Patient characteristics associated with conventional schedule vs. dose dense chemotherapy in women with stage I-IIIA breast cancer.

Introduction: Compared to conventional chemotherapy schedules, use of dose-dense chemotherapy, which refers to administration of chemotherapy at standard doses with reduced cycle lengths, is known to improve survival, although may confer greater toxicity risk. We evaluated the patient factors associated with use of conventional vs. dose-dense chemotherapy administration schedules.

Patient factors and modifications to intended chemotherapy for women with Stages I-IIIA breast cancer.

Modifications to intended chemotherapy regimens may be due to various reasons and may impact patient outcomes. Understanding which factors are associated with chemotherapy modifications can help inform treatment planning and improve cancer care. We examined the association between patient/tumor factors and modifications to intended chemotherapy in women with Stages I-IIIA breast cancer who were treated at Kaiser Permanente Northern California and Kaiser Permanente Washington from 2005 to 2019.

Plant-based diet, inflammation biomarkers and body composition among women with breast cancer: the Pathways Study.

The World Cancer Research Fund and the American Institute for Cancer Research recommend a plant-based diet to cancer survivors, which may reduce chronic inflammation and excess adiposity associated with worse survival. We investigated associations of plant-based dietary patterns with inflammation biomarkers and body composition in the Pathways Study, in which 3659 women with breast cancer provided validated food frequency questionnaires approximately 2 months after diagnosis. We derived three plant-based diet indices: overall plant-based diet index (PDI), healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI).

Associations of Cruciferous Vegetable Intake with Breast Cancer Survival in a Diverse Population in the Pathways Study.

Background: Beneficial effects of cruciferous vegetable intake on breast cancer survival have long been postulated because they are primary sources of isothiocyanates, phytochemicals with multifaceted anticancer activities. However, observational studies have reported inconsistent results. We hypothesized that variations in vegetable types and polymorphisms in isothiocyanate-metabolizing genes across self-identified race and ethnicity contribute to such inconsistencies.

Endocrine therapy and risk of cardiovascular disease and mortality in postmenopausal breast cancer survivors.

Background: There are increasing concerns of cardiovascular safety related to endocrine therapy use in women with breast cancer (BC). We examined risk of cardiovascular disease (CVD) events and mortality associated with endocrine therapy use in postmenopausal women with early-stage BC.

Methods: Postmenopausal women diagnosed with stage I-III hormone receptor-positive BC from 2005 to 2013 were included (n = 8495).

Utilization of locally estimated scatterplot smoothing (LOESS) regression to estimate missing weights in a longitudinal cohort of breast cancer patients.

Introduction: Traditional methods to handle missing data rely on making assumptions about missing data patterns. Locally estimated scatterplot smoothing (LOESS) regression models were explored as a data-driven option to minimize missing weight data in a longitudinal cohort of breast cancer patients.

Methods: Outpatient weights from 2 years prior to breast cancer diagnosis to 10 years post were extracted from electronic health records for 10,778 women with invasive breast cancer diagnosed from 2005-2013 at Kaiser Permanente.

Methodologic Approach to Defining Comorbidities in a Cohort of Patients With Cancer: An Example in the Optimal Breast Cancer Chemotherapy Dosing Study.

Purpose: We evaluated the definitions of five comorbidities (renal and hepatic impairments, anemia, neutropenia, and thrombocytopenia) in women with breast cancer using data from electronic health records.

Methods: In 11,097 women receiving adjuvant chemotherapy for stage I-IIIA breast cancer at Kaiser Permanente Northern California or Kaiser Permanente Washington, we assessed comorbidity definitions in two commonly used lookback windows (1 year before diagnosis, T1; and extending until chemotherapy initiation, T1-2). Within each, we assessed data availability and agreement between International Classification of Diseases (ICD)-defined and lab-defined comorbidities of varying severity.

Diet quality and cardiometabolic health in breast cancer survivors: the Pathways Study.

Purpose: Breast cancer (BC) survivors experience higher rates of cardiometabolic conditions, partly due to treatment. While healthy eating decreases the risk of these conditions in the general population, its association in BC survivors is unclear.

Methods: We included 3415 participants from the Pathways Study, a prospective cohort of women diagnosed with invasive BC between 2005 and 2013 and followed through 2021.

Duration of aromatase inhibitor use and long-term cardiovascular risk in breast cancer survivors.

Background: There are limited data on duration of aromatase inhibitor (AI) and cardiovascular disease (CVD) risk in breast cancer (BC) survivors. We examined the risk of CVD and mortality associated with the duration of AI use in postmenopausal women with early stage hormone receptor-positive BC.

Methods: Postmenopausal women diagnosed with hormone receptor-positive BC (n = 5853) who used an AI were included.

Validation and Utility of Drug-Nutrient Interaction and Dietary Supplement Mechanistic Activity in the Natural Medicines Database.

Purpose: The increasing use of dietary supplements by patients with cancer and other chronic diseases requires the systematized review of potential interactions between prescription drugs and nutrients from supplements by health care and clinical research teams. Dietary supplement interaction databases are positioned to fill a gap in quantifying potential risks for patients, although none have been assessed for reliability in data interpretation. The NatMed database, a source for comprehensive reports on mechanistic and safety data for dietary supplement ingredients, was evaluated for use in future investigations.

Adherence to cardiovascular medications and risk of cardiovascular disease in breast cancer patients: A causal inference approach in the Pathways Heart Study.

