostic laboratories. Multi-gene sequencing using the NGS technology will be the upcoming strategies for mutation screening for HBOC patients.

Citation Format: Kwong A, Shin VY, Au CH, Law FB, Ho DN, Ip BK, Wong AT, Lau SS, To RM, Choy G, Ford JM, Ma ES, Chan TL. Evaluation on the mutation screening by next-generation sequencing in hereditary breast and ovarian cancer: Implementation of recurrent mutation panel. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-20.

Oxytocin administration selectively improves olfactory detection thresholds for lyral in patients with schizophrenia

BACKGROUND

Olfaction plays an important role in mammalian social behavior. Olfactory deficits are common in schizophrenia and correlate with negative symptoms and low social drive. Despite their prominence and possible clinical relevance, little is understood about the pathological mechanisms underlying olfactory deficits in schizophrenia and there are currently no effective treatments for these deficits. The prosocial neuropeptide oxytocin may affect the olfactory system when administered intranasally to humans and there is growing interest in its therapeutic potential in schizophrenia.

METHODS

To examine this model, we administered 40IU of oxytocin and placebo intranasally to 31 patients with a schizophrenia spectrum illness and 34 age-matched healthy control participants in a randomized, double-blind, placebo-controlled, cross-over study. On each test day, participants completed an olfactory detection threshold test for two different odors: (1) lyral, a synthetic fragrance compound for which patients with schizophrenia have specific olfactory detection threshold deficits, possibly related to decreased cyclic adenosine 3',5'-monophosphate (cAMP) signaling; and (2) anise, a compound for which olfactory detection thresholds change with menstrual cycle phase in women.

RESULTS

On the placebo test day, patients with schizophrenia did not significantly differ from healthy controls in detection of either odor. We found that oxytocin administration significantly and selectively improved olfactory detection thresholds for lyral but not for anise in patients with schizophrenia. In contrast, oxytocin had no effect on detection of either odor in healthy controls.

DISCUSSION

Our data indicate that oxytocin administration may ameliorate olfactory deficits in schizophrenia and suggest the effects of intranasal oxytocin may extend to influencing the olfactory system. Given that oxytocin has been found to increase cAMP signaling in vitro a possible mechanism for these effects is discussed.

Dynamic functional connectivity analysis reveals transient states of dysconnectivity in schizophrenia

Schizophrenia is a psychotic disorder characterized by functional dysconnectivity or abnormal integration between distant brain regions. Recent functional imaging studies have implicated large-scale thalamo-cortical connectivity as being disrupted in patients. However, observed connectivity differences in schizophrenia have been inconsistent between studies, with reports of hyperconnectivity and hypoconnectivity between the same brain regions. Using resting state eyes-closed functional imaging and independent component analysis on a multi-site data that included 151 schizophrenia patients and 163 age- and gender matched healthy controls, we decomposed the functional brain data into 100 components and identified 47 as functionally relevant intrinsic connectivity networks. We subsequently evaluated group differences in functional network connectivity, both in a static sense, computed as the pairwise Pearson correlations between the full network time courses (5.4 minutes in length), and a dynamic sense, computed using sliding windows (44 s in length) and k-means clustering to characterize five discrete functional connectivity states. Static connectivity analysis revealed that compared to healthy controls, patients show significantly stronger connectivity, i.e., hyperconnectivity, between the thalamus and sensory networks (auditory, motor and visual), as well as reduced connectivity (hypoconnectivity) between sensory networks from all modalities. Dynamic analysis suggests that (1), on average, schizophrenia patients spend much less time than healthy controls in states typified by strong, large-scale connectivity, and (2), that abnormal connectivity patterns are more pronounced during these connectivity states. In particular, states exhibiting cortical–subcortical antagonism (anti-correlations) and strong positive connectivity between sensory networks are those that show the group differences of thalamic hyperconnectivity and sensory hypoconnectivity. Group differences are weak or absent during other connectivity states. Dynamic analysis also revealed hypoconnectivity between the putamen and sensory networks during the same states of thalamic hyperconnectivity; notably, this finding cannot be observed in the static connectivity analysis. Finally, in post-hoc analyses we observed that the relationships between sub-cortical low frequency power and connectivity with sensory networks is altered in patients, suggesting different functional interactions between sub-cortical nuclei and sensorimotor cortex during specific connectivity states. While important differences between patients with schizophrenia and healthy controls have been identified, one should interpret the results with caution given the history of medication in patients. Taken together, our results support and expand current knowledge regarding dysconnectivity in schizophrenia, and strongly advocate the use of dynamic analyses to better account for and understand functional connectivity differences.

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Studied both static and dynamic connectivity changes in schizophrenia during rest

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Small but significant connectivity differences might be obscured in static analysis.

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Patients show significant differences in dwell times in multiple states.

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Disrupted thalamo-cortical connectivity in schizophrenia in a state-specific manner

Converging evidence for gamma synchrony deficits in schizophrenia

BACKGROUND

In electroencephalogram (EEG) studies of auditory steady-state responses (ASSRs), patients with schizophrenia show a deficit in power and/or phase-locking, particularly at the 40 Hz frequency where these responses resonate. In addition, studies of the transient gamma-band response (GBR) elicited by single tones have revealed deficits in gamma power and phase-locking in schizophrenia. We examined the degree to which the 40 Hz ASSR and the transient GBR to single tones are correlated and whether they assess overlapping or distinct gamma-band abnormalities in schizophrenia.

