Fracture Risk Among Older Cancer Survivors Compared With Older Adults Without a History of Cancer

Importance

The number of cancer survivors living in the US is projected to be 26.1 million by 2040. Cancer survivors may be at increased risk of bone fractures, but research is limited in several important ways.

Objective

To investigate the associations of cancer diagnoses, including time since diagnosis and stage at diagnosis, with risks of pelvic, radial, and vertebral fractures (separately and combined) among older cancer survivors and compared with fracture risk among older adults without a history of cancer. Secondarily, to examine differences in risk of fracture stratified by modifiable behaviors, treatment, and cancer type.

Design, Setting, and Participants

This longitudinal cohort study used data from 92 431 older adults in the US Cancer Prevention Study II Nutrition Cohort linked with 1999 to 2017 Medicare claims. Data were analyzed from July 15, 2021, to May 3, 2022.

Exposures

Cancer history, time since cancer diagnosis, and stage at cancer diagnosis.

Main Outcomes and Measures

Hazard ratios (HRs) and 95% CIs for the risk of pelvic, radial, vertebral, and total frailty-related fractures were estimated using multivariate Cox proportional hazards regression. Stratification was used for secondary aims.

Results

Among 92 431 participants (mean [SD] age, was 69.4 [6.0] years, 51 820 [56%] women, and 90 458 [97.9%] White], 12 943 participants experienced a frailty-related bone fracture. Compared with participants without a history of cancer, cancer survivors who were diagnosed 1 to less than 5 years earlier with advanced stage cancer had higher risk of fracture (HR, 2.12; 95% CI, 1.75-2.58). The higher fracture risk in cancer survivors with recent advanced stage diagnosis (vs no cancer) was driven largely by vertebral (HR, 2.46; 95% CI, 1.93-3.13) and pelvic (HR, 2.46; 95% CI, 1.84-3.29) fracture sites. Compared with cancer survivors who did not receive chemotherapy, survivors who received chemotherapy were more likely to have a fracture; this association was stronger within 5 years of diagnosis (HR, 1.31; 95% CI, 1.09-1.57) than 5 or more years after diagnosis (HR, 1.22; 95% CI, 0.99-1.51). Although the HR for risk of fracture was lower among physically active cancer survivors 5 or more years after diagnosis (HR, 0.76; 95% CI, 0.54-1.07), this result was not statistically significant, whereas current smoking was significantly associated with higher risk of fracture (HR, 2.27; 95% CI, 1.55-3.33).

Conclusions and Relevance

Findings from this cohort study suggest that older adults with a history of cancer may benefit from clinical guidance on prevention of frailty-related fractures. If study findings are replicated, fracture prevention programs for survivors might include referrals for physical activity with cancer exercise professionals and smoking cessation programs.

A prospective case-cohort analysis of plasma metabolites and breast cancer risk

BACKGROUND

Breast cancer incidence rates have not declined despite an improvement in risk prediction and the identification of modifiable risk factors, suggesting the need to identify novel risk factors and etiological pathways involved in this cancer. Metabolomics has emerged as a promising tool to find circulating metabolites associated with breast cancer risk.

METHODS

Untargeted metabolomic analysis was done on prediagnostic plasma samples from a case-cohort study of 1695 incident breast cancer cases and a 1983 women subcohort drawn from Cancer Prevention Study 3. The associations of 868 named metabolites (per one standard deviation increase) with breast cancer were determined using Prentice-weighted Cox proportional hazards regression modeling.

RESULTS

A total of 11 metabolites were associated with breast cancer at false discovery rate (FDR) < 0.05 with the majority having inverse association [ranging from RR = 0.85 (95% CI 0.80-0.92) to RR = 0.88 (95% CI 0.82-0.94)] and one having a positive association [RR = 1.14 (95% CI 1.06-1.23)]. An additional 50 metabolites were associated at FDR < 0.20 with inverse associations ranging from RR = 0.88 (95% CI 0.81-0.94) to RR = 0.91 (95% CI 0.85-0.98) and positive associations ranging from RR = 1.13 (95% CI 1.05-1.22) to RR = 1.11 (95% CI 1.02-1.20). Several of these associations validated the findings of previous metabolomic studies. These included findings that several progestogen and androgen steroids were associated with increased risk of breast cancer in postmenopausal women and four phospholipids, and the amino acids glutamine and asparagine were associated with decreased risk of this cancer in pre- and postmenopausal women. Several novel associations were also identified, including a positive association for syringol sulfate, a biomarker for smoked meat, and 3-methylcatechol sulfate and 3-hydroxypyridine glucuronide, which are metabolites of xenobiotics used for the production of pesticides and other products.

