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. We evaluated trends in chemotherapy receipt, duration over which chemotherapy was received, and number of associated infusion visits. In secondary analyses, we stratified by receipt of anti-HER2 therapies (trastuzumab and/or pertuzumab), given their longer duration. 38.9% received chemotherapy intravenously, declining from 40.2% in 2006 to 35.6% in 2019 (p-trend < 0.001). Among 13,089 women receiving chemotherapy, neoadjuvant treatment increased (4.1-14.7%; p-trend < 0.001), as did receipt of anti-HER2 therapies (20.8-30.9%) (p-trend < 0.001). The average treatment duration increased (5.3 to 6.0 months; p-trend < 0.001), as did the number of infusion visits (10.8 to 12.5; p-trend < 0.001). For those receiving anti-HER2 therapies, treatment duration and average number of visits decreased; among those not receiving anti-HER2 therapies, number of visits increased, with no change in duration. CONCLUSIONS: While the prevalence of chemotherapy receipt has decreased over time, the use of neoadjuvant chemotherapy has increased, as has use of anti-HER2 therapies; duration and number of administration visits have also increased. Understanding these trends is useful to inform clinical and administrative planning.

Patient characteristics associated with delayed time to adjuvant chemotherapy among women treated for stage I-IIIA breast cancer.

For patients with breast cancer, delays in chemotherapy initiation have been adversely associated with recurrence and survival. We evaluated patient-level factors associated with delayed chemotherapy initiation, from both diagnosis and surgery, in a community-based cohort of women with early-stage breast cancer. For the Optimal Breast Cancer Chemotherapy Dosing study, we identified a cohort of 34,109 women diagnosed with stage I-IIIA breast cancer at two U.S. integrated healthcare delivery systems between 2004 and 2019. We used logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) to identify patient factors associated with delays in chemotherapy initiation after diagnosis (≥90 days) and surgery (≥60 days). Among 10,968 women receiving adjuvant chemotherapy, 21.1% experienced delays in chemotherapy initiation after diagnosis and 21.3% after surgery. Older age, non-Hispanic Black and Hispanic race and ethnicity, and ER+ and/or PR+ disease were associated with increased likelihood of delays to chemotherapy initiation after diagnosis and surgery. People diagnosed in 2012-2019 (vs. 2005-2011), with a higher grade and larger tumor size were less likely to experience delays. Other factors were associated with a higher likelihood of delays specifically from diagnosis (earlier stage, mastectomy vs. breast-conserving surgery), or surgery (higher comorbidity, increased nodal number). Women diagnosed with breast cancer who were at highest risk of progression and recurrence were less likely to experience delays in chemotherapy initiation after diagnosis and surgery. Understanding reasons for chemotherapy delays beyond patient factors may be potentially important to reduce risk of breast cancer recurrence and progression.

Assessment of breast cancer chemotherapy dose reduction in an integrated healthcare delivery system.

PURPOSE: Most cytotoxic drugs are dosed using body surface area (BSA), yet not all cancer patients receive the full BSA-determined dose. Prior work suggests that breast cancer patients who are obese are more likely to experience dose reduction than normal weight patients. However, the factors driving dose reduction remain unclear. METHODS: In 452 women diagnosed with stage I-IIIA primary breast cancer at Kaiser Permanente Northern California, we evaluated the association between obesity and dose reduction, and further explored other factors in relation to dose reduction, including various sociodemographic characteristics, tumor characteristics, and comorbidities. Study participants were a part of the Pathways Study, diagnosed between 2006 and 2013 and treated with cyclophosphamide + doxorubicin, followed by paclitaxel (ACT). Dose reduction was assessed using first cycle dose proportion (FCDP) and average relative dose intensity (ARDI), a metric of dose intensity over the course of chemotherapy. RESULTS: Overall, 8% of participants received a FCDP < 90% and 21.2% had an ARDI < 90%, with dose reduction increasing with body mass index. In adjusted logistic regression models, obese women had 4.1-fold higher odds of receiving an ARDI < 90% than normal weight women (95% CI: 1.9-8.9; p-trend = 0.0006). Increasing age was positively associated with an ADRI < 90%, as was the presence of comorbidity. Dose reduction was less common in later calendar years. CONCLUSION: Results offer insight on factors associated with chemotherapy dosing for a common breast cancer regimen. Larger studies are required to evaluate relevance to other regimens, and further work will be needed to determine whether dose reductions impact outcomes in obese women.

