The search for clarity regarding "clinically meaningful outcomes" in Alzheimer disease clinical trials: CLARITY-AD and Beyond

CLARITY-AD is an 18-month, double-blinded, placebo-controlled, phase 3 trial which examined the safety and efficacy of the anti-amyloid agent, lecanemab, in mild cognitive impairment and mild dementia due to Alzheimer disease (AD). Lecanemab effectively reduced mean brain amyloid burden and was associated with statistically significant favorable effects, reflected by moderately less decline in the primary and secondary clinical outcomes, at 18 months compared to placebo. However, there is controversy within the AD community regarding the clinical significance of these results and whether they translate into clinically meaningful and tangible benefits on cognition or daily functions.We here review the primary and secondary clinical outcomes of CLARITY-AD and present our interpretation of the potential clinical meaningfulness of the group-level differences in study outcomes in the context of the 18-month study duration. We propose that the validation of stage-appropriate group-level thresholds for clinical meaningfulness of AD trial outcomes in biologically confirmed cohorts will allow objective interpretation of trial results and guide clinical decision-making. Further, in accordance with FDA guidance which emphasizes patient-focused drug development, the contextualization of AD clinical trial outcomes can be facilitated by supplementary individual-level data analyses which measure the risk of disease progression or summarize intraindividual change, using prespecified thresholds of clinically meaningful change, in each of the study groups over the trial period. The concepts of "time-saved" and "time-based" slowing in disease progression can be used to communicate clinical outcomes associated with emerging disease-modifying AD therapies to various stakeholders. We also describe several factors that need to be considered when evaluating outcomes of emerging AD therapies, including disease stage, the neuropathologic complexity of AD, time-based effects of disease-modifying therapies, and the possible influence of individual factors on treatment response and/or risk for adverse events. The consideration of these factors in the design and reporting of future trials of emerging AD therapies will guide clinicians regarding their appropriateness for use in various patient populations.Finally, we emphasize that data from clinical cohorts with longer durations of treatment and follow-up, including extension studies and patient registries, is needed to evaluate the long-term safety and efficacy of lecanemab in early symptomatic AD.

Outcomes of responders to PD-1/PD-L1 inhibitors who discontinue therapy after sustained disease control

BACKGROUND

PD-1/PD-L1 immune checkpoint inhibitors (ICIs) are widely used in the treatment of metastatic malignancies. Judiciously balancing disease control (DC) against development of immune-related adverse events (irAE) remains a crucial aspect of treatment. The effect of treatment discontinuation after sustained disease control (SDC) is unknown. The purpose of this analysis was to evaluate outcomes of responders to ICI who discontinue treatment after a minimum of 12 months (SDC).

METHODS

We retrospectively reviewed the database of the University of New Mexico Comprehensive Cancer Center (UNMCCC) between 2014 and 2021 and identified patients who had received ICI. Patients with metastatic solid tumors who had stopped ICI therapy after achieving SDC [stable disease, partial response, complete response (SD, PR, CR)] were selected and outcomes reviewed from their electronic health records.

RESULTS

We identified 204 patients who were treated with ICI for various solid cancers. Forty-four patients (21.6%) met the criteria, of whom 35 with follow-up data were included in the final analysis; including 11 melanoma, 5 non-small cell lung, 4 head & neck, 8 renal, 4 urothelial, 1 anal, 1 Merkel cell carcinoma, and 1 liposarcoma. Patients were divided into two groups: those who stopped ICI due to an irAE [irAE group, n = 14, median treatment time (MTT), 16.6 mo] and those who stopped due to other reasons (eg completion of 2 years of therapy, n = 20, non-cancer related surgery, n = 1) (non-irAE group, n = 21, MTT, 23.7 mo). Among the irAE group, the most common irAE included pneumonitis, rash, transaminitis, and fatigue. As of data cutoff date, 9 of 14 (64%) patients continued to show SDC. Only 5 of 14 (36%) patients in this group experienced progression of disease (PD), with 1 of 2 patients achieving DC (median follow-up of 19.2 mo after last dose of treatment, range 3-50.2 mo). Among the non-irAE group, 13 of 21 (62%) continued to have SDC. Eight of 21 (38%) experienced PD after stopping treatment, 7 of whom received ICI rechallenge, with 2 of 7 achieving DC (median follow-up of 22.2 mo, range 3.6-54.8 mo). At a median follow-up of 21.3 mo from stopping ICI therapy (range, 3-54.8 mo), 10 patients (71%) from the irAE group and 13 (61.9%) from the non-irAE group are in DC and have not experienced PD.

CONCLUSIONS

We demonstrate that 22 (66%) patients experienced SDC, regardless of cancer type or development of irAE. After including patients who were re-challenged with ICI due to PD, 25 (71%) remain in DC. Future prospective malignancy-specific trials are warranted to evaluate optimal treatment duration.

Abstract 1899: Breast density comparison of Hispanic versus Non-Hispanic patients undergoing screening mammograms: Influence of age, parity and breast-feeding

Background: Higher mammographic breast density is associated with a 4 to 6-fold increased risk of breast cancer. Some single institution retrospective studies show higher breast densities in Hispanic patients (Oppong et al. Breast J. 2018). The prevalence of breast density based on Hispanic ethnicity has not been studied in large database studies.

Methods: We performed a retrospective review of women > 40 years undergoing screening mammograms from 2016-2022. Patients with prior history of breast cancer were excluded. We reviewed demographic variables such as race, self-reported ethnicity, body mass index (BMI), parity, breastfeeding and menopausal status. Breast density was characterized as predominantly fatty (PF), scattered fibroglandular (SF), heterogeneously dense (HD) and extremely dense (ED). We used Chi-square and Kruskal-Wallace tests to compare breast density across measured variables, and Ordinal Logistic Regression to compare breast density levels between self-declared ethnicity while adjusting for other variables.

Results: 15946 patients were studied; 7317 (46%) identified as Hispanic, the rest non-Hispanic (NH). 6131 (83%) of Hispanics identified as white. Mean age on 1st screening mammogram was 57.64 (SD 7.21). Compared to NH, Hispanics had mean earlier age of 1st mammogram (56.8 vs. 58.3 years), higher BMI (30.5 vs. 28.6) and higher parity (2.53 vs. 1.71). There were significant differences in BI-RADS density categories by Hispanic vs. NH (p<0.001), with differences in PF (20.2% vs. 18.5%), SF (41.7% vs. 39.0%), HD (35.8% vs. 37.2%), and ED (2.3% vs. 5.3%). The ordinal logistic regression model suggests that Hispanics have 17% lower odds than NH of 1 category higher density (OR, 95% CI: 0.83, 0.78-0.88). There were also significant ethnicity differences in age at first exam, BMI, parity, and number of children breast-fed (P<0.001). Adjusting for these ethnicity-associated differences explained the observed differences in density between Hispanic and NH individuals (ORadj, 95% CI: 0.98, 0.92-1.04); adjusting only for BMI served to explain the observed differences in density (ORadj, 95% CI: 0.99, 0.94-1.05).

Conclusions: Hispanics were observed to have a lower age of first screening mammogram, higher BMI, higher parity, and breast-fed children compared to non-Hispanics. On univariate analysis, Hispanics were noted to have lower breast density compared to non-Hispanics, these differences do not persist on multivariate analysis. This suggests that BMI likely plays a predominant role in driving the ethnicity-related differences in breast density noted here. Further research efforts should focus on the influence of BMI and other individual-level factors on mammographic density, with a view towards understanding their potential roles in describing differential ethnicity-specific breast cancer risk.

Citation Format: Sangeetha Prabhakaran, Vernon S. Pankratz, Jennifer L. Saline, Emily J. Reese. Breast density comparison of Hispanic versus Non-Hispanic patients undergoing screening mammograms: Influence of age, parity and breast-feeding [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1899.

Abstract 6492: Body mass index characterization of patients undergoing neoadjuvant chemotherapy for breast cancer: Correlation with survival

Background: The significance of body mass index (BMI) on treatment outcomes of neoadjuvant chemotherapy for breast cancer and impact on overall survival is not well understood. We reviewed our single institution data on BMI of patients who underwent curative intent neoadjuvant chemotherapy for breast cancer.

Methods: An IRB-approved retrospective review identified demographics (including BMI), disease presentation, response to treatment, and outcomes. ER and PR status were categorized as low positive (1-9%), positive (≥ 10%) and negative. Treatment response was noted as percent residual cellularity(complete 0%, almost complete < 10%, good 10-30%, moderate >30-80% and poor >80%) in the surgical specimen. Cox proportional hazards models were used to assess relationships with overall survival.

Results: 372 patients underwent curative-intent from 2005-2020; mean age was 51.0 years (SD=11.8); mean BMI was 28.6 (SD=6.3). Median follow-up was 4.3 years. There are significant differences in BMI among racial groups: American Indian (mean 31, SD 6.35), black (mean 30.1, SD 6.89), white (mean 28.3, SD 6.11) (p=0.001). There are significant differences in BMI between Hispanic and non-Hispanic patients: Hispanic (mean 29.6, SD 6.07), non-Hispanic (mean 27.5, SD 6.44), (p=0.001). Hormone receptor status (ER, PR, HER2 status) was not significantly associated with BMI, nor was treatment response either as complete pathologic response (p=0.52) or percent residual cellularity (p=0.98). BMI was not significantly associated in tumor shrinkage noted by changes in T stage or N stage categorizations from pre- to post-NAC. BMI was significantly associated with overall survival through interactions with ER status (p=0.01), and residual percent cellularity (p=0.02). ER- vs. ER+ risk was higher for those with low (HR, 95% CI=7.87, 2.60-23.8 at BMI=20) and moderate (HR, 95% CI=3.25, 1.68-6.33 at BMI=27.5). A five-point higher BMI was associated with a 1.6-fold higher mortality risk for those with complete percent residual cellularity (95% CI: 1.1-2.4), but this risk differential was not observed for those with good, moderate, or poor residual percent residual cellularity.

Conclusions: In our study, BMI was significantly associated with race and Hispanic ethnicity. Although there were no significant association of BMI with treatment response to neoadjuvant chemotherapy, there appears to be a significant relationship between BMI and overall patient survival, through its interactions with other prognostic factors. Future research efforts should focus on exploring reductions in BMI through modifications of diet and exercise in improving survival of breast cancer patients, particularly those with higher risk tumors.

Citation Format: Sangeetha Prabhakaran, Vernon S. Pankratz, Christopher F. McNicoll, Jacklyn M. Nemunaitis, Nadja Falk, Jain Zhou. Body mass index characterization of patients undergoing neoadjuvant chemotherapy for breast cancer: Correlation with survival. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6492.