METHODS

EEG was recorded during 40 Hz ASSR and auditory oddball paradigms from 28 patients with schizophrenia or schizoaffective disorder (SZ) and 25 age- and gender-matched healthy controls (HC). The ASSR was elicited by 500 ms click trains, and the transient GBR was elicited by the standard tones from the oddball paradigm. Gamma phase and magnitude values, calculated using Morlet wavelet transformations, were used to derive total power and phase-locking measures.

RESULTS

Relative to HC, SZ patients had significant deficits in total gamma power and phase-locking for both ASSR- and GBR-based measures. Within both groups, the 40 Hz ASSR and GBR phase-locking measures were significantly correlated, with a similar trend evident for the total power measures. Moreover, co-varying for GBR substantially reduced 40 Hz ASSR power and phase-locking differences between the groups.

CONCLUSIONS

40 Hz ASSR and transient GBR measures provide very similar information about auditory gamma abnormalities in schizophrenia, despite the overall enhancement of 40 Hz ASSR total power and phase-locking values relative to the corresponding GBR values.

Abstract P4-11-02: Novel BRCA1 and BRCA2 genomic rearrangements in Southern Chinese breast/ovarian cancer patients

Background and Aims: Germline mutations in the two breast cancer susceptibility genes, BRCA1 and BRCA2 account for a significant portion of hereditary breast/ovarian cancer. Most of the BRCA mutations reported in Southern Chinese patients were point mutations, small deletions, and insertions. The spectrum of large genomic rearrangement (LGR) is largely unknown. Here we perform the first study on the LGR of BRCA genes in a Hong Kong Chinese population. We aimed to determine the spectrum of BRCA LGRs in Southern Chinese patients with breast cancer.

Methods: A total of 555 clinically high-risk breast and/or ovarian cancer patients were recruited from the Hong Kong Hereditary Breast Cancer Family Registry, diagnosed from March 2007 to November 2011. Multiplex ligation-dependent probe amplification (MLPA) for detecting BRCA LGRs together with comprehensive BRCA1 and BRCA2 gene sequencing of all coding exons were performed. cDNA sequencing of the LGRs was performed to locate the breakpoint of the deletions.

Results: Overall BRCA1/2 mutation prevalence among this cohort was 12.4% (69/555). Among the 69 mutations identified, 4 novel LGRs (2 in BRCA1 and 2 in BRCA2) were detected only by MLPA but not full gene sequencing. Overall the LGR genes accounted for 5.8% (4/69) of all BRCA mutations in our cohort, 6.9% (2/29) of all BRCA1 mutations and 5% (2/40) of all BRCA2 mutations.

Conclusions: These findings highlight the LGR spectrum of BRCA1 and BRCA2 genes in Southern Chinese breast cancer patients. LGR testing together with BRCA1/2 full gene sequencing is superior to other methods for comprehensive BRCA1/2 analysis in clinical settings.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-11-02.

Abstract P3-11-02: Male breast cancer: A comparison between BRCA mutation carriers and non-carriers in Hong Kong, Southern China

Background: Male breast cancer is suggested to be biologically different from female breast cancer. The differences in clinicopathology between male and female breast cancer raise the issues of establishing specific strategies and treatment regime for male breast cancer patients. The single most significant risk factor for male breast cancer is a mutation in the BRCA2 gene. The lack of information on hereditary breast cancer in male, particularly in Asians, leaves great but forgiven research area on epidemiological studies for this group of patients.

Methods: All male breast cancer patients and their family members, from a Hong Kong Hereditary and High Risk Breast Cancer Program since year 2007, were recruited in this study. All received genetic counseling and BRCA mutation testing using DNA extracted from blood samples. A questionnaire was administered at their first visit which included questions on their demographics and socioeconomic status. Other information including family history of breast cancer or other kinds of cancer, method of diagnosis, surgical strategies, pathological results, treatment regime, relapse, metastasis, and outcomes were obtained from their medical records. Descriptive analysis was performed describing the background characteristics. Chi-square test and Student's t-test were applied to calculate the associations between BRCA mutation and risk factors. Survival analysis was performed to look for their survival patterns.

Results: Thirty-six male breast cancer patients were recruited between year 2007 and 2012, while 21 were diagnosed before year 2007 (range: 1996 to 2012). Mean, standard deviation, and median follow-up time were 5.75±4.31 and 5.25 years. Seven were found to carry the BRCA mutation. All were BRCA2 mutation and the mutation rate was 19.4% (N = 7). Family history of cancer was found in 52.8% (N = 19). Male BRCA mutation carriers were found to have higher risk of secondary cancer, and their first and second degree family members had higher risk of either breast cancer or other kinds of cancers. T stage in BRCA patients was significantly higher than non-BRCA patients (p = 0.028). All BRCA mutation carriers had ER positive cancers compared with 96.2% who were non-carriers. Half of the male BRCA patients were PR positive compared with higher percentage in non-BRCA patients (50% vs. 80.8%, p = 0.117). Both groups had similar overall (p = 0.962) and disease-free survivals (p = 0.919). The means and standard deviations of 5-year overall survival between BRCA and non-BRCA patients were 2.08±0.25 and 4.24±0.12 years respectively, and 2.08±3.03 and 4.41±1.46 years for disease-free survival.

