Year Of Breast Cancer Diagnosis Research Articles

Triple-Negative Breast Cancer EVs Modulate Growth and Migration of Normal Epithelial Lung Cells.

Breast cancer is the most common cancer amongst women worldwide. Recently, owing to screening programs and new technologies, the survival rate has increased significantly. Breast cancer can potentially develop metastases, and, despite them, lung metastases generally occur within five years of breast cancer diagnosis. In this study, the objective was to analyze the effect of breast cancer-derived EVs on a lung epithelial cell line. BEAS-2B cells were treated with extracellular vesicles (EVs) derived from triple-negative breast cancer cells (TNBCs), e.g., MDA-MB-231 and HS578T, separated using differential ultracentrifugation. We observed an increased growth, migration, and invasiveness of normal epithelial lung cells over time in the presence of TNBC EVs compared to the control. Therefore, these data suggest that EVs released by tumor cells contain biological molecules capable of influencing the pro-tumorigenic activity of normal cells. Exploring the role of EVs in oncology research and their potential cargo may be novel biomarkers for early cancer detection and further diagnosis.

Abstract PS04-06: Breast cancer recurrence among women with pre-diagnostic major depression and co-existing substance abuse disorder: A retrospective study in the United States Veterans Health Administration Cohort

Abstract Background: Our prior study observed a 34% higher risk of breast cancer (BC) recurrence among women with major depressive disorder (MDD) at the time of their BC diagnosis compared to women without MDD after adjusting for sociodemographic, clinical, and prognostic factors. Given the high prevalence of substance abuse disorders among individuals with MDD and the positive association between alcohol use and mortality among BC survivors, we were interested to examine whether the risk of BC recurrence was compounded for women with both conditions. Objective: To investigate whether pre-diagnostic substance abuse disorders modify the association between MDD and BC recurrence. Methods: We established a retrospective cohort of women (age ≥ 18 years) with incident, early-stage BC diagnosed from 2010 through 2019 using the VHA’s electronic medical record database. A two-year window was used to identify women with MDD and co-existing substance abuse disorders prior to their BC diagnosis. We examined potential interactions between MDD and alcohol abuse and MDD and other substance abuse using multivariable proportional hazards regression, accounting for competing risk of death. Our outcome of interest was BC recurrence. The reference group for all analyses was women with BC alone. The models were adjusted for patient characteristics including age, race, ethnicity, marital status, rurality of primary residence, priority group rating (proxy for socioeconomic status), any homelessness or economic problems, comorbidity burden, body mass index, smoking status, receipt of a screening mammography, year of BC diagnosis, cancer stage, cancer subtype, and cancer treatment. Subgroup analyses were conducted by cancer subtype. Results: Our cohort comprised 6,045 women with BC, of whom 1,754 (29%) had a pre-diagnostic MDD diagnosis and 1,509 (25%) had a substance abuse disorder. Among women with MDD, 386 (22%) abused alcohol and 336 (19%) abused other substances. The median length of follow-up from BC diagnosis was 4.5 years (IQR=4.8 years). The average age at BC diagnosis was 57 years (SD=11 years) overall, 56 years (SD=10 years) among women with MDD, and 57 years (SD=9 years) among women with substance abuse disorders. On multivariable analysis, MDD (HR=1.33; 95% CI: 1.14, 1.53), alcohol abuse disorder (HR=1.37; 95% CI: 1.12, 1.68), and other substance abuse disorders (HR=1.33; 95% CI: 1.13, 1.56) were independent risk factors for BC recurrence. Further, there was a statistically significant interaction between pre-diagnostic MDD and alcohol abuse disorder (p-interaction=0.003). Women with BC who had both pre-diagnostic MDD and alcohol abuse disorder were at a 65% (HR=1.65; 95% CI: 1.29, 2.11) higher risk of BC recurrence compared to women with BC alone. A statistically significant interaction was also observed between pre-diagnostic MDD and other substance abuse disorders (p-interaction < 0.001). Women with BC who had both pre-diagnostic MDD and other substance abuse disorders were at a 90% (HR=1.90; 95% CI: 1.50, 2.42) higher risk of BC recurrence compared to women with BC alone. In subgroup analyses, the interaction between MDD and alcohol abuse disorders (p-interaction=0.001) and MDD and other substance abuse disorders (p-interaction < 0.001) was limited to women with estrogen receptor positive cancer but not estrogen receptor negative cancer. Conclusion: Women with incident BC who have prior diagnoses of both MDD and substance abuse disorder are at higher risk of recurrence than women with either exposure independently. Further research is needed to examine the etiology of our findings and to evaluate whether this newly defined risk group would benefit from closer monitoring and more tailored treatment options. Citation Format: Maya Aboumrad, Kala Visvanathan. Breast cancer recurrence among women with pre-diagnostic major depression and co-existing substance abuse disorder: A retrospective study in the United States Veterans Health Administration Cohort [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS04-06.

Abstract PO4-09-01: Survival of patients harboring a germline ATM pathogenic/likely pathogenic variant and diagnosed with breast cancer: A case-control study