Humanized Patient-derived Xenograft Models of Disseminated Ovarian Cancer Recapitulate Key Aspects of the Tumor Immune Environment within the Peritoneal Cavity

The importance of the immune microenvironment in ovarian cancer progression, metastasis, and response to therapies has become increasingly clear, especially with the new emphasis on immunotherapies. To leverage the power of patient-derived xenograft (PDX) models within a humanized immune microenvironment, three ovarian cancer PDXs were grown in humanized NBSGW (huNBSGW) mice engrafted with human CD34+ cord blood-derived hematopoietic stem cells. Analysis of cytokine levels in the ascites fluid and identification of infiltrating immune cells in the tumors demonstrated that these humanized PDX (huPDX) established an immune tumor microenvironment similar to what has been reported for patients with ovarian cancer. The lack of human myeloid cell differentiation has been a major setback for humanized mouse models, but our analysis shows that PDX engraftment increases the human myeloid population in the peripheral blood. Analysis of cytokines within the ascites fluid of huPDX revealed high levels of human M-CSF, a key myeloid differentiation factor as well as other elevated cytokines that have previously been identified in ovarian cancer patient ascites fluid including those involved in immune cell differentiation and recruitment. Human tumor-associated macrophages and tumor-infiltrating lymphocytes were detected within the tumors of humanized mice, demonstrating immune cell recruitment to tumors. Comparison of the three huPDX revealed certain differences in cytokine signatures and in the extent of immune cell recruitment. Our studies show that huNBSGW PDX models reconstitute important aspects of the ovarian cancer immune tumor microenvironment, which may recommend these models for preclinical therapeutic trials.

Significance

huPDX models are ideal preclinical models for testing novel therapies. They reflect the genetic heterogeneity of the patient population, enhance human myeloid differentiation, and recruit immune cells to the tumor microenvironment.

Colorectal Cancer Survival Trends in the United States From 1992 to 2018 Differ Among Persons From Five Racial and Ethnic Groups According to Stage at Diagnosis: A SEER-Based Study

Introduction

Survival following colorectal cancer (CRC) has improved in the US since 1975, but there is limited information on stage-specific survival trends among racial and ethnic subgroups.

Objectives

The purpose of this study was to estimate and compare trends in 1- and 5-year CRC cause-specific survival in the United States by both stage and race/ethnicity.

Methods

We performed a retrospective cohort study of individuals diagnosed with CRC using the 1992-2018 Surveillance, Epidemiology and End Results (SEER) database. We estimated and compared time trends in 1- and 5-year survival for CRC stage by race/ethnicity.

Results

Data from 399 220 individuals diagnosed with CRC were available. There were significant differences in stage-specific 1-year survival trends by race and ethnicity. Differences were most notable for distant stage CRC: survival probabilities increased most consistently for non-Hispanic American Indian/Alaska Native (AIAN) and Black (NHB) persons, but their trend lines were lower than those of Hispanic, and non-Hispanic Asian/Pacific Islander (API) and White (NHW) persons, whose initially greater gains appear to be slowing. Although the data do not support significant racial/ethnic differences in 5-year CRC survival trends by stage, AIAN and NHB persons have the lowest average survival probabilities for multiple CRC stages, and no racial/ethnic group has 5-year survival probabilities above 20% for distant-stage CRC.

Conclusion

Although there has been an overall improvement in adjusted CRC-specific survival probabilities since 1992, AIAN and NHB persons continue to experience worse prognosis than those of other races/ethnicities. This highlights the importance of reinvigorating efforts to understand the causes of mortality in CRC, including those which may differ according to an individual’s race or ethnicity.

Association between Quality of Life and Physical Functioning in a Gardening Intervention for Cancer Survivors

Purpose: To examine potential factors associated with maintaining or improving self-reported physical function (PF) among older cancer survivors participating in a gardening intervention impacted by the Coronavirus 2019 (COVID-19) pandemic. Methods: Thirty cancer survivors completed a home-based gardening intervention to encourage a healthier diet and a more active lifestyle. Device-based measures of physical activity (PA) and surveys to evaluate quality of life (QOL; PROMIS-57 questionnaire) were administered at baseline, mid-intervention (6 months), and post-intervention (9 months). Results: Depression, fatigue, and sleeplessness at baseline were significantly associated with worse average PF scores across follow-up (2.3 to 4.9 points lower for every decrease of 5 points in the QOL score; p-values < 0.02). Worsening of these QOL domains during the intervention was also associated with an additional decrease of 2.1 to 2.9 points in PF over follow-up (p values < 0.01). Better social participation and PA at baseline were significantly associated with better average PF scores during the intervention (2.8 to 5.2 points higher for every 5-point increase in social participation or 30 min more of PA; p values < 0.05). Every 5-point increase in pain at baseline, or increases in pain during the intervention, was associated with decreases of 4.9 and 3.0 points, respectively, in PF. Conclusions: Worse QOL scores before and during the intervention were significantly associated with worse PF over follow-up. Encouraging social participation and PA through interventions such as home-based gardening may improve long-term health among older cancer survivors.

Abstract 3686: Differences in disease presentation, and treatment outcomes of neoadjuvant chemotherapy for breast cancer among Hispanics in a minority-serving institution

Background: Response to neoadjuvant chemotherapy (NAC) for breast cancer varies by tumor characteristics and therapy regimen. Studies suggest that patient ethnicity is associated with differences in disease presentation, response to treatment, and outcomes. There exists a paucity of literature on the presentation and outcomes of NAC for breast cancer in Hispanic women.

Methods: This is an IRB-approved retrospective study of breast cancer patients who underwent NAC at an NCI-designated Comprehensive Cancer Center from 2005-2020. We reviewed demographics, disease presentation, response to treatment, and outcomes. ER and PR status were categorized as low positive (1-9%), positive (≥ 10%) and negative. Treatment factors reviewed included completion of chemotherapy and type of surgery performed. Treatment response was noted as percent residual cellularity (0%, &lt;10%, 10-30%, &gt;30-80% and &gt;80%) in the surgical specimen and pathologic stage. Outcomes were assessed as overall survival (OS) and recurrence.

Results: 365 patients received neoadjuvant chemotherapy from 2005-2020, and 196 (53.7%) self-identified as Hispanic. Median follow-up was 13.65 years. Highest clinical stage at diagnosis was most frequently IIA (31.2%), followed by IIB (32.3%), with non-significant Hispanic ethnicity differences, although Hispanic patients presented with higher clinical prognostic stages: IIIA or higher (40.5% vs. 24.0%).

Hispanics more frequently had grade 3 tumors (60% vs. 48%), ER low positive (10% vs. 7%) and ER negative (48% vs. 36%) (p=0.02). No significant differences were noted in triple negative disease or HER2 positive disease. Hispanics were diagnosed at younger average ages (48.9 vs. 53.0 years, p=0.001). No statistically significant differences were noted in time from diagnosis to NAC initiation, completion of chemotherapy, or surgical treatment received (lumpectomy vs. mastectomy, and sentinel node biopsy vs. dissection). Mastectomy was more likely for late-stage disease (OR=2.73, 95% CI: 1.66-4.49, p&lt;0.001); Hispanic women with late-stage disease had 1.09-fold higher odds of receiving mastectomy, but this was non-significant (95% CI: 0.66-1.79). No significant ethnic differences were noted in pCR (p=0.69) or residual tumor cellularity (p=0.63). There was no significant association between residual cellularity and OS. OS rates were similar for Hispanic vs. Non-Hispanic women (HR: 1.15, 95% CI: 0.64-2.08, p=0.63). No difference was noted in ethnicity-based recurrence rates (21.4 vs. 20.1%).

Conclusion: Self-identified Hispanic patients were diagnosed at a younger age, presented with higher ER negative and low-positive disease and worse prognostic clinical stage. However, given standard of care chemotherapy, there were no significant differences in their treatment response or outcomes compared to non-Hispanic patients.

Citation Format: Sangeetha Prabhakaran, Christopher McNicoll, Vernon S. Pankratz, Nadja Falk, Jacklyn Nemunaitis, Jain Zhou, Payton A. Sandoval-Belt. Differences in disease presentation, and treatment outcomes of neoadjuvant chemotherapy for breast cancer among Hispanics in a minority-serving institution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3686.

Using big data to gauge effectiveness of breast cancer awareness month

Breast Cancer Awareness Month (BCAM) has been used for decades to increase awareness and screening for breast cancer, but its geographic reach and effectiveness is difficult to judge. Using Internet Search Interest (ISI) could allow for better evaluation of BCAM effects. Using Google Trends, we evaluated the ISI for "breast cancer" and "mammogram" for each state and metropolitan area from 2006 to 2019. The ISI represents population level Google internet searches relative to the highest number of searches for the United States over a given period, with a max number of 100. The ISI for each term in October (BCAM) was compared against all other months during this period, across states and across major metropolitan regions. ISI was 2.34 times higher (95% Confidence Interval [CI]: 2.10-2.61, P < .001) in BCAM than the average for all other months combined. Geographically categorized data revealed that there were significant differences in the ISI for "breast cancer" and for "mammogram" among the 50 states, and among major metropolitan areas (P < .001for each). ISI suggests that BCAM is effective at increasing breast cancer related internet searches, with significant heterogeneity across states and metro areas. Google Trends is a publicly available free tool that can be used to assess penetrance of awareness campaigns in a time sensitive and location specific manner for future targeting of populations with low breast cancer awareness. Future research is needed to assess relationships between preventive outcomes and ISI scores.

Association of Daily Alcohol Intake, Volumetric Breast Density, and Breast Cancer Risk

High alcohol intake and breast density increase breast cancer (BC) risk, but their interrelationship is unknown. We examined whether volumetric density modifies and/or mediates the alcohol-BC association. BC cases (n = 2233) diagnosed from 2006 to 2013 in the San Francisco Bay area had screening mammograms 6 or more months before diagnosis; controls (n = 4562) were matched on age, mammogram date, race or ethnicity, facility, and mammography machine. Logistic regression was used to estimate alcohol-BC associations adjusted for age, body mass index, and menopause; interaction terms assessed modification. Percent mediation was quantified as the ratio of log (odds ratios [ORs]) from models with and without density measures. Alcohol consumption was associated with increased BC risk (2-sided P_trend = .004), as were volumetric percent density (OR = 1.45 per SD, 95% confidence interval [CI] = 1.36 to 1.56) and dense volume (OR = 1.30, 95% CI = 1.24 to 1.37). Breast density did not modify the alcohol-BC association (2-sided P > .10 for all). Dense volume mediated 25.0% (95% CI = 5.5% to 44.4%) of the alcohol-BC association (2-sided P = .01), suggesting alcohol may partially increase BC risk by increasing fibroglandular tissue.