CONCLUSIONS

Our study validated previous metabolite findings and identified novel metabolites associated with breast cancer risk, demonstrating the utility of large metabolomic studies to provide new leads for understanding breast cancer etiology. Our novel findings suggest that consumption of smoked meats and exposure to catechol and pyridine should be investigated as potential risk factors for breast cancer.

Modification of the Association Between Frequent Aspirin Use and Ovarian Cancer Risk: A Meta-Analysis Using Individual-Level Data From Two Ovarian Cancer Consortia

PURPOSE

Frequent aspirin use has been associated with reduced ovarian cancer risk, but no study has comprehensively assessed for effect modification. We leveraged harmonized, individual-level data from 17 studies to examine the association between frequent aspirin use and ovarian cancer risk, overall and across subgroups of women with other ovarian cancer risk factors.

METHODS

Nine cohort studies from the Ovarian Cancer Cohort Consortium (n = 2,600 cases) and eight case-control studies from the Ovarian Cancer Association Consortium (n = 5,726 cases) were included. We used Cox regression and logistic regression to assess study-specific associations between frequent aspirin use (≥ 6 days/week) and ovarian cancer risk and combined study-specific estimates using random-effects meta-analysis. We conducted analyses within subgroups defined by individual ovarian cancer risk factors (endometriosis, obesity, family history of breast/ovarian cancer, nulliparity, oral contraceptive use, and tubal ligation) and by number of risk factors (0, 1, and ≥ 2).

RESULTS

Overall, frequent aspirin use was associated with a 13% reduction in ovarian cancer risk (95% CI, 6 to 20), with no significant heterogeneity by study design (P = .48) or histotype (P = .60). Although no association was observed among women with endometriosis, consistent risk reductions were observed among all other subgroups defined by ovarian cancer risk factors (relative risks ranging from 0.79 to 0.93, all P-heterogeneity > .05), including women with ≥ 2 risk factors (relative risk, 0.81; 95% CI, 0.73 to 0.90).

CONCLUSION

This study, the largest to-date on aspirin use and ovarian cancer, provides evidence that frequent aspirin use is associated with lower ovarian cancer risk regardless of the presence of most other ovarian cancer risk factors. Risk reductions were also observed among women with multiple risk factors, providing proof of principle that chemoprevention programs with frequent aspirin use could target higher-risk subgroups.

Distinct Reproductive Risk Profiles for Intrinsic-Like Breast Cancer Subtypes: Pooled Analysis of Population-Based Studies

BACKGROUND

Reproductive factors have been shown to be differentially associated with risk of estrogen receptor (ER)-positive and ER-negative breast cancer. However, their associations with intrinsic-like subtypes are less clear.

METHODS

Analyses included up to 23 353 cases and 71 072 controls pooled from 31 population-based case-control or cohort studies in the Breast Cancer Association Consortium across 16 countries on 4 continents. Polytomous logistic regression was used to estimate the association between reproductive factors and risk of breast cancer by intrinsic-like subtypes (luminal A-like, luminal B-like, luminal B-HER2-like, HER2-enriched-like, and triple-negative breast cancer) and by invasiveness. All statistical tests were 2-sided.

RESULTS

Compared with nulliparous women, parous women had a lower risk of luminal A-like, luminal B-like, luminal B-HER2-like, and HER2-enriched-like disease. This association was apparent only after approximately 10 years since last birth and became stronger with increasing time (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.49 to 0.71; and OR = 0.36, 95% CI = 0.28 to 0.46 for multiparous women with luminal A-like tumors 20 to less than 25 years after last birth and 45 to less than 50 years after last birth, respectively). In contrast, parous women had a higher risk of triple-negative breast cancer right after their last birth (for multiparous women: OR = 3.12, 95% CI = 2.02 to 4.83) that was attenuated with time but persisted for decades (OR = 1.03, 95% CI = 0.79 to 1.34, for multiparous women 25 to less than 30 years after last birth). Older age at first birth (Pheterogeneity < .001 for triple-negative compared with luminal A-like breast cancer) and breastfeeding (Pheterogeneity < .001 for triple-negative compared with luminal A-like breast cancer) were associated with lower risk of triple-negative breast cancer but not with other disease subtypes. Younger age at menarche was associated with higher risk of all subtypes; older age at menopause was associated with higher risk of luminal A-like but not triple-negative breast cancer. Associations for in situ tumors were similar to luminal A-like.

CONCLUSIONS

This large and comprehensive study demonstrates a distinct reproductive risk factor profile for triple-negative breast cancer compared with other subtypes, with implications for the understanding of disease etiology and risk prediction.