Abstract Introduction: Patients harboring a pathogenic/likely pathogenic variant (PV/LPV) in ATM present an increased lifetime risk of developing breast cancer (BC). The survival outcomes of these patients are not well-known. Methods: Retrospective, multicentric case-control study. Case group included patients with stage I-III breast cancer harboring a PV/LPV in ATM. Control group included patients with stage I-III breast cancer with a negative germline BC multigene panel testing including ATM gene analysis. Clinical outcomes defined as locoregional relapse-free survival (RFS), distant RFS and breast cancer specific survival were compared between cases and controls. Case group was obtained from five hereditary cancer units and control group was obtained from a sporadic clinic-based cohort. Cases and controls were matched 1:2 by stage, molecular subtype by immunohistochemistry, age at BC diagnosis and year of BC diagnosis. Baseline continuous variables were presented as mean and standard deviation and comparison was performed with Student´s t-test. Baseline categorical variables were presented with number and percentage and comparison were performed using chi-square test. Survival analyses were estimated by Kaplan-Meier curves, the comparison of survival was tested by stratified log-rank testing. Cox proportional hazards model was used to estimate the hazard ratio and confidence intervals. Results: We identified 64 patients (p) with an ATM PV/LPV and 120 controls. Median age at diagnosis was 47 years (28-84) and 46 years (25-88), respectively. The main tumoral characteristics in both groups were ductal (87.5% and 83.5%), luminal B-HER2 negative (37.5% and 45.8%) with histological grade II (54.7% and 58.5%) tumors. Majority of tumors in both groups were diagnosed at stage II (53.1% and 54.2%). Differences between groups were observed in first-degree BC family history (39p (61.9%) vs 51p (43.6%); p=0.02); frequency of multicentric/multifocal tumors (15p (25%) vs 13p (11.1%); p=0.018); contralateral breast cancer (16p (25%) vs 8p (6.7%); p=0.0004) and type of surgery (46.8% conservative surgery in cases and 69.2% in controls; p< 0.001). The result of the germline genetic study was not available for all patients before surgery. Baseline characteristics are summarized in Table 1. With a median follow-up of 6.7 years, we observed more locoregional recurrence and distant recurrence in the control group (ipsilateral local or lymphatic recurrence: 0p (0%) vs 15p (12.5%); p=0.078; metachronic contralateral breast cancer: 7p (12.7%) vs 3p (2.6%); p=0.02; distance recurrence 5p (7.8%) vs 24p (20%); p=0.03. No differences between groups were observed in BC-specific survival analysis, with a median BC-specific survival of 6.24y (4.67-12.1) in patients with ATM and 6.68y (6.12-7.94) in the control group (HR: 1.21 (0.88-1.65); p=0.24). Conclusions: Patients with BC harboring a germline ATM PV/LPV had more multifocal and multicentric disease at diagnosis; and more synchronous and metachronous contralateral BC compared to controls, with no differences in BC-specific survival. Further studies in a larger cohort are warranted to analyze sensitivity to systemic therapies. Table 1. Baseline characteristics of cases and control groups. ER (Estrogen Receptor) positive if > or equal to 1%; PR (Progesterone Receptor) positive if > or equal to 1%; HER2 (Human epidermal growth factor receptor-2); ChTh: Chemotherapy; SLNB: Sentinel Lymph Node Biopsy; AL: Axillar lymphadenectomy Citation Format: Mara Cruellas, Ariadna Roqué, Nuria Dueñas, Iris Teruel, Noemí Tuset Der-Abrain, Alejandra Rezqallah, Víctor Navarro, Laia Joval-Ramentol, Maite Torres, Cristina Saura, Joan Brunet, Judith Balmaña. Survival of patients harboring a germline ATM pathogenic/likely pathogenic variant and diagnosed with breast cancer: A case-control study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-09-01.

Abstract SY15-02: Health insurance and outcome disparities in adolescents and young adults with cancer

Abstract SY15-02: Health insurance and outcome disparities in adolescents and young adults with cancer

Abstract 4828: Effect of county-level income and rurality on cardiovascular disease mortality among Asian and Pacific Islander breast cancer survivors in the US, 2000-2018

Abstract Purpose: To examine differences in cardiovascular disease (CVD) mortality by county-level income and rurality for Asian versus Pacific Islander (PI) breast cancer survivors. Background: Asian and PI individuals experience varying cancer burden, and prior studies have reported disparities in treatment-related CVD mortality among breast cancer survivors by socioeconomic status and race and ethnicity. However, the impact of county-level income and rurality on CVD mortality among Asian and PI breast cancer survivors, separately, are not well described. Methods: We included 60,184 Non-Hispanic Asian and PI women diagnosed with first primary, invasive breast cancer between 2000-2017 in the U.S. Surveillance, Epidemiology, and End Results program (aged 18-84, survived 12+ months, and received initial surgery). We estimated the hazard ratio (HR) of CVD mortality using Cox proportional hazard models assessing the impact of county-level income (median household income: low = <$75,000; high [ref] = ≥$75,000) and rurality (urban [ref] = metropolitan counties, population ≥ 250,000; rural = nonmetropolitan counties), separately for Asian and PI breast cancer survivors. Models adjusted for continuous age, stage (localized, regional/distant), and year of breast cancer diagnosis (2000-2004, 2005-2009, 2010-2017). We calculated 10-year cumulative CVD mortality for Asian and PI women accounting for competing risks (e.g., non-CVD deaths). Results: Of 55,602 Asian and 4,582 PI breast cancer survivors, 1,114 Asian and 178 PI women died from CVD through 2018 (median follow-up, Asian = 6.0 years; PI = 5.5 years). PI women had a higher median age at breast cancer diagnosis (57 vs. 55 years) and more advanced stage (37% vs. 33%) than Asian women. Among Asian breast cancer survivors, low county-level income was associated with elevated CVD mortality (HR = 1.17, 95% CI = 1.04, 1.31), but not rurality (HR = 1.20, 95% CI = 0.91, 1.58). For PI breast cancer survivors, there were no significant associations observed for low county-level income (HR = 0.83, 95% CI = 0.60, 1.14) or rurality (HR = 1.11, 95% CI = 0.76, 1.61). At 10 years after breast cancer diagnosis, 1 in 40 Asian women and 1 in 20 PI women died of CVD. Conclusion: Asian breast cancer survivors living in low-income counties had heightened risk of CVD mortality compared with those living in higher income counties, highlighting potential healthcare access barriers to cancer survivorship care. Although PI women did not experience significant differences in CVD mortality across groups of county-level income and rurality, they had twice as high absolute risk of CVD mortality than Asian women, warranting further investigation. Future studies that disaggregate Asian and PI individuals into more diverse and granular ethnicity groups are needed to understand heterogeneity in breast cancer survivorship outcomes. Citation Format: Katherine L. Ho, Cody Ramin, Jaimie Z. Shing, Kekoa Taparra, Jacqueline B. Vo. Effect of county-level income and rurality on cardiovascular disease mortality among Asian and Pacific Islander breast cancer survivors in the US, 2000-2018 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4828.