Abstract PS3-24: Using big data to gauge effectiveness of breast cancer awareness month

Introduction: Breast Cancer Awareness Month (BCAM) has been used for decades to increase awareness and screening for breast cancer but it’s reach and effectiveness is difficult to judge. Using Internet Search Interest (ISI) could allow better evaluation of BCAM effects.Methods: Using Google Trends, we evaluated the ISI of a given term(s) as compared to that cancer’s awareness month. The ISI represents population level Google internet searches relative to the highest number of searches for the United States from 2004-2019 with a max number of 100. The ISI for breast cancer and mammogram in October, which is BCAM, was compared against all other months during this period. Results: The BCAM of October was associated with statistically significant more ISI for breast cancer 77.0 vs. 34.6 (95% CI 69.5-84.5, CI 32.9-35.3, p &lt; 0.0005) as compared to the rest of the year. ISI for mammogram was similar (41.6 vs. 60.2, 95% CI 39.4-43.7, 48.5-71.9, p = 0.007). There was significant differences between the top half of states with Mississippi (100), Delaware (97) and West Virginia (95) having the highest ISI while Nevada (60), Oregon (60) and Utah (57) the lowest (87.6 vs 71.8, 95% CI, 85.5-89.7, 69.0-74.6, p &lt; 0.0005). There was significant differences between the top half of 208 United States metro areas with Rochester MN (100), Greenwood MS (85) and Jackson MS (80) having the highest ISI while Salt Lake City UT (43), Idaho Falls UT (41) and Roanoke VA (40) the lowest (67.5 vs 54.4, 95% CI, 66.4-68.6, 53.4-55.4, p &lt; 0.0005). Conclusion: ISI suggests that BCAM is effective at increasing breast cancer awareness with significant heterogeneity across states and metro areas. This publicly available free tool can be used to assess penetrance of awareness campaigns in a time sensitive manor for future targeting of populations with low breast cancer awareness. Future research is needed to correlate outcomes and ISI.

Citation Format: Diamone A. Gathers, Vernon S. Pankratz, Bernard Tawfik. Using big data to gauge effectiveness of breast cancer awareness month [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-24.

Remote Assessment of Functional Mobility and Strength in Older Cancer Survivors: Protocol for a Validity and Reliability Study

BACKGROUND

Older cancer survivors, faced with both age- and treatment-related morbidity, are at increased and premature risk for physical function limitations. Physical performance is an important predictor of disability, quality of life, and premature mortality, and thus is considered an important target of interventions designed to prevent, delay, or attenuate the physical functional decline. Currently, low-cost, valid, and reliable methods to remotely assess physical performance tests that are self-administered by older adults in the home-setting do not exist, thus limiting the reach, scalability, and dissemination of interventions.

OBJECTIVE

This paper will describe the rationale and design for a study to evaluate the accuracy, reliability, safety, and acceptability of videoconferencing and self-administered tests of functional mobility and strength by older cancer survivors in their own homes.

METHODS

To enable remote assessment, participants receive a toolkit and instructions for setting up their test course and communicating with the investigator. Two standard gerontologic performance tests are being evaluated: the Timed Up and Go test and the 30-second chair stand test. Phase 1 of the study evaluates proof-of-concept that older cancer survivors (age ≥60 years) can follow the testing protocol and use a tablet PC to communicate with the study investigator. Phase 2 evaluates the criterion validity of videoconference compared to direct observation of the two physical performance tests. Phase 3 evaluates reliability by enrolling 5-10 participants who agree to repeat the remote assessment (without direct observation). Phase 4 enrolls 5-10 new study participants to complete the remote assessment test protocol. Feedback from participants in each phase is used to refine the test protocol and instructions.

RESULTS

Enrollment began in December 2019. Ten participants completed the Phase 1 proof-of-concept. The study was paused in mid-March 2020 due to the COVID-19 pandemic. The study is expected to be completed by the end of 2020.

CONCLUSIONS

This validity and reliability study will provide important information on the acceptability and safety of using videoconferencing to remotely assess two tests of functional mobility and strength, self-administered by older adults in their homes. Videoconferencing has the potential to expand the reach, scalability, and dissemination of interventions to older cancer survivors, and potentially other older adults, especially in rural areas.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04339959; https://clinicaltrials.gov/ct2/show/NCT04339959.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/20834.

American Indian chronic Renal insufficiency cohort study (AI-CRIC study)

Background

Chronic kidney disease (CKD) is an increasing epidemic globally that is associated with adverse health outcomes including end stage kidney disease (ESKD), cardiovascular disease (CVD), and death. American Indians (AIs) have a higher prevalence of CKD than most other racial/ethnic groups, due in part to a high prevalence of type 2 diabetes. Other genetic and environmental factors not yet identified may also contribute to the disproportionate burden of CKD in AIs.

Method

We will establish 3 clinical centers to recruit AIs from the Southwest United States (US) to expand the Chronic Renal Insufficiency Cohort (CRIC) study. We will follow the current CRIC protocol for kidney and cardiovascular measures and outcomes, which include ambulatory monitoring of kidney function and the use of mobile health technologies for CVD sub-phenotyping, and compare the outcomes in AIs with those in other racial/ethnic groups in CRIC.

Discussion

AI-CRIC will identify the role of various risk factors for rapid loss of kidney function among AIs of the Southwest US. In addition, to better understand the natural history of CKD and CVD in this high-risk population, we will identify unique risk factors for CKD and CVD progression in AIs. We will also compare event rates and risk factors for kidney and cardiovascular events in AIs with the other populations represented in CRIC.

Enhancer Domains in Gastrointestinal Stromal Tumor Regulate KIT Expression and Are Targetable by BET Bromodomain Inhibition

Gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm characterized by activating mutations in the related receptor tyrosine kinases KIT and PDGFRA. GIST relies on expression of these unamplified receptor tyrosine kinase (RTK) genes through a large enhancer domain, resulting in high expression levels of the oncogene required for tumor growth. Although kinase inhibition is an effective therapy for many patients with GIST, disease progression from kinase-resistant mutations is common and no other effective classes of systemic therapy exist. In this study, we identify regulatory regions of the KIT enhancer essential for KIT gene expression and GIST cell viability. Given the dependence of GIST upon enhancer-driven expression of RTKs, we hypothesized that the enhancer domains could be therapeutically targeted by a BET bromodomain inhibitor (BBI). Treatment of GIST cells with BBIs led to cell-cycle arrest, apoptosis, and cell death, with unique sensitivity in GIST cells arising from attenuation of the KIT enhancer domain and reduced KIT gene expression. BBI treatment in KIT-dependent GIST cells produced genome-wide changes in the H3K27ac enhancer landscape and gene expression program, which was also seen with direct KIT inhibition using a tyrosine kinase inhibitor (TKI). Combination treatment with BBI and TKI led to superior cytotoxic effects in vitro and in vivo, with BBI preventing tumor growth in TKI-resistant xenografts. Resistance to select BBI in GIST was attributable to drug efflux pumps. These results define a therapeutic vulnerability and clinical strategy for targeting oncogenic kinase dependency in GIST. SIGNIFICANCE: Expression and activity of mutant KIT is essential for driving the majority of GIST neoplasms, which can be therapeutically targeted using BET bromodomain inhibitors.

Surveillance of CKD epidemiology in the US - a joint analysis of NHANES and KEEP

Chronic Kidney Disease (CKD), is highly prevalent in the United States. Epidemiological systems for surveillance of CKD rely on data that are based solely on the NHANES survey, which does not include many patients with the most severe and less frequent forms of CKD. We investigated the feasibility of estimating CKD prevalence from the large-scale community disease detection Kidney Early Evaluation and Program (KEEP, n = 127,149). We adopted methodologies from the field of web surveys to address the self-selection bias inherent in KEEP. Primary outcomes studied were CKD Stage 3-5 (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2, and CKD Stage 4-5 (eGFR <30 mL/min/1.73 m2). The unweighted prevalence of Stage 4-5 CKD was higher in KEEP (1.00%, 95%CI: 0.94-1.05%) than in NHANES (0.51%, 95% CI: 0.43-0.59%). Application of a selection model that used  variables related to demographics, recruitment and socio-economic factors resulted in estimates similar to NHANES (0.55%, 95% CI: 0.50-0.60%). Weighted prevalence of Stages 3-5 CKD in KEEP was 6.45% (95% CI: 5.70-7.28%) compared to 6.73% (95% CI: 6.30-7.19%) for NHANES. Application of methodologies that address the self-selection bias in the KEEP program may allow the use of this large, geographically diverse dataset for CKD surveillance.

Abstract 3226: Overweight and obese women with high volumetric breast density at high breast cancer risk

Purpose: Volumetric breast density and body mass index (BMI) are increasingly used for breast cancer risk stratification. We examine if the effect of volumetric breast density on breast cancer risk increases with increasing BMI.

Methods: Participants were from two case-control studies within mammography practices, the San Francisco Mammography Registry and the Mayo Clinic Rochester, Breast Screening Practice. Breast cancers were included if diagnosed between January 2007 and 2015 and with a screening full-field digital mammogram at least 6 months prior to diagnosis; the earliest mammogram within 5 years of diagnosis was selected. Up to three controls were matched to each case on age, race, date, mammography machine, and state of residence. Volumetric percent density (VPD), dense volume (DV) and non-dense volume (NDV) were measured using VolparaTM software. Breast cancer risk was assessed using logistic regression stratified by menopause status and adjusted for matching factors, family history of breast cancer, parity/age at first birth, and postmenopausal hormone therapy. Models for DV were additionally adjusted for NDV, and NDV models for DV. Multiplicative interactions were fit between BMI categories [&lt;25 (underweight), 25-30 (normal weight) and &gt;30 (overweight/obese) kg/m2] and VPD, DV, and NDV, and trend tests assessed for increasing odds ratios (OR) with increasing BMI.

Results: A total of 781 premenopausal and 1850 postmenopausal breast cancers and 3535 controls were included in the analysis. Median age of premenopausal women was 45 years (IQR: 6.1) and 63.3 years (IQR: 14) for postmenopausal women. Cases vs. controls had greater VPD and DV for both premenopausal (VPD: 14.9% vs. 12.0%, DV: 74.1 cm3 vs. 64.4 cm3) and postmenopausal women (VPD: 6.8% vs. 6.1%, DV: 53.4 cm3 vs. 48.0 cm3)(all p's&lt;0.001). Trends between increasing BMI and VPD were evident for both pre (ptrend=0.0007) and postmenopausal (ptrend=0.0005) women. Among premenopausal women, the odds ratio (OR) for breast cancer associated with a 10% increase in VPD was of 1.39, 2.19 and 2.88 for BMI &lt;25, 25-30 and &gt;30 kg/m2 (p-trend=0.0007), respectively. For DV, OR's were 1.39, 1.33 and 1.51 for a 1 SD increase in DV, respectively, though the interaction with DV was not significant (ptrend=0.68). Among postmenopausal women, a 10% increase in VPD was associated with OR's of 1.35, 2.03, 3.6 for BMI &lt;25, 25-29, &gt;30-kg/m2 (ptrend =0.0001), respectively, and 1.31, 1.34 and 1.65 for a 1 SD increase in DV (ptrend =0.01), respectively. Associations between NDV and breast cancer risk did not differ by BMI category for premenopausal (ptrend =0.52) or postmenopausal (ptrend =0.07) women.