Distinct germline genetic susceptibility profiles identified for common non-Hodgkin lymphoma subtypes

Lymphoma risk is elevated for relatives with common non-Hodgkin lymphoma (NHL) subtypes, suggesting shared genetic susceptibility across subtypes. To evaluate the extent of mutual heritability among NHL subtypes and discover novel loci shared among subtypes, we analyzed data from eight genome-wide association studies within the InterLymph Consortium, including 10,629 cases and 9505 controls. We utilized Association analysis based on SubSETs (ASSET) to discover loci for subsets of NHL subtypes and evaluated shared heritability across the genome using Genome-wide Complex Trait Analysis (GCTA) and polygenic risk scores. We discovered 17 genome-wide significant loci (P < 5 × 10-8) for subsets of NHL subtypes, including a novel locus at 10q23.33 (HHEX) (P = 3.27 × 10-9). Most subset associations were driven primarily by only one subtype. Genome-wide genetic correlations between pairs of subtypes varied broadly from 0.20 to 0.86, suggesting substantial heterogeneity in the extent of shared heritability among subtypes. Polygenic risk score analyses of established loci for different lymphoid malignancies identified strong associations with some NHL subtypes (P < 5 × 10-8), but weak or null associations with others. Although our analyses suggest partially shared heritability and biological pathways, they reveal substantial heterogeneity among NHL subtypes with each having its own distinct germline genetic architecture.

Anthropometric traits and risk of multiple myeloma: a pooled prospective analysis

BACKGROUND

Obesity is a risk factor for multiple myeloma (MM), yet results of prior studies have been mixed regarding the importance of early and/or later adult obesity; other measures of body composition have been less well studied.

METHODS

We evaluated associations of early adult (ages 18-21) and usual adult body mass index (BMI), waist circumference, and predicted fat mass with MM by pooling data from six U.S. prospective cohort studies comprising 544,016 individuals and 2756 incident diagnoses over 20-37 years of follow-up. We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations, adjusted for age and other risk factors.

RESULTS

Each 5 kg/m2 increase in usual adult BMI was associated with a 10% increased risk of MM (HR: 1.10; 95% CI: 1.05-1.15). Positive associations were also noted for early adult BMI (HR per 5 kg/m2: 1.14; 95% CI: 1.04-1.25), height (HR per 10 cm: 1.28; 95% CI: 1.20-1.37), waist circumference (HR per 15 cm: 1.09; 95% CI: 1.00-1.19), and predicted fat mass (HR per 5 kg: 1.06; 95% CI: 1.01-1.11).

CONCLUSIONS

These findings highlight the importance of avoidance of overweight/obesity and excess adiposity throughout adulthood as a potential MM risk-reduction strategy.

The Role of Individual-Level Factors in Rural Mortality Disparities

Introduction

The role of individual risk factors in the rural‒urban mortality disparity is poorly understood. The purpose of this study was to explore the role of individual-level demographics and health behaviors on the association between rural residence and the risk of mortality.

Methods

Cancer Prevention Study-II participants provided updated addresses throughout the study period. Rural‒Urban Commuting Area codes were assigned to participants' geocoded addresses as a time-varying exposure. Cox proportional hazards regression was used to estimate hazard ratios and 95% CIs for mortality associated with Rural‒Urban Commuting Area groups.

Results

After adjustment for age and sex, residents of rural areas/small towns had a small but statistically significant elevated risk of all-cause mortality compared with metropolitan residents (hazard ratio=1.04; 95% CI=1.01, 1.06). Adjustment for additional covariates attenuated the association entirely (hazard ratio=0.99; 95% CI=0.97, 1.01). Individually, adjustment for education (hazard ratio=0.99; 95% CI=0.97, 1.01), alcohol use (hazard ratio=1.01; 95% CI=0.99, 1.04), and moderate-to-vigorous intensity aerobic physical activity (hazard ratio=1.00; 95% CI=0.97, 1.02) eliminated the elevated risk.

Conclusions

The elevated risk of death for rural compared with that for metropolitan residents appeared to be largely explained by individual-level demographics and health behaviors. If replicated in other subpopulations, these results suggest that modifiable factors may play an important role in reducing the rural mortality disparity.

Incorporating progesterone receptor expression into the PREDICT breast prognostic model

BACKGROUND

Predict Breast (www.predict.nhs.uk) is an online prognostication and treatment benefit tool for early invasive breast cancer. The aim of this study was to incorporate the prognostic effect of progesterone receptor (PR) status into a new version of PREDICT and to compare its performance to the current version (2.2).