The Risk of Cancer-Associated and Radiotherapy-Associated Cardiovascular Diseases among Patients with Breast Cancer

BackgroundThe cardio-related issues should be emphasized as the survival rates of breast cancer increased. We investigated the risk of coronary artery disease (CAD) and stroke due to breast cancer or radiotherapy. MethodsIn this retrospective cohort study, breast cancer patients diagnosed between 2007 and 2016 were recruited from Taiwan Cancer Registry Database and were followed until the end of 2018 by linking with the Taiwan National Health Insurance Database. The general population was randomly selected from the whole population in 2007. Standardized incidence ratios (SIR) were calculated to compare the risk of CAD and stroke between patients and the general population. Within the cohort, we included the patients diagnosed between 2011 and 2016. Cox proportional hazards model and subdistribution hazard function were used to investigate the associations of radiotherapy with the risk of CAD and stroke. ResultsOverall SIR of CAD was 0.82 (95% confidence interval [CI]: 0.78-0.86), while were 1.43 and 1.08 (95% CI: 1.30-1.55 and 1.00-1.16) 1 and 2 years after diagnosis, respectively. Overall SIR of stroke was 0.63 (95% CI: 0.60-0.67), the results were similar after considering the time since diagnosis. The adjusted hazard ratios (HR) for the associations of radiotherapy with CAD and stroke risk were 0.91 (95% [CI] = 0.76-1.09) and 0.84 (95% CI = 0.68-1.04), respectively. The results were similar by using subdistribution hazard function. ConclusionsThe risk of CAD was higher within the first 2 years of breast cancer diagnosis. We found no association between radiotherapy and the risk of CAD and stroke.

Long-term and real-life incidence of cancer therapy-related cardiovascular toxicity in patients with breast cancer: a swedish cohort study

Abstract Background Cancer treatment and cancer itself increase the risk for cardiovascular disease (CVD) which in its turn contributes to cancer therapy-related cardiovascular toxicity (CTR-CVT). The aim of this study was to evaluate the long-term risk and predictors of CTR-CVT as well as all-cause mortality in women diagnosed with early breast cancer (BC) who were candidates for adjuvant chemotherapy. Methods Data from 433 women aged 18-60 years who were diagnosed with lymph node-positive BC between 1998-2002 and were eligible for adjuvant chemotherapy, were collected from Swedish health registers and medical records. For this study CTR-CVT was defined as hypertension (HT), coronary artery disease (CAD), heart failure (HF) or atrial fibrillation (AF) after the diagnosis of BC. Follow-up was from the date of BC diagnosis until November 30, 2021, or death. The incidence of CTR-CVT and all-cause mortality were calculated and hazard ratios (HR) for various factors associated with CTR-CVT were determined. Results The median age of the study population was 50 years (interquartile range (IQR) 32 years). A total of 910 CTR-CVT events were diagnosed in 311 women with a median of 19.3 years of follow-up (IQR 15.3 years). The proportions of CTR-CVT events were as follows: HT 281 (64%); CAD 198 (46%); HF 206 (47%); and AF 225 (51%). The cumulative incidence of CTR-CVT was 71.8% and 50% of all 433 patients developed CTR-CVT within 11.7 years of BC diagnosis (standard deviation (SD) 0.57, 95% confidence interval (CI) 10.6-12.9). Age was a risk factor for CTR-CVT. Treatment with anthracyclines increased the risk for HF (p=0.001; HR 2.0; 95%CI 1.4-2.8), CAD (p= 0.002; HR 1.7; 95% CI 1.2-2.4), and AF (p=0.013; HR 1.5; 95%CI 1.0-2.0). At the end of the 24-year study period, 227 of the 433 women were alive and the total cumulative mortality was 47.6%. Chemotherapy (anthracyclines or other agent) and older age at the time of BC diagnosis were associated with higher mortality rate. Conclusions In this cohort study the incidence of CTR-CVT and all-cause mortality after BC diagnosis and treatment was high, particularly in older patients and those receiving anthracyclines. This finding together with the time to onset of CTR-CVT, supports the current cardio-oncology guidelines recommending initial risk stratification, cardiovascular monitoring during treatment, followed by long-term annual screening for cardiovascular risk factors and CTR-CVT among BC survivors.Incidence CTR-CVTSurvival rate

Concomitant Discontinuation of Cardiovascular Therapy and Adjuvant Hormone Therapy Among Patients With Breast Cancer

A large proportion of patients with breast cancer concomitantly use adjuvant hormone therapy and cardiovascular therapy. To examine the relative risk of discontinuing cardiovascular therapy during the periods before and after discontinuation of adjuvant hormone therapy. This population-based cohort study included all women aged 40 to 74 years in Stockholm, Sweden, who were diagnosed with breast cancer and concomitantly using adjuvant hormone therapy and cardiovascular therapy. Patients were enrolled from July 1, 2005, to August 31, 2020, with a median follow-up of 7.2 years. Data were analyzed from November 3, 2021, to May 12, 2022. Discontinuation of adjuvant hormone therapy. The main outcome was discontinuation of cardiovascular therapy (cardiovascular drugs, statins, or aspirin) within 1 year before and after discontinuation of adjuvant hormone therapy. Incidence rate ratios with 95% CIs were estimated using Poisson regression. Furthermore, hazard ratios (HRs) with 95% CIs for cause-specific mortality were estimated using Cox proportional hazards regression models, comparing those who discontinued and continued adjuvant hormone therapy. A total of 5493 patients with breast cancer who concomitantly used cardiovascular therapy were identified; 1811 who discontinued adjuvant hormone therapy were individually matched to 1 patient each who continued therapy by year of breast cancer diagnosis, age at diagnosis, and use of the same cardiovascular therapy. Most patients (4070 [74.1%]) were aged 60 years or older at diagnosis. At the time when patients discontinued adjuvant hormone therapy, 248 (12.2%) concomitantly discontinued their cardiovascular therapy. During follow-up, a higher discontinuation rate of cardiovascular therapy was also observed among those who discontinued adjuvant hormone therapy. Consistently, adjuvant hormone therapy discontinuation was associated with an increased risk of death not only due to breast cancer (HR, 1.43; 95 CI%, 1.01-2.01) but also cardiovascular disease (HR, 1.79; 95 CI%, 1.15-2.81). Stratifying the analyses on baseline type of adjuvant hormone therapy yielded consistent results. In this cohort study of data from population-based registers in Sweden, patients who discontinued adjuvant hormone therapy were also more likely to discontinue cardiovascular therapy, especially at the time when they discontinued adjuvant hormone therapy. These findings suggest that clinicians should shift from single- to multiple-disease focus to prevent discontinuation of therapies for other diseases among patients with breast cancer.

Long-term and real-life incidence of cancer therapy-related cardiovascular toxicity in patients with breast cancer: a Swedish cohort study.

