Risk of Cardiovascular Disease in Women With and Without Breast Cancer: The Pathways Heart Study

PURPOSE

To examine cardiovascular disease (CVD) and mortality risk in women with breast cancer (BC) by cancer therapy received relative to women without BC.

METHODS

The study population comprised Kaiser Permanente Northern California members. Cases with invasive BC diagnosed from 2005 to 2013 were matched 1:5 to controls without BC on birth year and race/ethnicity. Cancer treatment, CVD outcomes, and covariate data were from electronic health records. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% CIs of CVD incidence and mortality by receipt of chemotherapy treatment combinations, radiation therapy, and endocrine therapy.

RESULTS

A total of 13,642 women with BC were matched to 68,202 controls without BC. Over a 7-year average follow-up (range < 1-14 years), women who received anthracyclines and/or trastuzumab had high risk of heart failure/cardiomyopathy relative to controls, with the highest risk seen in women who received both anthracyclines and trastuzumab (HR, 3.68; 95% CI, 1.79 to 7.59). High risk of heart failure and/or cardiomyopathy was also observed in women with BC with a history of radiation therapy (HR, 1.38; 95% CI, 1.13 to 1.69) and aromatase inhibitor use (HR, 1.31; 95% CI, 1.07 to 1.60), relative to their controls. Elevated risks for stroke, arrhythmia, cardiac arrest, venous thromboembolic disease, CVD-related death, and death from any cause were also observed in women with BC on the basis of cancer treatment received.

CONCLUSION

Women with BC had increased incidence of CVD events, CVD-related mortality, and all-cause mortality compared with women without BC, and risks varied according to the history of cancer treatment received. Studies are needed to determine how women who received BC treatment should be cared for to improve cardiovascular outcomes.

UACA locus is associated with breast cancer chemoresistance and survival

Few germline genetic variants have been robustly linked with breast cancer outcomes. We conducted trans-ethnic meta genome-wide association study (GWAS) of overall survival (OS) in 3973 breast cancer patients from the Pathways Study, one of the largest prospective breast cancer survivor cohorts. A locus spanning the UACA gene, a key regulator of tumor suppressor Par-4, was associated with OS in patients taking Par-4 dependent chemotherapies, including anthracyclines and anti-HER2 therapy, at a genome-wide significance level (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P = 1.27 \times 10^{ - 9}$$\end{document}P=1.27×10−9). This association was confirmed in meta-analysis across four independent prospective breast cancer cohorts (combined hazard ratio = 1.84, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P = 1.28 \times 10^{ - 11}$$\end{document}P=1.28×10−11). Transcriptome-wide association study revealed higher UACA gene expression was significantly associated with worse OS (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P = 4.68 \times 10^{ - 7}$$\end{document}P=4.68×10−7). Our study identified the UACA locus as a genetic predictor of patient outcome following treatment with anthracyclines and/or anti-HER2 therapy, which may have clinical utility in formulating appropriate treatment strategies for breast cancer patients based on their genetic makeup.

Abstract PD5-03: Development of cardiometabolic risk factors following endocrine therapy: The pathways heart study

Purpose: Endocrine therapy is associated with cardiovascular disease among breast cancer (BC) survivors, with observed opposing effects between aromatase inhibitors (AIs) and tamoxifen. AIs deplete endogenous estrogen levels, while tamoxifen has mixed estrogenic and antiestrogenic activity. Yet, observational studies comparing AI vs. tamoxifen use may be confounded by indication and few have tested their associations with cardiometabolic risk factors. Therefore, we examined the association of AI or tamoxifen use on the incidence of newly diagnosed hypertension, diabetes, and dyslipidemia in a cohort of BC survivors within Kaiser Permanente Northern California (KPNC). Methods: The Pathways Heart Study is an ongoing cohort study within KPNC examining incident CVD outcomes and risk factors in 14,942 women with history of BC. Eligibility was: 1) stage I-IV invasive BC diagnosis between Nov 2005 and Mar 2013; 2) &ge;21 years; and 3) active KPNC membership &ge;12 months at diagnosis. KPNC records were used to collect demographic, socioeconomic, and health characteristics. Endocrine therapy was collected from outpatient pharmacy data. Incident hypertension, diabetes, and dyslipidemia were identified from ICD-9/10 codes, laboratory results, and/or medication use. Hazard ratios (HR) and 95% confidence intervals (CI) from Cox proportional models were used to determine whether AI and tamoxifen use were associated with incident hypertension, diabetes, and dyslipidemia compared to BC survivors not receiving either of these therapies. For each cardiometabolic risk factor, models adjusted for demographic, socioeconomic, and health characteristics and excluded women with the cardiometabolic risk factor at baseline. Results: Among 14,942 women with a history of BC, mean age at baseline was 61.2±12.8 years and mean follow-up time was 7.0±3.5 years (range 1-13.4). The frequency of use was: AI, n=6,070 (40.6%); tamoxifen, n=1,755 (11.8%); and neither, n=7,117 (47.6%). Regression models showed AI use was associated with increased risk of incident hypertension (HR: 1.1, 95% CI: 1.00-1.21) and increased risk of incident dyslipidemia (HR: 1.18, 95% CI: 1.07-1.3) relative to BC survivors who did not use endocrine therapy. (Table). In contrast, tamoxifen use was associated with decreased risk of dyslipidemia (HR: 0.8, 95% CI: 0.68-0.94) relative to BC survivors who did not use endocrine therapy. Neither AI nor tamoxifen use was associated with risk of incident diabetes. Conclusion: Compared to BC survivors who did not use endocrine therapy, women treated with AIs had a higher risk of incident hypertension and dyslipidemia, while women treated with tamoxifen had a lower risk of dyslipidemia. AIs reduce endogenous estrogen levels, which can alter lipid profiles, although prior studies have been inconsistent, possibly due to differences in steroidal and non-steroidal AIs. More work is needed to understand the implications of these associations on long-term cardiovascular health and how to best manage cardiometabolic risk factors in BC survivors with a history of endocrine therapy use.

Table. Adjusted1 hazard ratios (95% confidence intervals) of incident cardiometabolic risk factors among women with a history of breast cancer, by endocrine therapy useNo Endocrine Therapy(n=7,117)Endocrine TherapyAromatase inhibitor(n=6,070)Tamoxifen(n=1,755)Incident HypertensionRef1.10 (1.00, 1.21)0.98 (0.85, 1.14)Incident DiabetesRef0.99 (0.87, 1.13)0.98 (0.80, 1.20)Incident DyslipidemiaRef1.18 (1.07, 1.30)0.80 (0.68, 0.94)1Adjusted for age, race/ethnicity, baseline body mass index, AJCC stage, menopausal status, smoking status, education level, income, chemotherapy, radiation therapy, and prevalent cardiovascular disease.