METHOD

The prognostic effect of PR status was based on the analysis of data from 45,088 European patients with breast cancer from 49 studies in the Breast Cancer Association Consortium. Cox proportional hazard models were used to estimate the hazard ratio for PR status. Data from a New Zealand study of 11,365 patients with early invasive breast cancer were used for external validation. Model calibration and discrimination were used to test the model performance.

RESULTS

Having a PR-positive tumour was associated with a 23% and 28% lower risk of dying from breast cancer for women with oestrogen receptor (ER)-negative and ER-positive breast cancer, respectively. The area under the ROC curve increased with the addition of PR status from 0.807 to 0.809 for patients with ER-negative tumours (p = 0.023) and from 0.898 to 0.902 for patients with ER-positive tumours (p = 2.3 × 10-6) in the New Zealand cohort. Model calibration was modest with 940 observed deaths compared to 1151 predicted.

CONCLUSION

The inclusion of the prognostic effect of PR status to PREDICT Breast has led to an improvement of model performance and more accurate absolute treatment benefit predictions for individual patients. Further studies should determine whether the baseline hazard function requires recalibration.

Key risk factors for the relative and absolute 5-year risk of cancer to enhance cancer screening and prevention

Background

This study identifies populations who may benefit most from expanded cancer screening.

Methods

Two American Cancer Society prospective cohort studies, Cancer Prevention Study‐II Nutrition Cohort and Cancer Prevention Study‐3, were used to identify the risk factors associated with a > 2% absolute risk of any cancer within 5 years. In total, 429,991 participants with no prior personal history of cancer were followed for cancer for up to 5 years. Multivariable Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for association. By using these hazard ratios, individualized coherent absolute risk estimation was used to calculate absolute risks by age.

Results

Overall, 15,226 invasive cancers were diagnosed among participants within 5 years of enrollment. The multivariable‐adjusted relative risk of any cancer was strongest for current smokers compared with never‐smokers. In men, alcohol intake, family history of cancer, red meat consumption, and physical inactivity were also associated with risk (p < .05). In women, body mass index, type 2 diabetes, hysterectomy, parity, family history of cancer, hypertension, tubal ligation, and physical inactivity were associated (p < .05). The absolute 5‐year risk exceeded 2% among nearly all participants older than 50 years and among some participants younger than 50 years, including current or former smokers (<30 years since quitting) and long‐term nonsmokers with a body mass index >25 kg/m² or a first‐degree family history of cancer. The absolute 5‐year risk was as high as 29% in men and 25% in women.

Conclusions

Older age and smoking were the two most important risk factors associated with the relative and absolute 5‐year risk of developing any cancer.

Older age and smoking are the two most important risk factors associated with the relative and absolute 5‐year risk of developing any cancer. These results quantified the absolute risks for population subgroups to identify those who may benefit most from expanded cancer screening and prevention.

Prospective investigation of herpesvirus infection and risk of glioma

Glioma is an aggressive neoplasm of the brain with poorly understood etiology. A limited number of pathogens have been examined as glioma risk factors, but data from prospective studies with infection status determined before disease are lacking. Herpesviruses comprise a large family of DNA viruses that infect humans and are linked to a range of chronic diseases. We conducted a prospective evaluation of the association between antibody to six human herpesviruses and glioma risk in the Janus Serum Bank (Janus) and the Cancer Prevention Study-II (CPS-II). In Janus and CPS-II, the risk for glioma was not related to seroprevalence of herpes simplex virus-1, varicella zoster virus, or human herpes viruses 6A or 6B. In Janus, seropositivity to either the Epstein Barr virus (EBV) EA[D] or VCAp18 antigen was associated with a lower risk of glioma (ORs: 0.55 [95% CI 0.32-0.94] and 0.57 [95% CI 0.38-0.85]). This inverse association was consistent by histologic subtype and was observed for gliomas diagnosed up to two decades following antibody measurement. In Janus, seropositivity to at least one of three examined cytomegalovirus (CMV) antigens (pp150, pp52, pp28) was associated with an increased risk of nonglioblastoma (OR: 2.08 [95% CI 1.07-4.03]). This association was limited to tumors diagnosed within 12 years of antibody measurement. In summary, we report evidence of an inverse association between exposure to EBV and glioma. We further report that CMV exposure may be related to a higher likelihood of the nonglioblastoma subtype.

Abstract 2235: Identifying populations at elevated risk of cancer outside those traditionally targeted for screening and prevention

Introduction: Currently, populations are identified for cancer screening interventions one cancer type at a time. With new developments in cancer screening, including multi-cancer early detection tests, it is important and timely to understand the overall cancer burden in populations outside those traditionally targeted for single-cancer screenings. Thus, we sought to identify the most important risk factors for developing any invasive cancer, and to calculate associated 5-year absolute risks, with a particular focus on persons under age 50 years.