The administration of anticancer drugs in females with comorbidity increases the risk for cancer therapy-related cardiovascular toxicity (CTR-CVT), which in turn contributes to cardiovascular disease (CVD). Furthermore, a pathophysiological connection between cancer and cardiovascular disease may exist. To assess the long-term risks and predictors of CTR-CVT, including clinical hypertension (HT), coronary artery disease (CAD), heart failure (HF), atrial fibrillation (AF), as well as all-cause mortality in women diagnosed with early breast cancer (BC) and eligible for adjuvant chemotherapy in Sweden. Data were extracted from Swedish registers and medical records on 433 women, 18-60 years of age, diagnosed 1998-2002 with lymph node-positive BC, and considered for adjuvant chemotherapy. CTR-CVT was defined as HT, CAD, HF, or AF after the diagnosis of BC. Follow-up was from the date of BC diagnosis until November 30, 2021, or death. Prevalence of CTR-CVT and all-cause mortality were calculated. Hazard ratios (HR) were determined for factors associated with CTR-CVT. The median age was 50 (interquartile range (IQR) 32) years. 910 CTR-CVT events were diagnosed in 311 women with a median of 19.3 (IQR 15,3) years follow-up. The proportions of CTR-CVT events were: HT 281 (64%); CAD 198 (46%); HF 206 (47%); and AF 225 (51%). The cumulative incidence of CTR-CVT was 71.8%, and 50% of all 433 patients developed CTR-CVT within 11.7 years of BC diagnosis (standard deviation (SD) 0.57, 95% confidence interval (CI) 10.6-12.9). Age was a risk factor for CTR-CVT. Anthracycline increased the risk for HF (p=0,001; HR 2,0; 95%CI 1,4-2,8), CAD (p= 0,002; HR 1,7; 95% CI 1,2-2,4), and AF (p=0,013; HR 1,5; 95% CI 1,0-2,0). At the end of the 24-year study period, 227 of the 433 women were alive, and the total cumulative mortality was 47,6%. The prevalence of CTR-CVT and all-cause mortality is high after BC diagnosis and treatment, particularly in older patients and those receiving anthracyclines. These findings and the onset of CTR-CVT support cardio-oncology guidelines recommending initial risk stratification and cardiovascular monitoring during treatment, followed by long-term annual screening for cardiovascular risk factors and CTR-CVT among BC survivors.

Abstract P5-08-01: Pilot study of a patient-reported outcome (PRO) measurement strategy to determine impact of screening for minimal residual disease (MRD) in high-risk breast cancer survivors

Abstract Background: Patients treated for early stage breast cancer (BC) have a 30% lifetime risk of developing metastatic disease. Numerous studies have demonstrated that dormant bone marrow disseminated tumor cells (DTCs) are independently associated with risk of recurrence and death, yet interventions targeting these cells are lacking. The PENN-SURMOUNT (Surveillance Markers of Utility for Recurrence after (Neo)adjuvant Therapy) Screening Study was launched in 2016 to screen high risk BC survivors for DTCs using bone marrow aspirate (BMA) and identify eligible DTC positive patients for clinical trials. Given the novelty of this approach, we concurrently developed and pilot tested a PRO measurement strategy to study how the screening method of BMA and disclosure of DTC results impacts early-stage BC patients. Methods: PENN-SURMOUNT is a single center prospective, longitudinal cohort study examining BM and blood biomarkers of MRD among patients within 5 years of BC diagnosis who have high risk criteria (positive axillary nodes, triple negative biology, ER+ with Oncotype Dx ≥ 25 and/or high risk Mammaprint, or pathologic residual disease after neoadjuvant chemotherapy). From May 2019 – August 2021, we recruited patients on SURMOUNT to complete PRO surveys at baseline (T0), after BMA (T1), and after disclosure of DTC results (T2). Surveys were administered in paper form initially, then electronic form starting Feb 2021. PRO survey instruments were selected through literature review, followed by consensus among multidisciplinary clinical and research experts and patient advocates. PRO measures assess recurrence distress (Quality of Life in Adult Cancer Survivors, QLACS), illness intrusiveness (Illness Intrusiveness Ratings Scale, IIRS), and decision making (Decision Regret Scale). Additional survey items assess tolerability of the BMA and patients’ risk perception and cognitive understanding after DTC results disclosure. Descriptive statistics summarize PRO survey compliance and responses at T0, T1, and T2 in the total population and the population who reported longitudinal data for T2. Results: 61 of 66 eligible patients on the SURMOUNT trial enrolled in the PRO pilot study and completed a baseline survey, of which 47 (77%) tested negative for DTCs. Mean completion rates were 0.92 at T0, 0.85 at T1, and 0.56 at T2. After electronic survey implementation, completion rates increased to 0.94 (T0), 0.97 (T1) and 0.81 (T2). At T0, 36 (59%) patients reported a high risk perception of developing BC recurrence at 5 years and 42 (69%) during their lifetime. Mean T0 recurrence distress using the QLACS subscale was 14.6 (SD 6.3) out of possible score 4-28, compared to an expected mean of 11.42 (SD 5.48) in a general survivorship population. Mean T0 illness intrusiveness was 27.3 (SD 13.9) out of possible score 13-91. At T1, approximately 85% of patients agreed that they correctly understood the purpose of the bone marrow procedure and what the procedure would entail. 44 (72%) of patients reported a maximum pain score <= 4 in the week post-procedure and 42 (69%) reported the BMA was same or better than expected tolerability. Exploratory subset analysis of patients with complete longitudinal data at T2 (n = 34) showed average scores of 13.4 (SD 6.0), 30.1 (SD 14.0), and 2.8 (SD 6.2) for recurrence distress, illness intrusive, and decision regret scores (scale 0-100), respectively. At T2, 26 (76%) of patients reported no decision regret for undergoing testing for DTCs; 27 (79%) reported feeling less anxious after DTC results disclosure. Conclusions: Participants of PENN-SURMOUNT perceived risk of recurrence as high. The BMA procedure was well-tolerated and better than expected among the majority of this cohort, and most did not regret having undergone BMA after DTC status disclosure. Longitudinal completion rates were low, limiting assessment of PROs at later time points, a major focus of future work in this setting. Citation Format: Tara Kaufmann, Patrick Chang, Shoshana Rosenberg, Elizabeth Frank, Brian Hobbs, Lauren J. Bayne, Isoris Nivar, Brooke L. Goodspeed, Killian M. Rohn, Emily M. Kugler, Kevin Fox, Susan Domchek, Angela Bradbury, Payal Shah, Hayley Knollman, Rachel C. Jankowitz, Igor Makhlin, Amy S. Clark, Lewis A. Chodosh, Angela DeMichele, Katherine Goodfellow. Pilot study of a patient-reported outcome (PRO) measurement strategy to determine impact of screening for minimal residual disease (MRD) in high-risk breast cancer survivors [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-08-01.

