Cardiovascular event-free survival after adjuvant radiation therapy in breast cancer patients stratified by cardiovascular risk

Different prognosis of left compared to right breast cancer: A systematic review and meta-analysis

BACKGROUND

There is an ongoing debate in the medical community about the association between the laterality of breast cancer (BC: whether it arises in the left or right breast) and its outcome. This study aims to assess the disparities in overall survival (OS), cardiac mortality, and cancer-specific survival (CSS) between BC affecting the left side and BC affecting the right side.

MATERIALS AND METHODS

We conducted a thorough search of databases, such as PubMed, EMBASE, and the Cochrane Library, starting from their inception up until December 1, 2023. The primary outcome was OS. Additional endpoints included cardiac mortality and CSS.

RESULTS

The meta-analysis included 50 publications (n = 7,527,156 patients) with similar rates of left and right BCs. Patients with left-sided BC showed a marginally decreased OS (HR = 1.03, 95 %CI 1.01-1.04; P < .01) and a 10% increase in cardiac mortality (HR = 1.1, 95 %CI 1.04-1.16; P < .01). Cancer-specific survival was similar for both groups (HR = 1.01, 95 %CI 0.98-1.03; P = .32).

CONCLUSIONS

According to this study, there is a slight increase in mortality and a 10 % rise in cardiac-related deaths associated with left-sided breast cancer compared to right-sided breast cancer.

Racial disparities in treatment-related cardiovascular toxicities amongst women with breast cancer: a scoping review

PURPOSE

Black women often experience poorer breast cancer-related outcomes and higher mortality than white women. A contributor to this disparity may relate to the disproportionate burden of cancer treatment-related cardiovascular (CV) toxicities. The objective of this review is to identify studies that report racial differences in CV toxicity risk.

METHODS

Medline and Embase were searched for studies that assessed CV toxicities as the outcome(s) and included Black and White women with breast cancer. Studies were selected based on inclusion/exclusion criteria and through the use of multiple reviewers.

RESULTS

The review included 13 studies following a review of 409 citations and 49 full-text articles. All studies were retrospective and 8/13 utilized data from the Surveillance, Epidemiology, and End Results-Medicare linked database. Trastuzumab was the most frequently studied treatment. The proportion of Black women in these studies ranged from 5.5 to 63%. A majority of studies reported a higher risk of CV toxicity amongst Black women when compared to white women (93%). Black women had up to a two times higher risk of CV toxicity (HR, 2.73 (CI, 1.24 to 6.01)) compared to white women. Only one study evaluated the role of socioeconomic factors in explaining racial differences in CV toxicity; however, the disparity remained even after adjusting for these factors.

CONCLUSIONS

There is a critical need for more longitudinal studies that evaluate multilevel factors (e.g., psychosocial, biological) that may help to explain this disparity.

IMPLICATIONS FOR CANCER SURVIVORS

Black cancer survivors may require additional surveillance and mitigation strategies to decrease disproportionate burden of CV toxicities.

Characteristics and research status among clinical trials in cardio-oncology by bibliometric and visualized analysis

BACKGROUND

We aim to establish the characteristics of published cardio-oncology research of clinical trials by bibliometric analysis and to talk about the prospects and difficulties facing the development of cardio-oncology.

METHODS

Search of data related to clinical trials in cardiac oncology from 1990 to 2022 from the Web of Science core collection. Using CiteSpace to perform co-citation analysis of authors, countries (regions) and institutions, journals and cited journals, cited authors and cited literature, and keywords.

RESULTS

Of the 607 clinical trial studies, the number of papers published per year has increased over time. The regions with the greatest influence were North America (especially the United States) and Europe. Multicenter research has always been the focus of cardio-oncology research, but cross-regional cooperation was still lacking. Myocardial toxicity caused by anthracyclines has received the earliest attention and has been studied for the longest time. Meanwhile, the efficacy and cardiotoxicity of new anticancer drugs always came into focus, but at a slow pace. Few studies on myocardial toxicity were related to the treatment of tumors except breast cancer. Risk factors, heart disease, adverse outcomes, follow-up, and intervention protection were the major hotspots revealed by co-citation cluster.

CONCLUSIONS

There is great potential for the development of clinical trials in cardio-oncology, especially in multicenter cooperation across different regions. Expansion of tumor types, myocardial toxicity of different drugs, and effective interventions in the research direction and design of clinical trials are necessary.