Methods: Two large American Cancer Society cohorts followed prospectively for cancer, the Cancer Prevention Study-II Nutrition Cohort (CPS-IINC) enrolled from 1992-1993 and Cancer Prevention Study 3 (CPS-3) enrolled from 2006-2013, were used to examine a broad range of cancer risk factors. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CIs) for associations between potential risk factors and subsequent overall risk of any invasive cancer. The Individualized Coherent Absolute Risk Estimation tool used these HRs to estimate absolute risk in 5-year age groups.

Results: 15,226 cancers were identified among 429,991 participants within 5 years of follow-up. Several risk factors including smoking history, obesity, alcohol, family history of cancer, and various chronic medical conditions (e.g., diabetes, hypertension) were associated with a higher risk of cancer. Persons above age 50 years, regardless of other risk factors considered, had at least 2% absolute risk per 5 years. Among persons under age 50 years, smoking status was the most important factor differentiating risk. For men under age 50, absolute risk of any cancer did not exceed 2% except for men ages 45-49 years who currently smoke or recently quit (within 30 years). For women under age 50, absolute risk exceeded 2% starting at age 35-39 years for current or recent former smokers, and all women, even long-term nonsmokers, at age 45-49 had over 2% absolute risk.

Conclusions: Smoking history is important in differentiating absolute risk of any cancer in adults under age 50 years. More research to understand the extent to which other cancer risk factors influence risk for specific populations aged &lt;50 years should be carried out.

Citation Format: Alpa V. Patel, Emily Deubler, Lauren R. Teras, Graham A. Colditz, Cari J. Lichtman, William G. Cance, Christina A. Clarke. Identifying populations at elevated risk of cancer outside those traditionally targeted for screening and prevention [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 2235.

Age-related health deficits and five-year mortality among older, long-term cancer survivors

INTRODUCTION

Geriatric assessment evaluates multiple domains of health that, together, are superior to using chronologic age for predicting outcomes, such as hospitalization and mortality among patients with cancer. Most studies have not included comparison groups of individuals without cancer and assessed domains around the time of initial cancer diagnosis. Further, the potential for brief, self-reported measures to capture deficits that similarly predict mortality has not been well examined. This study compared age-related health deficit prevalence between older, long-term cancer survivors and individuals without a cancer history, and estimated associations between deficits and mortality risk among survivors.

MATERIALS AND METHODS

Analyses included participants in the Cancer Prevention Study (CPS)-II Nutrition Cohort who were cancer-free at enrollment in 1992/1993 and completed the Patient Reported Outcome Measurement Information System® (PROMIS®) global health questionnaire in 2011. Age-related deficits in five domains (comorbidities, functional status, mental health, malnutrition/weight loss, and social support) were self-reported. Cancer information was self-reported and confirmed via medical records or state cancer registries. Vital status through 2016 and cause of death was ascertained by linkage with the National Death Index.

RESULTS

Analyses included 9979 participants (median age = 80) diagnosed with invasive cancer 5-20 years prior to completing the 2011 survey and 63,578 participants without a cancer history (median age = 79). Overall deficits in the five domains were similar among long-term cancer survivors and controls. However, survivors of specific cancer types - non-Hodgkin lymphoma (NHL), lung, and kidney cancer - were more likely to report deficits in mental health and functional status than the control group. Among all survivors, each domain was independently associated with all-cause mortality, particularly functional status (hazard ratio [HR] = 2.02; 95% confidence interval [CI]: 1.80-2.27) and mental health (HR = 1.84; 95% CI: 1.65-2.04). Mortality risk increased with the number of deficits.

DISCUSSION

These results suggest that, several years after treatment, NHL, lung, and kidney cancer survivors are still more likely to experience age-related deficits compared to other similarly-aged individuals. Furthermore, results show that shorter, self-reported physical and mental health assessments, such as the PROMIS® global health questions, are predictive of mortality among older, long-term cancer survivors and, therefore, may be useful in clinical and research settings.

Genome-wide interaction analysis of menopausal hormone therapy use and breast cancer risk among 62,370 women