Abstract P3-03-08: Depression and breast cancer recurrence among female veterans in the United States: a retrospective cohort study

Abstract Background: The importance of mental health to improve the quality of cancer survivorship and outcomes is gaining increased attention. Major depressive disorder (MDD) has been associated with higher breast cancer (BC) incidence, BC-specific and all-cause mortality. The effect of MDD on BC recurrence remains under-studied. The Veterans Health Administration (VHA) provides a unique opportunity to examine this relationship as it mandates annual MDD screening in the primary care setting and reports national screening rates of 96%. Objective: To examine the relationship between pre-existing MDD and BC recurrence among a diverse cohort of women in the United States. Methods: We established a retrospective cohort of women (age ≥ 18 years) diagnosed with early-stage incident BC from 2010 through 2019 using the VHA’s electronic medical record database. We used a two-year window to identify women with clinically diagnosed MDD prior to their BC diagnosis. Our outcome of interest was BC recurrence (local recurrence/second primary and distant recurrence). We used multivariable proportional hazards regression to examine the association between MDD and BC recurrence, accounting for competing risk of death. Our analyses were adjusted for age, race, ethnicity, marital status, priority group rating (proxy for socioeconomic status), rurality of primary residence, geographical region, cancer stage, year of BC diagnosis, and comorbidity burden. Priority group rating is a metric that incorporates patients’ income, receipt of VHA assistance benefits, capacity for gainful employment, and severity of service-connected conditions. We conducted subgroup analyses by tumor subtype. RESULTS: Our cohort consists of 6,045 women with BC, of whom 1,750 (29.0%) had a pre-existing MDD diagnosis. The median length of follow-up from BC diagnosis was 4.5 years (IQR=4.8 years). The average age at BC diagnosis was 57 years (SD=11 years) overall and 56 years (SD=10 years) among women with MDD. Sixty-one percent of women were white, 29% were black, 27% were married, and 28% were rural dwelling. Forty-four percent of invasive carcinomas were localized and 21% were regional. Thirty-five percent of patients had ductal carcinoma in situ. Women with MDD had a higher average Charlson Comorbidity Index score (mean=0.75, SD=1.13 vs. mean=0.58, SD=1.03) and proportion with a priority group rating between 1-4 (40% vs. 32%). The distribution of other described patient characteristics among women with MDD were similar to the overall cohort. On multivariable analysis, women with MDD had a 31% (95% CI: 1.11, 1.56) higher risk of BC recurrence compared to women without MDD. MDD was associated with a 29% (95% CI: 1.01, 1.66) and 33% (95% CI: 1.05, 1.67) higher risk of local recurrence/second primary and distant recurrence, respectively. The relationship between MDD and BC recurrence remained significant after adjusting for tumor subtype (HR=1.40, 95% CI: 1.07, 1.83). In subgroup analyses stratified by tumor subtype, MDD was associated with a higher risk of BC recurrence among women with estrogen receptor positive versus negative tumors (HR=1.65, 95% CI: 1.27, 2.14 vs. HR=0.71, 95% CI: 0.34, 1.46) and HER2/neu negative versus positive tumors (HR=1.53, 95% CI: 1.16, 2.00 vs. HR=1.24, 95% CI: 0.51, 2.96). The interaction between estrogen receptor status and MDD was statistically significant (p-interaction=0.02). CONCLUSION: Women with incident BC should be screened for MDD early in the cancer care continuum given the prevalence of MDD and association with increased risk of local recurrence/second primary and distant BC recurrence. Further research is needed to understand the interplay between these two diseases and their treatments. Citation Format: Maya Aboumrad, Brian Shiner, Avonne Connor, Bradley V. Watts, Kala Visvanathan. Depression and breast cancer recurrence among female veterans in the United States: a retrospective cohort study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-03-08.

County-level geographic disparities in cardiovascular disease mortality among US breast cancer survivors, 2000-2018.

Disparities in cardiovascular disease mortality among breast cancer survivors are documented, but geographic factors by county-level socioeconomic status (SES) and rurality are not well described. We analyzed 724 518 women diagnosed with localized or regional stage breast cancer between 2000 and 2017 within Surveillance, Epidemiology, and End Results Program-18 with follow-up until 2018. We calculated relative risks (RRs) of cardiovascular disease mortality using Poisson regression, accounting for age- and race-specific rates in the general population, according to county-level quintiles of SES (measured by Yost index), median income, and rurality at breast cancer diagnosis. We also calculated 10-year cumulative mortality risk of cardiovascular disease accounting for competing risks. Cardiovascular disease mortality was 41% higher among breast cancer survivors living in the lowest SES (RR = 1.41, 95% confidence interval [CI] = 1.36 to 1.46, Ptrend < .001) and poorest (RR = 1.41, 95% CI = 1.36 to 1.47, Ptrend < .001) counties compared with the highest SES and wealthiest counties, and 24% higher for most rural relative to most urban counties (RR = 1.24, 95% CI = 1.17 to 1.30, Ptrend < .001). Disparities for the lowest SES relative to highest SES counties were greatest among younger women aged 18-49 years (RR = 2.32, 95% CI = 1.90 to 2.83) and aged 50-59 years (RR = 2.01, 95% CI = 1.77 to 2.28) and within the first 5 years of breast cancer diagnosis (RR = 1.53, 95% CI = 1.44 to 1.64). In absolute terms, however, disparities were widest for women aged 60+ years, with approximately 2% higher 10-year cumulative cardiovascular disease mortality risk in the poorest compared with wealthiest counties. Geographic factors at breast cancer diagnosis were associated with increased cardiovascular disease mortality risk. Studies with individual- and county-level information are needed to inform public health interventions and reduce disparities among breast cancer survivors.

Intimate Partner Violence against Mastectomized Women: Victims' Experiences.