Conclusions: The prevalence of male breast cancer patients with BRCA2 mutation in Hong Kong is comparable with other similar studies. Male breast cancer patients with BRCA2 mutation are suspected to have higher chance of secondary cancer and familial cancer. Although percentage of ER positive cancers are similar to the two groups, BRCA2 mutation carriers tend to have less PR positive cancers which may suggest a poorer prognosis although due to a small sample size this cannot be shown in this cohort. Further collaborative studies to better understand male breast cancer patients carrying the BRCA mutation is warranted.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-11-02.

Utilizing BRCA1/2 mutation status to select patients for breast cancer clinical trials: Experience from a prospective phase II trial

161

Background: Information from BRCA1/2 mutation testing is used to guide cancer screening and risk reduction strategies. More recently, BRCA1/2 mutation status is being used to select patients for breast cancer (BC) clinical trials employing new targeted therapies, such as PARP inhibitors. There is concern that current testing practices do not produce results within the timeframe necessary for clinical trial eligibility assessment.

Methods: We analyzed BRCA1/2 mutation testing patterns in the context of a prospective phase II neoadjuvant study of gemcitabine, carboplatin and BSI-201 (iniparib) for women with Stage I-IIIA triple-negative or BRCA1/2 mutation-associated BC. Specifically, we analyzed: 1) the proportion of participants who met BRCA1/2 mutation testing criteria per NCCN Guidelines v1.2011 and 2) the proportion who had the Myriad Genetics Single Site, Multisite 3 (Ashkenazi Panel), BRACAnalysis and Comprehensive Rearrangement tests performed and their results. For patients without a known BRCA1/2 mutation prior to BC diagnosis who met testing criteria, we assessed the length of time from BC diagnosis to receipt of test results.

Results: Sixty-four patients between the ages of 26 and 73 were enrolled. Results are summarized below. For patients who had BRCA1/2 testing after BC diagnosis, the median number of days from BC diagnosis to receipt of results was 42.

Conclusions: The frequency of BRCA1/2 mutations in this cohort is high (20%), though nearly half of these mutations were found after patients provided trial consent. Current standard processes for testing women with newly diagnosed BC for BRCA1/2 mutations do not occur expeditiously enough for many to guide clinical trial selection.

[Table: see text]

Electrophysiological and diffusion tensor imaging evidence of delayed corollary discharges in patients with schizophrenia

BACKGROUND

Patients with schizophrenia (SZ) characteristically exhibit supranormal levels of cortical activity to self-induced sensory stimuli, ostensibly because of abnormalities in the neural signals (corollary discharges, CDs) normatively involved in suppressing the sensory consequences of self-generated actions. The nature of these abnormalities is unknown. This study investigated whether SZ patients experience CDs that are abnormally delayed in their arrival at the sensory cortex.

METHOD

Twenty-one patients with SZ and 25 matched control participants underwent electroencephalography (EEG). Participants' level of cortical suppression was calculated as the amplitude of the N1 component evoked by a button press-elicited auditory stimulus, subtracted from the N1 amplitude evoked by the same stimulus presented passively. In the three experimental conditions, the auditory stimulus was delivered 0, 50 or 100 ms subsequent to the button-press. Fifteen SZ patients and 17 healthy controls (HCs) also underwent diffusion tensor imaging (DTI), and the fractional anisotropy (FA) of participants' arcuate fasciculus was used to predict their level of cortical suppression in the three conditions.

RESULTS

While the SZ patients exhibited subnormal N1 suppression to undelayed, self-generated auditory stimuli, these deficits were eliminated by imposing a 50-ms, but not a 100-ms, delay between the button-press and the evoked stimulus. Furthermore, the extent to which the 50-ms delay normalized a patient's level of N1 suppression was linearly related to the FA of their arcuate fasciculus.

CONCLUSIONS

These data suggest that SZ patients experience temporally delayed CDs to self-generated auditory stimuli, putatively because of structural damage to the white-matter (WM) fasciculus connecting the sites of discharge initiation and destination.

Long-term survivorship in gastric cancer

14

Background: Gastric cancer is the fourth most prevalent malignancy and second leading cause of cancer death worldwide. For all stages, gastric cancer is rapidly fatal with a 5-year survival rate of 25%. Of those patients who survive, very little is known about their demographic and tumor characteristics.

Methods: Cases of gastric and gastroesophageal junction (GEJ) adenocarcinoma diagnosed between 1998 and 2005 were identified within the California Cancer Registry, a SEER registry. Univariate and multivariate logistic regression models were constructed predicting the outcome of survival to 3, 5 and 8 years based on demographic, disease and treatment variables.