The Influence of Dietary Isothiocyanates on the Effectiveness of Mitomycin C and Bacillus Calmette-Guérin in Treating Nonmuscle-Invasive Bladder Cancer.

PURPOSE: Nonmuscle-invasive bladder cancer (NMIBC) has high recurrence rates and is often treated with mitomycin C (MMC) and bacillus Calmette-Guérin (BCG). Their efficacy relies on phase 2 enzyme metabolism and immune response activation, respectively. Dietary isothiocyanates, phytochemicals in cruciferous vegetables, are phase 2 enzyme inducers and immunomodulators, and may impact treatment outcomes. We investigated the modifying effects of cruciferous vegetable and isothiocyanate intake on recurrence risk following MMC or BCG treatment. MATERIALS AND METHODS: Self-reported cruciferous vegetable intake, estimated isothiocyanate intake, and urinary isothiocyanate metabolites were collected from 1158 patients with incident NMIBC in the prospective Be-Well Study. Hazard ratios (HRs) and 95% CIs were calculated from Cox proportional hazards regression models for risk of first recurrences, and random effects Cox shared frailty models for multiple recurrences. RESULTS: Over median follow-up of 23 months, 343 (30%) recurrences occurred. Receipt of MMC and BCG was associated with decreased risks of first recurrence (MMC: HR = 0.58; 95% CI: 0.46-0.73; BCG: HR = 0.66; 95% CI: 0.49-0.88) and multiple recurrences (MMC: HR = 0.55; 95% CI: 0.44-0.68; BCG: HR = 0.72; 95% CI: 0.55-0.95). Patients receiving BCG and having high intake (>2.4 servings/mo), but not low intake, of raw cruciferous vegetables had reduced risk of recurrence (HR: 0.56; 95% CI: 0.36-0.86; P for interaction = .02) and multiple recurrences (HR: 0.51; 95% CI: 0.34-0.77; P for interaction < .001). The inverse association between MMC receipt and recurrence risk was not modified. CONCLUSIONS: For NMIBC patients who receive induction BCG, increasing consumption of raw cruciferous vegetables could be a promising strategy to attenuate recurrence risk.

Environmental and Occupational Exposures and Prognosis in Patients with Non-Muscle Invasive Bladder Cancer in the Be-Well Study.

Bladder cancer is primarily diagnosed as non-muscle invasive bladder cancer (NMIBC) with high recurrence and progression rates. Environmental and occupational exposures to carcinogens are well-known risk factors for developing bladder cancer, yet their effects on prognosis remain unknown. In the Be-Well Study, a population-based prospective cohort study of 1,472 patient with newly diagnosed NMIBC from 2015 to 2019, we examined history of environmental and occupational exposures in relation to tumor stage and grade at initial diagnosis by multivariable logistic regression, and subsequent recurrence and progression by Cox proportional hazards regression. Exposure to environmental and occupational carcinogens was significantly associated with increased risk of progression (HR = 1.79; 95% CI: 1.04, 3.09), specifically increased progression into muscle-invasive disease (HR = 2.28; 95% CI: 1.16, 4.50). Exposure to asbestos and arsenic were associated with increased odds of advanced stage at diagnosis (asbestos: OR = 1.43; 95% CI: 1.11, 1.84; arsenic, OR = 1.27; 95% CI: 1.01, 1.63), and formaldehyde exposure was associated with increased risk of recurrence (HR = 1.38; 95% CI: 1.12, 1.69). Our findings suggest that history of these exposures may benefit current risk stratification systems to tailor clinical care and improve prognosis in patients with NMIBC.

Alcohol consumption and prognosis and survival in breast cancer survivors: The Pathways Study.

