Risk of cardiac disease after adjuvant radiation therapy among breast cancer survivors

Association Between Cancer and Cardiovascular Toxicity: A Nationwide Cross-Sectional Study on NHANES 1999-2018

There is a dearth of evidence pertaining to the relationship of cardiovascular disease (CVD) and its subtype with adjudicated cancer, thereby limiting our understanding of the heightened risk of CVD resulting from long-term complications of cancer and its therapies. The aim of this study was to quantify the risks of CVD and its subtypes in adult cancer survivors compared with cancer-free controls in a nationwide cross-sectional study on Continuous National Health and Nutrition Examination Survey (NHANES). We included 44,442 participants ranging in age from 20 to 85 years. Cancer and CVD diagnoses were ascertained via the household questionnaires. The association of cancer status with the risk of CVD and CVD subtype was examined using weighted logistic regression. Stratification analyses were also performed by age, sex, race, marital status, income status, educational level, and hyperlipidemia. The Wald test was used to calculate P-value for interaction. A total of 4178 participants have cancer, while 4829 participants had CVD, respectively. In the multivariable-adjusted model, the cancer was consistently linked to an elevated risk of CVD. Stratification analyses showed that stronger association between cancer status and CVD risk was found in younger adults, non-white, and participants living without a spouse or partner, and without hyperlipidemia. Our study confirmed that cancer participants were strongly linked to living with CVD, independent of traditional cardiovascular risk factors, especially in younger adults, non-white, and participants living without a spouse or partner, and without hyperlipidemia. There exists a pressing requirement to establish effective strategies for the prevention of CVD within this population characterized by a heightened risk.

Cardiovascular outcomes in breast cancer survivors: a systematic review and meta-analysis

AIMS

It is unclear whether the future risk of cardiovascular events in breast cancer (Bc) survivors is greater than in the general population. This meta-analysis quantifies the risk of cardiovascular disease development in Bc patients, compared to the risk in a general matched cancer-free population, and reports the incidence of cardiovascular events in patients with Bc.

METHODS AND RESULTS

We searched PubMed, Scopus, and Web of Science databases (up to 23 March 2022) for observational studies and post hoc analyses of randomized controlled trials. Cardiovascular death, heart failure (HF), atrial fibrillation (AF), coronary artery disease (CAD), myocardial infarction (MI), and stroke were the individual endpoints for our meta-analysis. We pooled incidence rates (IRs) and risk in hazard ratios (HRs), using random-effects meta-analyses. Heterogeneity was reported through the I2 statistic, and publication bias was examined using funnel plots and Egger's test in the meta-analysis of risk. One hundred and forty-two studies were identified in total, 26 (836 301 patients) relevant to the relative risk and 116 (2 111 882 patients) relevant to IRs. Compared to matched cancer-free controls, Bc patients had higher risk for cardiovascular death within 5 years of cancer diagnosis [HR = 1.09; 95% confidence interval (CI): 1.07, 1.11], HF within 10 years (HR = 1.21; 95% CI: 1.1, 1.33), and AF within 3 years (HR = 1.13; 95% CI: 1.05, 1.21). The pooled IR for cardiovascular death was 1.73 (95% CI 1.18, 2.53), 4.44 (95% CI 3.33, 5.92) for HF, 4.29 (95% CI 3.09, 5.94) for CAD, 1.98 (95% CI 1.24, 3.16) for MI, 4.33 (95% CI 2.97, 6.30) for stroke of any type, and 2.64 (95% CI 2.97, 6.30) for ischaemic stroke.

CONCLUSION

Breast cancer exposure was associated with the increased risk for cardiovascular death, HF, and AF. The pooled incidence for cardiovascular endpoints varied depending on population characteristics and endpoint studied.

REGISTRATION

CRD42022298741.

Long-term atherosclerotic cardiovascular disease risk in patients with cancer: a population-based study

BACKGROUND

The long-term risk of incident atherosclerotic cardiovascular diseases (ASCVD) among cancer patients remains incompletely defined. This study aimed to evaluate the long-term ASCVD risk in cancer patients compared with the non-cancer population.

METHODS

This was a prospective population-based study using data from the Kailuan cohort, 6,204 individuals with newly diagnosed cancer, free of ASCVD, were matched in a 1:1 ratio to non-cancer controls for age (±1) and sex, from June 2006 to December 2020. Multivariable competing risk analyses were performed to evaluate the association between cancer diagnosis and risk of incident ASCVD events (including myocardial infarction, ischemic stroke, heart failure, and revascularization with coronary artery bypass graft surgery or percutaneous coronary intervention).