Citation Format: Heather Greenlee, Eileen Rillamas-Sun, Carlos Iribarren, Richard Cheng, Romain Neugebauer, Jamal S. Rana, Mai Nguyen-Huynh, Zaixing Shi, Cecile A. Laurent, Valerie S. Lee, Janise M. Roh, Hanjie Shen, Dawn L. Hershman, Lawrence H. Kushi, Marilyn L. Kwan. Development of cardiometabolic risk factors following endocrine therapy: The pathways heart study [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 PD5-03.

Abstract PD5-01: Cardiovascular disease risk of breast cancer therapies: The pathways heart study

Purpose: Studies on long-term cardiovascular disease (CVD) risk in breast cancer (BC) survivors are limited. We examined CVD risk associated with exposure to specific BC therapies and explored whether body mass index (BMI) or prevalent CVD risk factors at BC diagnosis modified these associations. Methods: The Pathways Heart Study is a prospective cohort study examining incident CVD outcomes and risk factors in women with BC at Kaiser Permanente Northern California (KPNC). Eligible women were diagnosed with stage I-IV invasive BC from 2005-2013, &ge;21 years old, and KPNC members &ge;12 months at diagnosis. KPNC records provided demographic and BC therapy characteristics. Incident CVD outcomes [ischemic heart disease, heart failure/cardiomyopathy (HF/CM), stroke] were assessed from ICD9/10 codes. Multivariable Cox models estimated hazard ratios (HR) and 95% confidence intervals (CI) of each CVD outcome by cancer therapy received compared to not receiving that therapy, excluding those with prevalent CVD. Separate regression models included interaction terms for cancer therapy by overweight, obesity, diabetes, dyslipidemia, and hypertension to test whether the CVD outcome risk varied by presence of these factors at diagnosis. Results: Among 4,181 BC survivors with mean age of 59.6±12.0 years and mean follow-up of 7.9±3.5 years (range: 0.04-13.3), cancer therapies were not associated with incident CVD. However, CVD risks varied by BMI and prevalence of CVD risk factors at BC diagnosis. Normal weight (NW) women who received anthracyclines had higher risk of ischemic heart disease and HF/CM relative to NW women not receiving these therapies; interaction terms indicated HF/CM risk was statistically different than risks for obese women (Table). NW women who received cyclophosphamide or left-sided radiation had higher risk of HF/CM and stroke relative to NW women not receiving these therapies; these risks were statistically different from obese (for cyclophosphamide) or overweight (for radiation) women. Relative to women not receiving these therapies, higher HRs for HF/CM were observed among non-diabetic women who received cyclophosphamide (2.03, CI: 1.22-3.37), non-dyslipidemic women who received anthracyclines (3.65, CI: 1.69-7.87), and non-hypertensive women who received either anthracyclines (4.04, CI: 1.81-9.03) or cyclophosphamide (2.66, CI: 1.23-5.74) (P for interaction range: 0.04 to 0.06). Conclusion: Certain chemotherapy drugs may increase the risk of CVD in NW BC survivors; overweight and obese BC survivors may experience less risk than NW women. While chemotherapy also appears to increase HF/CM risk for women without diabetes, dyslipidemia, and hypertension, these conditions are more prevalent among overweight/obese women. Analysis within these subgroups is needed and forthcoming.

Table. Adjusted HRs (95% CI) of CVD outcomes among breast cancer survivors receiving select cancer therapies* stratified by BMI status at diagnosisBMI Ischemic heart diseaseHeart failure/CardiomyopathyStrokeAnthracycline, n=1283Normal4.22 (1.59, 11.2)5.27 (2.54, 10.9)1.89 (0.79, 4.53)Overweight1.66 (0.73, 3.77)2.17 (1.15, 4.11)0.40 (0.16, 0.99)Obese1.26 (0.56, 2.85)1.1 (0.54, 2.27)a0.33 (0.13, 0.83)aCyclophosphamide, n=1705Normal1.63 (0.61, 4.31)3.28 (1.59, 6.75)2.21 (1.01, 4.84)Overweight1.59 (0.75, 3.39)1.63 (0.9, 2.97)0.73 (0.34, 1.58)Obese0.85 (0.39, 1.86)0.75 (0.38, 1.47)a0.31 (0.13, 0.71)aLeft-Side Radiation, n=1331Normal1.44 (0.56, 3.69)2.04 (1.0, 4.18)2.38 (1.28, 4.42)Overweight1.47 (0.68, 3.16)0.68 (0.34, 1.34)b0.72 (0.37, 1.4)bObese1.32 (0.73, 2.38)1.30 (0.79, 2.16)1.05 (0.61, 1.82)*Cancer therapies with non-significant findings (i.e., Trastuzumab, taxanes, aromatase inhibitors, Tamoxifen, and any-side radiation) are not shown.ap≤0.05 normal weight v. obese; bp≤0.05 normal weight v. overweight

Citation Format: Heather Greenlee, Eileen Rillamas-Sun, Carlos Iribarren, Richard Cheng, Romain Neugebauer, Jamal S. Rana, Mai Nguyen-Huynh, Zaixing Shi, Cecile A. Laurent, Valerie S. Lee, Janise M. Roh, Hanjie Shen, Dawn L. Hershman, Lawrence H. Kushi, Marilyn L. Kwan. Cardiovascular disease risk of breast cancer therapies: The pathways heart study [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 PD5-01.

Risk of Cardiometabolic Risk Factors in Women With and Without a History of Breast Cancer: The Pathways Heart Study

PURPOSE

The incidence of cardiometabolic risk factors in breast cancer (BC) survivors has not been well described. Thus, we compared risk of hypertension, diabetes, and dyslipidemia in women with and without BC.

METHODS

Women with invasive BC diagnosed from 2005 to 2013 at Kaiser Permanente Northern California (KPNC) were identified and matched 1:5 to noncancer controls on birth year, race, and ethnicity. Cumulative incidence rates of hypertension, diabetes, and dyslipidemia were estimated with competing risk of overall death. Subdistribution hazard ratios (sHRs) were estimated by Fine and Gray regression, adjusted for cardiovascular disease-related risk factors, and stratified by treatment and body mass index (BMI).

RESULTS

A total of 14,942 BC cases and 74,702 matched controls were identified with mean age 61.2 years and 65% non-Hispanic White. Compared with controls, BC cases had higher cumulative incidence rates of hypertension (10.9% v 8.9%) and diabetes (2.1% v 1.7%) after 2 years, with higher diabetes incidence persisting after 10 years (9.3% v 8.8%). In multivariable models, cases had higher risk of diabetes (sHR, 1.16; 95% CI, 1.07 to 1.26) versus controls. Cases treated with chemotherapy (sHR, 1.23; 95% CI, 1.11 to 1.38), left-sided radiation (sHR, 1.29; 95% CI, 1.13 to 1.48), or endocrine therapy (sHR, 1.23; 95% CI, 1.12 to 1.34) continued to have higher diabetes risk. Hypertension risk was higher for cases receiving left-sided radiation (sHR, 1.11; 95% CI, 1.02 to 1.21) or endocrine therapy (sHR, 1.10; 95% CI, 1.03 to 1.16). Normal-weight (BMI < 24.9 kg/m²) cases had higher risks overall and within treatment subgroups versus controls.