BACKGROUND: The impact of alcohol consumption on breast cancer (BC) prognosis remains unclear. METHODS: The authors examined short-term alcohol intake in relation to recurrence and mortality in 3659 women who were diagnosed with stage I-IV BC from 2003 to 2013 in the Pathways Study. Alcohol drinking in the past 6 months was assessed at cohort entry (mean, 2 months postdiagnosis) and 6 months later using a food-frequency questionnaire. Study end points were recurrence and death from BC, cardiovascular disease, and all causes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards models. RESULTS: Over an average follow-up of 11.2 years, 524 recurrences and 834 deaths (369 BC-specific and 314 cardiovascular disease-specific) occurred. Compared with nondrinkers (36.9%), drinkers were more likely younger, more educated, and current or past smokers. Overall, alcohol consumption was not associated with recurrence or mortality. However, women with higher body mass index (BMI ≥ 30 kg/m2 ) had lower risk of overall mortality with increasing alcohol consumption for occasional drinking (HR, 0.71; 95% CI, 0.54-0.94) and regular drinking (HR, 0.77; 95% CI, 0.56-1.08) around the time of diagnosis, along with 6 months later, in a dose-response manner (p < .05). Women with lower BMI (<30 kg/m2 ) were not at higher risk of mortality but were at possibly higher, yet nonsignificant, risk of recurrence for occasional drinking (HR, 1.29; 95% CI, 0.97-1.71) and regular drinking (HR, 1.19; 95% CI, 0.88-1.62). CONCLUSIONS: Alcohol drinking around the time of and up to 6 months after BC diagnosis was associated with lower risk of all-cause mortality in obese women. A possible higher risk of recurrence was observed in nonobese women.

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.

The Be-Well Study: a prospective cohort study of lifestyle and genetic factors to reduce the risk of recurrence and progression of non-muscle-invasive bladder cancer.

PURPOSE: Bladder cancer is one of the top five cancers diagnosed in the U.S. with a high recurrence rate, and also one of the most expensive cancers to treat over the life-course. However, there are few observational, prospective studies of bladder cancer survivors. METHODS: The Bladder Cancer Epidemiology, Wellness, and Lifestyle Study (Be-Well Study) is a National Cancer Institute-funded, multi-center prospective cohort study of non-muscle-invasive bladder cancer (NMIBC) patients (Stage Ta, T1, Tis) enrolled from the Kaiser Permanente Northern California (KPNC) and Southern California (KPSC) health care systems, with genotyping and biomarker assays performed at Roswell Park Comprehensive Cancer Center. The goal is to investigate diet and lifestyle factors in recurrence and progression of NMIBC, with genetic profiles considered, and to build a resource for future NMIBC studies. RESULTS: Recruitment began in February 2015. As of 30 June 2018, 1,281 patients completed the baseline interview (774 KPNC, 511 KPSC) with a recruitment rate of 54%, of whom 77% were male and 23% female, and 80% White, 6% Black, 8% Hispanic, 5% Asian, and 2% other race/ethnicity. Most patients were diagnosed with Ta (69%) or T1 (27%) tumors. Urine and blood specimens were collected from 67% and 73% of consented patients at baseline, respectively. To date, 599 and 261 patients have completed the 12- and 24-month follow-up questionnaires, respectively, with additional urine and saliva collection. CONCLUSIONS: The Be-Well Study will be able to answer novel questions related to diet, other lifestyle, and genetic factors and their relationship to recurrence and progression among early-stage bladder cancer patients.

Personal and clinical social support and adherence to adjuvant endocrine therapy among hormone receptor-positive breast cancer patients in an integrated health care system.