Use of menopausal hormone therapy (MHT) is associated with increased risk for breast cancer. However, the relevant mechanisms and its interaction with genetic variants are not fully understood. We conducted a genome-wide interaction analysis between MHT use and genetic variants for breast cancer risk in 27,585 cases and 34,785 controls from 26 observational studies. All women were post-menopausal and of European ancestry. Multivariable logistic regression models were used to test for multiplicative interactions between genetic variants and current MHT use. We considered interaction p-values < 5 × 10-8 as genome-wide significant, and p-values < 1 × 10-5 as suggestive. Linkage disequilibrium (LD)-based clumping was performed to identify independent candidate variants. None of the 9.7 million genetic variants tested for interactions with MHT use reached genome-wide significance. Only 213 variants, representing 18 independent loci, had p-values < 1 × 105. The strongest evidence was found for rs4674019 (p-value = 2.27 × 10-7), which showed genome-wide significant interaction (p-value = 3.8 × 10-8) with current MHT use when analysis was restricted to population-based studies only. Limiting the analyses to combined estrogen-progesterone MHT use only or to estrogen receptor (ER) positive cases did not identify any genome-wide significant evidence of interactions. In this large genome-wide SNP-MHT interaction study of breast cancer, we found no strong support for common genetic variants modifying the effect of MHT on breast cancer risk. These results suggest that common genetic variation has limited impact on the observed MHT-breast cancer risk association.

A genome-wide gene-based gene-environment interaction study of breast cancer in more than 90,000 women

Background

Genome-wide association studies (GWAS) have identified more than 200 susceptibility loci for breast cancer, but these variants explain less than a fifth of the disease risk. Although gene-environment interactions have been proposed to account for some of the remaining heritability, few studies have empirically assessed this.

Methods

We obtained genotype and risk factor data from 46,060 cases and 47,929 controls of European ancestry from population-based studies within the Breast Cancer Association Consortium (BCAC). We built gene expression prediction models for 4,864 genes with a significant (P<0.01) heritable component using the transcriptome and genotype data from the Genotype-Tissue Expression (GTEx) project. We leveraged predicted gene expression information to investigate the interactions between gene-centric genetic variation and 14 established risk factors in association with breast cancer risk, using a mixed-effects score test.

Results

After adjusting for number of tests using Bonferroni correction, no interaction remained statistically significant. The strongest interaction observed was between the predicted expression of the C13orf45 gene and age at first full-term pregnancy (PGXE=4.44×10-6).

Conclusion

In this transcriptome-informed genome-wide gene-environment interaction study of breast cancer, we found no strong support for the role of gene expression in modifying the associations between established risk factors and breast cancer risk.

Impact

Our study suggests a limited role of gene-environment interactions in breast cancer risk.

Abstract P2-11-01: Breast cancer (BC) risk among patients with benign breast disease (BBD) by NSAID use

Background: Approximately one million U.S women are diagnosed with benign breast disease (BBD) annually, which increases breast cancer (BC) risk between 1.5- and four-fold, depending on the pathologic characteristics of the lesion and other factors. BBD lesions are associated with inflammation and fibrosis, suggesting that inflammatory pathways may play a role in progression of BBD to BC. Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) are well tolerated, widely used drugs that block inflammation by inhibiting cyclooxygenase enzymes, which lowers prostaglandin synthesis, and by exerting numerous additional anti-inflammatory effects. NSAIDs are inversely associated with several types of cancer, including BC in some, but not all studies, and have been linked to lower BC risk among BBD patients in prior publications. We examined the association between NSAID use and BC risk, overall and by self-reported history of BBD, using data from the American Cancer Society Cancer Prevention Study II (CPS-II). Methods: The Cancer Prevention Study-II (CPS-II) Nutrition Cohort is a study of approximately 189,000 U.S. men and women followed prospectively for cancer incidence and mortality. Study participants filled out a detailed questionnaire at baseline in 1992/1993 and follow-up surveys in 1997 and every two years until 2017. On each follow-up survey, participants reported type, quantity, and duration of NSAID use as well as diagnoses of BBD. Incident BCs were either self-reported and validated via medical records or cancer registry linkage, or identified via National Death Index linkage. Women in the analytic cohort were followed from date of 1997 survey until diagnosis of BC, reported use of tamoxifen, report of cancer other than BC, date of death, loss to follow-up or end of follow-up. Hazard ratios (HRs) and 95% confidence intervals (CIs) assessing associations of BBD and NSAID use with BC risk were estimated using Cox proportional hazards regression analysis. Statistical interactions between BBD and NSAID were evaluated by fitting and testing the corresponding cross-product terms, along with the main effects of each. Both NSAID use and BBD were modeled as time-dependent variables, allowing exposure status to change over the course of the multiple surveys returned. Results: Of the 60,517 women included in the study, 3,899 (6.4%) developed BC. Mean follow-up time was 12.7 years. A total of 23,661 women (39%) reported a diagnosis of BBD at some point during the study period, and 54,656 (90%) reported some NSAID use. Women self-reporting BBD were 46% more likely to develop BC than those without self-reported BBD (HR 1.46, 95% CI 1.36-1.57). Overall, BC risk was not increased among NSAID users versus non-users (HR 0.95, 95% CI 0.88-1.02). In contrast, BC risk was reduced among current NSAID users with a history of BBD (HR 0.87, 95% CI 0.78-0.97), but not among NSAID users who did not report a history of BBD (HR 1.02, 95% CI 0.92-1.13, p-interaction=0.04). Risk did not differ across number of pills per month (RR=0.84 for &lt;15 pills/month, 0.89 for 15-29, 0.88 for 30-44, 0.78 for 45-59, 0.88 for 60+). Conclusion: In our study, NSAID use had a statistically-significant protective effect on BC risk among women with BBD, suggesting its potential use as a chemopreventive agent in this high-risk group of women, but not among those who did not report a history of BBD.