CONCLUSION

BC survivors at KPNC experienced elevated risks of diabetes and hypertension compared with women without BC depending on treatments received and BMI. Future studies should examine strategies for cardiometabolic risk factor prevention in BC survivors.

Modeling risks of cardiovascular and cancer mortality following a diagnosis of loco-regional breast cancer

Background

Many women with breast cancer also have a high likelihood of cardiovascular mortality, and while there are several cardiovascular risk prediction models, none have been validated in a cohort of breast cancer patients. We first compared the performance of commonly-used cardiovascular models, and then derived a new model where breast cancer and cardiovascular mortality were modeled simultaneously, to account for the competing risk endpoints and commonality of risk factors between the two events.

Methods

We included 20,462 women diagnosed with stage I–III breast cancer between 2000 and 2010 in Kaiser Permanente Northern California (KPNC) with follow-up through April 30, 2015, and examined the performance of the Framingham, CORE and SCOREOP cardiovascular risk models by area under the receiver operating characteristic curve (AUC), and observed-to -expected (O/E) ratio. We developed a multi-state model based on cause-specific hazards (CSH) to jointly model the causes of mortality.

Results

The extended models including breast cancer characteristics (grade, tumor size, nodal involvement) with CVD risk factors had better discrimination at 5-years with AUCs of 0.85 (95% CI 0.83, 0.86) for cardiovascular death and 0.80 (95% CI 0.78, 0.87) for breast cancer death compared with the existing cardiovascular models evaluated at 5 years AUCs ranging 0.71–0.78. Five-year calibration for breast and cardiovascular mortality from our multi-state model was also excellent (O/E = 1.01, 95% CI 0.91–1.11).

Conclusion

A model incorporating cardiovascular risk factors, breast cancer characteristics, and competing events, outperformed traditional models of cardiovascular disease by simultaneously estimating cancer and cardiovascular mortality risks.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01469-w.

Clinically sufficient vitamin D levels at breast cancer diagnosis and survival outcomes in a prospective cohort of 3,995 patients after a median follow-up of 10 years

10510

Background: There have been suggestive findings for better cancer survival with vitamin D supplementation in the recent VITAL trial. The findings are consistent with meta-analyses based on earlier randomized trials testing daily supplement vitamin D intake. As there is no ongoing or planned randomized trial of vitamin D supplementation in sight for women after breast cancer diagnosis, we evaluated relationships between serum levels of vitamin D and breast cancer outcomes in a large prospective cohort of breast cancer survivors. Methods: We measured 25-hydroxyvitamin D (25OHD) levels in serum samples collected at the time of diagnosis from 3,995 women with incident breast cancer enrolled in the Pathways Study, a large prospective cohort established in 2006 at Kaiser Permanente Northern California with active follow-up (FU). Potential determinants of 25OHD levels, including a polygenic score, were examined. Vitamin D levels were categorized based on clinical cutoffs as deficient ( < 20 ng/ml), insufficient (20 to < 30 ng/ml), or sufficient (≥30 ng/ml). These levels were then evaluated in relation to overall survival (OS), breast cancer-specific survival (BCSS), recurrence-free survival (RFS), and invasive disease-free survival (IDFS). Cox proportional hazards models were adjusted for non-clinical, clinical, and treatment factors and were further stratified by stage, estrogen receptor (ER) status, and body mass index (BMI). Results: Vitamin D supplement use, lower BMI, and self-reported white race were the strongest determinants of higher 25OHD levels. The polygenic score was significantly associated with 25OHD levels but explained only 0.3% of the variance. The median FU was 9.6 years (range: 0.3-13). Compared to those with deficient vitamin D levels, patients with sufficient levels had significantly better survival outcomes, which remained after controlling for various covariates (OS: HR [95% CI] = 0.73 [0.58-0.91]; BCSS: HR = 0.78 [0.56-1.09]; RFS: HR = 0.79 [0.65-0.97]; IDFS: HR = 0.82 [0.68-0.99]). Associations were similar by ER status, but stronger among patients with more advanced stage disease and those with under-weight or normal BMI. Black patients had the lowest 25OHD levels, which contributed to their poorer survival compared to white patients. Adding 25OHD levels to the Cox model of OS lowered the HR associated with Black vs. white race from 2.03 (1.57-2.62) to 1.79 (1.37-2.32). Conclusions: Sufficient vitamin D levels at the time of diagnosis were associated with improved breast cancer prognosis. Consistent with results from randomized trials, our findings from a large observational cohort of breast cancer survivors with long FU provide the strongest evidence to date for maintaining sufficient vitamin D levels in breast cancer patients, including among Black women and those with more advanced stage disease.

Diet Quality and Breast Cancer Recurrence and Survival: The Pathways Study

Background

Prior research suggests a relationship between overall diet quality and breast cancer survival, although few studies have reported on this topic. We evaluated whether 4 dietary quality indices consistent with healthy eating recommendations around the time of breast cancer diagnosis were associated with risk of recurrence, cause-specific, and all-cause mortality.

Methods

A total of 3660 women diagnosed with invasive breast cancer were included. Diet was assessed an average of 2.3 (range = 0.7-18.7) months after diagnosis, from which 4 dietary quality indices were derived: the American Cancer Society guidelines (ACS), the alternate Mediterranean Diet Index (aMED), the Dietary Approaches to Stop Hypertension (DASH), and the 2015 Healthy Eating Index (HEI). Over 40 888 person-years of follow-up, 461 breast cancer recurrences, and 655 deaths were ascertained. Cox models were used to estimate hazards ratios (HRs) and 95% confidence intervals (CIs).

Results

Adjusted comparisons between extreme quintiles showed all 4 dietary quality indices to be inversely associated with all-cause mortality, suggesting a 21%-27% lower risk (ACS HR = 0.73, 95% CI = 0.56 to 0.95; aMED HR = 0.79, 95% CI = 0.61 to 1.03; DASH HR = 0.76, 95% CI = 0.58 to 1.00; HEI HR = 0.77, 95% CI = 0.60 to 1.01). Similar patterns were noted for non-breast cancer mortality (ACS HR = 0.69, 95% CI = 0.48 to 0.98; aMED HR = 0.73, 95% CI = 0.50 to 1.05; DASH HR = 0.55, 95% CI = 0.38 to 0.79; HEI HR = 0.67, 95% CI = 0.48 to 0.94). None of the dietary quality indices were associated with recurrence or breast cancer-specific mortality.