PURPOSE: We evaluated associations between personal and clinical social support and non-adherence to adjuvant endocrine therapy (AET) in a large, Northern California breast cancer (BC) cohort from an integrated healthcare network. METHODS: This study included 3382 women from the Pathways Study diagnosed from 2005 to 2013 with stages I-III hormone receptor-positive BC and who responded to the Medical Outcomes Study Social Support and Interpersonal Processes of Care surveys, approximately 2 months post-diagnosis. We used logistic regression to evaluate associations between tertiles of social support and non-initiation (< 2 consecutive prescription fills within a year after diagnosis). Among those who initiated treatment, we used proportional hazards regression to evaluate associations with discontinuation (≥ 90 day gap) and non-adherence (< 80% medical possession ratio). RESULTS: Of those who initiated AET (79%), approximately one-fourth either discontinued AET or were non-adherent. AET non-initiation was more likely in women with moderate (adjusted OR 1.18, 95% CI 0.96-1.46) or low (OR 1.30, 95% CI 1.05-1.62) versus high personal social support (P trend = 0.02). Women with moderate (HR 1.20, 95% CI 0.99-1.45) or low (HR 1.32, 95% CI 1.09-1.60) personal social support were also more likely to discontinue treatment (P trend = 0.01). Furthermore, women with moderate (HR 1.25, 95% CI 1.02-1.53) or low (HR 1.38, 95% CI 1.12-1.70) personal social support had higher non-adherence (P trend = 0.007). Associations with clinical social support and outcomes were similar. Notably, high clinical social support mitigated the risk of discontinuation when patients' personal support was moderate or low (P value = 0.04). CONCLUSIONS: Women with low personal or clinical social support had higher AET non-adherence. Clinician teams may need to fill support gaps that compromise treatment adherence.

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.

Race/ethnicity, genetic ancestry, and breast cancer-related lymphedema in the Pathways Study.

Breast cancer-related lymphedema (BCRL) is a serious chronic condition after breast cancer (BC) surgery and treatment. It is unclear if BCRL risk varies by race/ethnicity. In a multiethnic prospective cohort study of 2953 BC patients, we examined the association of self-reported BCRL status with self-reported race/ethnicity and estimated genetic ancestry. Hazard ratios (HR) and 95 % confidence intervals (CI) were calculated by multivariable Cox proportional hazards models, with follow-up starting 6 months post-BC diagnosis. Estimates were further stratified by body mass index (BMI). By 48 months of follow-up, 342 (11.6 %) women reported having BCRL. Younger age at BC diagnosis, higher BMI at baseline, and lower physical activity were associated with greater BCRL risk. African American (AA) women had a 2-fold increased risk of BCRL compared with White women (HR = 2.04; 95 % CI 1.35-3.08). African genetic ancestry was also associated with an increased risk (HR = 2.50; 95 % CI 1.43, 4.36). Both risks were attenuated but remained elevated after adjusting for known risk factors and became more pronounced when restricted to the nonobese women (adjusted HR = 2.31 for AA and HR = 3.70 for African ancestry, both p < 0.05). There was also evidence of increased BCRL risk with Hispanic ethnicity in the nonobese women. Nonobese AA women had a higher risk of BCRL than White women, which cannot be fully explained by known risk factors. This is the first large-scale, prospective study demonstrating differences in BCRL risk according to race/ethnicity as assessed by both self-report and genetic ancestry data, with a potential ancestry-obesity interaction.

Changes in vitamin and mineral supplement use after breast cancer diagnosis in the Pathways Study: a prospective cohort study.

BACKGROUND: Vitamin and mineral supplement use after a breast cancer diagnosis is common and controversial. Dosages used and the timing of initiation and/or discontinuation of supplements have not been clearly described. METHODS: We prospectively examined changes in use of 17 vitamin/mineral supplements in the first six months following breast cancer diagnosis among 2,596 members (28% non-white) of Kaiser Permanente Northern California. We used multivariable logistic regression to examine demographic, clinical, and lifestyle predictors of initiation and discontinuation. RESULTS: Most women used vitamin/mineral supplements before (84%) and after (82%) diagnosis, with average doses far in excess of Institute of Medicine reference intakes. Over half (60.2%) reported initiating a vitamin/mineral following diagnosis, 46.3% discontinuing a vitamin/mineral, 65.6% using a vitamin/mineral continuously, and only 7.2% not using any vitamin/mineral supplement before or after diagnosis. The most commonly initiated supplements were calcium (38.2%), vitamin D (32.01%), vitamin B6 (12.3%) and magnesium (11.31%); the most commonly discontinued supplements were multivitamins (17.14%), vitamin C (15.97%) and vitamin E (45.62%). Higher education, higher intake of fruits/vegetables, and receipt of chemotherapy were associated with initiation (p-values <0.05). Younger age and breast-conserving surgery were associated with discontinuation (p-values <0.05). CONCLUSIONS: In this large cohort of ethnically diverse breast cancer patients, high numbers of women used vitamin/mineral supplements in the 6 months following breast cancer diagnosis, often at high doses and in combination with other supplements. The immediate period after diagnosis is a critical time for clinicians to counsel women on supplement use.

