Adjuvant aromatase inhibitor therapy and early markers for cardiovascular disease in breast cancer survivors.

PURPOSE: Aromatase inhibitors (AIs) are an important component of the adjuvant treatment of hormone receptor positive breast cancer (BC) but concerns regarding their cardiovascular safety remain. In this cross-sectional study nested in a breast cancer cohort, we investigated the association between AI exposure and early markers for cardiovascular disease in BC survivors. METHODS: The study population consisted of 569 women, who were 5-7 years (n = 277) or 10-12 years (n = 292) after BC diagnosis. All participants underwent carotid ultrasound, skin autofluorescence measurement and laboratory evaluation. To quantify AI exposure, we obtained the AI ratio by dividing the duration of AI use by the total duration of endocrine therapy (ET). Patients were classified according to their AI ratio into low (no ET or AI ratio < 0.40), intermediate (0.40 ≤ AI ratio ≤ 0.60) or high AI exposure (AI ratio > 0.60). The association between AI ratio and carotid intima media thickness (cIMT), advanced glycation end products (AGEs) and the presence of dyslipidemia was assessed using linear and logistic regression. RESULTS: Median age at study visit was 55.5 years (range 45.2-63.8). Forty percent (n = 231) of the study population had used AIs, of whom the majority sequentially with tamoxifen; median duration of AI use was 3.0 years. Mean cIMT and mean AGEs did not differ across AI exposure groups in univariable and multivariable analysis. The occurrence of dyslipidemia did not vary across AI exposure groups. Intermediate AI exposure was associated with more frequent occurrence of the combined endpoint (elevated cIMT, elevated AGEs and/or dyslipidemia). This association, however, was not present in the group with highest AI exposure. CONCLUSION: AI exposure was not associated with cIMT, AGEs or the presence of dyslipidemia. These results do not prompt a change in current clinical practice, although further research is warranted to validate our findings over time and in different BC populations. Trial registration number (clinicaltrials.gov): NCT02485626, June 30, 2015.

Breast cancer and cardiovascular outcomes after breast cancer in survivors of Hodgkin lymphoma.

BACKGROUND: Hodgkin lymphoma (HL) survivors treated with chest radiotherapy have an increased risk of breast cancer (BC). Prior HL treatment and associated cardiovascular disease (CVD) risk may limit BC treatment options. It is unknown how treatment adaptations affect BC and CVD outcomes. METHODS: The authors compared 195 BC patients treated with chest/axillary radiotherapy for HL (BC-HL) with 5988 age- and calendar year-matched patients with first primary BC (BC-1). Analyses included cumulative incidence functions and Cox regression models, accounting for tumor characteristics and BC treatment. RESULTS: Compared to BC-1 patients, BC-HL patients received anthracycline-containing chemotherapy (23.7% vs. 43.8%, p < .001) and breast-conserving surgery followed by radiotherapy (7.1% vs. 57.7%, p < .001) less often. BC treatment considerations were reported for 71% of BC-HL patients. BC-HL patients had a significantly higher risk of 15-year overall mortality than BC-1 patients (61% vs. 23%). Furthermore, risks of BC-specific mortality and nonfatal BC events were significantly increased among BC-HL patients, also when accounting for tumor and treatment characteristics (2.2- to 4.5-fold). BC-HL patients with a screen-detected BC had a significantly reduced (61%) BC-specific mortality. One-third of BC-HL patients had CVD at BC-diagnosis, compared to <0.1% of BC-1 patients. Fifteen-year CVD-specific mortality and CVD incidence were significantly higher in BC-HL patients than in BC-1 patients (15.2% vs. 0.4% and 40.4% vs. 6.8%, respectively), which was due to HL treatment rather than BC treatment. CONCLUSIONS: BC-HL patients experience a higher burden of CVD and worse BC outcomes than BC-1 patients. Clinicians should be aware of increased CVD risk when selecting BC treatment for HL survivors. LAY SUMMARY: Patients with breast cancer after Hodgkin lymphoma (BC-HL) may have limited options for BC treatment, due to earlier HL treatment and an associated increased risk of cardiovascular disease (CVD). BC treatment considerations were reported for 71% of BC-HL patients. We examined whether BC-HL patients have a higher risk of CVD or BC events (recurrences/metastases) compared to patients with breast cancer that had no earlier tumors (BC-1). We observed a higher burden of CVD and worse BC outcomes in HL patients compared to BC-1 patients. Clinicians should be aware of increased CVD risk when selecting BC treatment for HL survivors.

Exposure of the heart and cardiac valves in women irradiated for breast cancer 1970-2009.