Citation Format: Robert A Vierkant, Matthew Masters, Lauren R Teras, Mark E Sherman. Breast cancer (BC) risk among patients with benign breast disease (BBD) by NSAID use [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-11-01.

Rare germline copy number variants (CNVs) and breast cancer risk

Germline copy number variants (CNVs) are pervasive in the human genome but potential disease associations with rare CNVs have not been comprehensively assessed in large datasets. We analysed rare CNVs in genes and non-coding regions for 86,788 breast cancer cases and 76,122 controls of European ancestry with genome-wide array data. Gene burden tests detected the strongest association for deletions in BRCA1 (P = 3.7E-18). Nine other genes were associated with a p-value < 0.01 including known susceptibility genes CHEK2 (P = 0.0008), ATM (P = 0.002) and BRCA2 (P = 0.008). Outside the known genes we detected associations with p-values < 0.001 for either overall or subtype-specific breast cancer at nine deletion regions and four duplication regions. Three of the deletion regions were in established common susceptibility loci. To the best of our knowledge, this is the first genome-wide analysis of rare CNVs in a large breast cancer case-control dataset. We detected associations with exonic deletions in established breast cancer susceptibility genes. We also detected suggestive associations with non-coding CNVs in known and novel loci with large effects sizes. Larger sample sizes will be required to reach robust levels of statistical significance.

Common variants in breast cancer risk loci predispose to distinct tumor subtypes

BACKGROUND

Genome-wide association studies (GWAS) have identified multiple common breast cancer susceptibility variants. Many of these variants have differential associations by estrogen receptor (ER) status, but how these variants relate with other tumor features and intrinsic molecular subtypes is unclear.

METHODS

Among 106,571 invasive breast cancer cases and 95,762 controls of European ancestry with data on 173 breast cancer variants identified in previous GWAS, we used novel two-stage polytomous logistic regression models to evaluate variants in relation to multiple tumor features (ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and grade) adjusting for each other, and to intrinsic-like subtypes.

RESULTS

Eighty-five of 173 variants were associated with at least one tumor feature (false discovery rate < 5%), most commonly ER and grade, followed by PR and HER2. Models for intrinsic-like subtypes found nearly all of these variants (83 of 85) associated at p < 0.05 with risk for at least one luminal-like subtype, and approximately half (41 of 85) of the variants were associated with risk of at least one non-luminal subtype, including 32 variants associated with triple-negative (TN) disease. Ten variants were associated with risk of all subtypes in different magnitude. Five variants were associated with risk of luminal A-like and TN subtypes in opposite directions.

CONCLUSION

This report demonstrates a high level of complexity in the etiology heterogeneity of breast cancer susceptibility variants and can inform investigations of subtype-specific risk prediction.

Prospective changes in physical activity, sedentary time and sleep during the COVID-19 pandemic in a US-based cohort study

OBJECTIVES

Assess differences in movement behaviours within the 24-hour cycle, including light intensity physical activity (LPA), moderate-to-vigorous physical activity (MVPA), sedentary time and sleep, before and during the COVID-19 pandemic and assess these differences stratified by several relevant factors in a subcohort of the Cancer Prevention Study-3.

DESIGN AND SETTING

US-based longitudinal cohort study (2018-August 2020).

PARTICIPANTS

N=1992 participants, of which 1304 (65.5%) are women, and 1512 (75.9%) are non-Latino white, with a mean age 57.0 (9.8) years.

MEASURES

Age, sex, race/ethnicity, education; self-reported LPA, MVPA, sedentary time and sleep duration collected before and during the pandemic; pandemic-related changes in work, childcare and living arrangement; COVID-19 health history.

RESULTS

Compared to 2018, participants spent an additional 104 min/day sedentary, 61 fewer min/day in LPA and 43 fewer min/day in MVPA during the pandemic. Time spent sleeping was similar at the two time points. Differences in movement behaviours were more pronounced among men, those with a higher level of education, and those who were more active before the pandemic.