A Prospective Population-Based Study of Cardiovascular Disease Mortality following Treatment for Breast Cancer among Men in the United States, 2000-2019

Male breast cancer is rare but its incidence and mortality are increasing in the United States, with racial/ethnic disparities in survival reported. There is limited evidence for cardiotoxicity of cancer treatment among men with breast cancer. We evaluated the relation between breast cancer treatment and cardiovascular disease (CVD) mortality among men and investigated the salient roles that race/ethnicity play on this relation. Data were from 5216 men with breast cancer aged ≥ 40 years from the Surveillance, Epidemiology, and End Results program who were diagnosed from 2000 to 2019 and underwent surgery. Competing risk models were used to estimate hazards ratios (HR) and 95% confidence intervals (CI). During a median follow-up of 5.6 years, 1914 deaths occurred with 25% attributable to CVD. In multivariable-adjusted models, men who received chemotherapy had elevated risk for CVD (HR: 1.55, 95%CI: 1.18-2.04). This risk was higher among Hispanic men (HR: 3.96, 95%CI: 1.31-12.02) than non-Hispanic Black and non-Hispanic White men. There was no significant association between radiotherapy and CVD deaths. In this population-based study, treatment with chemotherapy was associated with elevated risk of CVD mortality in men with breast cancer. Racial/ethnic disparities in the association of chemotherapy and CVD mortality were observed.

Nuclear medicine imaging methods of radiation-induced cardiotoxicity

Breast cancer survival is significantly improved over the past decades due to major improvements in anti-tumor therapies and the implementation of regular screening, which leads to early detection of breast cancer. Therefore, it is of utmost importance to prevent patients from long-term side effects, including radiotherapy-induced cardiotoxicity. Radiotherapy may contribute to damage of myocardial structures on the cellular level, which eventually could result in various types of cardiovascular problems, including coronary artery disease and (non-)ischemic cardiomyopathy, leading to heart failure. These cardiac complications of radiotherapy are preceded by alterations in myocardial perfusion and blood flow. Therefore, early detection of these alterations is important to prevent the progression of these pathophysiological processes. Several radionuclide imaging techniques may contribute to the early detection of these changes. Single-Photon Emission Computed Tomography (SPECT) cameras can be used to create Multigated Acquisition scans in order to assess the left ventricular systolic and diastolic function. Furthermore, SPECT cameras are used for myocardial perfusion imaging with radiopharmaceuticals such as ^99mTc-sestamibi and ^99mTc-tetrofosmin. Accurate quantitative measurement of myocardial blood flow (MBF), can be performed by Positron Emission Tomography (PET), as the uptake of some of the tracers used for PET-based MBF measurement almost creates a linear relationship with MBF, resulting in very accurate blood flow quantification. Furthermore, there are PET and SPECT tracers that can assess inflammation and denervation of the cardiac sympathetic nervous system. Research over the past decades has mainly focused on the long-term development of left ventricular impairment and perfusion defects. Considering laterality of the breast cancer, some early studies have shown that women irradiated for left-sided breast cancer are more prone to cardiotoxic side effects than women irradiated for right-sided breast cancer. The left-sided radiation field in these trials, which predominantly used older radiotherapy techniques without heart-sparing techniques, included a larger volume of the heart and left ventricle, leading to increased unavoidable radiation exposure to the heart due to the close proximity of the radiation treatment volume. Although radiotherapy for breast cancer exposes the heart to incidental radiation, several improvements and technical developments over the last decades resulted in continuous reduction of radiation dose and volume exposure to the heart. In addition, radiotherapy reduces loco-regional tumor recurrences and death from breast cancer and improves survival. Therefore, in the majority of patients, the benefits of radiotherapy outweigh the potential very low risk of cardiovascular adverse events after radiotherapy. This review addresses existing nuclear imaging techniques, which can be used to evaluate (long-term) effects of radiotherapy-induced mechanical cardiac dysfunction and discusses the potential use of more novel nuclear imaging techniques, which are promising in the assessment of early signs of cardiac dysfunction in selected irradiated breast cancer patients.