Purpose: To describe cardiac exposure from breast cancer radiotherapy regimens used during 1970-2009 for the development of dose-response relationships and to consider the associated radiation-risks using existing dose-response relationships. Material and methods: Radiotherapy charts for 771 women in the Netherlands selected for case control studies of heart disease after breast cancer radiotherapy were used to reconstruct 44 regimens on a typical CT-dataset. Doses were estimated for the whole heart (WH), left ventricle (LV) and cardiac valves. Results: For breast/chest wall radiotherapy average WH doses decreased during 1970-2009. For internal mammary chain (IMC) radiotherapy WH doses were highest during the 1980s and 1990s when direct anterior fields were used and reduced in the 2000s when oblique fields were introduced. Average doses varied substantially for IMC regimens (WH 2-33 Gy, LV < 1-23 Gy). For cardiac valves, at least one valve received >30 Gy from most regimens. Conclusions: Radiation-risks of IHD from breast/chest wall regimens likely reduced during 1970-2009. Direct anterior IMC regimens likely increased the risks of IHD and VHD over this time period but the use of oblique IMC fields from 2003 may have lowered these risks. These data provide a unique opportunity to develop dose-response relationships.

Physical Activity and Cardiac Function in Long-Term Breast Cancer Survivors: A Cross-Sectional Study.

Background: Higher levels of physical activity are associated with a lower risk of cardiovascular disease in the general population. Whether the same holds for women who underwent treatment for breast cancer is unclear. Objectives: The aim of this study was to evaluate the association between physical activity in a typical week in the past 12 months and cardiac dysfunction in breast cancer survivors. Methods: We used data from a cohort of breast cancer survivors who were treated at ages 40 to 50 years (N = 559). The association between physical activity and global longitudinal strain (GLS) and left ventricular ejection fraction (LVEF) was evaluated using both linear and modified Poisson regression analyses adjusted for relevant confounders. Results: In total, 559 breast cancer survivors were included, with median age of 55.5 years and a median time since treatment of 10.2 years. GLS was less favorable in inactive survivors (-17.1%) than in moderately inactive (-18.4%), moderately active (-18.2%), and active survivors (-18.5%), with an adjusted significant difference for active versus inactive survivors (ß = -1.31; 95% CI: -2.55 to -0.06)). Moderately active (n = 57/130) and active survivors (n = 87/124) had significantly lower risks of abnormal GLS (defined as >-18%) compared with inactive survivors (n = 17/26) (RR: 0.65 [95% CI: 0.45-0.94] and RR: 0.61 [95% CI: 0.43-0.87], respectively). LVEF, in normal ranges in all activity categories, was not associated with physical activity. Conclusions: In long-term breast cancer survivors, higher physical activity levels were associated with improved GLS but not LVEF, with the relatively largest benefit for doing any activity versus none. This finding suggests that increasing physical activity may contribute to cardiovascular health benefits, especially in inactive survivors.

Risk of heart failure after systemic treatment for early breast cancer: results of a cohort study.

PURPOSE: Anthracyclines and trastuzumab can increase the risk of heart failure (HF), but long-term cardiotoxicity data in breast cancer (BC) patients treated at younger ages are limited. Furthermore, it is unknown whether aromatase inhibitors are associated with HF risk. METHODS: HF risk was studied in a multicenter cohort of BC survivors treated during 2000-2009, at age < 61 years. Information on treatment and cardiovascular disease incidence was collected through medical records, general practitioners and cardiologists. Analyses included multivariable Cox regression and cumulative incidence curves. RESULTS: In total, 10,209 women with a median age at BC diagnosis of 50.3 years and a median follow-up of 8.9 years were enrolled in the study. Anthracycline-based chemotherapy was associated with HF (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.41-3.39) and risk increased with increasing cumulative anthracycline dose. For trastuzumab, HF risk was highest within the first 2 years after treatment (HR0-2 years: 13.06, 95% CI 5.70-29.92) and decreased thereafter (HR2-4 years: 4.84, 95% CI 1.99-11.75 and HR≥4 years: 0.64, 95% CI 0.23-1.81). The 10-year cumulative incidence of HF was 4.8% (95% CI 3.2-6.8) among patients treated with anthracyclines and trastuzumab. One-third of patients who developed HF after trastuzumab had long-term impaired cardiac function. Patients treated with aromatase inhibitors alone also had higher HF risk (HR 2.18, 95% CI 1.24-3.82) compared to patients not receiving endocrine therapy. CONCLUSIONS: Our results stress the importance of considering anthracycline-free regimens in BC patients who need trastuzumab-containing treatment. The association between aromatase inhibitors and HF needs confirmation.