Results: Of the 47,049 patients with gastric or GEJ cancer, 38,380 (82%) died within 3 years of diagnosis, 8,669 (18%) survived at least 3 years, 5,336 (11%) survived at least 5 years, and 3,002 (6%) survived at least 8 years. The 5-year survivors had a median age at diagnosis of 67 years with a male predominance (64%). The majority were non-Hispanic whites (64%), followed by Asian/Pacific Islanders (23%), and Hispanics (18%). Most had localized (48%) or regional (41%) disease. In the multivariate model, odds of surviving to 5 years were highest with localized stage (odds datio=27), surgery (7.8), regional stage (5.9), fundus/body/antrum site (1.7), Asian/Pacific Islander race (1.5), intestinal histology (1.5), high SES (1.4), and well/moderately differentiated tumors (1.4). Kaplan-Meier curves for cause-specific death were examined by anatomic site and histology. Persons with tumors originating in the fundus/body/antrum had longer median OS compared to patients with tumors originating in the esophagus/cardia (15 vs. 12 months). Intestinal histology had longer median OS (30 months) compared to other or diffuse (both approx 12 months).

Conclusions: Long-term survivors of gastric and GEJ cancer have distinct demographic patterns when compared to patients who died within three years. The multivariate analyses demonstrated that earlier stage, surgery, anatomic site (fundus/body), Asian race, intestinal histology, high SES, well/moderately differentiated tumors, and radiation were the strongest independent predictors of survival.

No significant financial relationships to disclose.

Long-term survivorship in pancreatic adenocarcinoma

175

Background: Pancreatic cancer is one of the most lethal malignancies, with an estimated 5-year survival rate of 6%, often due to advanced stage at diagnosis. However, there is a small population of patients, even with metastatic disease, who survive 3 years and beyond.

Methods: Cases of pancreatic adenocarcinoma diagnosed from 1998 to 2005 were identified in the California Cancer Registry. A multivariate logistic regression model was constructed to predict the outcome of 3+ year survival according to demographic, disease and treatment variables defined a priori: age, gender, race/ethnicity, socioeconomic status (SES), histology, stage, treatment within 4 months of diagnosis (surgery, chemotherapy, and/or radiation), prior cancer history, and treatment at an academic hospital.

Results: Among 54,475 cases of pancreatic cancer with ≥3 years of follow-up data available, median survival was 3.5 months. 2,855 patients (5.2%) survived at least 3 years, of whom 19% had remote stage disease at diagnosis. On multivariate analysis, advanced age was associated with decreased odds of long-term survival (p<0.01). By race, Asian/Pacific Islanders (odds ratio (OR) 1.76, p<0.01), Hispanics (OR 1.29, p=0.01) and non-Hispanic blacks (OR 1.24, p=0.14) were more likely to be long-term survivors than non-Hispanic whites. There was a gradient toward increased long- term survival for patients with higher SES (OR 1.49 for highest vs. lowest quintile, p<0.01). Mucinous tumors were associated with higher long-term survival than other adenocarcinomas (OR 2.21, p<0.01). Localized (OR 6.82) and regional stage disease (OR 2.61) showed more long-term survival than remote stage disease, both p<0.01. Surgery (OR 8.20, p<0.01), chemotherapy (OR 1.44, p<0.01), and radiation therapy (OR 1.25, p=0.02) increased the odds of long-term survival, as did treatment at an academic hospital (OR 1.54, p<0.01).

Conclusions: In a well- characterized population-based registry with rigorous follow-up, we were able to identify a cohort of long-term survivors of pancreatic adenocarcinoma as well as factors associated with their exceptional survival. Planned future work with this cohort includes case-control studies making use of tumor and germline specimens, as well as survivorship research.

No significant financial relationships to disclose.

Abstract ES2-1: DNA Repair Pathways and Tumorigenesis

The genome is constantly undergoing DNA damage from endogenous and environmental sources. DNA damage response pathways detect and repair DNA damage and signal to cell cycle checkpoints to allow repair to take place, thus promoting genomic stability. Multiple DNA repair pathways exist: single-strand damage or base errors are repaired by base excision repair, nucleotide excision repair or mismatch repair, while DNA doublestrand breaks are repaired by nonhomologous end joining or homologous recombination repair. These pathways may be used to repair damage caused by anticancer chemotherapy and radiotherapy. Some defects in DNA damage responses are associated with the genomic instability that is a characteristic of cancer. Targeting the remaining DNA damage response pathways could potentially result in tumor selective therapies. Poly(ADP-ribose) polymerase (PARP) inhibitors have shown great promise in this respect, and early clinical data are beginning to emerge. PARP inhibitors enhance the activity of several DNA damaging and crosslinking chemotherapeutic agents and ionizing radiation. An exciting aspect is the selective toxicity of PARP inhibitors in DNA defective tumors, such as those associated with BRCA mutations or breast cancers exhibiting the triple-negative phenotype. This discovery has led to a paradigm shift in cancer therapy representing a targeted, tumor-specific, nontoxic therapy that is supported by emerging clinical data.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr ES2-1.

Pathological response after chemoradiation for T3 rectal cancer

OBJECTIVE

The aim of this study was to investigate the effect of preoperative chemoradiotherapy (CRT) on nodal disease in locally advanced rectal adenocarcinoma.

METHOD

Thirty-two patients staged uT3N0 and 27 patients staged uT3N1 rectal adenocarcinoma who underwent pre-CRT staging using endoscopic ultrasound or rectal protocol CT were included. The median radiation dose was 50.4 Gy (range: 45-50.4 Gy) at 1.8 Gy per fraction and all patients received concurrent 5-FU or capecitabine-based chemotherapy. Low anterior resection or abdomino-perineal resection occurred at a median of 46 days (range: 27-112 days) after CRT.