Conclusion

Food intake patterns concordant with dietary quality indices consistent with recommendations for healthy eating may be beneficial for women with breast cancer.

Abstract GS2-05: Genome-wide association study identifies UACA as a modulator of breast cancer chemoresistance and survival

Prior studies suggest a strong genetic influence on breast cancer prognosis. Six genome-wide association studies (GWAS) on breast cancer prognosis have been published to date. However, none of the reported loci was replicated across studies and only two passed genome-wide significance (P &lt; 5 x 10-8). In the Pathways Study, a prospective cohort of breast cancer survivors begun in Kaiser Permanente Northern California (KPNC) in 2006, we carried out a GWAS of overall survival (OS) in 3,973 patients. Trans-ethnic meta-GWAS identified an association with OS of a locus on chromosome 15 that almost reached genome-wide significance (P = 9.42 x 10-8). This locus spanned the UACA gene, a key regulator of tumor suppressor Par-4. We found that receipt of chemotherapy modified the effect of the UACA locus on OS (Pinteraction = 2.4 x 10-4). This observation led us to hypothesize that the UACA locus effect on OS may be specific to Par-4 dependent chemotherapies, which include anti-HER2 therapy and doxorubicin. We stratified patients into two groups, those who received Par-4 dependent chemotherapy agents versus other patients. In separate trans-ethnic meta-GWAS, the UACA locus was significantly associated with OS in patients taking Par-4 dependent chemotherapies (P = 1.27 x 10-9), while no association was observed in the other patients (P = 0.21). To evaluate whether the UACA gene may be responsible for this association, we performed a transcriptome-wide association study (TWAS) of OS in White patients taking Par-4 dependent chemotherapies. Higher UACA gene expression was significantly associated with OS (P = 4.68 x 10-7), the only gene reaching transcriptome-wide significance (P &lt; 4.34 x 10-6). These results suggest that higher UACA expression may inhibit Par-4 induced apoptosis and lead to stronger chemoresistance and worse survival. We attempted to validate our findings in the independent KPNC Genetic Epidemiology Research on Aging (GERA) cohort. The GERA cohort included only 168 White patients with incident breast cancer after DNA collection who received Par-4 dependent chemotherapies. We found a non-significant association (hazard ratio (HR) = 1.46, P = 0.66) consistent with Pathways Study findings. However, the GERA cohort also included 1,983 prevalent breast cancer patients with biospecimen collection after diagnosis. In this group, the risk allele frequency in breast cancer survivors receiving Par-4 dependent chemotherapies was significantly lower than that in the White population (P = 5.50 x 10-3) while the risk allele frequency in the those not receiving these chemotherapies was similar to the population (P = 0.07). This is consistent with Pathways Study observations that the UACA locus risk allele significantly increased risk of mortality in patients taking Par-4 dependent chemotherapies. A higher mortality in breast cancer survivors carrying the risk allele would result in decreased risk allele frequency. We further validated our findings in Shanghai Breast Cancer Survival Study (SBCSS)and Shanghai Breast Cancer Study, which were conducted from 1996 to 2006 in urban Shanghai and recruited 5,575 breast cancer patients. In this independent Asian breast cancer population, the UACA locus was modestly associated with OS in the overall population (HR = 1.18, P = 0.012), and more significantly in 1,289 SBCSS patients who received anthracyclines (HR = 1.66, P = 1.55 x 10-4). This is the first human study suggesting the Par-4 pathway affects breast cancer patient survival with UACA a key modulator of treatment outcomes by anti-Her2 therapy and doxorubicin. Our findings suggest a path toward new predictive pharmacogenetic markers for personalized medicine targeting the Par-4 pathway for breast cancer treatment.

Citation Format: Lawrence H Kushi, Qianqian Zhu, Emily Schultz, Jirong Long, Janise M Roh, Emily Valice, Cecile A Laurent, Li Yan, Isaac J Ergas, Warren Davis, Dilrini K Ranatunga, Marilyn L Kwan, Ping-Ping Bao, Wei Zheng, Xiao-Ou Shu, Christine B Ambrosone, Song Yao. Genome-wide association study identifies UACA as a modulator of breast cancer chemoresistance and survival [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS2-05.

Effects of cooking methods on total isothiocyanate yield from cruciferous vegetables

Cruciferous vegetables are primary sources of dietary isothiocyanates (ITCs), a group of phytochemicals showing promising cancer-chemopreventive activities in multiple cancer models. However, no study has thoroughly examined how cooking affects the yields of ITCs from cruciferous vegetables. In this study, a high-performance liquid chromatography (HPLC)-based cyclocondensation assay was performed to examine the ITC yields from four major cruciferous vegetables (broccoli, cabbage, cauliflower, and kale) under six cooking conditions (stir-frying, steaming, microwaving, boiling, stewing, and chip-baking for kale only) and measured the level of ITCs under the raw condition for a comprehensive list of cruciferous vegetables and ITC-containing condiments. A wide range of ITC yields was found across vegetables and condiments. Cooking significantly altered the ITC yields, showing an averagely four-fold increase by lightly cooking (stir-frying, steaming, and microwaving) and a 58% decrease by heavily cooking (boiling, stewing, and chip-baking). These findings will provide the evidence-based cooking guidance on cruciferous vegetable consumption and help better estimate dietary ITC exposure in epidemiologic studies.

Distinct trajectories of moderate to vigorous physical activity and sedentary behavior following a breast cancer diagnosis: the Pathways Study

PURPOSE

To identify distinct trajectories of total moderate-to-vigorous physical activity (MVPA) and sedentary behavior following a breast cancer diagnosis and their correlates.

METHODS

The analysis examined 3000 female breast cancer survivors within Kaiser Permanente Northern California between 2006 and 2013. Self-reported time spent on total MVPA and sedentary behaviors were assessed at baseline (mean = 1.8 months post-diagnosis) and at 6 and 24 months follow up. Trajectory groups were identified using group-based trajectory modeling and K-means for longitudinal data analysis. Trajectory groups were named by baseline activity level (high, medium, or low) and direction of change (increaser, decreaser, or maintainer).

RESULTS

Trajectory analyses identified three MVPA trajectories [high decreaser (7%), medium decreaser (35%), low maintainer (58%)] and four sedentary behavior trajectories [high maintainer (18%), high decreaser (27%), low increaser (24%), and low maintainer (31%)]. Women with higher education (ORs: 1.63-4.37), income (OR: 1.37), dispositional optimism (ORs: 1.60-1.86), and social support (OR: 1.33) were more likely to be high or medium decreasers of MVPA (all P < 0.05). High maintainers and high decreasers of sedentary behavior were more likely to have higher education (OR: 1.84) and social support (ORs: 1.42-1.86), but lower income (OR: 0.66; all P < 0.05).