Epidemiology of early vs. Late recurrence among women with Early-Stage estrogen Receptor-Positive breast cancer in the pathways study.

BACKGROUND: Relatively little is known about the differences in prognostic factors for early vs late recurrence among women with early-stage estrogen receptor-positive (ER+) breast cancer. METHODS: We analyzed factors related to early (<5 years) vs late (≥5 years) recurrence in 2,992 women with stage I-IIB ER+ breast cancer in the Pathways Study, a prospective cohort of women with breast cancer enrolled between 2006 and 2013, with ascertainment of recurrence and death through December 2021. RESULTS: After a median follow-up of 13.3 years, 341 (13.8%) women had recurrences, including 181 (53.7%) with late recurrence. Higher stage and grade were associated with recurrence regardless of timing, whereas progesterone receptor (PR) negativity was associated with early but not late recurrence. Receipt of endocrine therapy was associated with reduced risk of overall recurrence, but the length of endocrine therapy was not significant in multivariable models. Minoritized racial and ethnic groups, including Asian, Black, and Hispanic women, had higher risk of early but not late recurrence, compared with non-Hispanic White women. The trend of higher risk of early recurrence among these groups remained after adjustment for clinical, demographic, and socioeconomic factors, but was statistically significant only in Asian women. CONCLUSIONS: Our study revealed potentially important distinctions for early vs late recurrence, including the associations with PR-negativity and self-identified race and ethnicity. Possible higher risk of early recurrence among Asian, Black, and Hispanic women provides novel evidence for the existence of disparities in cancer outcomes, even within the breast cancer subtype indicative of generally good prognosis.

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). The hematoxylin and eosin slides underwent centralized pathology review, including the percentage of tumor infiltrating lymphocytes (TILs). Breast biomarker results were extracted from pathology reports, and women were included if they had a documented ERBB2 value that was not classified ERBB2-positive. Data were analyzed from February 2023 through January 2024. Exposure: Clinical and tumor characteristics associated with BC and ERBB2-low or ERBB2-negative status. Main Outcome and Measures: ERBB2-low was defined as immunohistochemistry score of 1+ or 2+ (negative by in situ hybridization); ERBB2-negative was defined as immunohistochemistry score of 0+. Other data were collected by self-report or extraction from electronic health records, including BC risk factors, tumor characteristics, treatment modality, and survival outcomes, with recurrence-free survival (RFS) as the primary outcome and overall survival (OS) and BC-specific mortality (BCSM) as secondary outcomes. The clinical, pathological, and epidemiological variables were compared between ERBB2-low and ERBB2-negative BC. Results: Of 2200 eligible patients (all female; with mean [SD] age, 60.4 [11.9] years), 1295 (57.2%) had tumors that were ERBB2-low. Hormone receptors were positive in 1956 patients (88.9%). The sample included 291 Asian patients (13.2%), 166 Black patients (7.5%), 253 Hispanic patients (11.5%), 1439 White patients (65.4%), and 51 patients (2.3%) who identified as other race or ethnicity (eg, American Indian or Alaska Native and Pacific Islander). Within the hormone receptor-negative group, patients whose tumors had ERBB2-low staining, compared with those with ERBB2-negative tumors, had better OS (hazard ratio [HR], 0.54; 95% CI, 0.33-0.91; P = .02), RFS (HR, 0.53; 95% CI, 0.30-0.95; P = .03), and BCSM (HR, 0.43; 95% CI, 0.22-0.84; P = .01). In multivariable survival analysis stratified by hormone receptor status and adjusted for key covariates, patients with ERBB2-low and hormone receptor-negative tumors had lower overall mortality (HR, 0.48; 95% CI, 0.27-0.83; P = .009), RFS (HR, 0.45; 95% CI, 0.24-0.86; P = .02), and BCSM (subdistribution HR, 0.21; 95% CI, 0.10-0.46; P < .001) compared with patients with ERBB2-negative and hormone receptor-negative tumors. Within the hormone receptor-negative subtype, patients with ERBB2-low and high TILs tumors had better survival across all 3 outcomes compared with patients with ERBB2-negative and low TILs tumors. Additionally, patients with ERBB2-low and low TILs tumors had better BCSM (subdistribution HR, 0.36; 95% CI, 0.14-0.92; P = .03). Conclusions and Relevance: These findings suggest that there were clinical, pathological, and epidemiological differences between ERBB2-low and ERBB2-negative BC, raising the possibility that ERBB2-low might be a unique biologic entity.