CONCLUSIONS

From 2018 to Summer 2020, during the COVID-19 pandemic, US adults have made significant shifts in daily time spent in LPA, MVPA and sedentary. There is an urgent need to promote more physical activity and less sedentary time during this public health crisis to avoid sustaining these patterns long-term.

Development of High-Throughput Multiplex Serology to Detect Serum Antibodies against Coxiella burnetii

The causative agent of Q fever, the bacterium Coxiella burnetii (C. burnetii), has gained increasing interest due to outbreak events and reports about it being a potential risk factor for the development of lymphomas. In order to conduct large-scale studies for population monitoring and to investigate possible associations more closely, accurate and cost-effective high-throughput assays are highly desired. To address this need, nine C. burnetii proteins were expressed as recombinant antigens for multiplex serology. This technique enables the quantitative high-throughput detection of antibodies to multiple antigens simultaneously in a single reaction. Based on a reference group of 76 seropositive and 91 seronegative sera, three antigens were able to detect C. burnetii infections. Com1, GroEL, and DnaK achieved specificities of 93%, 69%, and 77% and sensitivities of 64%, 72%, and 47%, respectively. Double positivity to Com1 and GroEL led to a combined specificity of 90% and a sensitivity of 71%. In a subgroup of seropositives with an increased risk for chronic Q fever, the double positivity to these markers reached a specificity of 90% and a sensitivity of 86%. Multiplex serology enables the detection of antibodies against C. burnetii and appears well-suited to investigate associations between C. burnetii infections and the clinical manifestations in large-scale studies.

Germline variants and breast cancer survival in patients with distant metastases at primary breast cancer diagnosis

Breast cancer metastasis accounts for most of the deaths from breast cancer. Identification of germline variants associated with survival in aggressive types of breast cancer may inform understanding of breast cancer progression and assist treatment. In this analysis, we studied the associations between germline variants and breast cancer survival for patients with distant metastases at primary breast cancer diagnosis. We used data from the Breast Cancer Association Consortium (BCAC) including 1062 women of European ancestry with metastatic breast cancer, 606 of whom died of breast cancer. We identified two germline variants on chromosome 1, rs138569520 and rs146023652, significantly associated with breast cancer-specific survival (P = 3.19 × 10-8 and 4.42 × 10-8). In silico analysis suggested a potential regulatory effect of the variants on the nearby target genes SDE2 and H3F3A. However, the variants showed no evidence of association in a smaller replication dataset. The validation dataset was obtained from the SNPs to Risk of Metastasis (StoRM) study and included 293 patients with metastatic primary breast cancer at diagnosis. Ultimately, larger replication studies are needed to confirm the identified associations.

Association of germline genetic variants with breast cancer-specific survival in patient subgroups defined by clinic-pathological variables related to tumor biology and type of systemic treatment

BACKGROUND

Given the high heterogeneity among breast tumors, associations between common germline genetic variants and survival that may exist within specific subgroups could go undetected in an unstratified set of breast cancer patients.

METHODS

We performed genome-wide association analyses within 15 subgroups of breast cancer patients based on prognostic factors, including hormone receptors, tumor grade, age, and type of systemic treatment. Analyses were based on 91,686 female patients of European ancestry from the Breast Cancer Association Consortium, including 7531 breast cancer-specific deaths over a median follow-up of 8.1 years. Cox regression was used to assess associations of common germline variants with 15-year and 5-year breast cancer-specific survival. We assessed the probability of these associations being true positives via the Bayesian false discovery probability (BFDP < 0.15).

RESULTS

Evidence of associations with breast cancer-specific survival was observed in three patient subgroups, with variant rs5934618 in patients with grade 3 tumors (15-year-hazard ratio (HR) [95% confidence interval (CI)] 1.32 [1.20, 1.45], P = 1.4E-08, BFDP = 0.01, per G allele); variant rs4679741 in patients with ER-positive tumors treated with endocrine therapy (15-year-HR [95% CI] 1.18 [1.11, 1.26], P = 1.6E-07, BFDP = 0.09, per G allele); variants rs1106333 (15-year-HR [95% CI] 1.68 [1.39,2.03], P = 5.6E-08, BFDP = 0.12, per A allele) and rs78754389 (5-year-HR [95% CI] 1.79 [1.46,2.20], P = 1.7E-08, BFDP = 0.07, per A allele), in patients with ER-negative tumors treated with chemotherapy.

CONCLUSIONS

We found evidence of four loci associated with breast cancer-specific survival within three patient subgroups. There was limited evidence for the existence of associations in other patient subgroups. However, the power for many subgroups is limited due to the low number of events. Even so, our results suggest that the impact of common germline genetic variants on breast cancer-specific survival might be limited.