CONCLUSIONS

In the 24 months following breast cancer diagnosis, 42% of survivors decreased MVPA and 73% maintained or increased time on sedentary behavior. Socioeconomic status and stress coping at diagnosis predicted subsequent PA trajectory.

IMPLICATIONS FOR CANCER SURVIVORS

It is important to prioritize exercise intervention and counseling during early stage of breast cancer survivorship, especially in survivors who are at high risk of becoming physically inactive post-diagnosis.

Onset of cardiovascular disease risk factors in women with and without a history of breast cancer: The Pathways Heart Study

12017

Background: Women with a history of breast cancer (BC) are at increased long-term risk of dying from cardiovascular disease (CVD). However, the onset of CVD risk factors in women with BC has not been well-described. We compared risk of incident CVD risk factors in women with and without BC enrolled in the Kaiser Permanente Northern California (KPNC) integrated health system. Methods: Data were extracted from KPNC electronic health records. All invasive BC cases diagnosed between 2005-2013 were identified and matched 1:5 with controls on birth year, race/ethnicity and KPNC membership at the date of BC diagnosis. Cox regression models assessed the hazard of incident hypertension (based on diagnosis codes and filled prescriptions), dyslipidemia (based on diagnosis codes, filled prescriptions, and lab values), and diabetes (KPNC Diabetes Registry). Models were adjusted for baseline BMI, menopausal status, smoking status, neighborhood median household income, education, prevalent CVD conditions, and other baseline CVD risk factors. Subgroups of women who received chemotherapy, radiation therapy, and endocrine therapy were compared with controls. Results: A total of 14,942 women with a new diagnosis of invasive BC were identified and matched to 74,702 controls. On average, women were 62.0 years, 28.3 kg/m2BMI, 64.9% non-Hispanic white. Overall, cases were more likely to develop hypertension (HR: 1.18, 95% CI: 1.13, 1.24) and diabetes (HR: 1.23, 95% CI: 1.16, 1.31). Across the board, receipt of any of the three therapies (chemotherapy, radiation therapy and endocrine therapy) was associated with increased risk of hypertension and diabetes, compared to controls. Risk-factor specific hazard ratios for receipt of chemotherapy were (HR 1.18, 95% CI: 1.10, 1.27) and (HR 1.38, 95% CI: 1.26, 1.51), for hypertension and diabetes, respectively. For receipt of radiation therapy, risk-factor specific hazard ratios were (HR: 1.17, 95% CI: 1.09, 1.26) and (HR: 1.15, 95% CI: 1.04, 1.27), for hypertension and diabetes, respectively. Risk-factor specific hazard ratios for receipt of endocrine therapy were (HR: 1.22, 95% CI: 1.14, 1.30) and (HR: 1.16, 95% CI: 1.06, 1.27), for hypertension and diabetes, respectively. Conclusions: The risk of developing hypertension and diabetes is increased in women with BC who received chemotherapy, radiation therapy, and/or endocrine therapy. Future studies should examine the roles of CVD risk factor diagnosis and management on cardiometabolic risk in women with a BC history.

Risk of cardiovascular disease in women with and without a history of breast cancer: The Pathways Heart Study

12016

Background: Breast cancer (BC) survivors are at increased risk of cardiovascular disease (CVD) following diagnosis, as compared to women without BC. To provide a population-based estimate of CVD risk in BC survivors, we compared risk of CVD events in women with and without BC history enrolled in the Kaiser Permanente Northern California (KPNC) integrated health system. Methods: Data were extracted from KPNC electronic health records. All invasive BC cases diagnosed between 2005-2013 were identified and matched 1:5 with non-BC controls on birth year, race/ethnicity and KPNC membership at date of BC diagnosis. Cox regression models were used to assess differences in the hazard of four major CVD events (ischemic heart disease (IHD), heart failure (HF), cardiomyopathy, and stroke). Models were adjusted for factors known to influence risk of breast cancer or CVD.Other CVD events included arrhythmia, cardiac arrest, carotid disease, myocarditis/pericarditis, transient ischemic attack, valvular disease, and venous thromboembolism (VTE). We additionally examined subgroups of cases who received chemotherapy, radiation, and endocrine therapy, and their controls. Results: A total of 14,942 women with a new diagnosis of invasive BC were identified and matched to 74,702 women without BC history. On average, women were 62.0 years, 28.3 kg/m2BMI, 64.9% non-Hispanic white. Among all cases and controls, there were no significant differences in hazard of developing IHD, cardiomyopathy, and stroke; there was a borderline difference in HF (HR: 1.08, 95% CI: 0.99, 1.19). Cases were more likely to have a cardiac arrest (HR: 1.39, 95% CI: 1.09, 1.78) and develop VTE (HR: 1.97, 95% CI: 1.74, 2.23). Women treated with chemotherapy were more likely than controls to develop HF (HR: 1.44, 95% CI: 1.21, 1.72), cardiomyopathy (HR: 2.01, 95% CI: 1.02, 3.98), and VTE (HR: 3.15, 95% CI: 2.62, 3.79). Women who received radiation therapy were more likely to develop carotid disease (HR: 5.49, 95% CI: 1.22, 24.66) and VTE (HR: 1.65, 95% CI: 1.35, 2.03) than controls. Women who received endocrine therapy were more likely to experience a cardiac arrest (HR: 1.49, 95% CI: 1.07, 2.09) and develop VTE (HR: 1.70, 95% CI: 1.42, 2.03) than controls. Conclusions: Women with BC were at increased risk of heart failure, cardiomyopathy, cardiac arrest, VTE and carotid disease. These risks varied by cancer treatment, with higher risk in those who received chemotherapy. Future studies should explore the effects of chemotherapy class and radiation dose exposure on diverse CVD endpoints in BC survivors.

Serum bone markers and risk of osteoporosis and fragility fractures in women who received endocrine therapy for breast cancer: a prospective study

PURPOSE

Osteoporosis and fragility fracture are major bone toxicities of aromatase inhibitors (AIs) for postmenopausal hormone receptor-positive breast cancer. Except for a few small studies on bone turnover markers and reduced bone mineral density after AI treatment, data on the associations of bone markers and risk of osteoporosis or fracture from prospective studies are lacking.

METHODS

In a prospective study of 1709 women on AIs, two bone turnover markers, BALP and TRACP, and two bone regulatory markers, RANKL and OPG, were measured and examined in relation to risk of osteoporosis and fragility fractures during a median follow-up time of 6.1 years.

RESULTS

Higher levels of BALP and TRACP were both associated with increased risk of osteoporosis and higher BALP/TRACP ratios were associated with lower risk of osteoporosis, but no associations were observed for fracture risk. Higher levels of OPG were associated with increased risk of fracture, whereas higher levels of RANKL were associated with lower risk. As a result, OPG/RANKL ratios were positively associated with fracture risk [hazard ratio (HR) = 2.49, 95% confidence interval (CI) 1.34-4.61]. After controlling for age and fracture history, the associations became non-significant but a suggestive trend remained (HR = 1.80, 95% CI 0.96-3.37).