Conclusions: The effect of VPD on breast cancer risk is strongest in overweight/obese women. As volumetric breast density and BMI are commonly used in clinical risk stratification, these differences in risk have high clinical relevance for informing prevention decisions.

Citation Format: Natalie J. Engmann, Christopher G. Scott, Matthew R. Jensen, Stacey J. Winham, Lin Ma, Kathleen R. Brandt, Amir Mahmoudzadeh, Serghei Malkov, Dana Whaley, Carrie Hruska, Fang Fang Wu, Diana L. Miglioretti, Aaron D. Norman, John Heine, John Shepherd, Vernon S. Pankratz, Celine M. Vachon, Karla Kerlikowske. Overweight and obese women with high volumetric breast density at high breast cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3226.

Analysis of shared heritability in common disorders of the brain

Disorders of the brain can exhibit considerable epidemiological comorbidity and often share symptoms, provoking debate about their etiologic overlap. We quantified the genetic sharing of 25 brain disorders from genome-wide association studies of 265,218 patients and 784,643 control participants and assessed their relationship to 17 phenotypes from 1,191,588 individuals. Psychiatric disorders share common variant risk, whereas neurological disorders appear more distinct from one another and from the psychiatric disorders. We also identified significant sharing between disorders and a number of brain phenotypes, including cognitive measures. Further, we conducted simulations to explore how statistical power, diagnostic misclassification, and phenotypic heterogeneity affect genetic correlations. These results highlight the importance of common genetic variation as a risk factor for brain disorders and the value of heritability-based methods in understanding their etiology.

Assessment of the Clinical Relevance of BRCA2 Missense Variants by Functional and Computational Approaches

Many variants of uncertain significance (VUS) have been identified in BRCA2 through clinical genetic testing. VUS pose a significant clinical challenge because the contribution of these variants to cancer risk has not been determined. We conducted a comprehensive assessment of VUS in the BRCA2 C-terminal DNA binding domain (DBD) by using a validated functional assay of BRCA2 homologous recombination (HR) DNA-repair activity and defined a classifier of variant pathogenicity. Among 139 variants evaluated, 54 had ?99% probability of pathogenicity, and 73 had ?95% probability of neutrality. Functional assay results were compared with predictions of variant pathogenicity from the Align-GVGD protein-sequence-based prediction algorithm, which has been used for variant classification. Relative to the HR assay, Align-GVGD significantly (p < 0.05) over-predicted pathogenic variants. We subsequently combined functional and Align-GVGD prediction results in a Bayesian hierarchical model (VarCall) to estimate the overall probability of pathogenicity for each VUS. In addition, to predict the effects of all other BRCA2 DBD variants and to prioritize variants for functional studies, we used the endoPhenotype-Optimized Sequence Ensemble (ePOSE) algorithm to train classifiers for BRCA2 variants by using data from the HR functional assay. Together, the results show that systematic functional assays in combination with in silico predictors of pathogenicity provide robust tools for clinical annotation of BRCA2 VUS.

Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

We identified rare coding variants associated with Alzheimer's disease in a three-stage case-control study of 85,133 subjects. In stage 1, we genotyped 34,174 samples using a whole-exome microarray. In stage 2, we tested associated variants (P < 1 × 10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, we used an additional 14,997 samples to test the most significant stage 2 associations (P < 5 × 10-8) using imputed genotypes. We observed three new genome-wide significant nonsynonymous variants associated with Alzheimer's disease: a protective variant in PLCG2 (rs72824905: p.Pro522Arg, P = 5.38 × 10-10, odds ratio (OR) = 0.68, minor allele frequency (MAF)cases = 0.0059, MAFcontrols = 0.0093), a risk variant in ABI3 (rs616338: p.Ser209Phe, P = 4.56 × 10-10, OR = 1.43, MAFcases = 0.011, MAFcontrols = 0.008), and a new genome-wide significant variant in TREM2 (rs143332484: p.Arg62His, P = 1.55 × 10-14, OR = 1.67, MAFcases = 0.0143, MAFcontrols = 0.0089), a known susceptibility gene for Alzheimer's disease. These protein-altering changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified risk genes in Alzheimer's disease. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to the development of Alzheimer's disease.

PALB2, CHEK2 and ATM rare variants and cancer risk: data from COGS

BACKGROUND

The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study.

METHODS

We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2 c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant.

RESULTS

For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p=7.1×10-5), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p=6.9×10-8) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p≤0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p=0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p=0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants.

CONCLUSIONS

This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important.

Abstract 2593: Association of mammographic density measures and breast cancer ‘intrinsic’ molecular subtypes

Percent mammographic density (PMD) is a risk factor for estrogen receptor (ER)-positive and ER-negative invasive breast cancer (BC). Gene expression profiling has identified molecular signatures that classify invasive BC into distinct subtypes that vary in their clinical behavior, response to treatment and likely, etiology. Immunohistochemical (IHC) staining of tumor sections using antibody panels can be used to classify these ‘intrinsic’ molecular subtypes. We evaluated whether density measures [PMD, absolute dense area (DA) and non-dense area (NDA)], are associated equally with all ‘intrinsic’ molecular subtypes.

Pooled analysis of six cohort or case-control studies included 3492 women with invasive BC and 10,148 without, who underwent screening mammography a median 4 years prior to diagnosis (for cases). PMD, DA, and NDA were assessed from digitized film-screen mammograms using a computer-assisted thresholding technique, and categorized as 0-10%, 11-25%, 26-50% and 51%+ (PMD) or into quartiles (DA and NDA). Receptor status was abstracted from pathology records and supplemented by IHC staining. We classified tumors as Luminal A (ER+ and/or PR+ and HER2- and grade 1 or 2), Luminal B (ER+ and/or PR+ and HER2+ or Luminal A and grade 3), HER2 expressing (HER2+/ER-/PR-) and triple negative (TN) (ER-/PR-/HER2-). For TN, we also differentiated basal-like tumors (positive for EGFR and/or CK 5/6) from unclassified (negative on both markers). We used polytomous logistic regression to calculate the odds ratio (OR) of each ‘intrinsic’ subtype of BC by categories of PMD, DA or NDA, adjusting for age, body mass index and study. We tested for statistical heterogeneity of associations by subtype.

Of 3492 invasive BC cases, 2217 (63%) were classified as Luminal A, 747 (21%) as Luminal B, 159 (5%) as HER2 expressing, and 369 (11%) as TN. Of TN, 203 were evaluated for CK 5/6 and EGFR, with 167 (82%) classified as basal-like and 36 (18%) unclassified. PMD was associated with BC risk across all subtypes. For Luminal A, compared to women with 11-25% PMD (reference), women with 0-10% had a reduced risk of BC (OR = 0.63 [95% confidence interval: 0.55, 0.74]) while women with 26-50% had an OR = 1.5 [1.3, 1.7] and women with 51%+ had the highest risk, OR = 2.3 [2.0, 2.7]. Similar BC associations were seen across PMD categories when comparing the five subtypes (P-heterogeneity = 0.63). Similar trends were seen for DA and BC across the five subtypes (P-het = 0.25). NDA was inversely associated with BC across subtypes, and there was suggestion of a stronger inverse trend among HER2-expressing BC compared to other subtypes (P-het = 0.09).

Our results suggest mammographic density measures are associated with all ‘intrinsic’ molecular subtypes. However, NDA may be more strongly inversely associated with HER2-expressing than other subtypes. Understanding the importance of density measures for BC subtypes has significance for subtype-specific risk models.

Citation Format: Aaron D. Norman, Rulla M. Tamimi, Christopher G. Scott, Kimberly A. Bertrand, Matthew R. Jensen, Daniel W. Visscher, Fergus J. Couch, John Shepherd, Bo Fan, Yunn-Yi Chen, Lin Ma, Andrew Beck, Vernon S. Pankratz, Karla Kerlikowske, Celine M. Vachon. Association of mammographic density measures and breast cancer ‘intrinsic’ molecular subtypes. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2593.

Association of Elevated Amyloid Levels With Cognition and Biomarkers in Cognitively Normal People From the Community

IMPORTANCE

The role of amyloid in the progression of Alzheimer disease (AD) pathophysiology is of central interest to the design of randomized clinical trials. The presence of amyloid has become a prerequisite for enrollment in several secondary prevention trials for AD, yet the precise effect of elevated amyloid levels on subsequent clinical and biomarker events is less certain.

OBJECTIVE

To explore the effect of elevated amyloid levels on subsequent changes in cognition and biomarkers.

DESIGN, SETTING, AND PARTICIPANTS

A total of 564 cognitively normal individuals (median age, 78 years) from the Mayo Clinic Study of Aging, a population-based longitudinal study in Olmsted County, Minnesota, with serial cognitive data were selected for this study. The data used in this study were collected from January 12, 2006, to January 9, 2014. Individuals included in this study had undergone magnetic resonance imaging, fluorodeoxyglucose positron emission tomography (FDG-PET), and Pittsburgh Compound B (PiB) PET at baseline were not cognitively impaired at baseline and had at least 1 clinical follow-up. A subset of 286 individuals also underwent serial imaging. Elevated amyloid level was defined as a standardized uptake value ratio of greater than 1.5 on PiB PET. Associations with baseline amyloid status and baseline and longitudinal change in clinical and imaging measures were evaluated after adjusting for age and hippocampal volume. APOE4 effects were also evaluated.

MAIN OUTCOMES AND MEASURES

Cognitive measures of memory, language, attention/executive function, visuospatial skills, PiB levels, hippocampal and ventricular volumes, and FDG-PET measures.

RESULTS

At baseline, 179 (31.7%) individuals with elevated amyloid levels had poorer cognition in all domains measured, reduced hippocampal volume, and greater FDG-PET hypometabolism. Elevated amyloid levels at baseline were associated with a greater rate of cognitive decline in all domains (0.04 to 0.09 z score units per year) except language and a greater rate of amyloid accumulation (1.6% per year), hippocampal atrophy (30 mm3 per year), and ventricular enlargement (565 mm3 per year). Elevated amyloid levels were also associated with an increased risk of mild cognitive impairment (hazard ratio, 2.9; 95% CI, 1.7-5.0, and hazard ratio, 1.6; 95% CI, 0.9-2.8, for PiB+ APOE4 carriers and PiB+ noncarriers, respectively, compared with PiB- noncarriers). These associations were largely independent of APOE4.

CONCLUSIONS AND RELEVANCE

In persons selected from a population-based study, elevated amyloid levels at baseline were associated with worse cognition and imaging biomarkers at baseline and with greater clinical decline and neurodegeneration. These results have implications for the design of randomized clinical trials for AD.