Biomarkers for the detection of apparent and subclinical cancer therapy-related cardiotoxicity

Progress in cancer therapy over the past decades improved long-term survival but increased cancer therapy-related cardiotoxicity. Many novel treatment options have been implemented with yet incompletely characterized cardiovascular side effects including heart failure, coronary artery disease, arrhythmias, valvular disease, venous thromboembolism and myocarditis. Diagnosis of potential cardiotoxic side effects is essential for an optimal treatment but remains challenging. Cardiac biomarkers troponin and brain natriuretic peptide/N-terminal proBNP (BNP/NT-proBNP) have been extensively studied in heart failure and acute coronary syndromes. Emerging evidence implicates a significant role in the detection of cardiotoxicity and guidance of therapy in cancer patients. Elevated troponin or BNP/NT-proBNP levels were associated with increased all-cause mortality in cancer patients and have been shown to predict manifest heart failure. BNP/NT-proBNP may be useful for the prediction of cancer therapy-related heart failure and response to heart failure therapy in adult and pediatric cancer patients while troponin can indicate acute myocardial infarction in patients with cancer therapy-related risk for coronary artery disease. Furthermore, troponin may be used for the identification of immune checkpoint inhibitor-related myocarditis with very high sensitivity. Finally, even D-dimer levels have been shown to improve risk stratification and diagnosis in cancer-associated venous thromboembolism. This review aims to summarize the current knowledge about biomarkers in cancer therapy-related cardiotoxicity. We also outline possible clinical recommendations for the detection and treatment of subclinical and clinically apparent cardiotoxic effects using biomarkers.

Acute Coronary Syndrome in Cancer Patients

Cardiologists are seeing an increasing number of oncology patients every day, and acute coronary syndrome (ACS) is one of the problems patients encounter during follow-up. Cardio-oncology is the care of patients with cancer and cardiovascular disease, whether overt or occult, already established or acquired during treatment. Cardiovascular complications can occur acutely during or shortly after treatment and persist as long-term effects for months to years after treatment. As a delayed effect of cancer treatment, cardiovascular damage can occur months to years after the initial treatment. Vasospasm, thrombosis, and radiation-induced cardiovascular diseases can all cause ACS. Careful surveillance of ACS symptoms and regular screening during follow-up of patients with malignancy are suggested. In this review, we summarize the ACS we usually encounter during a range of cancer treatments or post cancer survival by providing illustrative case examples.

Nonadherence to Statins and Antihypertensives and Hospitalizations Among Elderly Medicare Beneficiaries With Incident Cancer

Background: Incident cancer diagnosis may increase the risk of coronary artery disease (CAD)-related hospitalizations, especially in older individuals. Adherence to statins and/or angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin II receptor blockers (ARBs)/β-blockers reduces CAD-related hospitalizations. This study examined the relationship between medication adherence and CAD-related hospitalizations immediately following cancer diagnosis. Patients and Methods: A retrospective observational longitudinal study was conducted using SEER-Medicare data. Elderly Medicare fee-for-service beneficiaries with preexisting CAD and incident breast, colorectal, or prostate cancer (N=12,096) were observed for 12 months before and after cancer diagnosis. Hospitalizations measured every 120 days were categorized into CAD-related hospitalization, other hospitalization, and no hospitalization. Medication adherence was categorized into 5 mutually exclusive groups: adherent to both statins and ACEIs/ARBs/β-blockers (reference group), not adherent to both statins and ACEIs/ARBs/β-blockers, adherent to either statins or ACEIs/ARBs/β-blockers, use of one medication class and adherent to that class, and use of one medication class and not adherent to that class. The relationship between medication adherence and hospitalization was analyzed using repeated measures multinomial logistic regressions. Inverse probability treatment weights were used to control for observed group differences among medication adherence categories. Results: Adherence to both statins and ACEIs/ARBs/β-blockers was estimated at 31.2% during the 120-day period immediately following cancer diagnosis; 13.7% were not adherent to both medication classes during the same period, and 27.4% had CAD-related hospitalizations immediately after cancer diagnosis, which declined to 10.6% during the last 4 months of the postdiagnosis period. In the adjusted analyses, those not adherent to both statins and ACEIs/ARBs/β-blockers were more likely to have CAD-related hospitalization compared with those adherent to both medication classes (adjusted odds ratio, 1.82; 95% CI, 1.72-1.92; P<.0001). Conclusions: Given the complexity of interaction between CAD and cancer, it is important to routinely monitor medication adherence in general clinical practice and to provide linkages to support services that can increase medication adherence.

The risk of cardiovascular disease following breast cancer by Framingham risk score

OBJECTIVES

This study evaluates the risk of cardiovascular disease (CVD) following breast cancer, accounting for baseline CVD risk.

METHODS

Within the EPIC-NL (Dutch part of the European Prospective Investigation into Nutrition and Cancer) cohort, 1103 women were diagnosed with breast cancer. For every breast cancer patient, 3-4 women without breast cancer (n = 4328) were selected matched for age, year, and time since cohort enrollment. Based on CVD risk factors at cohort enrollment, 10-year risk of CVD was calculated and categorized: low (< 10%), intermediate (10-20%), high (> 20%). Cox proportional hazard models assessed the risk of CVD events (hospitalization or mortality) and CVD mortality of women with versus without breast cancer, adjusted for baseline CVD risk.