RESULTS

Eleven of 32 uT3N0 patients (34.4%) and 13 of 26 uT3N1 patients (50.0%) had ypN+ (P = 0.29). For patients with uT3N0, 10 of 20 (50.0%) with ypT2-3 and 1 of 12 (8.3%) with ypT0-1 were ypN+ (P = 0.02). For patients with uT3N1, 12 of 20 (60.0%) with ypT2-3 and 1 of 6 (16.7%) with ypT0-1 were ypN+ (P = 0.16). Overall, the ypN+ rate was 11.1% in the ypT0-yT1 group compared with 55.0% in the ypT2-yT3 group (P = 003). Among patients with uT3N0 disease, the ypN+ rate in patients who had surgery > 46 days vs<or= 46 days was 7.1%vs 55.6% (P = 0.01) respectively. Among patients with uT3N1 disease, the ypN+ rate in patients who had surgery > 46 days vs<or= 46 days was 54.5%vs 46.7%, (P = 0.99) respectively. Overall, the ypN+ rate in patients who had surgery > 46 days vs<or= 46 days was 28.0%vs 51.5% (P = 0.11).

CONCLUSIONS

The risk of residual nodal disease after CRT is significant. Primary tumour response is associated with nodal response.

SALTANT PRODUCTION BY WAVE LENGTHS OF VISIBLE AND LONG ULTRAVIOLET MONOCHROMATIC IRRADIATION, AND A COMPARISON WITH SALTANTS PRODUCED BY SHORT WAVE LENGTHS OF MONOCHROMATIC ULTRAVIOLET IRRADIATION IN THE FUNGUS CHAETOMIUM GLOBOSUM

1. Saltants have been produced in the fungus Chaetomium globosum by longer wave lengths than previously reported-by 365 mmicro and by a visible line 404 mmicro. 2. Absence at these wave lengths of the K saltant, which is so abundant at short wave lengths, is marked. 3. Ratio of percentage irradiated spores germinating to control spores germinating decreases from 83 per cent at 265 mmicro, a short ultraviolet wave length, to 57 per cent at 404 mmicro, a visible violet wave length.

Multimodality treatment with intensity modulated radiation therapy for esophageal cancer

The objective of this study is to determine the feasibility and report the outcome of patients with locally advanced esophageal cancer treated with preoperative or definitive chemoradiotherapy (CRT) using intensity-modulated radiation therapy (IMRT). Between 2003 and 2007, 30 patients with non-cervical esophageal cancer received concurrent chemotherapy and IMRT at Stanford University. Eighteen patients were planned for definitive CRT and 12 were planned for preoperative CRT. All patients had computed tomography-based treatment planning and received IMRT. The median dose delivered was 50.4 Gy. Patients planned for preoperative CRT underwent surgery 4-13 weeks (median 8.3 weeks) following completion of CRT. Median follow-up of surviving patients from start of RT was 24.2 months (range 8.2-38.3 months). The majority of tumors were adenocarcinomas (67%) and poorly differentiated (57%). Tumor location was 7% upper, 20% mid, 47% lower, and 27% gastroesophageal junction. Actuarial 2-year local-regional control (LRC) was 64%. High tumor grade was an adverse prognostic factor for LRC and overall survival (OS) (P= 0.015 and 0.012, respectively). The 2-year LRC was 83% vs. 51% for patients treated preoperatively vs. definitively (P= 0.32). The 2-year disease-free and OS were 38% and 56%, respectively. Twelve patients (40%) required feeding tube placement, and the average weight loss from baseline was 4.8%. Twelve (40%) patients experienced grade 3+ acute complications and one patient died of complications following feeding tube placement. Three patients (10%) required a treatment break. Eight patients (27%) experienced grade 3 late complications. No grade 4 complications were seen. IMRT was effective and well tolerated. Disease recurrence remains a challenge and further investigation with dose escalation to improve LRC and OS is warranted.

Adjuvant chemoradiotherapy with carboplatin and a fluoropyrimidine for resectable gastric and gastroesophageal junction cancer: A retrospective review of the Stanford experience

e15674

Background: The standard of care for the adjuvant treatment of resected gastric or gastroesophageal junction (GEJ) adenocarcinoma in the U.S. is post-operative 5FU and radiotherapy per the MacDonald regimen. At Stanford Cancer Center (SCC) we have adopted a modified regimen of chemoradiotherapy using carboplatin and a fluoropyrimidine. Methods: A retrospective review was performed of patients at SCC with T2-T4 or node positive gastric or GEJ cancer who underwent surgery with curative intent, and then received the following treatment. Carboplatin (AUC 6) was administered on days 1 and 22. Patients also received either 5FU at 200 mg/m2/day (via continuous infusion) plus leucovorin for six weeks, or capecitabine at 1,000 mg/po BID for 14 days, repeated every 21 days for 2 cycles. At week 8, infusional 5FU or capecitabine was combined with external beam radiotherapy to the gastric bed for five weeks (total 4,500 cGy). At week 14, patients repeated an additional 2 cycles of carboplatin and fluoropyrimidine as tolerated. Results: Forty-nine patients were identified. The majority (76%) were male. Median age at diagnosis was 57 years. Thirty-nine had gastric and 10 had GEJ cancers. With a mean follow up of 35 months, twenty-one patients (43%) have died; median disease free and overall survival have not been reached. Eighteen patients (37%) have recurred. The percentage of patients alive by stage was 100% (4/4) for stage IB, 62% (8/13) for stage 2, 53% (9/17) for stage IIIA, 33% (2/6) for stage IIIB and 22% (2/9) for stage IV. Grade 3 or 4 toxicities occurred in 27 patients (55%); most common were neutropenia (16), thrombocytopenia (11) and gastrointestinal toxicity in (8). Conclusions: Adjuvant chemoradiotherapy with carboplatin and a fluoropyrimidine after curative resection of gastric and GEJ cancer was well tolerated and yielded survival results similar to historical data.