Abstract A03: ERβ expression and breast cancer risk prediction for women with atypias

Introduction: Estrogen receptor beta (ERβ), which is highly expressed in benign breast epithelium, is postulated to function as a tumor suppressor of breast cancer. Atypias of the breast increase the lifetime risk of breast cancer four-fold. However, little is known about ERβ expression in association with atypias or whether ERβ plays a role in mitigating breast cancer risk in high-risk individuals. We therefore undertook this study to examine the relationship of ERβ expression in atypias and adjacent normal lobules with the risk of subsequent breast cancer.

Methods: We studied women in a well-characterized benign breast disease cohort with atypical ductal hyperplasia (ADH) or atypical lobular hyperplasia (ALH) diagnosed from 1967 to 1991. Nuclear and cytoplasmic ERβ expression was assessed via immunohistochemistry in both the atypical hyperplasia epithelium (atypia) and background normal lobules for percent (scores 0-4 for &lt;1%, 1-25%, 26-50%, 51-75%, &gt;75%, respectively) and intensity (scores 0-3 for negative, weak, intermediate, strong, respectively) using a highly specific ERβ monoclonal antibody (PPG5/10). For nuclear staining, an ERβ sum score (percent + intensity, range 0-7) was created and grouped as low (0-2), moderate (3-5) or high (6-7). Competing risks regression was used to assess the association of ERβ expression with future breast cancer risk while also accounting for the competing risk of death from other causes.

Results: 171 women, median age 56, were studied (79 ADH and 92 ALH). Median follow-up was 15 years overall, and 36 women developed breast cancer at a median of 13 years after their atypia biopsy. ERβ expression was lower in the atypia versus normal lobules whether evaluated by nuclear percent stained, nuclear intensity or cytoplasmic intensity (all p &lt; 0.001). For nuclear staining specifically, ERβ expression in the atypia was low in 44 (26%), moderate in 117 (68%) and high in only 10 (6%) based on the sum score. In contrast, ERβ was higher in the normal lobules with a majority showing high expression (n = 96, 56%), moderate expression in 74 (43%) and low expression in only 1 (0.6%). Lower ERβ nuclear expression in the atypia was associated with increased breast cancer risk, whether evaluated by percent staining, intensity or sum score; the same was true for ERβ nuclear expression in the background normal lobules. Low ERβ expression in the atypia (sum score 0-2) was associated with a 2-fold increased risk of subsequent breast cancer compared to atypia with moderate-high expression (sum score 3-7), HR 2.0, 95% CI: 1.02-3.8, p = 0.04. Lower ERβ expression in the normal lobules was also associated with an increased risk of future breast cancer: HR = 2.5 (95% CI: 1.3-5.1, p = 0.009) for low-moderate versus high expression.

Conclusions: Increased ERβ expression in normal and atypical lobules was associated with a significantly decreased risk of breast cancer in our high-risk patient cohort. These data suggest that in women with atypical hyperplasia, ERβ expression is protective against the future development of breast cancer. ERβ may serve as a useful biomarker to further stratify breast cancer risk in women with benign breast disease.

Citation Format: Tina J. Hieken, Jodi M. Carter, John R. Hawse, IV, Tanya L. Hoskin, Marlene Frost, Lynn C. Hartmann, Derek C. Radisky, Daniel W. Visscher, Vernon S. Pankratz, Amy C. Degnim. ERβ expression and breast cancer risk prediction for women with atypias. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A03.

Abstract P6-10-06: Histologic features of benign breast biopsy tissue and association with ER positive and ER negative breast cancer in the Mayo BBD cohort study

Introduction: Current models to predict breast cancer risk do not differentiate risk for estrogen receptor (ER) positive and negative breast cancer (BC), despite growing evidence that these tumors are biologically very different. We hypothesized that women with ER+ BC cancers have different clinical risk factors and histologic findings on prior benign breast biopsies than those with ER- BC.

Methods: After IRB approval, we examined associations of age at benign biopsy and histologic features of the benign biopsy with ER status of incident BCs within the Mayo Benign Breast Disease Cohort. Benign biopsy slides were reviewed for extent of lobular involution and degree of epithelial proliferation by a single breast pathologist blinded to BC events. Invasive BCs occurring within 15 years after benign biopsy were classified as ER+ if ER staining was &gt;1%. BC case-only associations with ER status were evaluated using multivariate logistic regression. Full-cohort hazard ratios (HR) and 95% confidence intervals (CI) for risk of ER-specific subtypes were estimated using Cox proportion hazards regression.

Results: Among 13,410 women undergoing a benign breast biopsy from 1967-2001, 656 invasive BCs (459 ER+, 106 ER, 106 unknown) occurred within 15 years. Women who developed ER+ and ER- BCs were similar in age at the time of their prior benign breast biopsy (p=0.34). Although benign biopsies in women who later developed ER+ BC were more likely to show complete involution (23% vs 15% for ER- BC), this was not statistically significant (p=0.06). However, the degree of epithelial proliferation was significantly associated with ER status of later BCs (p=0.001), with ER+ BCs more likely than ER- BCs to have had a prior biopsy with atypical hyperplasia (16% vs 8%), and ER+ BCs less likely than ER- BCs to have had a prior biopsy with proliferative disease without atypia (33% vs 52%); this association remained after multivariate adjustment (p=0.003). We further pursued the association of epithelial proliferation with differential risk of ER+ and ER- BC in our overall cohort of 13,410 women (Table 1). Compared to women with non-proliferative disease, women with proliferative disease +/- atypia had ∼2-fold hazard ratios for ER- BC, whereas hazard ratios for ER+ BC were higher in women with atypical hyperplasia (∼4-fold) compared to proliferative disease.

Hazard Ratio of ER+ and ER- BC within 15 years of BBD based upon degree of epithelial proliferation at benign biopsyCancer TypeGroupNN EventsHazard Ratio (95% CI)p-valueInvasive ER- ≤15 yearsNP8478421.00 (ref)&lt;0.0001 PD4229542.63 (1.76, 3.93)  AH70382.60 (1.22, 5.54)       Invasive ER+ ≤15 yearsNP84782321.00 (ref)&lt;0.0001 PD42291511.33 (1.09, 1.64)  AH703744.41 (3.39, 5.73) NP=nonproliferative disease, PD=proliferative disease without atypia; AH=atypical hyperplasia

Conclusion: ER+ and ER- breast cancers appear to have different features on prior benign breast biopsy, with atypical hyperplasia showing increased risk for both types of breast cancer, but a greater risk for ER+ tumors.

Citation Format: Amy C Degnim, Derek C Radisky, Robert A Vierkant, Ryan D Frank, Marlene H Frost, Vernon S Pankratz, Celine M Vachon, Tanya L Hoskin, Julie M Cunningham, Chen Wang, Jean-Pierre Kocher, Teresa M Allers, Joanne L Johnson, Tina J Hieken, Karthik Ghosh, Lynn C Hartmann, Daniel W Visscher. Histologic features of benign breast biopsy tissue and association with ER positive and ER negative breast cancer in the Mayo BBD cohort study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-10-06.

Abstract P4-12-03: Triple-negative breast cancer: Frequency of inherited mutations in breast cancer susceptibility genes

Background: Guidelines recommend germline mutation testing of breast cancer predisposition genes in triple negative (TN) breast cancer cases with a family history of breast or ovarian cancer or when diagnosed under age 60. However, the prevalence of mutations in these genes among TN cases unselected for family history of breast or ovarian cancer is not known.

Methods: To assess the frequency of mutations in 16 predisposition genes in TN cases we screened a large cohort of TN patients (n=1824) unselected for family history of breast or ovarian cancer from 12 centers and 824 study matched unaffected controls for mutations using a panel-based sequencing approach.

Results: Deleterious mutations were identified in 15% of TN patients: 8.5% had BRCA1, 2.7% had BRCA2, and 3.6% had mutations in 12 other genes. Mutations in non-BRCA1/2 genes encoding proteins implicated in homologous recombination repair of DNA double strand breaks were detected at the same frequency as in breast cancer families. TN cases with mutations had high-grade tumors and were diagnosed at an earlier age than non-mutated cases. However, 10% of TN cases diagnosed at ≥60 years and 5% with no family history of cancer were also found to carry mutations. Inactivating mutations in non-BRCA1/2 predisposition genes were associated with moderate to high risks of TN breast cancer.

Conclusions: National Comprehensive Cancer Network (NCCN) guidelines support clinical genetic testing of breast cancer predisposition genes in 95% of TN breast cancer patients carrying mutations in susceptibility genes. In contrast, National Institute of Health and Care Excellence (NICE) guidelines in the U.K. do not support genetic testing of a substantial proportion of TN patients with predisposing alleles. Frequency tables for inherited mutations in known predisposition genes based on age of diagnosis and family history of cancer will allow for selection of TN patients most likely to carry mutations in the predisposition genes.

Citation Format: Fergus J Couch, Steven N Hart, Priyanka Sharma, Amanda Ewart Toland, Penelope Miron, Janet E Olson, Andrew Godwin, Vernon S Pankratz, Curtis Olswold, Seth Slettedahl, Lucia Guidugli, Matthias W Beckmann, Brigitte Rack, Arif B Ekici, Irene Konstantopoulou, Florentia Fostira, George Fountzilas, Liisa M Pelttari, Song Yao, Judy Garber, Angela Cox, Hiltrud Brauch, Christine Ambrosone, Heli Nevanlinna, Drakoulis Yannoukakos, Susan L Slager, Celine M Vachon, Diana M Eccles, Peter A Fasching. Triple-negative breast cancer: Frequency of inherited mutations in breast cancer susceptibility genes [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-12-03.

Prediction of breast cancer risk based on profiling with common genetic variants

BACKGROUND

Data for multiple common susceptibility alleles for breast cancer may be combined to identify women at different levels of breast cancer risk. Such stratification could guide preventive and screening strategies. However, empirical evidence for genetic risk stratification is lacking.

METHODS

We investigated the value of using 77 breast cancer-associated single nucleotide polymorphisms (SNPs) for risk stratification, in a study of 33 673 breast cancer cases and 33 381 control women of European origin. We tested all possible pair-wise multiplicative interactions and constructed a 77-SNP polygenic risk score (PRS) for breast cancer overall and by estrogen receptor (ER) status. Absolute risks of breast cancer by PRS were derived from relative risk estimates and UK incidence and mortality rates.

RESULTS

There was no strong evidence for departure from a multiplicative model for any SNP pair. Women in the highest 1% of the PRS had a three-fold increased risk of developing breast cancer compared with women in the middle quintile (odds ratio [OR] = 3.36, 95% confidence interval [CI] = 2.95 to 3.83). The ORs for ER-positive and ER-negative disease were 3.73 (95% CI = 3.24 to 4.30) and 2.80 (95% CI = 2.26 to 3.46), respectively. Lifetime risk of breast cancer for women in the lowest and highest quintiles of the PRS were 5.2% and 16.6% for a woman without family history, and 8.6% and 24.4% for a woman with a first-degree family history of breast cancer.