RESULTS

After median follow-up of 5 and 6 years, 92 (8.3%) and 325 (7.5%) CVD events occurred in women with and without breast cancer, respectively. In the low CVD risk group, women with breast cancer had 1.44 (95% CI 1.00-2.06) times higher risk of CVD events than women without breast cancer. In the intermediate and high CVD risk categories, risk of CVD events was similar in women with and without breast cancer. Overall, women with breast cancer had 1.77 (95% CI 1.10-2.86) times higher risk of CVD mortality than women without breast cancer.

CONCLUSIONS

Among women with low CVD risk, women with breast cancer have a higher risk of CVD event than women without breast cancer. Overall, women with breast cancer have a higher risk of CVD mortality than women without breast cancer.

Which Patients with Left Breast Cancer Should be Candidates for Heart-Sparing Radiotherapy?

Purpose

This study aimed to identify risk factors that have significant interaction with radiation exposure to the heart, and thus to determine candidates for heart-sparing radiotherapy (RT) among women with left breast cancer.

Methods

We identified 4,333 patients who received adjuvant RT following breast-conserving surgery for ductal carcinoma in situ or invasive breast cancer from 1996 to 2010. Incidence rates of cardiovascular disease were compared between left-sided and right-sided RT, and stratified by age and risk factors such as body mass index (BMI), smoking, hyperlipidemia, hypertension, diabetes, administration of anthracycline, and trastuzumab.

Results

In all patients, the cumulative incidence of cardiovascular disease was greater in patients treated with left-sided RT than in those treated with right-sided RT, but the difference was not significant (p=0.428). Smoking (hazard ratio [HR], 5.991; 95% confidence interval [CI], 2.109-17.022; p=0.002) and hyperlipidemia (HR, 5.567; 95% CI, 3.235-9.580; p<0.001) were the most powerful risk factors for cardiovascular disease. There was no significant factor that further increased the risk of cardiovascular disease after left breast RT compared to right breast RT.

Conclusion

Although hyperlipidemia and smoking are risk factors for cardiovascular disease, they have not been proven to increase the risk of RT-related cardiovascular disease in Korean women.

Associations between adjuvant radiotherapy and different causes of death in a German breast cancer cohort

BACKGROUND

Studies of cohorts of breast cancer (BC) patients diagnosed before 1990 showed radiotherapy (RT) to be associated with increased cardiovascular (CVD) and lung cancer mortality many years after diagnosis. In the late 1990s, improvements in RT planning techniques reduced radiation doses to normal tissues. Recent studies did not consistently report higher RT-related mortality for CVD and second cancers. Aim of the study was to analyze specific causes of death after 3D-conformal RT in a recent BC cohort.

METHODS

Stage I-III BC patients diagnosed 2001-2005 and enrolled in the population based MARIEplus study were followed-up for 11.9 years (median). Associations between adjuvant RT and cause-specific mortality were analyzed by using competing risks models, yielding subdistribution hazard ratios (SHR) for RT directly related to cumulative incidences. Models were adjusted for differences in baseline characteristics applying inverse-probability-of-treatment-weighting (IPTW).

RESULTS

Of the 2951 patients, 2439 (83.0%) received RT. No significant association of RT with lung cancer mortality (SHR_IPTW 0.88, 0.35-2.12), other cancer mortality (SHR_IPTW 1.04, 95% CI 0.62-1.73) or cardiac mortality was observed (SHR_IPTW 1.57, 0.75-3.29). Mortality from lung and other diseases were significantly lower in irradiated women (SHR_IPTW 0.39, 95% CI 0.17-0.90 and SHR_IPTW 0.58, 95% CI 0.34-0.97, respectively).

CONCLUSION

In line with recent studies, 3D-conformal RT did not significantly increase mortality from non-BC causes in the German MARIEplus cohort. Since long-term data are still sparse and event rates low in BC-cohorts, who received modern RT, investigation of possible late RT effects on mortality beyond 14 years of follow-up is warranted.

