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.

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.

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.

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.

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.

Cardiovascular Disease Risk in a Large, Population-Based Cohort of Breast Cancer Survivors.

PURPOSE: To conduct a large, population-based study on cardiovascular disease (CVD) in breast cancer (BC) survivors treated in 1989 or later. METHODS AND MATERIALS: A large, population-based cohort comprising 70,230 surgically treated stage I to III BC patients diagnosed before age 75 years between 1989 and 2005 was linked with population-based registries for CVD. Cardiovascular disease risks were compared with the general population, and within the cohort using competing risk analyses. RESULTS: Compared with the general Dutch population, BC patients had a slightly lower CVD mortality risk (standardized mortality ratio 0.92, 95% confidence interval [CI] 0.88-0.97). Only death due to valvular heart disease was more frequent (standardized mortality ratio 1.28, 95% CI 1.08-1.52). Left-sided radiation therapy after mastectomy increased the risk of any cardiovascular event compared with both surgery alone (subdistribution hazard ratio (sHR) 1.23, 95% CI 1.11-1.36) and right-sided radiation therapy (sHR 1.19, 95% CI 1.04-1.36). Radiation-associated risks were found for not only ischemic heart disease, but also for valvular heart disease and congestive heart failure (CHF). Risks were more pronounced in patients aged <50 years at BC diagnosis (sHR 1.48, 95% CI 1.07-2.04 for left- vs right-sided radiation therapy after mastectomy). Left- versus right-sided radiation therapy after wide local excision did not increase the risk of all CVD combined, yet an increased ischemic heart disease risk was found (sHR 1.14, 95% CI 1.01-1.28). Analyses including detailed radiation therapy information showed an increased CVD risk for left-sided chest wall irradiation alone, left-sided breast irradiation alone, and internal mammary chain field irradiation, all compared with right-sided breast irradiation alone. Compared with patients not treated with chemotherapy, chemotherapy used ≥1997 (ie, anthracyline-based chemotherapy) increased the risk of CHF (sHR 1.35, 95% CI 1.00-1.83). CONCLUSION: Radiation therapy regimens used in BC treatment between 1989 and 2005 increased the risk of CVD, and anthracycline-based chemotherapy regimens increased the risk of CHF.

Cardiovascular morbidity and mortality after treatment for ductal carcinoma in situ of the breast.

BACKGROUND: Recent concerns about potential overdiagnosis and overtreatment of ductal carcinoma in situ of the breast (DCIS) render evaluation of late effects of treatment, such as cardiovascular disease (CVD), of great importance. We studied cardiovascular morbidity and mortality in a large population-based cohort of DCIS patients. METHODS: Data on all incident DCIS case patients in the Netherlands between 1989 and 2004 who were diagnosed before the age of 75 years were obtained (n = 10468). CVD data was acquired through linkage with population-based registries. Standardized mortality ratios were calculated by comparing mortality in our cohort with that in the Dutch female population, taking into account person-years of observation. Within-cohort comparisons were based on multivariable competing-risk regression. RESULTS: Compared with the general population, 5-year survivors of DCIS had a similar risk of dying due to any cause (standardized mortality ratio [SMR] = 1.04; 95% confidence interval [CI] = 0.97 to 1.11) but a lower risk of dying of CVD (SMR = 0.77; 95% CI = 0.67 to 0.89). No difference in CVD risk was found when comparing 5-year survivors treated with radiotherapy with those treated with surgery only. Left-sided vs right-sided radiotherapy also did not increase this risk (hazard ratio [HR] = 0.94; 95% CI = 0.67 to 1.32). In a subgroup analysis of all DCIS patients diagnosed between 1997 and 2005, we were able to account for history of CVD and did not observe a risk difference between treatment groups (left-sided vs right-sided radiotherapy: HR = 0.94; 95% CI = 0.68 to 1.29). CONCLUSIONS: After a median follow-up of 10 years, we did not find an increased risk for cardiovascular morbidity or mortality after radiotherapy for DCIS when comparing surgery and radiotherapy vs surgery only, nor when comparing radiotherapy for left-sided vs right-sided DCIS. Compared with the general population, DCIS patients have a decreased risk of cardiovascular death, independent of treatment.

Genetic variants in TGFß-1 and PAI-1 as possible risk factors for cardiovascular disease after radiotherapy for breast cancer.

BACKGROUND AND PURPOSE: It has been established that radiotherapy can increase cardiovascular disease (CVD) risk. Genetic variants, which play a role in the tissue, damage response and angiogenesis regulating TGFß pathway might give us insight into the mechanisms underlying radiation-induced CVD. We examined the effects of two polymorphisms, TGFß1 29C>T and PAI-1 5G>4G, on CVD incidence. MATERIALS AND METHODS: This retrospective cohort study included 422 10-year breast cancer survivors, aged <50 years at diagnosis, treated between 1977 and 1995. We collected information on treatment, oncological follow-up, CVD, CVD risk factors and genotypes. RESULTS: During a mean follow-up of 19.4 years, 61 patients developed CVD. Internal mammary chain (IMC) irradiation, exposing a part of the heart to radiation, was associated with a hazard ratio of 2.36 (95% CI: 1.27-4.37, p=0.01) compared to no IMC irradiation. Compared to the C/C+C/T genotype, the T/T genotype of the TGFß1 polymorphism was associated with hazard ratios of 1.79 (0.99-3.26, p=0.06) and 1.74 (0.90-3.34, p=0.10) in the total and IMC-irradiated group, respectively. We found no evidence for an association between PAI-1 5G>4G and CVD risk. CONCLUSION: Our study suggests there might be an association between the TGFß1 29C>T polymorphism and CVD risk in long-term breast cancer survivors.