CONCLUSIONS

The PRS stratifies breast cancer risk in women both with and without a family history of breast cancer. The observed level of risk discrimination could inform targeted screening and prevention strategies. Further discrimination may be achievable through combining the PRS with lifestyle/environmental factors, although these were not considered in this report.

An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

INTRODUCTION

Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers.

METHODS

We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals.

RESULTS

We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk.

CONCLUSIONS

This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.

Association of type and location of BRCA1 and BRCA2 mutations with risk of breast and ovarian cancer

IMPORTANCE

Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists.

OBJECTIVE

To identify mutation-specific cancer risks for carriers of BRCA1/2.

DESIGN, SETTING, AND PARTICIPANTS

Observational study of women who were ascertained between 1937 and 2011 (median, 1999) and found to carry disease-associated BRCA1 or BRCA2 mutations. The international sample comprised 19,581 carriers of BRCA1 mutations and 11,900 carriers of BRCA2 mutations from 55 centers in 33 countries on 6 continents. We estimated hazard ratios for breast and ovarian cancer based on mutation type, function, and nucleotide position. We also estimated RHR, the ratio of breast vs ovarian cancer hazard ratios. A value of RHR greater than 1 indicated elevated breast cancer risk; a value of RHR less than 1 indicated elevated ovarian cancer risk.

EXPOSURES

Mutations of BRCA1 or BRCA2.

MAIN OUTCOMES AND MEASURES

Breast and ovarian cancer risks.

RESULTS

Among BRCA1 mutation carriers, 9052 women (46%) were diagnosed with breast cancer, 2317 (12%) with ovarian cancer, 1041 (5%) with breast and ovarian cancer, and 7171 (37%) without cancer. Among BRCA2 mutation carriers, 6180 women (52%) were diagnosed with breast cancer, 682 (6%) with ovarian cancer, 272 (2%) with breast and ovarian cancer, and 4766 (40%) without cancer. In BRCA1, we identified 3 breast cancer cluster regions (BCCRs) located at c.179 to c.505 (BCCR1; RHR = 1.46; 95% CI, 1.22-1.74; P = 2 × 10(-6)), c.4328 to c.4945 (BCCR2; RHR = 1.34; 95% CI, 1.01-1.78; P = .04), and c. 5261 to c.5563 (BCCR2', RHR = 1.38; 95% CI, 1.22-1.55; P = 6 × 10(-9)). We also identified an ovarian cancer cluster region (OCCR) from c.1380 to c.4062 (approximately exon 11) with RHR = 0.62 (95% CI, 0.56-0.70; P = 9 × 10(-17)). In BRCA2, we observed multiple BCCRs spanning c.1 to c.596 (BCCR1; RHR = 1.71; 95% CI, 1.06-2.78; P = .03), c.772 to c.1806 (BCCR1'; RHR = 1.63; 95% CI, 1.10-2.40; P = .01), and c.7394 to c.8904 (BCCR2; RHR = 2.31; 95% CI, 1.69-3.16; P = .00002). We also identified 3 OCCRs: the first (OCCR1) spanned c.3249 to c.5681 that was adjacent to c.5946delT (6174delT; RHR = 0.51; 95% CI, 0.44-0.60; P = 6 × 10(-17)). The second OCCR spanned c.6645 to c.7471 (OCCR2; RHR = 0.57; 95% CI, 0.41-0.80; P = .001). Mutations conferring nonsense-mediated decay were associated with differential breast or ovarian cancer risks and an earlier age of breast cancer diagnosis for both BRCA1 and BRCA2 mutation carriers.

CONCLUSIONS AND RELEVANCE

Breast and ovarian cancer risks varied by type and location of BRCA1/2 mutations. With appropriate validation, these data may have implications for risk assessment and cancer prevention decision making for carriers of BRCA1 and BRCA2 mutations.

Assessing associations between the AURKA-HMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood approach. The association of HMMR rs299290 with breast cancer risk in BRCA1 mutation carriers was confirmed: per-allele hazard ratio (HR) = 1.10, 95% confidence interval (CI) 1.04-1.15, p = 1.9 x 10(-4) (false discovery rate (FDR)-adjusted p = 0.043). Variation in CSTF1, located next to AURKA, was also found to be associated with breast cancer risk in BRCA2 mutation carriers: rs2426618 per-allele HR = 1.10, 95% CI 1.03-1.16, p = 0.005 (FDR-adjusted p = 0.045). Assessment of pairwise interactions provided suggestions (FDR-adjusted pinteraction values > 0.05) for deviations from the multiplicative model for rs299290 and CSTF1 rs6064391, and rs299290 and TUBG1 rs11649877 in both BRCA1 and BRCA2 mutation carriers. Following these suggestions, the expression of HMMR and AURKA or TUBG1 in sporadic breast tumors was found to potentially interact, influencing patients' survival. Together, the results of this study support the hypothesis of a causative link between altered function of AURKA-HMMR-TPX2-TUBG1 and breast carcinogenesis in BRCA1/2 mutation carriers.

Candidate pathway-based genetic association study of platinum and platinum-taxane related toxicity in a cohort of primary lung cancer patients

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity secondary to chemotherapy. Genetic factors may be important in predisposing patients to this adverse effect.

PATIENTS AND METHODS

We studied 950 primary lung cancer patients, who received platinum or platinum-combination drug chemotherapy and who had DNA available for study. We analyzed epidemiological risk factors in 279 CIPN patients and 456 non-CIPN patients and genetic risk factors in 141 CIPN patients and 259 non-CIPN patients. The risk factors studied included demographic, diagnostic, and treatment data, as well as 174 tag SNPs (single nucleotide polymorphisms) across 43 candidate genes in the glutathione, cell cycle, DNA repair, cell signaling, and apoptosis pathways.

RESULTS

Patients who had diabetes mellitus were more likely to have CIPN (p=0.0002). Other epidemiologic risk factors associated with CIPN included number of cycles (p=0.0004) and type of concurrent chemotherapy (p<0.001). SNPs most associated with CIPN were in glutathione peroxidase 7 (GPX7) gene (p values 0.0015 and 0.0028, unadjusted and adjusted) and in ATP-binding cassette sub-family C member 4 (ABCC4) gene (p values 0.037 and 0.006, unadjusted and adjusted). We also found other suggestive associations in methyl-o-guanine-methyl-transferase (MGMT) and glutathione-S-transferase (GST) isoforms.

CONCLUSIONS

Epidemiological and genetic risk factors associated with CIPN in this cohort, included the type of chemotherapy drug, intensity of chemotherapy treatment, and genes known to be associated with chemotherapy resistance. These findings suggest that differentiating between cytotoxic and neurotoxic mechanisms of chemotherapy drugs is challenging but represents an important step toward individualized therapy and improving quality of life for patients.

Identification of six new susceptibility loci for invasive epithelial ovarian cancer

Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.

Abstract 44: Associations of Atrial Fibrillation, Neuroimaging Measures of Cerebrovascular Disease and Alzheimer’S Disease-related Pathology, and Cognitive Impairment

The objective of this study was to investigate the cross-sectional associations of atrial fibrillation with neuroimaging measures of cerebrovascular disease and Alzheimer’s disease-related pathology, and their interaction with cognitive impairment. MRI scans of non-demented individuals (n=1044) from the population-based Mayo Clinic Study of Aging were analyzed for infarctions, total grey matter, hippocampal and white matter hyperintensity volumes. A subset of 496 individuals underwent FDG and C-11 Pittsburgh compound B (PiB) PET scans. We assessed the associations of atrial fibrillation with i) categorical MRI measures (cortical and subcortical infarctions) using multivariable logistic regression models, and with ii) continuous MRI measures ( hippocampal, total grey matter, and white matter hyperintensity volumes) and FDG-PET and PiB-PET measures using multivariable linear regression models, and adjusting for confounders. Among participants who underwent MRI (median age, 77.8, 51.6% male), 13.5% had atrial fibrillation. Presence of atrial fibrillation was associated with subcortical infarctions (odds ratio [OR], 1.83; p=0.002), cortical infarctions (OR, 1.91; p=0.03), total grey matter volume (Beta [β], -.025, p<.0001) after controlling for age, education, gender, APOE e4 carrier status, coronary artery disease, diabetes, history of clinical stroke, and hypertension. However, atrial fibrillation was not associated with white matter hyperintensity volume, hippocampal volume, Alzheimer’s pattern of FDG hypometabolism or PiB uptake. There was a significant interaction of cortical infarction (p for interaction=0.004) and subcortical infarction (p for interaction =0.015) with atrial fibrillation with regards to odds of mild cognitive impairment (MCI). Using subjects with no atrial fibrillation and no infarction as the reference, the OR (95% confidence intervals [CI]) for MCI was 2.98 (1.66, 5.35;p = 0.0002) among participants with atrial fibrillation and any infarction, 0.69 (0.36, 1.33;p= 0.27) for atrial fibrillation and no infarction, and 1.50 (0.96, 2.32;p = 0.07) for no atrial fibrillation and any infarction. These data highlight that atrial fibrillation is associated with MCI in the presence of infarctions.

Associations of common breast cancer susceptibility alleles with risk of breast cancer subtypes in BRCA1 and BRCA2 mutation carriers

INTRODUCTION

More than 70 common alleles are known to be involved in breast cancer (BC) susceptibility, and several exhibit significant heterogeneity in their associations with different BC subtypes. Although there are differences in the association patterns between BRCA1 and BRCA2 mutation carriers and the general population for several loci, no study has comprehensively evaluated the associations of all known BC susceptibility alleles with risk of BC subtypes in BRCA1 and BRCA2 carriers.

METHODS

We used data from 15,252 BRCA1 and 8,211 BRCA2 carriers to analyze the associations between approximately 200,000 genetic variants on the iCOGS array and risk of BC subtypes defined by estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and triple-negative- (TN) status; morphologic subtypes; histological grade; and nodal involvement.

RESULTS

The estimated BC hazard ratios (HRs) for the 74 known BC alleles in BRCA1 carriers exhibited moderate correlations with the corresponding odds ratios from the general population. However, their associations with ER-positive BC in BRCA1 carriers were more consistent with the ER-positive associations in the general population (intraclass correlation (ICC) = 0.61, 95% confidence interval (CI): 0.45 to 0.74), and the same was true when considering ER-negative associations in both groups (ICC = 0.59, 95% CI: 0.42 to 0.72). Similarly, there was strong correlation between the ER-positive associations for BRCA1 and BRCA2 carriers (ICC = 0.67, 95% CI: 0.52 to 0.78), whereas ER-positive associations in any one of the groups were generally inconsistent with ER-negative associations in any of the others. After stratifying by ER status in mutation carriers, additional significant associations were observed. Several previously unreported variants exhibited associations at P <10(-6) in the analyses by PR status, HER2 status, TN phenotype, morphologic subtypes, histological grade and nodal involvement.