Monitoring deep inspiration breath hold for left-sided localized breast cancer radiotherapy with an in-house developed laser distance meter system

Deep inspiration breath hold (DIBH) in left-sided breast cancer radiotherapy is a technique to reduce cardiac and pulmonary doses while maintaining target coverage. This study aims at evaluating an in-house developed DIBH system. Free-breathing (FB) and DIBH plans were generated for 22 left-sided localized breast cancer patients who had radiation therapy (RT) after breast-conserving surgery. All patients were treated utilizing an in-house laser distance measuring system. 50 Gy was prescribed, and parameters of interest were target coverage, left anterior descending coronary artery, (LAD) and heart doses. Portal images were acquired and the reproducibility and stability of DIBH treatment were compared to FB. The comparing result shows there is a significant reduction in all LAD and heart dose statistics for DIBH compared to FB plans without compromising the target coverage. The maximum LAD dose was reduced from 43.7 Gy to 29.0 Gy and the volume of the heart receiving >25 Gy was reduced from 3.3% to 1.0% using the in-house system, both statistically significant. The in-house system gave a reproducible and stable DIBH treatment where the systematic error ∑, and random error σ, were less than 2.2 mm in all directions, but were not significantly better than at FB. The system was well tolerated and all patients completed their treatment sessions with DIBH.

Do patients have worse outcomes in heart failure than in cancer? A primary care-based cohort study with 10-year follow-up in Scotland

AIMS

This study was designed to evaluate whether survival rates in patients with heart failure (HF) are better than those in patients with diagnoses of the four most common cancers in men and women, respectively, in a contemporary primary care cohort in the community in Scotland.

METHODS AND RESULTS

Data were obtained from the Primary Care Clinical Informatics Unit from a database of 1.75 million people registered with 393 general practices in Scotland. Sex-specific survival modelling was undertaken using Cox proportional hazards models, adjusted for potential confounders. A total of 56 658 subjects were eligible for inclusion in the study. These represented a total of 147 938 person-years of follow-up (median follow-up: 2.04 years). In men, HF (reference group; 5-year survival: 55.8%) had worse mortality outcomes than prostate cancer [hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.57-0.65; 5-year survival: 68.3%], and bladder cancer (HR 0.88, 95% CI 0.81-0.96; 5-year survival: 57.3%), but better outcomes than lung cancer (HR 3.86, 95% CI 3.65-4.07; 5-year survival: 8.4%) and colorectal cancer (HR 1.23, 95% CI 1.16-1.31; 5-year survival: 48.9%). In women, HF (reference group; 5-year survival: 49.5%) had worse mortality outcomes than breast cancer (HR 0.55, 95% CI 0.51-0.59; 5-year survival 77.7%), but better outcomes than colorectal cancer (HR 1.21, 95% CI 1.13-1.29; 5-year survival 51.5%), lung cancer (HR 3.82, 95% CI 3.60-4.05; 5-year survival 10.4%), and ovarian cancer (HR 1.98, 95% CI 1.80-2.17; 5-year survival 38.2%).

CONCLUSIONS

Despite advances in management, HF remains as 'malignant' as some of the common cancers in both men and women.

Long-term arterial complications of chemotherapy in patients with cancer

The number of cancer survivors has gradually increased in recent decades. However, the cancer survivors are at risk for conditions related to their initial disease and its treatment, i.e. surgery, systemic treatment or radiotherapy. Cardiovascular complications, such as myocardial infarction, are common side effects of these therapies. Cardiovascular damage can occur during treatment or month to years after the initial treatment, as late effect of the cancer treatment. The pathophysiology of these effects is not yet fully understood, but an important part of the cardiovascular complications are thought to be the result of effects of anticancer agents on the structural and functional properties of the endothelium. Because these conditions can result in a high degree of morbidity and mortality, understanding how to improve the prevention, recognition, and treatment of vascular disease is an important medical priority in the care for cancer survivors. This review will focus on the long-term arterial complications of chemotherapy in cancer survivors. It will summarize the epidemiology and pathophysiology of these complications. Furthermore, important long-term clinical conditions related to these effects will be outlined, including cardiovascular risk management in terms of prevention, evaluation and therapy.

Radiation Therapy and Cardiac Death in Long-Term Survivors of Esophageal Cancer: An Analysis of the Surveillance, Epidemiology, and End Result Database

Objective

Radiation therapy (RT) for esophageal cancer often results in unintended radiation doses delivered to the heart owing to anatomic proximity. Using the Surveillance, Epidemiology, and End Results (SEER) database, we examined late cardiac death in survivors of esophageal cancer that had or had not received RT.