Prognosis of acute coronary syndromes after radiotherapy for breast cancer.

BACKGROUND AND PURPOSE: Breast cancer patients treated with radiotherapy are at increased risk of subsequent acute coronary syndromes (ACS). We aimed to study if radiotherapy also influences the prognosis of these ACS. MATERIALS AND METHODS: We included all 398 patients diagnosed with ACS following radiotherapy from our hospital-based cohort of early breast cancer patients aged <71 years, treated 1970-2009. Cardiovascular disease incidence and cause of death were acquired through questionnaires to general practitioners and cardiologists. Internal mammary chain (IMC) irradiation delivers the highest heart doses in breast cancer radiotherapy. Hence, we compared ACS prognosis between patients treated with/without IMC-irradiation. ACS prognosis was assessed through cardiac death, death due to ACS and cardiovascular disease incidence, using multivariable Cox proportional hazard models and by estimating cumulative incidence. RESULTS: In total, 62% of patients with ACS had received IMC-irradiation and 38% did not (median age at ACS diagnosis, 67 years). Median time between breast cancer and ACS was 15 years. After ACS, ten-year cumulative risk of cardiac death was 35% for patients who had IMC-irradiation (95% confidence interval [95%CI] 29-41) compared to 24% (95%CI 17-31) for patients without IMC-irradiation (p = 0.04). After correction for confounders, IMC-irradiation remained associated with a less favourable prognosis of ACS compared to no IMC-irradiation (hazard ratio cardiac death = 1.7, 95%CI 1.1-2.5). CONCLUSION: Our results suggest that radiotherapy, in case of substantial heart doses,may worsen ACS prognosis. This is an important, novel finding that may impact upon the risk-based care for breast cancer survivors with ACS.

High-Dose Chemotherapy With Hematopoietic Stem Cell Transplant in Patients With High-Risk Breast Cancer and 4 or More Involved Axillary Lymph Nodes: 20-Year Follow-up of a Phase 3 Randomized Clinical Trial.

Importance: Trials of adjuvant high-dose chemotherapy (HDCT) have failed to show a survival benefit in unselected patients with breast cancer, but long-term follow-up is lacking. Objective: To determine 20-year efficacy and safety outcomes of a large trial of adjuvant HDCT vs conventional-dose chemotherapy (CDCT) for patients with stage III breast cancer. Design, Setting, and Participants: This secondary analysis used data from a randomized phase 3 multicenter clinical trial of 885 women younger than 56 years with breast cancer and 4 or more involved axillary lymph nodes conducted from August 1, 1993, to July 31, 1999. Additional follow-up data were collected between June 1, 2016, and December 31, 2017, from medical records, general practitioners, the Dutch national statistical office, and nationwide cancer registries. Analysis was performed on an intention-to-treat basis. Statistical analysis was performed from February 1, 2018, to October 14, 2019. Interventions: Participants were randomized 1:1 to receive 5 cycles of CDCT consisting of fluorouracil, 500 mg/m2, epirubicin, 90 mg/m2, and cyclophosphamide, 500 mg/m2, or HDCT in which the first 4 cycles were identical to CDCT and the fifth cycle was replaced by cyclophosphamide, 6000 mg/m2, thiotepa, 480 mg/m2, and carboplatin, 1600 mg/m2, followed by hematopoietic stem cell transplant. Main Outcomes and Measures: Main end points were overall survival and safety and cumulative incidence risk of a second malignant neoplasm or cardiovascular events. Results: Of the 885 women in the study (mean [SD] age, 44.5 [6.6] years), 442 were randomized to receive HDCT, and 443 were randomized to receive CDCT. With 20.4 years median follow-up (interquartile range, 19.2-22.0 years), the 20-year overall survival was 45.3% with HDCT and 41.5% with CDCT (hazard ratio, 0.89; 95% CI, 0.75-1.06). The absolute improvement in 20-year overall survival was 14.6% (hazard ratio, 0.72; 95% CI, 0.54-0.95) for patients with 10 or more invoved axillary lymph nodes and 15.4% (hazard ratio, 0.67; 95% CI, 0.42-1.05) for patients with triple-negative breast cancer. The cumulative incidence risk of a second malignant neoplasm at 20 years or major cardiovascular events was similar in both treatment groups (20-year cumulative incidence risk for second malignant neoplasm was 12.1% in the HDCT group vs 16.2% in the CDCT group, P = .10), although patients in the HDCT group more often had hypertension (21.7% vs 14.3%, P = .02), hypercholesterolemia (15.7% vs 10.6%, P = .04), and dysrhythmias (8.6% vs 4.6%, P = .005). Conclusions and Relevance: High-dose chemotherapy provided no long-term survival benefit in unselected patients with stage III breast cancer but did provide improved overall survival in very high-risk patients (ie, with ≥10 involved axillary lymph nodes). High-dose chemotherapy did not affect long-term risk of a second malignant neoplasm or major cardiovascular events. Trial Registration: ClinicalTrials.gov Identifier: NCT03087409.