Purpose: Women with breast cancer (BC) are at high risk of developing cardiovascular disease (CVD). We examined adherence to CVD medications and their association with major CVD events over 14 years of follow-up in the Pathways Heart Study, a prospective study of 4,776 stage I-III BC patients diagnosed from 2005-2013.

Methods: Eligibility included being alive 6 months post-BC diagnosis, with dyslipidemia, hypertension, or diabetes at diagnosis along with ≥1 prior outpatient order or dispensing for a statin, anti-hypertensive, or diabetes medication, respectively, in the 30 months prior.

Blood Pressure and Cardiovascular Risk in Women With Breast Cancer: The Pathways Heart Study.

Background: Hypertension is an important contributor to cardiovascular disease (CVD) in breast cancer (BC) survivors; however, research on blood pressure (BP) and CVD outcomes in BC survivors is limited.

Objectives: The purpose of this study was to better characterize the association between BP and CVD in a large, longitudinal cohort of BC patients.

Methods: Women with invasive BC diagnosed from 2005 to 2013 at Kaiser Permanente Northern California were matched 1:5 to women without BC.

The landscape of use of NCCN-guideline chemotherapy regimens in stage I-IIIA breast cancer in an integrated healthcare delivery system.

Purpose: The National Comprehensive Cancer Network (NCCN) guidelines recommend a variety of drug combinations with specific administration schedules for the treatment of early-stage breast cancer, allowing physicians to deliver treatments recognizing individual patient complexities, including comorbidities, and patient-physician preference. While use of guideline regimens has shifted over time, there is little data to describe changes in how treatment for early-stage breast cancer has evolved over time.

Methods: In a cohort of 34,109 women treated for stage I-IIIA breast cancer between 2006-2019 at Kaiser Permanente Northern California and Kaiser Permanente Washington, we present the changes in chemotherapy regimens over time, and explore use of NCCN-guideline regimens (GR), guideline regimens used when said regimens were not included in guidelines, referred to as time-discordant regimens (TDR), and non-guideline regimens (NGR).

Patient Characteristics Associated with Intended Nonguideline Chemotherapy in Women with Stage I to IIIA Breast Cancer.

Background: Guidelines informing chemotherapy regimen selection are based on clinical trials with participants who do not necessarily represent general populations with breast cancer. Understanding who receives nonguideline regimens is important for understanding real-world chemotherapy administration and how it relates to patient outcomes.

Methods: Using data from the Optimal Breast Cancer Chemotherapy Dosing (OBCD) study, based at Kaiser Permanente Northern California (2006-2019) and Kaiser Permanente Washington (2004-2015), we use logistic regression to examine the associations between patient characteristics and receipt of nonguideline chemotherapy regimens among 11,293 women with primary stage I to IIIA breast cancer receiving chemotherapy.

A prospective study of vitamin D, proinflammatory cytokines, and risk of fragility fractures in women on aromatase inhibitors for breast cancer.

Background: Vitamin D is critical to bone health by regulating intestinal absorption of calcium, whereas proinflammatory cytokines, including IL-1, IL-6, IL-12, and TNF-α, are known to increase bone resorption. We hypothesized that vitamin D and these cytokines at the time of breast cancer diagnosis were predictive for fragility fractures in women receiving aromatase inhibitors (AIs).

Methods: In a prospective cohort of 1,709 breast cancer patients treated with AIs, we measured the levels of 25-hydroxyvitamin D (25OHD), IL-1β, IL-6, IL-12, and TNF-α from baseline blood samples.

Trends in chemotherapy use for early-stage breast cancer from 2006 to 2019.

Background: Little is known about how use of chemotherapy has evolved in breast cancer patients. We therefore describe chemotherapy patterns for women with stage I-IIIA breast cancer in the Optimal Breast Cancer Chemotherapy Dosing (OBCD) Study using data from KPNC (Kaiser Permanente Northern California) and KPWA (Kaiser Permanente Washington).

Findings: Among 33,670 women, aged 18 + y, diagnosed with primary stage I-IIIA breast cancer at KPNC and KPWA from 2006 to 2019, we explored patterns of intravenous chemotherapy use, defined here as receipt of intravenous cytotoxic drugs and/or anti-HER2 therapies.

Methodology for Using Real-World Data From Electronic Health Records to Assess Chemotherapy Administration in Women With Breast Cancer.

Purpose: Identification of patients' intended chemotherapy regimens is critical to most research questions conducted in the real-world setting of cancer care. Yet, these data are not routinely available in electronic health records (EHRs) at the specificity required to address these questions. We developed a methodology to identify patients' intended regimens from EHR data in the Optimal Breast Cancer Chemotherapy Dosing (OBCD) study.

Clinical, Epidemiologic, and Pathologic Significance of ERBB2-Low Expression in Breast Cancer.

Importance: It is unclear whether breast cancer (BC) with low ERBB2 expression (ERBB2-low) is a distinct clinical, pathological, and epidemiological entity from BC classified as no ERBB2 expression (ERBB2-negative).

Objective: To evaluate the clinical, pathological, and epidemiologic features of BC with ERBB2-low expression compared with ERBB2-negative BC in a large population study.

Design, Setting, And Participants: This cohort study was conducted as part of the Pathways Study, a prospective, racially and ethnically diverse cohort study of women with BC enrolled between 2006 and 2013 in Kaiser Permanente Northern California (KPNC).