No significant financial relationships to disclose.

Correlation of a family history of cancer with risk of relapse and death in pediatric cancer patients

10029

Background: The association between family history of cancer (FHC) and outcome remains uncertain. Relapse and survival of children with FHC has not been well studied. Such information would be valuable for prognosis, refining treatment protocols, and long-term follow-up in pediatric patients with FHC. Methods: An historical cohort study of all pediatric patients diagnosed with cancer at Lucile Packard Children's Hospital at Stanford from 1999 - 2002 was performed (n = 363, mean age: 8.4 yrs [0–28 yrs]). FHC among 1st, 2nd and 3rd degree relatives was obtained from the first 10 consecutive encounters in the electronic medical record. Relapse, secondary malignancy, and survival data were also acquired. The relative risks for these endpoints were calculated between patients with FHC among 1st and/or 2nd degree relatives and those with negative FHC. Patients without documented FHC were excluded (n = 100). Results: 108 (41%) newly diagnosed pediatric patients had reported FHC (1st Degree: n = 14 [5%], 2nd Degree: n = 58 [22%], 3rd Degree: n = 36 [14%]). Patients with reported FHC among 1st and/or 2nd degree relatives were at increased relative risk [RR] for relapse (1.96, 95% confidence interval [CI] 1.27–3.02) compared to patients with negative FHC (n = 191). In particular, patients with Hodgkin Disease (HD) and FHC (n = 12) were more likely to relapse (RR 1.79, 95% CI 1.19–2.72) and at increased risk of death (RR 1.72, 95% CI 1.18–2.53), compared to HD with negative FHC (n = 8). Similarly, patients diagnosed with ALL and FHC (n = 22) had increased risk of death (RR 2.25, 95% CI 1.06–4.8) compared to ALL patients with negative FHC (n = 56). For patients diagnosed with any pediatric cancer and positive FHC in 1st degree relative, RR of death was significantly elevated (3.74, 95% CI 1.20–11.70). Conclusions: Pediatric cancer patients with positive FHC among 1st and/or 2nd degree relatives appear to have higher relative risk of relapse compared to those with negative FHC. Additionally, an increased risk of death was associated with HD and ALL patients with positive FHC. Patients with 1st degree relative with malignancy had an increased risk for death compared to those without cancer among 1st degree relatives. These findings may reflect underlying genetic predispositions in children which contribute to outcome.

No significant financial relationships to disclose.

Novel de novo BRCA1 mutation in a woman with early onset breast cancer

e22143

Background: Germline mutations in BRCA1/2 account for a significant portion of hereditary breast/ovarian cancer. Mutation carriers usually have a family history of breast/ovarian cancer or early onset disease. Rarely, germline mutations are found only in the probands but not in any family members. Such de novo mutations have been reported in diseases such as hemophilia A, thalassaemia and familial adenomatous polyposis. De novo mutations in the BRCA1 or BRCA2 genes are rare and the few reported have been in BRCA2. Here, we describe de novo as well as novel mutation of the BRCA1 gene in a breast cancer patient. Methods: Blood DNA samples from a 30 year old Chinese woman with breast cancer and no family history of cancer was tested for a BRCA1/2 mutation by full gene sequencing and Multiple Ligation-dependent Probe Amplification (MLPA). Family members were analyzed for the same mutation. Paternity was determined by a set of highly polymorphic short tandem repeat (STR) markers. Results: Full gene sequencing found no deleterious mutation. MLPA revealed a large deletion of exons 1 to 12 of BRCA1 in the proband. MLPA performed on 5 family members: proband's mother and father (who were 1st degree relative- cousins), stepmother (mother's biological sister), 2 sisters (1, same parents; 1, same father and stepmother) found no similar deletion. By using a set of highly polymorphic STR markers, the proband's father and mother were confirmed to be her biological parents. Conclusions: We report a novel de novo BRCA1 deletion mutation encompassing exons 1 - 12 in a Chinese breast cancer patient of early onset with no family history. Identification of this large deletion confirms the importance of pursuing rearrangement testing if full gene sequencing fails to detect a point mutation or short insertion deletion. The mutation found in this study is de novo. This may simply be a random mutation event which occurred in the parents' germ cells during their lifetime which passed onto one of their offspring or maybe a result of gene inversion or splicing deficiency. The relations of such mutations with consanguineous marriage cannot be ruled out. Mutation screening is important in early onset breast cancer patients even if there is no family history.