Relative contribution of COVID-19 vaccination and SARS-CoV-2 infection to population-level seroprevalence of SARS-CoV-2 spike antibodies in a large integrated health system.

BACKGROUND: Understanding the relative contributions of SARS-CoV-2 infection-induced and vaccine-induced seroprevalence is key to measuring overall population-level seroprevalence and help guide policy decisions. METHODS: Using a series of six population-based cross-sectional surveys conducted among persons aged ≥7 years in a large health system with over 4.5 million members between May 2021 and April 2022, we combined data from the electronic health record (EHR), an electronic survey and SARS-CoV-2 spike antibody binding assay, to assess the relative contributions of infection and vaccination to population-level SARS-CoV-2 seroprevalence. EHR and survey data were incorporated to determine spike antibody positivity due to SARS-CoV-2 infection and COVID-19 vaccination. We used sampling and non-response weighting to create population-level estimates. RESULTS: We enrolled 4,319 persons over six recruitment waves. SARS-CoV-2 spike antibody seroprevalence increased from 83.3% (CI 77.0-88.9) in May 2021 to 93.5% (CI 89.5-97.5) in April 2022. By April 2022, 68.5% (CI 61.9-74.3) of the population was seropositive from COVID-19 vaccination only, 13.9% (10.7-17.9) from COVID-19 vaccination and prior diagnosed SARS-CoV-2 infection, 8.2% (CI 4.5-14.5) from prior diagnosed SARS-CoV-2 infection only and 2.9% (CI 1.1-7.6) from prior undiagnosed SARS-CoV-2 infection only. We found high agreement (≥97%) between EHR and survey data for ascertaining COVID-19 vaccination and SARS-CoV-2 infection status. CONCLUSIONS: By April 2022, 93.5% of persons had detectable SARS-CoV-2 spike antibody, predominantly from COVID-19 vaccination. In this highly vaccinated population and over 18 months into the pandemic, SARS-CoV-2 infection without COVID-19 vaccination was a small contributor to overall population-level seroprevalence.

Relative contribution of COVID-19 vaccination and SARS-CoV-2 infection to population-level seroprevalence of SARS-CoV-2 spike antibodies in a large integrated health system.