CONCLUSIONS

Differences in associations of common BC susceptibility alleles between BRCA1 and BRCA2 carriers and the general population are explained to a large extent by differences in the prevalence of ER-positive and ER-negative tumors. Estimates of the risks associated with these variants based on population-based studies are likely to be applicable to mutation carriers after taking ER status into account, which has implications for risk prediction.

Refined histopathological predictors of BRCA1 and BRCA2 mutation status: a large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia

INTRODUCTION

The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling.

METHODS

Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the likelihood of mutation status by histopathological markers were derived using a Mantel-Haenszel approach.

RESULTS

ER-positive phenotype negatively predicted BRCA1 mutation status, irrespective of grade (LRs from 0.08 to 0.90). ER-negative grade 3 histopathology was more predictive of positive BRCA1 mutation status in women 50 years or older (LR = 4.13 (3.70 to 4.62)) versus younger than 50 years (LR = 3.16 (2.96 to 3.37)). For BRCA2, ER-positive grade 3 phenotype modestly predicted positive mutation status irrespective of age (LR = 1.7-fold), whereas ER-negative grade 3 features modestly predicted positive mutation status at 50 years or older (LR = 1.54 (1.27 to 1.88)). Triple-negative tumor status was highly predictive of BRCA1 mutation status for women younger than 50 years (LR = 3.73 (3.43 to 4.05)) and 50 years or older (LR = 4.41 (3.86 to 5.04)), and modestly predictive of positive BRCA2 mutation status in women 50 years or older (LR = 1.79 (1.42 to 2.24)).

CONCLUSIONS

These results refine likelihood-ratio estimates for predicting BRCA1 and BRCA2 mutation status by using commonly measured histopathological features. Age at diagnosis is an important variable for most analyses, and grade is more informative than ER status for BRCA2 mutation carrier prediction. The estimates will improve BRCA1 and BRCA2 variant classification and inform patient mutation testing and clinical management.

Effects of multiple genetic loci on age at onset in late-onset Alzheimer disease: a genome-wide association study

IMPORTANCE

Because APOE locus variants contribute to risk of late-onset Alzheimer disease (LOAD) and to differences in age at onset (AAO), it is important to know whether other established LOAD risk loci also affect AAO in affected participants.

OBJECTIVES

To investigate the effects of known Alzheimer disease risk loci in modifying AAO and to estimate their cumulative effect on AAO variation using data from genome-wide association studies in the Alzheimer Disease Genetics Consortium.

DESIGN, SETTING, AND PARTICIPANTS

The Alzheimer Disease Genetics Consortium comprises 14 case-control, prospective, and family-based data sets with data on 9162 participants of white race/ethnicity with Alzheimer disease occurring after age 60 years who also had complete AAO information, gathered between 1989 and 2011 at multiple sites by participating studies. Data on genotyped or imputed single-nucleotide polymorphisms most significantly associated with risk at 10 confirmed LOAD loci were examined in linear modeling of AAO, and individual data set results were combined using a random-effects, inverse variance-weighted meta-analysis approach to determine whether they contribute to variation in AAO. Aggregate effects of all risk loci on AAO were examined in a burden analysis using genotype scores weighted by risk effect sizes.

MAIN OUTCOMES AND MEASURES

Age at disease onset abstracted from medical records among participants with LOAD diagnosed per standard criteria.

RESULTS

Analysis confirmed the association of APOE with earlier AAO (P = 3.3 × 10(-96)), with associations in CR1 (rs6701713, P = 7.2 × 10(-4)), BIN1 (rs7561528, P = 4.8 × 10(-4)), and PICALM (rs561655, P = 2.2 × 10(-3)) reaching statistical significance (P < .005). Risk alleles individually reduced AAO by 3 to 6 months. Burden analyses demonstrated that APOE contributes to 3.7% of the variation in AAO (R(2) = 0.256) over baseline (R(2) = 0.221), whereas the other 9 loci together contribute to 2.2% of the variation (R(2) = 0.242).

CONCLUSIONS AND RELEVANCE

We confirmed an association of APOE (OMIM 107741) variants with AAO among affected participants with LOAD and observed novel associations of CR1 (OMIM 120620), BIN1 (OMIM 601248), and PICALM (OMIM 603025) with AAO. In contrast to earlier hypothetical modeling, we show that the combined effects of Alzheimer disease risk variants on AAO are on the scale of, but do not exceed, the APOE effect. While the aggregate effects of risk loci on AAO may be significant, additional genetic contributions to AAO are individually likely to be small.

Abstract 1652: Immune infiltration of normal and benign breast lobules varies in breast tissues based on cancer risk

Introduction: Histologic characteristics of nonmalignant breast tissues (epithelial proliferation and involution) are associated with future breast cancer (BC) risk. We evaluated immune infiltration (lobulitis) in benign breast lobules and its association with features of BC risk.

Methods: We analyzed archived nonmalignant breast tissue samples from 81 women in age-matched groups of varying cancer risk: 27 with benign breast disease (BBD) who later developed BC (cases), 27 with BBD without subsequent BC (controls), and 27 normal women without clinical breast disease from the Komen Tissue Bank at Indiana University (KTB). Up to 10 lobules in each sample were characterized by H&E for lobulitis, involution (none, partial, complete), and fibrocystic (FC) status (normal, nonproliferative, proliferative). Lobulitis was defined by H&E staining as lymphocyte nuclei in the intralobular stroma at low magnification and between adjacent acini at high magnification. Data was analyzed by mixed effects logistic regression.

Results: Median age was 57 years (range 37-70). Among 81 breast tissue samples, 750 lobules were evaluated: 249 in BBD Cases, 265 in BBD Controls, and 236 in KTB donors. 56% of lobules were normal and 44% were FC, with 87% of FC lobules occurring in BBD samples. Lobulitis was present in 44% of lobules and varied according to subject age and individual lobule features. Younger women were more likely to have lobulitis (p=0.002); among women &lt;50 the median proportion of lobules with lobulitis was 50%, versus 30% among women 50+. Lobulitis was less frequent in lobules with complete involution (37%) compared to partial (74%) or no involution (84%), p&lt;0.0001. Lobulitis was common in normal lobules (52%) and decreased with increasing epithelial abnormality-39% of nonproliferative lobules and 27% of proliferative lobules (p&lt;0.0001). In multivariate analysis including all 3 variables, all 3 remained significantly associated with lobulitis: age (p=0.03), proliferation (p&lt;0.0001), and involution (p=0.0001). Lobules with lobulitis were less frequent in groups of women with increased breast cancer risk-55% of lobules in normal KTB samples, 43% in BBD controls, and 35% in BBD cases (p = 0.02).

Conclusion: Lobulitis is common in normal and benign breast tissue lobules but varies with age, involution status, and epithelial abnormality. Further work is needed to understand the role of immune infiltrates in breast cancer risk.

Citation Format: Rushin D. Brahmbhatt, Daniel W. Visscher, Tanya L. Hoskin, Derek C. Radisky, Linda M. Murphy, Melody L. Stallings Mann, Erin Miller, Vernon S. Pankratz, Lynn C. Hartmann, Marlene H. Frost, Amy C. Degnim. Immune infiltration of normal and benign breast lobules varies in breast tissues based on cancer risk. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1652. doi:10.1158/1538-7445.AM2014-1652

Age-specific population frequencies of cerebral β-amyloidosis and neurodegeneration among people with normal cognitive function aged 50-89 years: a cross-sectional study

BACKGROUND

As preclinical Alzheimer's disease becomes a target for therapeutic intervention, the overlap between imaging abnormalities associated with typical ageing and those associated with Alzheimer's disease needs to be recognised. We aimed to characterise how typical ageing and preclinical Alzheimer's disease overlap in terms of β-amyloidosis and neurodegeneration.

METHODS

We measured age-specific frequencies of amyloidosis and neurodegeneration in individuals with normal cognitive function aged 50-89 years. Potential participants were randomly selected from the Olmsted County (MN, USA) population-based study of cognitive ageing and invited to participate in cognitive and imaging assessments. To be eligible for inclusion, individuals must have been judged clinically to have no cognitive impairment and have undergone amyloid PET, (18)F-fluorodeoxyglucose ((18)F-FDG) PET, and MRI. Imaging results were obtained from March 28, 2006, to Dec 3, 2013. Amyloid status (positive [A(+)] or negative [A(-)]) was determined by amyloid PET with (11)C Pittsburgh compound B. Neurodegeneration status (positive [N(+)] or negative [N(-)]) was determined by an Alzheimer's disease signature (18)F-FDG PET or hippocampal volume on MRI. We determined age-specific frequencies of the four groups (amyloid negative and neurodegeneration negative [A(-)N(-)], amyloid positive and neurodegeneration negative [A(+)N(-)], amyloid negative and neurodegeneration positive [A(-)N(+)], or amyloid positive and neurodegeneration positive [A(+)N(+)]) cross-sectionally using multinomial regression models. We also investigated associations of group frequencies with APOE ɛ4 status (assessed with DNA extracted from blood) and sex by including these covariates in the multinomial models.

FINDINGS

The study population consisted of 985 eligible participants. The population frequency of A(-)N(-) was 100% (n=985) at age 50 years and fell to 17% (95% CI 11-24) by age 89 years. The frequency of A(+)N(-) increased to 28% (24-32) at age 74 years, then decreased to 17% (11-25) by age 89 years. The frequency of A(-)N(+) increased from age 60 years, reaching 24% (16-34) by age 89 years. The frequency of A(+)N(+) increased from age 65 years, reaching 42% (31-52) by age 89 years. The results from our multinomial models suggest that A(+)N(-) and A(+)N(+) were more frequent in APOE ɛ4 carriers than in non-carriers and that A(+)N(+) was more, and A(+)N(-) less frequent in men than in women.

INTERPRETATION

Accumulation of amyloid and neurodegeneration are nearly inevitable by old age, but many people are able to maintain normal cognitive function despite these imaging abnormalities. Changes in the frequency of amyloidosis and neurodegeneration with age, which seem to be modified by APOE ɛ4 and sex, suggest that pathophysiological sequences might differ between individuals.

FUNDING

US National Institute on Aging and Alexander Family Professorship of Alzheimer's Disease Research.

Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: a case-control study

INTRODUCTION

We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years.

METHODS

We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics.

RESULTS

We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P(trend) = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P(trend) = 0.005) but not cases (P(trend) = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P(het) = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≥15 years (OR(het) = 0.84, 95% CI 0.75, 0.94; OR(hom) = 0.81, 95% CI 0.51, 1.30; P(trend) = 0.002) but not for those who had their menarche age ≤11 years (OR(het) = 1.06, 95% CI 0.95, 1.19, OR(hom) = 1.07, 95% CI 0.67, 1.72; P(trend) = 0.29).