No significant financial relationships to disclose.

Carboplatin and fluoropyrimidine-based treatment for metastatic gastric and gastroesophageal junction cancer: A retrospective review of the Stanford experience

e15686

Background: There is no single standard chemotherapy regimen for the treatment of metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma. At Stanford Cancer Center (SCC) we regularly use a regimen of carboplatin and 5- fluorouracil (CF) or carboplatin and capecitabine (CX) for the treatment of these patients. Methods: A single institution retrospective review of patients with metastatic gastric and GEJ adenocarcinoma treated with CF or CX was conducted. Patients received carboplatin AUC 6 on day 1 and either 5-FU at 200 mg/m2/day (via continuous IV infusion) or capecitabine at 1,000 mg/m2 po BID for 14 days, repeated every 21 days. Only patients treated at SCC who received ≥ 2 cycles of chemotherapy were included. Results: Fourty-five patients were identified. The majority (62%) were male. Median age at diagnosis was 66 years. Twenty-nine (64%) had gastric and 16 (36%) had GEJ cancers. Thirty-six patients (80%) were chemotherapy-naïve. Twenty-nine (64%) had poorly differentiated and 10 (22%) had moderately differentiated adenocarcinomas; 13 (29%) had signet ring features. The average number of cycles administered was 5.4; one possible treatment-related death (2%) was identified. Median time to progression was 4.9 months and median overall survival was 7.3 months. Conclusions: CF and CX are well tolerated and yield acceptable outcomes in high-risk metastatic gastric and gastroesophageal junction cancers. The tolerability allows for the addition of novel targeted agents in future studies.

No significant financial relationships to disclose.

Clinical and pathological characteristics of Chinese patients with BRCA related breast cancer

e22226

Background: Breast cancers due to underlying germline BRCA1 and BRCA2 mutations are associated with particular pathological features that may differ from sporadic breast cancers. We report clinical and pathologic characteristics of breast cancer in a clinical cohort of high risk Chinese women with BRCA mutations and those without mutations. Methods: 202 high risk women based on their age and family history were recruited from March 2007 to November 2008. Medical information was prospectively collected from the patients and medical records. BRCA1 and BRCA2 mutations were detected using full gene sequencing and multiplex ligation-dependent probe amplification (MLPA). Results: Of the 202 female probands tested, 25 (12.3 %) were BRCA mutation carriers of which 11 (44%) were BRCA1 and 14 (56%) were BRCA2 mutations. Breast cancer risk factors, other than family history, did not differ between carriers and non-carriers. Mutation carriers were more likely to have a familial history of breast cancer (p=0.07) and personal and family history of ovarian cancer (p=0.005; p=0.007). Other cancers found in carriers families included pancreatic, gastric, colon, lung, liver, and nasopharyngeal. 23% of women diagnosed with DCIS had BRCA mutations compared with 11.4% of those with invasive cancers. BRCA related tumors were more likely to be ER, PR and Her-2 negative (Triple negative, TN) (p= 0.006). Overall 9.6% of non-BRCA cancers were TN whereas 25.9% of BRCA cancers were TN. Prevalence of TN in BRCA1 carriers is 71% compared with 13.4% in BRCA2 carriers. BRCA1 mutation related cancers were significantly more likely to be ER negative than BRCA2 and this is only significant in those who are under 40 years of age (p=0.070). Conclusions: We have a high BRCA2 mutation rate in our cohort. BRCA related breast cancer is associated with families with increasing number of first degree relatives with breast and/or ovarian cancers and were higher for DCIS cancers. Prevalence of TN breast cancers was high compared to Caucasian cohorts. BRCA mutations were associated with pathologically, poor prognostic features (TN and high grade) especially in younger women.

No significant financial relationships to disclose.

Differences in breast cancer subtype distribution exist among ethnic subgroups of Asian women in California

Abstract #2088

Background: Distinct breast cancer subtypes have been identified by gene expression analysis. Little is known about the distribution of these subtypes among Asian women. We previously reported an increased frequency of HER2-positive breast cancers among certain ethnic subgroups of Asian women in California. To follow up on that finding in detail, we undertook the current analysis to explore factors associated with differences in breast cancer subtype distribution among Asian women in California.&#x2028; Methods: We defined immunohistochemical surrogates for each breast cancer subtype among Chinese, Japanese, Filipina, Korean, Vietnamese and South Asian patients in the population-based California Cancer Registry diagnosed in the period 1999-2005. Subtypes were defined using combinations of immunohistochemical markers: luminal A (ER+ and/or PR+, HER2-), luminal B (ER+ and/or PR+, HER2+), basal-like (ER-, PR-, HER2-) and HER2+/ER- (ER-, PR-, HER2+). Polytomous logistic regression was used to evaluate associations between breast cancer subtype and age, race, AJCC stage, tumor grade, tumor histology, socioeconomic status, nativity and hospital ownership (private vs. public). Models were used to compare differences in these characteristics simultaneously across the four breast cancer subtypes.&#x2028; Results: Of 12,245 Asian women diagnosed with invasive breast cancer, 7,217 (59%) women had data for all three immunohistochemical markers. The majority of breast cancers among Japanese women were of the luminal A subtype (67%), with a low frequency of basal-like (10%) and HER2+ (22%) cancers. Korean, Filipina and Vietnamese women had a high frequency of HER2+ cancers (35%, 31% and 31%, respectively) compared to Non-Hispanic White women diagnosed during this period (n=12,996, 21%). In regression analyses among Asian women, the four subtypes varied significantly in their associations with age group (p=0.01), detailed Asian ethnicity (p&lt;0.0001), stage (p&lt;0.0001), grade (p&lt;0.0001), histology (p&lt;0.0001), year of diagnosis (continuous; p=0.03) and hospital ownership (p&lt;0.0001). However, there was no significant variation among the subtypes in their relationships with socioeconomic status (p=0.94) or nativity (p=0.29).&#x2028; Conclusions: Differences in the distribution of breast cancer subtypes exist among Asian women according to ethnicity, as well as other demographic and disease characteristics. These differences were not associated with place of birth or socioeconomic status. Breast cancers among Japanese women had the most favorable subtype distribution, while Korean women had the least favorable distribution. Further study may identify genetic and environmental risk factors responsible for these differences, with implications for prevention and treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2088.