Exposure to situations of domestic violence during the treatment for breast cancer may compromise the treatment and quality of life of women patients, so it is essential that health professionals act in tracking this phenomenon in the approach to and care of women with breast cancer. The purpose of this study was to examine experiences of violence against women by their intimate partners after mastectomy. This is an exploratory descriptive study, with a qualitative approach, carried out in the Rehabilitation Program for Mastectomized Women in a Brazilian reference hospital for oncological treatment. Semi-structured interviews were conducted with 16 mastectomized women. For data analysis, a content analysis technique was performed. The women interviewed were predominantly brown, with a minimum age of 44 years and maximum of 72 years. They presented with low education, were married, and had a mean period of five years of breast cancer diagnosis. The participants reported that after mastectomy, they experienced episodes of violence at a time when they were extremely vulnerable due to the various cancer treatments. Three major thematic categories emerged from interview data across the data collection: (1) experiences of psychological violence, (2) experiences of physical violence, and (3) experiences of sexual violence. Psychological violence took the form of humiliation and contempt for their condition. Physical violence involved assault and sexual violence in the form of forced sex by coercion. Violence was a phenomenon present after mastectomy, practiced in the domestic environment by the intimate partner. We emphasize the importance of health professionals in screening for this issue by listening to and welcoming women, recording cases, exposing this situation, and contributing to prevention.

Reporting consistency in radiation therapy after breast conservative surgery between Arkansas Cancer Registry and all payers claims database.

e18685 Background: Cancer registries linked to insurance claims databases are an important source for real-world evidence cancer research. However, most studies used SEER-Medicare linked data, which limits studies by location and age. Arkansas has developed an all-payers claims databases (APCD) that includes insurance claims from both public and private payers, enabling tracking patients of all ages throughout the continuum of care and across payers. However, APCD lacks tumor-specific characteristics. Arkansas is one of only four known states that have linked APCD to the state cancer registry. Using Arkansas APCD linked to Arkansas cancer registry (ACR), we evaluated the reporting consistency of radiation therapy (RT) in the two sources. Methods: We identified women &gt; = 18 years who were diagnosed in 2013-2017 with stage 0-3 hormone receptor positive breast cancer who received breast-conserving surgery. Patients must have continuous insurance coverage (any private plans, Medicaid, Medicare Part A and B without any Part C coverage) in the 13 months (month of diagnosis and 12 months after). Receipt of RT was identified independently from ACR and APCD. ACR collects information on RT if it is part of the first course of therapy. In APCD, RT claims within one year of breast cancer diagnosis were identified using procedure codes. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for receipt of RT coded by the registry compared with APCD billing claims as the gold standard. We assessed the degree of concordance between the data sources by Cohen’s kappa statistic. Results: Of the 2348 patients, 1477 (62.9%) were documented in the ACR as received RT and had RT claims in the APCD, 498 (21%) were documented in the ACR as not received RT and had no RT claims in the APCD, 183 (7.8%) were documented as received RT in ACR but had no RT claims in the APCD, and 190 (8.1%) were documented as not received RT but had RT claims in the APCD. Using APCD claims as the gold standard, the sensitivity, specificity, PPV and NPV were 88.8%, 72.8%, 88.6%, and 73.1%. Findings were very similar using ACR as the gold standard, the sensitivity, specificity, PPV and NPV were 88.6%, 73.1%, 89.0% and 72.4%. The kappa statistic for agreement between the two sources was 0.62 (95% CI: 0.58-0.65, p = 0.7170). Conclusions: In patients who received BCS, recording of RT receipt was moderately consistent between Arkansas APCD and ACR. Future studies are needed to identify factors affecting reporting consistency to better utilize this unique resource in addressing population health problems.[Table: see text]

Risk factors associated with venous thromboembolism in breast cancer: a narrative review.

To date, there is no universally acceptable risk assessment tool in clinical practice that accurately estimates the risk of venous thromboembolism (VTE) in patients with breast cancer, despite the large number of published studies. Thus, the aim of this narrative review was to summarize the most relevant risk factors for VTE in these patients. We searched Ovid Embase and Ovid MEDLINE, from inception to March 26, 2021, to identify all articles that focused on breast cancer and multiple thromboembolic diseases. We also searched the references section of relevant articles to identify studies. We did not include case reports or case series with small sample size, N < 20. VTE in patients with breast cancer was strongly associated with patient-, tumor-, and non-tumor-related risk factors, such as age, disease stage, central catheter placement, and chemotherapy and tamoxifen use, especially within 2years of breast cancer diagnosis. CDK inhibitors are emerging factors that may also increase the risk of VTE. The risk of VTE in patients with breast cancer depends on various patient-, tumor-, and non-tumor-related risk factors. Identifying these risk factors during breast cancer diagnosis and treatment is essential in developing a practical dynamic predictive tool that can help individualize strategies to prevent VTE.

Abstract GS1-08: CCTGMA.32, a phase III randomized double-blind placebo controlled adjuvant trial of metformin (MET) vs placebo (PLAC) in early breast cancer (BC): Results of the primary efficacy analysis (clinical trials.gov NCT01101438)