RESULTS

During a median follow-up of 5.3 (1.7, 9.7) years, 1,019 incident ASCVD events were observed. Compared to participants without cancer, there was a similar risk for incident ASCVD events among cancer patients within the first few years after cancer diagnosis, and the risk declined over time. Overall, cancer patients showed lower risks of incident ASCVD compared to the non-cancer patients over the long term, with a hazard ratio (95% confidence interval) of 0.52 (0.45-0.60) for composite ASCVD events, 0.43 (0.35-0.53) for ischemic stroke, 0.63 (0.42-0.95) for myocardial infarction, 0.63 (0.48-0.83) for heart failure, and 0.82 (0.60-1.11) for coronary revascularization. Baseline level of low-density lipoprotein cholesterol, fasting blood glucose, blood pressure, and high-sensitivity C-reactive protein could independently predict the incident ASCVD among the study population. Subgroup analyses according to cancer types revealed a significantly lower risk of ASCVD events among patients with digestive cancer or respiratory cancer compared with non-cancer controls, but not for urologic or genital cancer. Multiple sensitivity analyses yielded similar results to the primary analysis.

CONCLUSIONS

Long-term ASCVD risk among cancer survivors is not increased compared with the non-cancer individuals, probably driven by a favorable profile of baseline risk factor in cancer population.

An overview of radiation-induced heart disease

Radiation therapy (RT) has dramatically improved cancer survival, leading to several inevitable complications. Unintentional irradiation of the heart can lead to radiation-induced heart disease (RIHD), including cardiomyopathy, pericarditis, coronary artery disease, valvular heart disease, and conduction system abnormalities. Furthermore, the development of RIHD is aggravated with the addition of chemotherapy. The screening, diagnosis, and follow-up for RIHD in patients who have undergone RT are described by the consensus guidelines from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE). There is compelling evidence that chest RT can increase the risk of heart disease. Although the prevalence and severity of RIHD are likely to be reduced with modern RT techniques, the incidence of RIHD is expected to rise in cancer survivors who have been treated with old RT regimens. However, there remains a gap between guidelines and clinical practice. Currently, therapeutic modalities followed in the treatment of RIHD are similar to the non-irradiated population. Preventive measures mainly reduce the radiation dose and radiation volume of the heart. There is no concrete evidence to endorse the preventive role of statins, angiotensin-converting enzyme inhibitors, and antioxidants. This review summarizes the current evidence of RIHD subtypes and risk factors and suggests screening regimens, diagnosis, treatment, and preventive approaches.

Two-dimensional Speckle Tracking Echocardiography in Evaluating Radiation-induced Heart Damage

Objective

Radiation-induced heart damage (RIHD) in malignant tumor patients with thoracic radiotherapy has been well documented. However, there is no study on the cardiac toxicity of stereotactic body radiotherapy (SBRT) based on two-dimensional speckle tracking echocardiography (2D STE).

Methods

In a prospective cohort trial, 48 patients with malignant tumor (including patients with lung cancer, pulmonary metastases and other tumor) were assigned to receive thoracic SBRT. Circulating biomarkers, electrocardiogram (ECG), echocardiography, and 2D STE were performed prior to and within two months after thoracic radiotherapy. The primary outcome of the trial was a decrease in global longitudinal strain (GLS) ≥ 10%. The secondary outcomes were major adverse cardiovascular events (MACE). Analysis were conducted using paired sample t-test, Wilcoxon signed rank test and Chi square test.