Background: Understanding the relative contributions of SARS-CoV-2 infection-induced and vaccine- induced seroprevalence is key to measuring overall population-level seroprevalence and help guide policy decisions. Methods: Using a series of six population-based cross-sectional surveys conducted among persons aged ≥7 years in a large health system with over 4.5 million members between May 2021 and April 2022, we combined data from the electronic health record (EHR), an electronic survey and SARS-CoV-2 spike antibody binding assay, to assess the relative contributions of infection and vaccination to population- level SARS-CoV-2 seroprevalence. EHR and survey data were incorporated to determine spike antibody positivity due to SARS-CoV-2 infection and COVID-19 vaccination. We used sampling and non-response weighting to create population-level estimates. Results: We enrolled 4,319 persons over six recruitment waves. SARS-CoV-2 spike antibody seroprevalence increased from 83.3% (CI 77.0-88.9) in May 2021 to 93.5% (CI 89.5-97.5) in April 2022. By April 2022, 68.5% (CI 61.9-74.3) of the population was seropositive from COVID-19 vaccination only, 13.9% (10.7-17.9) from COVID-19 vaccination and prior diagnosed SARS-CoV-2 infection, 8.2% (CI 4.5- 14.5) from prior diagnosed SARS-CoV-2 infection only and 2.9% (CI 1.1-7.6) from prior undiagnosed SARS-CoV-2 infection only. We found high agreement (≥97%) between EHR and survey data for ascertaining COVID-19 vaccination and SARS-CoV-2 infection status. Conclusions: By April 2022, 93.5% of persons had detectable SARS-CoV-2 spike antibody, predominantly from COVID-19 vaccination. In this highly vaccinated population and over 18 months into the pandemic, SARS-CoV-2 infection without COVID-19 vaccination was a small contributor to overall population-level seroprevalence. Article summary: By April 2022, >93% of people had antibodies to SARS-CoV-2 with COVID-19 vaccination as the main driver of overall population-level seroprevalence in our healthcare system. SARS-CoV-2 infection without vaccination made a small contribution to population-level seroprevalence in our healthcare system.

Diet quality and cardiovascular disease risk among breast cancer survivors in the Pathways Study.

BACKGROUND: Women with breast cancer are at higher risk of cardiovascular disease (CVD) compared with women without breast cancer. Whether higher diet quality at breast cancer diagnosis lowers this risk remains unknown. We set out to determine if higher diet quality at breast cancer diagnosis was related to lower risk of CVD and CVD-related death. METHODS: This analysis included 3415 participants from the Pathway Study, a prospective cohort of women diagnosed with invasive breast cancer at Kaiser Permanente Northern California between 2005 and 2013 and followed through December 31, 2021. Scores from 5 diet quality indices consistent with healthy eating were obtained at the time of breast cancer diagnosis. Scores were categorized into ascending quartiles of concordance for each diet quality index, and multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated. P values were 2-sided. RESULTS: The Dietary Approaches to Stop Hypertension diet quality index was associated with lower risk of heart failure (HR = 0.53, 95% CI = 0.33 to 0.87; Ptrend = .03), arrhythmia (HR = 0.77, 95% CI = 0.62 to 0.94; Ptrend = .008), cardiac arrest (HR = 0.77, 95% CI = 0.61 to 0.96; Ptrend = .02), valvular heart disease (HR = 0.79, 95% CI = 0.64 to 0.98; Ptrend = .046), venous thromboembolic disease (HR = 0.75, 95% CI = 0.60 to 0.93; Ptrend = .01), and CVD-related death (HR = 0.70, 95% CI = 0.50 to 0.99; Ptrend = .04), when comparing the highest with lowest quartiles. Inverse associations were also found between the healthy plant-based dietary index and heart failure (HR = 0.60, 95% CI = 0.39 to 0.94; Ptrend = .02), as well as the alternate Mediterranean dietary index and arrhythmia (HR = 0.74, 95% CI = 0.60 to 0.93; Ptrend = .02). CONCLUSION: Among newly diagnosed breast cancer patients, higher diet quality at diagnosis was associated with lower risk of CVD events and death.

Modifying Effects of Genetic Variations on the Association Between Dietary Isothiocyanate Exposure and Non-muscle Invasive Bladder Cancer Prognosis in the Be-Well Study.