CONCLUSION

Our study provides suggestive evidence for the potential utility of OPG/RANKL ratios in predicting risk of fracture in women treated with AIs for breast cancer. Further validation may be warranted.

Distinct trajectories of fruits and vegetables, dietary fat, and alcohol intake following a breast cancer diagnosis: the Pathways Study

PURPOSE

To identify distinct diet trajectories after breast cancer (BC) diagnosis, and to examine the characteristics associated with diet trajectories.

METHODS

We analyzed 2865 Pathways Study participants who completed ≥ 2 food frequency questionnaires at the time of BC diagnosis (baseline), and at 6 and 24 months after baseline. Trajectory groups of fruit and vegetable (F/V) intake, % calories from dietary fat, and alcohol intake over 24 months were identified using group-based trajectory modeling. Associations between diet trajectories and sociodemographic, psychosocial, and clinical factors were analyzed using multinomial logistic regression.

RESULTS

Analyses identified 3 F/V trajectory groups, 4 dietary fat groups, and 3 alcohol groups. All 3 F/V trajectory groups reported slightly increased F/V intake post-diagnosis (mean increase = 0.2-0.5 serving/day), while 2 groups (48% of participants) persistently consumed < 4 servings/day of F/V. Dietary fat intake did not change post-diagnosis, with 45% of survivors maintaining a high-fat diet (> 40% of calories from fat). While most survivors consumed < 1 drink/day of alcohol at all times, 21% of survivors had 1.4-3.0 drinks/day at baseline and temporarily decreased to 0.1-0.5 drinks/day at 6 months. In multivariable analysis, diet trajectory groups were significantly associated with education (ORs: 1.93-2.49), income (ORs: 1.32-2.57), optimism (ORs: 1.93-2.49), social support (OR = 1.82), and changes in physical well-being (ORs: 0.58-0.61) and neuropathy symptoms after diagnosis (ORs: 1.29-1.66).

CONCLUSIONS

Pathways Study participants reported slightly increasing F/V and decreasing alcohol intake after BC diagnosis. Nearly half of survivors consumed insufficient F/V and excessive dietary fat. It is important to prioritize nutrition counseling and education in BC survivors.

Breast Cancer Chemoprevention in an Integrated Health Care Setting

PURPOSE

National guidelines encourage counseling high-risk women about pharmacologic breast cancer risk reduction. We evaluated the use of integrated health care data to identify and characterize breast cancer chemoprevention use. Chemoprevention included US Food and Drug Administration-approved use of tamoxifen and raloxifene and off-label use of aromatase inhibitors (AIs).

PATIENTS AND METHODS

Using electronic medical and pharmacy records (EMRs) in the Kaiser Permanente Northern California health care system, we sampled cancer-free women age 35 to 69 years who used tamoxifen, raloxifene, exemestane, anastrozole, or letrozole from 2005 to 2013. Risk-benefit profiles were calculated for tamoxifen and raloxifene using published indices. The proportion of days covered was calculated from pharmacy records to assess adherence.

RESULTS

Among 90 chemoprevention users (confirmed with EMR review from a sample of 371 women), 74% used tamoxifen, 11% used raloxifene, and 13% used an AI. For tamoxifen and raloxifene users, the risk-benefit index indicated 23% of women had insufficient evidence that benefits would outweigh risks. For all agents, adherence decreased from an average proportion of days covered of 75% at 1 year to 67% at 5 years. Automated EMR searches identified breast cancer chemoprevention users with 60% positive predictive value overall and 75% for tamoxifen after post hoc modifications.

CONCLUSION

Our study contributes to an emerging picture of breast cancer chemoprevention use in real-world settings, where evidence of net benefit is not uniform and nonadherence is common. Among breast cancer chemoprevention agents, our automated selection best performed for tamoxifen use. We also identified off-label use of AIs for chemoprevention, suggesting that expansion of risk-benefit indices to include AIs is warranted.

Early-onset triple-negative breast cancer in multiracial/ethnic populations: Distinct trends of prevalence of truncation mutations

Young black women are at higher risk of triple‐negative breast cancer (TNBC); however, a majority of the genetic studies on cancer predisposition were carried out in White populations. The underrepresentation of minority racial/ethnic populations in cancer genetic studies may have led to disproportionate gaps in our knowledge of cancer predisposition genes in these populations. We surveyed the protein‐truncating mutations at the exome‐wide scale and in known breast cancer predisposition genes among 170 patients of multiple racial/ethnic groups with early‐onset (≤age 50) TNBC from two independent cohorts. Black patients, on average, had a higher number of truncating mutations than Whites at the exome‐wide level, but fewer truncating mutations in the panel of known breast cancer genes. White TNBC patients showed a strong enrichment of truncating variants in known breast cancer genes, whereas no such enrichment was found among Black patients. Our findings indicate likely more breast cancer disposition genes yet to be discovered in minority racial/ethnic groups, and the current multigene panels may result in unequal benefits from cancer genetic testing.

Opportunities to Improve Detection and Treatment of Depression Among Patients With Breast Cancer Treated in an Integrated Delivery System

CONTEXT

Patients with cancer commonly experience depression. If not addressed, depression can lead to reduced quality of life and survival.

OBJECTIVE

Given the introduction of national initiatives to improve management of psychiatric symptoms among patients with cancer, we examined patterns of depression detection and treatment over time, and with respect to patient characteristics.

METHODS

This cross-sectional study linked data from the Pathways Study, a prospective cohort study of women diagnosed with breast cancer at Kaiser Permanente Northern California between 2005 and 2013, with data from Kaiser Permanente Northern California's electronic medical record. Pathways participants eligible for this analysis had no known prior depression but reported depressive symptoms at baseline. We used modified Poisson regression to assess the association of cancer diagnosis year and other patient characteristics with receipt of a documented clinician response to depressive symptoms (depression diagnosis, mental health referral, or antidepressant prescription).

RESULTS

Of the 725 women in our sample, 34% received a clinician response to depression. We observed no statistically significant association of breast cancer diagnosis year with clinician response. Characteristics associated with clinician response included Asian race (adjusted risk ratio, Asian vs. white: 0.44, 95% CI: 0.29-0.68) and depression severity (adjusted risk ratio, mild-moderate vs. severe depression: 1.45, 95% CI: 1.11-1.88).

CONCLUSION

Most patients in our sample did not receive a clinician response to their study-reported depression, and rates of response do not appear to have improved over time. Asian women, and those with less severe depression, appeared to be at increased risk of having unmet mental health care needs.