Abstract Background: MET has been associated with beneficial anti-cancer effects in epidemiologic and preclinical research. It may act indirectly by reversing obesity associated physiologic changes or directly via mitochondrial mediated effects on LKB1/AMPK/mTOR and other mechanisms. MA.32 investigated the effect of MET vs PLAC (in addition to standard therapy) on adjuvant BC outcomes. Design: Randomized, placebo-controlled double-blind Phase III clinical trial conducted within the NCI US National Clinical Trials Network, NCRI (UK) BG, IBCSG. Methods: Between 2010-2013 BC patients &amp;lt; 75 yo without diabetes (DM) with high risk T1-3, N0-3 M0 BC regardless of ER, PgR, HER2 and with adequate cardiac, renal and hepatic function were randomized (stratified for ER/PgR + vs -, BMI &amp;lt; vs &amp;gt; 30 kg/m2, HER2 +ve vs -ve, any vs no chemo) within 1 year of BC diagnosis to MET 850 mg po bid or PLAC bid for 5 years. Dose was reduced for toxicity with re-escalation when possible. Subjects were followed for Invasive Disease-Free Survival (IDFS primary outcome; events included invasive local/regional recurrences, distant recurrences, new ipsilateral/contralateral invasive BCs, new non-breast primary cancers, any death), Overall Survival (OS), Distant Relapse Free Survival (DRFS), BC Specific Survival (BCSS), BC Free Interval (BCFI), contralateral BC and cardiovascular (CV) events/new DM. 3582 subjects were required for 80% power to detect HR 0.76 (431 events). In 2011, entry was restricted to higher risk BC, leading to 80% power to detect HR 0.785 (544 events). In 2016, after the 2nd interim analysis at 29.5 months median F/U, the DSMB recommended (i) the intervention be continued with primary analysis triggered at 544 events be conducted in ER/PgR +ve (any HER2) subjects only and (ii) ER/PgR -ve subjects stop study drug for futility but blinding and follow-up continue. In 2021, a time driven analysis in ER/PgR +ve BC was approved (465 events providing 80% power to detect the original HR 0.76). Time to event survival described by the Kaplan-Meier method. Two-sided log-rank tests adjusting for stratification factors were primarily used to compare IDFS between arms. Cox proportional hazards models were used to identify and adjust for factors significantly related to IDFS. Results: 3649 subjects were enrolled. In the 2533 ER/PgR +ve subjects included in the primary analysis, baseline mean (± SD) age was 52.7 (±9.9 yrs); mean BMI 28.8 (±6.4) kg/m2. Baseline tumor characteristics were balanced: T stage 1/2/3/4 = 832/1351/349/1; N stage 0/1/2/3 = 964/1097/449/23; HER2+ 429. 1901 (75%) received XRT. 2150 (84.9%) received (neo)adj chemo, 2223 (87.8%) (neo)adj hormones and 434 (17.1%) HER2 targeted therapy. Any Grade ≥ 3 toxicity was similar in MET and PLAC arms (21.7% and 18.7%, P = 0.06). Median follow-up was 96.2 (range 0.2-121.0) months with 465 IDFS events (234 MET, 231 PLAC, 76% due to BC). Efficacy results are shown below. MET vs PLACMET vs PLACIDFSOSPopulation Included# subjectsHR (95% CI)HR (95% CI)PRIMARY ANALYSISER/PgR +ve (any HER2)*25331.01 (0.84-1.21). P=0.920.89 (0.64-1.23). P=0.46ER/PgR -ve (any HER211161.01 (0.79-1.30. P=0.92)0.89 (0.64-1.23). P=0.46Exploratory. AnalysisHER2 +ve (any ER/PgR)6200.64 (0.43-0.95. P=0.0260.53 (0.30-0.98. P=0.0398**in ER/PgR pos BC HRs were similar for BCFI, DRFS, BCSS (ranging from 0.98-1.09)Conclusions: MET did not improve IDFS or other BC outcomes in ER/PgR positive or ER/PgR negative BC and should not be used as adjuvant treatment. Exploratory findings suggesting benefit in HER2+ve BC should be further investigated. Funded by: CCSRI, NCI (US), CBCF, BCRF, CRUK, Hold’Em for Life Charity, Apotex (Canada) Citation Format: Pamela J. Goodwin, Bingshu E Chen, Karen A Gelmon, Timothy J Whelan, Marguerite Ennis, Julie Lemieux, Jennifer A Ligibel, Dawn L Hershman, Ingrid A Mayer, Timothy J Hobday, Judith M Bliss, Priya Rastogi, Manuela Rabaglio-Poretti, Som D. Mukherjee, Robert R Mackey, Vandana G Abramson, Conrad Oja, Robert Wesolowski, Alastair M Thompson, Daniel W Rea, Paul M Stos, Lois E Shepherd, Vuk Stambolic, Wendy R Parulekar. CCTGMA.32, a phase III randomized double-blind placebo controlled adjuvant trial of metformin (MET) vs placebo (PLAC) in early breast cancer (BC): Results of the primary efficacy analysis (clinical trials.gov NCT01101438) [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 GS1-08.

Abstract P2-09-15: Frequency of germline mutations in breast cancer susceptibility genes among women under age 50 presenting with parity associated breast cancer

Abstract Background: Epidemiologic data have demonstrated an increased risk of breast cancer development following pregnancy which can last up to 10 years, particularly in women with older age at childbirth. The majority of women with parity associated breast cancer (PABC) undergo genetic testing based on their young age at onset, per current NCCN guidelines. Prior studies have evaluated the interaction of parity and germline BRCA1/2 mutation status, but these have not been extended to other pathogenic germline mutations in known breast cancer susceptibility genes (PALB2, TP53, PTEN, CDH1, CHEK2, ATM, and STK11). Our goal was to evaluate the prevalence of pathogenic germline mutations in a contemporary cohort of women less than 50 diagnosed with breast cancer in relation to their parity status and the time since their most recent pregnancy. Methods: The Northwestern Electronic Database Warehouse was queried for women diagnosed with a new breast cancer between 2010 - 2020 at the age of less than 50 and underwent genetic testing with results available. Patient demographic data, parity history, and genetic testing results were obtained from the structured electronic health records data as well as from semi-structured clinical notes using rule-based text mining methods. 929 women were identified with complete information on parity status, age at first birth, age at most recent birth, breastfeeding status, and germline mutation status. Statistical analyses included Pearson’s chi-square and logistic regression with adjustment for age at diagnosis. Results: 85 women (9.1%) had a germline genetic mutation, with the most prevalent mutations being BRCA1 (3.9%), BRCA2 (2.5%), CHEK2 (0.8%), PALB2 (0.6%) and ATM (0.5%). 90 women (9.7%) had a variant of uncertain significance (VUS) and were included in the no mutation group for analysis. There was no statistically significant difference between nulliparous and parous women in regard to likelihood of having a pathogenic germline genetic mutation (age-adjusted OR 0.85, CI 0.53 -1.29). Among parous women stratified by recency of pregnancy (&amp;lt;5 years, 5-10 years, and &amp;gt;10 years), there was an increased likelihood of having a germline genetic mutation with recency of pregnancy &amp;lt; 5 years (age adjusted OR 2.2, CI 1.07-3.75) compared to women with &amp;gt; 10 years since last pregnancy. Evaluation of each separate germline mutation demonstrated mixed results with CHEK2 mutations more likely with more recent pregnancy (age adjusted OR 3.58, CI 1.13 - 7.57), while PALB2 mutations were less likely with more recent pregnancy (age adjusted OR 0.72, CI 0.52-0.85). The remainder of the mutations were not statistically significantly different among nulliparous vs parous women or when stratified by recency of pregnancy. Conclusions: Nulliparous women with a new diagnosis of breast cancer under the age of 50 were equally as likely to have a germline genetic mutation compared to parous women. After adjusting for age, recency of pregnancy within 5 years of breast cancer diagnosis was associated with increased likelihood of having a germline genetic mutation. The influence of family history of cancer will be addressed in additional analyses. Our data suggest that these mutations may confer an increased risk of parity-associated breast cancer, but need confirmation in larger studies. Citation Format: Erica Wrubel, Saya Rene Dennis, Takahiro Tsukioki, Theresa Sciaraffa, Yuan Luo, Seema A Khan. Frequency of germline mutations in breast cancer susceptibility genes among women under age 50 presenting with parity associated breast cancer [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 P2-09-15.