BRCA mutation in Chinese population: results from the Hong Kong hereditary and high risk breast cancer programme (HRBCP) and the Hong Kong hereditary and high risk breast cancer family registry

Abstract #3097

Background: Little is known about the frequency and spectrum of BRCA 1/2 mutations among Chinese population. Previous research suggests possible differences in the prevalence and penetrance of inherited mutations in these genes among Asians and the earlier presentation of breast cancer in Asian population may have more relevance to genetic causes. The access to genetic counseling and testing in Asia have been limited. The HRBCP (www.HRBCP.org) was established in 2007. This is first in Hong Kong and provides genetic testing, counseling and research on the spectrum of the disease in Asia and in particular Chinese population. The data from this programme will be entered in the newly established The Hong Kong Hereditary Breast Cancer Family Registry.&#x2028; Methods: Probands who were diagnosed to have breast cancer age 50 or below, have a family history or personal history of breast and/or ovarian cancer, bilateral breast cancer, male breast cancer, triple negative breast carcinoma were recruited. Genetic counseling were given and consent for testing were obtained. Blood and tumor samples were collected. The entire coding regions of the extracted DNA/RNA and flanking introns of BRCA1 and 2 were screened for germline mutations using full gene sequencing and MLPA.&#x2028; Results: A total of 119 Chinese have been sequenced and analysed. 21 (18%) deleterious mutations were identified of which 4 were novel mutations. 8 (38%) were BRCA 1 mutations and 13 (62%) were BRCA 2 mutations. 66.6% had first degree relatives with breast cancer. 49 (41.2%) were under the age of 40 years old of which 11 (22%) were found to carry a BRCA mutation. 7 (64%) of this younger age group with mutation have family history of breast cancer. For the other 4, 1 had triple negative cancer, 1 had a family history of ovarian cancer, 1 unknown and 1 with no risk except for young age. Of the 37 family members tested, 21 (57%) have BRCA mutations and only 9 of them have breast or ovarian cancers. 1 only had stomach cancer. 6 male family members were found to carry the BRCA mutation with no history of cancer.&#x2028; Conclusions: Approximately 18% of the tested blood samples from clinically high risk Chinese women carry a deleterious mutation in BRCA1 or 2. In contrast to Caucasian data, there was a comparative higher rate of BRCA2 mutations. Further research on the spectrum of the mutations in Chinese and other Asian population will allow the tailor-making of an ethnic-based risk assessment model and also screening, prophylactic and preventative measures to be taken.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3097.

Working memory and DLPFC inefficiency in schizophrenia: the FBIRN study

BACKGROUND

The Functional Imaging Biomedical Informatics Network is a consortium developing methods for multisite functional imaging studies. Both prefrontal hyper- or hypoactivity in chronic schizophrenia have been found in previous studies of working memory.

METHODS

In this functional magnetic resonance imaging (fMRI) study of working memory, 128 subjects with chronic schizophrenia and 128 age- and gender-matched controls were recruited from 10 universities around the United States. Subjects performed the Sternberg Item Recognition Paradigm1,2 with memory loads of 1, 3, or 5 items. A region of interest analysis examined the mean BOLD signal change in an atlas-based demarcation of the dorsolateral prefrontal cortex (DLPFC), in both groups, during both the encoding and retrieval phases of the experiment over the various memory loads.

RESULTS

Subjects with schizophrenia performed slightly but significantly worse than the healthy volunteers and showed a greater decrease in accuracy and increase in reaction time with increasing memory load. The mean BOLD signal in the DLPFC was significantly greater in the schizophrenic group than the healthy group, particularly in the intermediate load condition. A secondary analysis matched subjects for mean accuracy and found the same BOLD signal hyperresponse in schizophrenics.

CONCLUSIONS

The increase in BOLD signal change from minimal to moderate memory loads was greater in the schizophrenic subjects than in controls. This effect remained when age, gender, run, hemisphere, and performance were considered, consistent with inefficient DLPFC function during working memory. These findings from a large multisite sample support the concept not of hyper- or hypofrontality in schizophrenia, but rather DLPFC inefficiency that may be manifested in either direction depending on task demands. This redirects the focus of research from direction of difference to neural mechanisms of inefficiency.