Methods

5,630 patients were identified that were diagnosed with esophageal squamous cell carcinoma (SCC) or adenocarcinoma (AC) from 1973–2012, who were followed for at least 5 years after therapy. Examined risk factors for cardiac death included age (≤55/56-65/66-75/>75), gender, race (white/non-white), stage (local/regional/distant), histology (SCC/AC), esophageal location (<18cm/18-24cm/25-32cm/33-40cm from incisors), diagnosis year (1973-1992/1993-2002/2003-2012), and receipt of surgery and/or RT. Time to cardiac death was evaluated using the Kaplan-Meier method. A Cox model was used to evaluate risk factors for cardiac death in propensity score matched data.

Results

Patients who received RT were younger, diagnosed more recently, had more advanced disease, SCC histology, and no surgery. The RT group had higher risk of cardiac death than the no-RT group (log-rank p<0.0001). The median time to cardiac death in the RT group was 289 months (95% CI, 255–367) and was not reached in the no-RT group. The probability of cardiac death increased with age and decreased with diagnosis year, and this trend was more pronounced in the RT group. Multivariate analysis found RT to be associated with higher probability of cardiac death (OR 1.23, 95% CI 1.03–1.47, HR 1.961, 95% CI 1.466–2.624). Lower esophageal subsite (33–40 cm) was also associated with a higher risk of cardiac death. Other variables were not associated with cardiac death.

Conclusions

Recognizing the limitations of a SEER analysis including lack of comorbidity accountability, these data should prompt more definitive study as to whether a possible associative effect of RT on cardiac death could potentially be a causative effect.

Modern Radiation Therapy and Cardiac Outcomes in Breast Cancer

PURPOSE

Adjuvant radiation therapy, which has proven benefit against breast cancer, has historically been associated with an increased incidence of ischemic heart disease. Modern techniques have reduced this risk, but a detailed evaluation has not recently been conducted. The present study evaluated the effect of current radiation practices on ischemia-related cardiac events and procedures in a population-based study of older women with nonmetastatic breast cancer.

METHODS AND MATERIALS

A total of 29,102 patients diagnosed from 2000 to 2009 were identified from the Surveillance, Epidemiology, and End Results-Medicare database. Medicare claims were used to identify the radiation therapy and cardiac outcomes. Competing risk models were used to assess the effect of radiation on these outcomes.

RESULTS

Patients with left-sided breast cancer had a small increase in their risk of percutaneous coronary intervention (PCI) after radiation therapy-the 10-year cumulative incidence for these patients was 5.5% (95% confidence interval [CI] 4.9%-6.2%) and 4.5% (95% CI 4.0%-5.0%) for right-sided patients. This risk was limited to women with previous cardiac disease. For patients who underwent PCI, those with left-sided breast cancer had a significantly increased risk of cardiac mortality with a subdistribution hazard ratio of 2.02 (95% CI 1.23-3.34). No other outcome, including cardiac mortality for the entire cohort, showed a significant relationship with tumor laterality.

CONCLUSIONS

For women with a history of cardiac disease, those with left-sided breast cancer who underwent radiation therapy had increased rates of PCI and a survival decrement if treated with PCI. The results of the present study could help cardiologists and radiation oncologists better stratify patients who need more aggressive cardioprotective techniques.

Late cardiac morbidity of adjuvant radiotherapy for early breast cancer - A population-based study

PURPOSE

The purpose of this study was to assess the long-term cardiac morbidity and mortality after breast irradiation using contemporary irradiation techniques.

METHODS

We used the Catastrophic Illness dataset from the National Health Insurance Research Database to explore the possible association between late cardiotoxicity and women with early breast cancer treated with breast conservation therapy from 2000 to 2010. The Cox proportional-hazards model was used to compare breast cancer patients who received adjuvant radiotherapy versus without adjuvant radiotherapy for the end points with the following primary diagnoses (International Classification of Diseases, 9th Revision codes): ischemic heart disease (410-414, 36.0, 36.1), valvular heart disease (394-397, 424, 35), congestive heart failure (428, 402.01, 402.11, 402.91), and conduction abnormalities (426, 37.7-37.8, 37.94-37.99).

RESULTS

Three hundred and thirty patients received adjuvant radiotherapy and 4802 patients did not receive radiotherapy. Median follow-up was 3.5 years. There was no difference in overall morbidity and mortality from any cardiac cause (p=0.13) in breast cancer patients who received adjuvant radiotherapy versus without radiotherapy by using modern radiotherapy techniques.

CONCLUSION

There were no significant differences in cardiac morbidity and mortality after radiotherapy for breast cancer with a 9-year follow-up period in our population.