Recreational Physical Activity and Outcomes After Breast Cancer in Women at High Familial Risk

BackgroundRecreational physical activity (RPA) is associated with improved survival after breast cancer (BC) in average-risk women, but evidence is limited for women who are at increased familial risk because of a BC family history or BRCA1 and BRCA2 pathogenic variants (BRCA1/2 PVs).MethodsWe estimated associations of RPA (self-reported average hours per week within 3 years of BC diagnosis) with all-cause mortality and second BC events (recurrence or new primary) after first invasive BC in women in the Prospective Family Study Cohort (n = 4610, diagnosed 1993-2011, aged 22-79 years at diagnosis). We fitted Cox proportional hazards regression models adjusted for age at diagnosis, demographics, and lifestyle factors. We tested for multiplicative interactions (Wald test statistic for cross-product terms) and additive interactions (relative excess risk due to interaction) by age at diagnosis, body mass index, estrogen receptor status, stage at diagnosis, BRCA1/2 PVs, and familial risk score estimated from multigenerational pedigree data. Statistical tests were 2-sided.ResultsWe observed 1212 deaths and 473 second BC events over a median follow-up from study enrollment of 11.0 and 10.5 years, respectively. After adjusting for covariates, RPA (any vs none) was associated with lower all-cause mortality of 16.1% (95% confidence interval [CI] = 2.4% to 27.9%) overall, 11.8% (95% CI = -3.6% to 24.9%) in women without BRCA1/2 PVs, and 47.5% (95% CI = 17.4% to 66.6%) in women with BRCA1/2 PVs (RPA*BRCA1/2 multiplicative interaction P = .005; relative excess risk due to interaction = 0.87, 95% CI = 0.01 to 1.74). RPA was not associated with risk of second BC events.ConclusionFindings support that RPA is associated with lower all-cause mortality in women with BC, particularly in women with BRCA1/2 PVs.

Factors Associated With the Discussion of Fertility Preservation in a Cohort of 1,357 Young Breast Cancer Patients Receiving Chemotherapy.

PurposeFemale breast cancer (BC) patients exposed to gonadotoxic chemotherapy are at risk of future infertility. There is evidence of disparities in the discussion of fertility preservation for these patients. The aim of the study was to identify factors influencing the discussion of fertility preservation (FP).Material and MethodsWe analyzed consecutive BC patients treated by chemotherapy at Institut Curie from 2011-2017 and aged 18-43 years at BC diagnosis. The discussion of FP was classified in a binary manner (discussion/no discussion), based on mentions present in the patient’s electronic health record (EHR) before the initiation of chemotherapy. The associations between FP discussion and the characteristics of patients/tumors and healthcare practitioners were investigated by logistic regression analysis.ResultsThe median age of the 1357 patients included in the cohort was 38.7 years, and median tumor size was 30.3 mm. The distribution of BC subtypes was as follows: 702 luminal BCs (58%), 241 triple-negative breast cancers (TNBCs) (20%), 193 HER2+/HR+ (16%) and 81 HER2+/HR- (6%). All patients received chemotherapy in a neoadjuvant (n=611, 45%) or adjuvant (n= 744, 55%) setting. A discussion of FP was mentioned for 447 patients (33%). Earlier age at diagnosis (discussion: 34.4 years versus no discussion: 40.5 years), nulliparity (discussion: 62% versus no discussion: 38%), and year of BC diagnosis were the patient characteristics significantly associated with the mention of FP discussion. Surgeons and female physicians were the most likely to mention FP during the consultation before the initiation of chemotherapy (discussion: 22% and 21%, respectively). The likelihood of FP discussion increased significantly over time, from 15% in 2011 to 45% in 2017. After multivariate analysis, FP discussion was significantly associated with younger age, number of children before BC diagnosis, physicians’ gender and physicians’ specialty.ConclusionFP discussion rates are low and are influenced by patient and physician characteristics. There is therefore room for improvement in the promotion and systematization of FP discussion.

Dyadic effects of family resilience on post-traumatic stress symptoms among breast cancer patients and their primary family caregivers: A cross-sectional study.

The aims of this study were to verify actor and partner effects, by examining the effects of family resilience on post-traumatic stress symptoms (PTSS) among Chinese breast cancer patients and their primary family caregivers. In this cross-sectional study, 104 breast cancer patients (age range 20-75, Mean=47, Standard Deviation=10), and their principal caregivers (n=104), were recruited from a comprehensive cancer center of a public hospital in China. The patients and their caregivers self-reported sociodemographic, family resilience, and PTSS factors. The actor-partner interdependence model were adopted to examine whether the patients and caregivers' perceived family resilience could contribute to their own ("actor effect") and each other's ("partner effect") PTSS. There were significant correlations between patients' and caregivers' shortened Chinese version of Family Resilience Assessment Scale scores (r=0.58, p<0.01) and Post-traumatic Stress Disorder Checklist-Civilian Version scores (r=0.69, p<0.01). Caregivers' perceived family resilience was negatively related to their PTSS (actor effect), and the patients' PTSS (partner effect). However, the patients' perceived family resilience was not significantly related to their or the caregivers' PTSS. The primary caregivers' perceived family resilience had both actor and partner effects on patient/caregiver PTSS within the first year of breast cancer diagnosis. Family-based interventions should be designed to enhance family resilience to decrease PTSS within families dealing with cancer patients. Supportive care should focus on the primary family caregivers within the first year of breast cancer diagnosis.