CONCLUSIONS

To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels.

Baseline neuropsychiatric symptoms and the risk of incident mild cognitive impairment: a population-based study

OBJECTIVE

The authors conducted a prospective cohort study to estimate the risk of incident mild cognitive impairment in cognitively normal elderly (aged ≥70 years) individuals with or without neuropsychiatric symptoms at baseline. The research was conducted in the setting of the population-based Mayo Clinic Study of Aging.

METHOD

A classification of normal cognitive aging, mild cognitive impairment, and dementia was adjudicated by an expert consensus panel based on published criteria. Hazard ratios and 95% confidence intervals were computed using Cox proportional hazards model, with age as a time scale. Baseline Neuropsychiatric Inventory Questionnaire data were available for 1,587 cognitively normal persons who underwent at least one follow-up visit.

RESULTS

The cohort was followed to incident mild cognitive impairment (N=365) or censoring variables (N=179) for a median of 5 years. Agitation (hazard ratio=3.06, 95% CI=1.89-4.93), apathy (hazard ratio=2.26, 95% CI=1.49-3.41), anxiety (hazard ratio=1.87, 95% CI=1.28-2.73), irritability (hazard ratio=1.84, 95% CI=1.31-2.58), and depression (hazard ratio=1.63, 95% CI=1.23-2.16), observed initially, increased risk for later mild cognitive impairment. Delusion and hallucination did not. A secondary analysis, limited in significance by the small number of study participants, showed that euphoria, disinhibition, and nighttime behaviors were significant predictors of nonamnestic mild cognitive impairment but not amnestic mild cognitive impairment. By contrast, depression predicted amnestic mild cognitive impairment (hazard ratio=1.74, 95% CI=1.22-2.47) but not nonamnestic mild cognitive impairment.

CONCLUSIONS

An increased incidence of mild cognitive impairment was observed in community-dwelling elderly adults who had nonpsychotic psychiatric symptoms at baseline. These baseline psychiatric symptoms were of similar or greater magnitude as biomarkers (genetic and structural MRI) in increasing the risk of incident mild cognitive impairment.

Rates of β-amyloid accumulation are independent of hippocampal neurodegeneration

OBJECTIVE

To test the hypotheses predicted in a hypothetical model of Alzheimer disease (AD) biomarkers that rates of β-amyloid (Aβ) accumulation on PET imaging are not related to hippocampal neurodegeneration whereas rates of neurodegenerative brain atrophy depend on the presence of both amyloid and neurodegeneration in a population-based sample.

METHODS

A total of 252 cognitively normal (CN) participants from the Mayo Clinic Study of Aging had 2 or more serial visits with both amyloid PET and MRI. Subjects were classified into 4 groups based on baseline positive/negative amyloid PET (A+ or A-) and baseline hippocampal volume (N+ or N-). We compared rates of amyloid accumulation and rates of brain atrophy among the 4 groups.

RESULTS

At baseline, 148 (59%) were amyloid negative and neurodegeneration negative (A-N-), 29 (12%) amyloid negative and neurodegeneration positive (A-N+), 56 (22%) amyloid positive and neurodegeneration negative (A+N-), and 19 (8%) amyloid positive and neurodegeneration positive (A+N+). High rates of Aβ accumulation were found in those with abnormal amyloid at baseline and were not influenced by hippocampal neurodegeneration at baseline. In contrast, rates of brain atrophy were greatest in A+N+.

CONCLUSIONS

We describe a 2-feature biomarker approach to classifying elderly CN subjects that is complementary to the National Institute on Aging-Alzheimer's Association preclinical staging criteria. Our results support 2 key concepts in a model of the temporal evolution of AD biomarkers. First, the rate of Aβ accumulation is not influenced by neurodegeneration and thus may be a biologically independent process. Second, Aβ pathophysiology increases or catalyzes neurodegeneration.

Association of type 2 diabetes with brain atrophy and cognitive impairment

OBJECTIVE

We investigated the associations of diabetes and hypertension with imaging biomarkers (markers of neuronal injury and ischemic damage) and with cognition in a population-based cohort without dementia.

METHODS

Participants (n = 1,437, median age 80 years) were evaluated by a nurse and physician and underwent neuropsychological testing. A diagnosis of cognitively normal, mild cognitive impairment (MCI), or dementia was made by an expert panel. Participants underwent MRI to determine cortical and subcortical infarctions, white matter hyperintensity (WMH) volume, hippocampal volume (HV), and whole brain volume (WBV). The medical records were reviewed for diabetes and hypertension in midlife or later.

RESULTS

Midlife diabetes was associated with subcortical infarctions (odds ratio, 1.85 [95% confidence interval, 1.09-3.15]; p = 0.02), reduced HV (-4% [-7 to -1.0]; p = 0.01), reduced WBV (-2.9% [-4.1 to -1.6]), and prevalent MCI (odds ratio, 2.08; p = 0.01). The association between diabetes and MCI persisted with adjustment for infarctions and WMH volume but was attenuated after adjustment for WBV (1.60 [0.87-2.95]; p = 0.13) and HV (1.82 [1.00-3.32]; p = 0.05). Midlife hypertension was associated with infarctions and WMH volume and was marginally associated with reduced performance in executive function. Effects of late-life onset of diabetes and hypertension were few.

CONCLUSIONS

Midlife onset of diabetes may affect late-life cognition through loss of brain volume. Midlife hypertension may affect executive function through ischemic pathology. Late-life onset of these conditions had fewer effects on brain pathology and cognition.

Amyloid-first and neurodegeneration-first profiles characterize incident amyloid PET positivity

OBJECTIVE

To estimate the incidence of and to characterize cognitive and imaging findings associated with incident amyloid PET positivity.

METHODS

Cognitively normal (CN) participants in the Mayo Clinic Study of Aging who had 2 or more serial imaging assessments, which included amyloid PET, FDG-PET, and MRI at each time point, were eligible for analysis (n = 207). Twelve subjects with Alzheimer disease dementia were included for comparison.

RESULTS

Of the 123 CN participants who were amyloid-negative at baseline, 26 met criteria for incident amyloid PET positivity. Compared to the 69 subjects who remained stable amyloid-negative, on average these 26 did not differ on any imaging, demographic, or cognitive variables except amyloid PET (by definition) and task-free functional connectivity, which at baseline was greater in the incident amyloid-positive group. Eleven of the 26 incident amyloid-positive subjects had abnormal hippocampal volume, FDG-PET, or both at baseline.

CONCLUSIONS

The incidence of amyloid PET positivity is approximately 13% per year among CN participants over age 70 sampled from a population-based cohort. In 15/26 (58%), incident amyloid positivity occurred prior to abnormalities in FDG-PET and hippocampal volume. However, 11/26 (42%) incident amyloid-positive subjects had evidence of neurodegeneration prior to incident amyloid positivity. These 11 could be subjects with combinations of preexisting non-Alzheimer pathophysiologies and tau-mediated neurodegeneration who newly entered the amyloid pathway. Our findings suggest that both "amyloid-first" and "neurodegeneration-first" biomarker profile pathways to preclinical AD exist.

Mild cognitive impairment due to Alzheimer disease in the community

OBJECTIVE

The newly proposed National Institute on Aging-Alzheimer's Association (NIA-AA) criteria for mild cognitive impairment (MCI) due to Alzheimer disease (AD) suggest a combination of clinical features and biomarker measures, but their performance in the community is not known.

METHODS

The Mayo Clinic Study of Aging (MCSA) is a population-based longitudinal study of nondemented subjects in Olmsted County, Minnesota. A sample of 154 MCI subjects from the MCSA was compared to a sample of 58 amnestic MCI subjects from the Alzheimer's Disease Neuroimaging Initiative 1 (ADNI-1) to assess the applicability of the criteria in both settings and to assess their outcomes.

RESULTS

Fourteen percent of MCSA and 16% of ADNI-1 of subjects were biomarker negative. In addition, 14% of MCSA and 12% of ADNI-1 subjects had evidence for amyloid deposition only, whereas 43% of MCSA and 55% of ADNI-1 subjects had evidence for amyloid deposition plus neurodegeneration (magnetic resonance imaging atrophy, fluorodeoxyglucose positron emission tomography hypometabolism, or both). However, a considerable number of subjects had biomarkers inconsistent with the proposed AD model; for example, 29% of MCSA subjects and 17% of ADNI-1 subjects had evidence for neurodegeneration without amyloid deposition. These subjects may not be on an AD pathway. Neurodegeneration appears to be a key factor in predicting progression relative to amyloid deposition alone.

INTERPRETATION

The NIA-AA criteria apply to most MCI subjects in both the community and clinical trials settings; however, a sizeable proportion of subjects had conflicting biomarkers, which may be very important and need to be explored.

Risk factors for dementia with Lewy bodies: a case-control study

OBJECTIVE

To determine the risk factors associated with dementia with Lewy bodies (DLB).

METHODS

We identified 147 subjects with DLB and sampled 2 sex- and age-matched cognitively normal control subjects for each case. We also identified an unmatched comparison group of 236 subjects with Alzheimer disease (AD). We evaluated 19 candidate risk factors in the study cohort.

RESULTS

Compared with controls, subjects with DLB were more likely to have a history of anxiety (odds ratio; 95% confidence interval) (7.4; 3.5-16; p < 0.0001), depression (6.0; 3.7-9.5; p < 0.0001), stroke (2.8; 1.3-6.3; p = 0.01), a family history of Parkinson disease (PD) (4.6; 2.5-8.6; p < 0.0001), and carry APOE ε4 alleles (2.2; 1.5-3.3; p < 0.0001), but less likely to have had cancer (0.44; 0.27-0.70; p = 0.0006) or use caffeine (0.29; 0.14-0.57; p < 0.0001) with a similar trend for alcohol (0.65; 0.42-1.0; p = 0.0501). Compared with subjects with AD, subjects with DLB were younger (72.5 vs 74.9 years, p = 0.021) and more likely to be male (odds ratio; 95% confidence interval) (5.3; 3.3-8.5; p < 0.0001), have a history of depression (4.3; 2.4-7.5; p < 0.0001), be more educated (2.5; 1.1-5.6; p = 0.031), have a positive family history of PD (5.0; 2.4-10; p < 0.0001), have no APOE ε4 alleles (0.61; 0.40-0.93; p = 0.02), and to have had an oophorectomy before age 45 years (7.6; 1.5-39; p = 0.015).

CONCLUSION

DLB risk factors are an amalgam of those for AD and PD. Smoking and education, which have opposing risk effects on AD and PD, are not risk factors for DLB; however, depression and low caffeine intake, both risk factors for AD and PD, increase risk of DLB more strongly than in either.