Perioperative Intravesical Chemotherapy for Patients WithNon-Muscle-invasive Bladder Cancer: Understanding the Extent of and Sources of Variation in Guideline-recommended Use

OBJECTIVE

To examine intravesical chemotherapy (IVC) use according to non-muscle-invasive bladder cancer patient disease risk, and the contributions of multilevel factors to variation in proficient use among patients with low-intermediate disease.

METHODS

This study included 988 patients diagnosed with non-muscle-invasive bladder cancer in an integrated health system in Northern California from 2015-2017. We calculated IVC receipt by disease risk, and among patients with low-intermediate risk disease, assessed the relationship between multilevel factors and IVC receipt using a logistic regression model with random intercepts for provider and service area, and patient-, provider-, and service area-level fixed effects. We further assessed the association of provider- and service area-level factors with IVC use by examining intraclass correlation coefficients.

RESULTS

Similar proportions of low-intermediate (36%) and high-risk (34%) patients received IVC. In the multivariate analysis, including low-intermediate risk patients, service area volume was strongly and statistically significantly associated with IVC use (adjusted odds ratio, high- vs low-volume: 0.08, 95% Confidence Interval: 0.01-0.58). Provider- and service area-level intraclass correlation coefficients were large, (38%, P = .0009 and 39% P = .03, respectively) indicating that much of the variance in IVC use was explained by factors at these levels.

CONCLUSION

Our findings highlight opportunities to improve proficient use of IVC. Future research should assess provider- and practice-level barriers to IVC use among low-intermediate risk patients.

Understanding racial/ethnic differences in breast cancer-related physical well-being: the role of patient-provider interactions

PURPOSE

Racial/ethnic differences in cancer symptom burden are well documented, but limited research has evaluated modifiable factors underlying these differences. Our objective was to examine the role of patient-provider interactions to help explain the relationship between race/ethnicity and cancer-specific physical well-being (PWB) among women with breast cancer.

METHODS

The Pathways Study is a prospective cohort study of 4505 women diagnosed with breast cancer at Kaiser Permanente Northern California between 2006 and 2013. Our analysis included white, black, Hispanic, and Asian participants who completed baseline assessments of PWB, measured using the Functional Assessment of Cancer Therapy for Breast Cancer, and patient-provider interactions, measured by the Interpersonal Processes of Care Survey (IPC) (N = 4002). Using step-wise linear regression, we examined associations of race/ethnicity with PWB, and changes in associations when IPC domains were added.

RESULTS

We observed racial/ethnic differences in PWB, with minorities reporting lower scores than whites (beta, black: - 1.79; beta, Hispanic: - 1.92; beta, Asian: - 1.68; p < 0.0001 for all comparisons). With the addition of health and demographic covariates to the model, associations between race/ethnicity and PWB score became attenuated for blacks and Asians (beta: - 0.63, p = 0.06; beta: - 0.68, p = 0.02, respectively) and, to a lesser extent, for Hispanic women (beta: - 1.06, p = 0.0003). Adjusting for IPC domains did not affect Hispanic-white differences (beta: - 1.08, p = 0.0002), and slightly attenuated black-white differences (beta: - 0.51, p = 0.14). Asian-white differences narrowed substantially (beta: - 0.31, p = 0.28).

CONCLUSIONS

IPC domains, including those capturing perceived discrimination, respect, and clarity of communication, appeared to partly explain PWB differences for black and Asian women. Results highlight opportunities to improve providers' interactions with minority patients, and communication with minority patients about their supportive care needs.

Abstract IA27: Disparities in breast cancer survivorship and outcomes

In the U.S., women of European ancestry have historically had the highest incidence of breast cancer compared to other major race/ethnicity groups. In recent years, the incidence rate for black women has approached that of white women, while rates for Asian and Hispanic women are about 25% lower than for white or black women. However, once diagnosed with breast cancer, black women have poorer survival rates than white women. The most recent “Annual Report to the Nation on the Status of Cancer” using nationwide cancer-registry data from 2006-2013 (Jemal et al., JNCI, 2017) reported a higher age- and stage-adjusted relative mortality risk after breast cancer of 1.71 (95% confidence interval (CI), 1.66-1.76) for non-Hispanic blacks compared to non-Hispanic whites. Hispanic women also experienced a slightly increased relative mortality risk of 1.14 (95% CI, 1.10-1.18) compared to white women, while Asians experienced a lower relative mortality risk of 0.84 (95% CI, 0.80-0.88).

The reasons for such disparities in outcomes after breast cancer are complex. One suggested contributing factor is differences in access to care, as blacks and Hispanics tend to be of lower socioeconomic status than whites or Asians. It is possible to minimize the effects of access to health care by examining outcomes after breast cancer diagnosis in an integrated health care setting such as Kaiser Permanente Northern California (KPNC), in which all patients have health insurance coverage with access to the same health care providers. We are currently conducting the Pathways Study, a prospective cohort study of 4,505 women diagnosed with breast cancer with enrollment from 2006-2013. This diverse cohort includes 557 Hispanics, 578 Asians, and 358 blacks.

Preliminary analyses in the larger population of 11,176 women who were diagnosed with invasive breast cancer in KPNC and eligible for the Pathways Study found that, despite the uniform health care access, racial disparities in mortality after breast cancer were qualitatively similar to those observed nationally. With 1,738 total deaths as of September 20, 2016, and adjusted for age and stage at diagnosis, compared to white women, black women had an increased relative mortality risk of 1.59 (95% CI, 1.24-2.03). For Hispanic women, the relative risk was 0.92 (95% CI, 0.72-1.19), and for Asians it was 0.70 (95% CI, 0.51-0.97). Among the subset of women enrolled in the Pathways Study (n=538 total deaths), comparable relative risks were 1.74 (95% CI, 1.35-2.24) for black women, 0.99 (95% CI, 0.75-1.29) for Hispanic women, and 0.73 (95% CI, 0.52-1.02) for Asians. Similar black-white differences were also seen for breast cancer-specific mortality and recurrence in the Pathways Study cohort in which recurrences are being documented.

These observations indicate that health care access is unlikely to explain racial/ethnic disparities in breast cancer outcomes. As the Pathways Study, we will be able to explore aspects of health care utilization, such as treatment-related factors such as treatment delay, adherence, and early discontinuation. We will also be able to explore presence of comorbid conditions or use of non-cancer medications that may influence mortality and breast cancer outcomes. In the Pathways Study, we are collecting data on lifestyle and psychosocial factors (e.g., food intake, physical activity, social support, doctor-patient communications, and quality of life); linking to geospatial databases to characterize the social and built environment of cohort members; and conducting genome-wide assays. For example, in preliminary analyses that adjusted additionally for estrogen receptor status, body mass index, educational attainment, and physical activity, black-white differences in mortality persisted even though they were somewhat attenuated (relative risk of 1.43; 95% CI, 1.09-1.86).