SCOPE: Dietary isothiocyanate (ITC) exposure from cruciferous vegetable (CV) intake may improve non-muscle invasive bladder cancer (NMIBC) prognosis. This study aims to investigate whether genetic variations in key ITC-metabolizing/functioning genes modify the associations between dietary ITC exposure and NMIBC prognosis outcomes. METHODS AND RESULTS: In the Bladder Cancer Epidemiology, Wellness, and Lifestyle Study (Be-Well Study), a prospective cohort of 1472 incident NMIBC patients, dietary ITC exposure is assessed by self-reported CV intake and measured in plasma ITC-albumin adducts. Using Cox proportional hazards regression models, stratified by single nucleotide polymorphisms (SNPs) in nine key ITC-metabolizing/functioning genes, it is calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence and progression. The rs15561 in N-acetyltransferase 1 (NAT1) is alter the association between CV intake and progression risk. Multiple SNPs in nuclear factor E2-related factor 2 (NRF2) and nuclear factor kappa B (NFκB) are modify the associations between plasma ITC-albumin adduct level and progression risk (pint < 0.05). No significant association is observed with recurrence risk. Overall, >80% study participants are present with at least one protective genotype per gene, showing an average 65% reduction in progression risk with high dietary ITC exposure. CONCLUSION: Despite that genetic variations in ITC-metabolizing/functioning genes may modify the effect of dietary ITCs on NMIBC prognosis, dietary recommendation of CV consumption may help improve NMIBC survivorship.

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. METHODS: In women older than 18 years, diagnosed with primary stage I-IIIA breast cancer at Kaiser Permanente Northern California (2006-2019), we categorized participants into 24 drug combinations described in National Comprehensive Cancer Network guidelines for breast cancer treatment. Participants were categorized into 50 guideline chemotherapy administration schedules within these combinations using an iterative algorithm process, followed by chart abstraction where necessary. We also identified patients intended to receive nonguideline administration schedules within guideline drug combinations and nonguideline drug combinations. This process was adapted at Kaiser Permanente Washington using abstracted data (2004-2015). RESULTS: In the OBCD cohort, 13,231 women received adjuvant or neoadjuvant chemotherapy, of whom 10,213 (77%) had their intended regimen identified via the algorithm, 2,416 (18%) had their intended regimen identified via abstraction, and 602 (4.5%) could not be identified. Across guideline drug combinations, 111 nonguideline dosing schedules were used, alongside 61 nonguideline drug combinations. A number of factors were associated with requiring abstraction for regimen determination, including: decreasing neighborhood household income, earlier diagnosis year, later stage, nodal status, and human epidermal growth factor receptor 2 (HER2)+ status. CONCLUSION: We describe the challenges and approaches to operationalize complex, real-world data to identify intended chemotherapy regimens in large, observational studies. This methodology can improve efficiency of use of large-scale clinical data in real-world populations, helping answer critical questions to improve care delivery and patient outcomes.

Social networks, social support mechanisms, and quality of life after breast cancer diagnosis.

We examined mechanisms through which social relationships influence quality of life (QOL) in breast cancer survivors. This study included 3,139 women from the Pathways Study who were diagnosed with breast cancer from 2006 to 2011 and provided data on social networks (the presence of a spouse or intimate partner, religious/social ties, volunteering, and numbers of close friends and relatives), social support (tangible support, emotional/informational support, affection, positive social interaction), and QOL, measured by the FACT-B, approximately 2 months post diagnosis. We used logistic models to evaluate associations between social network size, social support, and lower versus higher than median QOL scores. We further stratified by stage at diagnosis and treatment. In multivariate-adjusted analyses, women who were characterized as socially isolated had significantly lower FACT-B (OR = 2.18, 95 % CI: 1.72-2.77), physical well-being (WB) (OR = 1.61, 95 % CI: 1.27-2.03), functional WB (OR = 2.08, 95 % CI: 1.65-2.63), social WB (OR = 3.46, 95 % CI: 2.73-4.39), and emotional WB (OR = 1.67, 95 % CI: 1.33-2.11) scores and higher breast cancer symptoms (OR = 1.48, 95 % CI: 1.18-1.87) compared with socially integrated women. Each social network member independently predicted higher QOL. Simultaneous adjustment for social networks and social support partially attenuated associations between social networks and QOL. The strongest mediator and type of social support that was most predictive of QOL outcomes was "positive social interaction." However, each type of support was important depending on outcome, stage, and treatment status. Larger social networks and greater social support were related to higher QOL after a diagnosis of breast cancer. Effective social support interventions need to evolve beyond social-emotional interventions and need to account for disease severity and treatment status.