Heart failure after treatment for breast cancer.

BACKGROUND: We aimed to develop dose-response relationships for heart failure (HF) following radiation and anthracyclines in breast cancer treatment, and to assess HF associations with trastuzumab and endocrine therapies. METHODS AND RESULTS: A case-control study was performed within a cohort of breast cancer survivors treated during 1980-2009. Cases (n = 102) had HF as first cardiovascular diagnosis and were matched 1:3 on age and date of diagnosis. Individual cardiac radiation doses were estimated, and anthracycline doses and use of trastuzumab and endocrine therapy were abstracted from oncology notes. For HF cases who received radiotherapy, the estimated median mean heart dose (MHD) was 6.8 Gy [interquartile range (IQR) 0.9-13.7]. MHD was not associated with HF risk overall [excess rate ratio (ERR) = 1%/Gy, 95% confidence interval (CI) -2 to 10]. In patients treated with anthracyclines, exposure of ≥20% of the heart to ≥20 Gy was associated with a rate ratio of 5.7 (95% CI 1.7-21.7) compared to <10% exposed to ≥20 Gy. For cases who received radiotherapy, median cumulative anthracycline dose was 247 mg/m2 (IQR 240-319). A dose-dependent increase was observed after anthracycline without trastuzumab (ERR = 1.5% per mg/m2 , 95% CI 0.5-4.1). After anthracycline and trastuzumab, the rate ratio was 34.9 (95% CI 11.1-110.1) compared to no chemotherapy. CONCLUSIONS: In absence of anthracyclines, breast cancer radiotherapy was not associated with increased HF risk. Strongly elevated HF risks were observed after treatment with anthracyclines and also after treatment with trastuzumab. The benefits of these systemic treatments usually exceed the risks of HF, but our results emphasize the need to support ongoing efforts to evaluate preventative strategies.

Myocardial dysfunction in long-term breast cancer survivors treated at ages 40-50 years.

AIMS: Anthracyclines increase heart failure (HF) risk, but the long-term prevalence of myocardial dysfunction in young breast cancer (BC) survivors is unknown. Early measures of left ventricular myocardial dysfunction are needed to identify BC patients at risk of symptomatic HF. METHODS AND RESULTS: Within an established cohort, we studied markers for myocardial dysfunction among 569 women, who were 5-7 years (n = 277) or 10-12 years (n = 292) after BC treatment at ages 40-50 years. Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) were assessed by echocardiography. N-terminal pro-brain natriuretic peptide (NT-proBNP) was measured in serum. Associations between patient-related and treatment-related risk factors and myocardial dysfunction were evaluated using linear and logistic regression. Median ages at BC diagnosis and cardiac assessment were 46.7 and 55.5 years, respectively. Anthracycline-treated patients (n = 313), compared to the no-anthracycline group (n = 256), more often had decreased LVEF (10% vs. 4%), impaired GLS (34% vs. 27%) and elevated NT-proBNP (23% vs. 8%). GLS and LVEF declined in a linear fashion with increasing cumulative anthracycline dose (GLS: +0.23 and LVEF: -0.40 per cycle of 60 mg/m2 ; P < 0.001) and GLS was worse for patients with left breast irradiation. The risk of NT-proBNP >125 ng/L was highest for patients who received 241-300 mg/m2 anthracycline dose compared to the no-anthracycline group (odds ratio: 3.30, 95% confidence interval: 1.83-5.96). CONCLUSION: Impaired GLS and increased NT-proBNP levels are present in a substantial proportion of young BC survivors treated with anthracyclines. Whether this will lead to future cardiac disease needs to be evaluated by longitudinal assessment.

Radiation Dose-Response for Risk of Myocardial Infarction in Breast Cancer Survivors.