Results

The morbidity of RIHD is 44% within 2 months after SBRT in malignant tumor patients. Compared with pre-RT, a significant decrease in GLS was observed post-RT (−17.98 ​± ​3.54% vs. −16.92 ​± ​3.41%; P ​= ​0.008), without any significant change in left ventricular ejection fraction (LVEF) (68.54 ​± ​6.06 vs. 69.63 ​± ​4.45; P ​= ​0.234), left ventricular mass (LVM) (P ​= ​0.342), ECG parameters, creatine kinase (P ​= ​0.074), cardiac troponin T (P ​= ​0.829) or N-terminal pro-B-type natriuretic peptide (P ​= ​0.453) at during the post-RT period. There was no evidence that RIHD was correlated with age (P ​= ​1.000), mean heart dose (P ​= ​0.602), BED (P ​= ​0.234), EQD2/2 (P ​= ​0.615), V5 (P ​= ​0.506), V10 (P ​= ​0.578), V20 (P ​= ​0.670) and V30 (P ​= ​0.741). Subgroup analysis showed, there is still a significant decline of GLS (−18.30 ​± ​3.79% vs. −17.11 ​± ​3.58%; P ​= ​0.018) in patients without anthracycline treatment. And the decrease of GLS (−19.14 ​± ​2.42% vs. −16.85 ​± ​2.46%; P ​= ​0.004) was more significantly post-RT in anthracycline treatment group. MACE were found in one patient over a period of two months after SBRT.

Conclusions

By using strain analysis subclinical cardiac dysfunction was found to be evident early after SBRT, despite unchanged conventional indices such as LVEF, ECG parameters or circulating biomarkers. And the decrease of GLS is still existed after the effect of anthracycline was removed.

Trial registration

ClinicalTrials.gov, registration number: NCT04443400.

Internal mammary node irradiation in node-positive breast cancer treated with mastectomy and taxane-based chemotherapy

BACKGROUND

It is important to continually reevaluate the risk/benefit calculus of internal mammary node irradiation (IMNI) in the era of modern systemic therapy. We aimed to investigate the effect of IMNI on survival in node-positive breast cancer treated with mastectomy and anthracycline plus taxane-based chemotherapy.

METHODS

We analyzed 348 patients who underwent mastectomy and anthracycline plus taxane-based chemotherapy for node-positive breast cancer between January 2006 and December 2011. All patients received postoperative radiation therapy (RT) with IMNI (n = 105, 30.2%) or without IMNI (n = 243, 69.8%). The benefit of IMNI for disease-free survival (DFS) and overall survival (OS) was evaluated using multivariate analysis and inverse probability of treatment weighting (IPTW) to adjust for unbalanced covariates between the groups.

RESULTS

After a median follow-up of 95 months, the 10-year locoregional recurrence-free survival rate, DFS, and OS in all patients were 94.8%, 77.4%, and 86.2%, respectively. The IPTW-adjusted hazard ratio (HR) for the association of IMNI (vs. no IMNI) with DFS and OS was 0.208 (95% confidence intervals (CI) 0.045-0.966) and 0.460 (95% CI, 0.220-0.962), respectively. In multivariate analysis, IMNI was a favorable factor for DFS (HR, 0.458; P = 0.021) and OS (HR 0.233, P = 0.018).

CONCLUSIONS

IMNI was associated with improved DFS and OS in node-positive patients treated with mastectomy, post-mastectomy RT, and taxane-based chemotherapy, although the rate of locoregional recurrence was low.

The Potential of Physical Exercise to Mitigate Radiation Damage-A Systematic Review

There is a need to investigate new countermeasures against the detrimental effects of ionizing radiation as deep space exploration missions are on the horizon. Objective: In this systematic review, the effects of physical exercise upon ionizing radiation-induced damage were evaluated. Methods: Systematic searches were performed in Medline, Embase, Cochrane library, and the databases from space agencies. Of 2,798 publications that were screened, 22 studies contained relevant data that were further extracted and analyzed. Risk of bias of included studies was assessed. Due to the high level of heterogeneity, meta-analysis was not performed. Five outcome groups were assessed by calculating Hedges' g effect sizes and visualized using effect size plots. Results: Exercise decreased radiation-induced DNA damage, oxidative stress, and inflammation, while increasing antioxidant activity. Although the results were highly heterogeneous, there was evidence for a beneficial effect of exercise in cellular, clinical, and functional outcomes. Conclusions: Out of 72 outcomes, 68 showed a beneficial effect of physical training when exposed to ionizing radiation. As the first study to investigate a potential protective mechanism of physical exercise against radiation effects in a systematic review, the current findings may help inform medical capabilities of human spaceflight and may also be relevant for terrestrial clinical care such as radiation oncology.

Late Sequelae of Radiotherapy—The Effect of Technical and Conceptual Innovations in Radiation Oncology

BACKGROUND

Approximately half of all patients with tumors need radiotherapy. Long-term survivors may suffer from late sequelae of the treatment. The existing radiotherapeutic techniques are being refined so that radiation can be applied more precisely, with the goal of limiting the radiation exposure of normal tissue and reducing late sequelae.