Along with other studies that are examining breast cancer outcomes in different populations, the Pathways Study is poised to contribute to better understanding of the persistent black-white differences in mortality after breast cancer, and thus identify avenues to improve outcomes for all women with breast cancer.

Citation Format: Lawrence H. Kushi, Isaac J. Ergas, Janise M. Roh, Scarlett Lin Gomez, Marilyn L. Kwan, Catherine Thomsen, Song Yao, Christine B. Ambrosone. Disparities in breast cancer survivorship and outcomes [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr IA27.

Genetic Ancestry Is not Associated with Breast Cancer Recurrence or Survival in U.S. Latina Women Enrolled in the Kaiser Permanente Pathways Study

Background: The U.S. Hispanic/Latino population is heterogeneous both socioculturally and by the proportion of European, Indigenous American, and African ancestry of the regions from which individuals originate. A previous study reported that genetic ancestry was associated with breast cancer survival among Latinas, independent of sociodemographic and tumor characteristics, suggesting that a genetic factor associated with ancestry may affect breast cancer survival.Methods: We evaluated the association of genetic ancestry with breast cancer outcomes among 506 Latina women with invasive breast cancer in the Pathways Study, a cohort study within Kaiser Permanente, an integrated health care delivery system. Proportional hazards models were used to assess the effect of ancestry on breast cancer recurrence (53 events), breast cancer-specific mortality (31 events) and all-cause mortality (54 events), with a mean follow-up time of 6 years.Results: Indigenous American ancestry was not associated with breast cancer recurrence [HR = 1.00 per 10% increase; 95% confidence interval (CI), 0.86-1.16], breast cancer mortality (HR = 0.95; 95% CI, 0.77-1.17), or all-cause mortality (HR = 0.93; 95% CI, 0.80-1.08). Adjustment for sociodemographic variables, tumor characteristics, and treatment did not alter the associations.Conclusions: Our results suggest that previously reported differences in breast cancer survival by genetic ancestry may be overcome by improving health care access and/or quality.Impact: Improving health care access and quality may reduce breast cancer disparities among U.S. Latinas. Cancer Epidemiol Biomarkers Prev; 26(9); 1466-9. ©2017 AACR.

Abstract P3-09-06: Predicting cardiovascular versus cancer mortality in a cohort of breast cancer survivors

Background: Given improved survival after breast cancer diagnosis for women with non-metastatic disease, many will likely survive their disease and ultimately die from causes other than breast cancer, the most frequent being cardiovascular disease. There are numerous risk prediction models, such as the Framingham risk score, to identify persons who are at high risk for a cardiovascular event or death. However, these models have been developed for use in the general population and have not been validated in any cohorts of cancer survivors, who are at increased risk for competing causes of death. We evaluated commonly used risk models for cardiovascular events on a contemporary cohort of breast cancer survivors, and developed a new risk model to simultaneously predict the likelihood of death from breast cancer or cardiovascular disease (CVD).

Methods: We included all women diagnosed with stage I-III breast cancer between January 1, 2000 and December 31, 2010 in Kaiser Permanente Northern California (KPNC) with follow-up through April 30, 2015. Specifically, we extracted from KPNC clinical and other databases: breast cancer characteristics, cardiovascular risk factors (cholesterol, blood pressure (BP), diabetes, BP lowering medication, smoking status), cardiovascular events, and cause of death. We assessed discrimination for the Framingham, CORE and SCOREOP cardiovascular risk models using the area under the receiver operating characteristic curve (AUC), and calibration by comparing the observed to the expected events. We used a multi-state model based on Cox cause specific hazards (CSH) to jointly model the risk of cardiovascular death and breast cancer death, while accounting for all other causes.

Results: In this population of 20,462 KPNC breast cancer survivors with a median follow-up of 7.5 years, there were 695 cardiovascular and 842 breast cancer deaths. The existing cardiovascular risk models discriminated adequately (AUCs ranging 0.64 – 0.78), though models predicting cardiovascular mortality tended to over-predict, while those predicting non-fatal events tended to under-predict. Models developed to predict in a shorter time frame (&lt;5 years), performed slightly better (E/O ratios of 1.08 and 1.18 for Framingham predicting events in the next 2 and 4 years, respectively). In our multi-state model, many of the traditional cardiovascular risk factors were no longer statistically significant (diabetes, BP) in predicting cardiovascular mortality, while the breast cancer characteristics (grade, tumor size, nodal involvement), as well as a prior history of CVD, were most useful in predicting cause of death. The model performed well, with AUCs of 0.85 (95% CI 0.83, 0.86) for 5-year risk of cardiovascular death and 0.85 (95% CI 0.84, 0.87) for breast cancer death.

Conclusion: If replicated in an independent cohort, our model suggests that breast cancer characteristics can help predict overall mortality as well as cardiovascular death. Given the risk of cardiovascular death in the population of breast cancer survivors, joint modeling of breast and cardiovascular mortality is warranted.

Citation Format: Leoce NM, Terry MB, Jin Z, Kushi LH, Roh JM, Laurent CA. Predicting cardiovascular versus cancer mortality in a cohort of breast cancer survivors [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-09-06.

Changes in bone mineral density in women with breast cancer receiving aromatase inhibitor therapy

PURPOSE

We assessed bone mineral density (BMD) change with aromatase inhibitor (AI) treatment in a contemporary cohort of women with breast cancer treated in Kaiser Permanente Northern California.

METHODS

Percent and estimated annual percent changes in BMD at the total hip and lumbar spine were examined in 676 women receiving AI therapy who had two serial BMD reports available (at least 1 year apart) before and after AI initiation (N = 317) or during continued AI therapy (N = 359). BMD changes were examined at the total hip and lumbar spine and compared by age and clinical subgroups.

RESULTS

Women experienced BMD declines after AI initiation or continued therapy, with median annual percent change - 1.2% (interquartile range, IQR - 2.4 to - 0.1%) at the hip and - 1.0% (IQR - 2.3 to 0.1%) at the spine after AI initiation, and - 1.1% (IQR - 2.4 to 0.1%) at the hip and - 0.9% (IQR - 2.4 to 0.5%) at the spine during continued therapy. Higher levels of bone loss were observed among younger (< 55 years) compared with older (≥ 75 years) women at the hip (- 1.6% vs. - 0.8%) and at the spine (- 1.5% vs. - 0.5%) after AI initiation, and at the hip (- 1.4% vs. - 1.2%) and at the spine (- 2.4% vs. - 0.001%) during continued therapy.

CONCLUSIONS

Small but consistent declines in total hip and lumbar spine BMD were present in breast cancer patients following AI therapy initiation or continued AI therapy. Although the overall rates of osteoporosis were low, greater estimated levels of annual bone loss were evident among women < 55 years.