PURPOSE: Previous reports suggest that radiation therapy for breast cancer (BC) can cause ischemic heart disease, with the radiation-related risk increasing linearly with mean whole heart dose (MWHD). This study aimed to validate these findings in younger BC patients and to investigate additional risk factors for radiation-related myocardial infarction (MI). METHODS AND MATERIALS: A nested case-control study was conducted within a cohort of BC survivors treated during 1970 to 2009. Cases were 183 patients with MI as their first heart disease after BC. One control per case was selected and matched on age and BC diagnosis date. Information on treatment and cardiovascular risk factors was abstracted from medical and radiation charts. Cardiac doses were estimated for each woman by reconstructing her regimen using modern 3-dimensional computed tomography planning on a typical patient computed tomography scan. RESULTS: Median age at BC of cases and controls was 50.2 years (interquartile range, 45.7-54.7). Median time to MI was 13.6 years (interquartile range, 9.9-18.1). Median MWHD was 8.9 Gy (range, 0.3-35.2 Gy). MI rate increased linearly with increasing MWHD (excess rate ratio [ERR] per Gy, 6.4%; 95% confidence interval, 1.3%-16.0%). Patients receiving ≥20 Gy MWHD had a 3.4-fold (95% confidence interval, 1.5-7.6) higher MI rate than unirradiated patients. ERRs were higher for younger women, with borderline significance (ERR<45years, 24.2%/Gy; ERR≥50years, 2.5%/Gy; Pinteraction = .054). Whole heart dose-volume parameters did not modify the dose-response relationship significantly. CONCLUSIONS: MI rate after radiation for BC increases linearly with MWHD. Reductions in MWHD are expected to contribute to better cardiovascular health of BC survivors.

Comparing causes of death of Hodgkin lymphoma and breast cancer patients between medical records and cause-of-death statistics.

OBJECTIVE: Obtaining accurate data about causes of death may be difficult in patients with a complicated disease history, including cancer survivors. This study compared causes of death derived from medical records (CODMR) with causes of death derived from death certificates (CODDC) as processed by Statistics Netherlands of patients primarily treated for Hodgkin lymphoma (HL) or breast cancer (BC). METHODS: Two hospital-based cohorts comprising 1,215 HL patients who died in the period 1980-2013 and 714 BC patients who died in the period 2000-2013 were linked with cause-of-death statistics files. The level of agreement was assessed for common underlying causes of death using Cohen's kappa, and original death certificates were reviewed when CODDC and CODMR showed discrepancies. We examined the influence of using CODDC or CODMR on standardized mortality ratio (SMR) estimates. RESULTS: Agreement for the most common causes of death, including selected malignant neoplasms and circulatory and respiratory diseases, was 81% for HL patients and 97% for BC patients. HL was more often reported as CODDC (CODDC=33.1% vs. CODMR=23.2%), whereas circulatory disease (CODDC=15.6% vs. CODMR=20.9%) or other diseases potentially related to HL treatment were more often reported as CODMR. Compared to SMRs based on CODDC, SMRs based on CODMR complemented with CODDC were lower for HL and higher for circulatory disease. CONCLUSION: Overall, we observed high levels of agreement between CODMR and CODDC for common causes of death in HL and BC patients. Observed discrepancies between CODMR and CODDC frequently occurred in the presence of late effects of treatment for HL.

Cardiovascular disease incidence after internal mammary chain irradiation and anthracycline-based chemotherapy for breast cancer.

BACKGROUND: Improved breast cancer (BC) survival and evidence showing beneficial effects of internal mammary chain (IMC) irradiation underscore the importance of studying late cardiovascular effects of BC treatment. METHODS: We assessed cardiovascular disease (CVD) incidence in 14,645 Dutch BC patients aged <62 years, treated during 1970-2009. Analyses included proportional hazards models and general population comparisons. RESULTS: CVD rate-ratio for left-versus-right breast irradiation without IMC was 1.11 (95% CI 0.93-1.32). Compared to right-sided breast irradiation only, IMC irradiation (interquartile range mean heart doses 9-17 Gy) was associated with increases in CVD rate overall, ischaemic heart disease (IHD), heart failure (HF) and valvular heart disease (hazard ratios (HRs): 1.6-2.4). IHD risk remained increased until at least 20 years after treatment. Anthracycline-based chemotherapy was associated with an increased HF rate (HR = 4.18, 95% CI 3.07-5.69), emerging <5 years and remaining increased at least 10-15 years after treatment. IMC irradiation combined with anthracycline-based chemotherapy was associated with substantially increased HF rate (HR = 9.23 95% CI 6.01-14.18), compared to neither IMC irradiation nor anthracycline-based chemotherapy. CONCLUSIONS: Women treated with anthracycline-based chemotherapy and IMC irradiation (in an older era) with considerable mean heart dose exposure have substantially increased incidence of several CVDs. Screening may be appropriate for some BC patient groups.