METHODS

This review is based on the findings of a selective search in PubMed for publications on late sequelae of conventional percutaneous radiotherapy, January 2000 to May 2020. Late sequelae affecting the central nervous system, lungs, and heart and the development of second tumors are presented, and radiobiological mechanisms and the relevant technical and conceptual considerations are discussed.

RESULTS

The current standard of treatment involves the use of linear accelerators, intensity-modulated radiotherapy (IMRT), image-guided and respiratory-gated radiotherapy, and the integration of positron emission tomography combined with computed tomography (PET-CT) in radiation treatment planning. Cardiotoxicity has been reduced with regard to the risk of coronary heart disease after radiotherapy for Hodgkin's lymphoma (hazard ratio [HR] 0.44 [0.23; 0.85]). It was also found that the rate of radiation- induced pneumonitis dropped from 7.9% with conformal treatment to 3.5% with IMRT in a phase III lung cancer trial. It is hoped that neurocognitive functional impairment will be reduced by hippocampal avoidance in modern treatment planning: an initial phase III trial yielded a hazard ratio of 0.74 [0.58; 0.94]. It is estimated that 8% of second solid tumors in adults are induced by radiotherapy (3 additional tumors per 1000 patients at 10 years).

CONCLUSION

Special challenges for research in this field arise from the long latency of radiation sequelae and the need for largescale, well-documented patient collectives in order to discern dose-effect relationships, and take account of cofactors, when the overall number of events is small. It is hoped that further technical and conceptual advances will be made in the areas of adaptive radiotherapy, proton and heavy-ion therapy, and personalized therapy.

Risk of Cardiac Disease in Patients With Breast Cancer: Impact of Patient-Specific Factors and Individual Heart Dose From Three-Dimensional Radiation Therapy Planning

PURPOSE

This retrospective cohort study aimed to determine whether adjuvant radiation therapy increases the risk of cardiac toxicity in Asian women with breast cancer, with a focus on patient-specific factors.

METHODS AND MATERIALS

We evaluated women who underwent primary breast surgery for breast cancer with (n = 520) or without (n = 774) adjuvant radiation therapy between January 2005 and May 2013. Patients who underwent breast surgery without radiation therapy were categorized as patients who received 0 Gy to the heart. The primary endpoint was the occurrence of a breast cancer treatment-related heart disease (BCT-HD), defined as a diagnosis of angina pectoris, unstable angina, myocardial infarction, ischemic heart disease, heart failure, or atrial fibrillation.

RESULTS

In total, 1294 patients were included. The overall 5- and 10-year BCT-HD rates were 2.4% and 5.7%, respectively. The risk of an BCT-HD significantly increased per 1-Gy increase in the mean heart dose (adjusted hazard ratio: 1.23). Additionally, histories of hypertension (hazard ratio: 1.92), and diabetes (hazard ratio: 2.51) were found to be adverse risk factors, whereas regular physical exercise (hazard ratio: 0.17) was a protective factor. Subgroup analysis according to risk groups showed that the effect of increasing mean heart dose (per Gy) was similar between women without or with minimal risk factors (hazard ratio: 1.23) and women with multiple risk factors (hazard ratio: 1.27).

CONCLUSIONS

The results indicate a radiation dose-effect relationship for cardiac disease in breast cancer patients, highlighting that there remains a considerable risk of cardiac toxicity even with 3-dimensional radiation therapy planning. Thus, measures to minimize the heart dose in breast cancer patients undergoing adjuvant radiation therapy, even in those without any risk factor for cardiac disease, should be routinely implemented.

Risk of Cardiovascular Diseases Among Older Breast Cancer Survivors in the United States: A Matched Cohort Study

BACKGROUND

It has been suggested that cardiovascular risks are increased in breast cancer survivors, but few studies have quantified the risks of a range of specific clinically important cardiovascular outcomes in detail.

PATIENTS AND METHODS

Women aged >65 years with incident breast cancer from 2004 to 2013 in the SEER-Medicare linked database were matched with 5 cancer-free female counterparts (5:1 ratio). Prevalence of specific cardiovascular outcomes at baseline was measured, then Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals for the risk of individual cardiovascular outcomes during follow-up. Modification of the effect was investigated by time since diagnosis, race/ethnicity, prior cardiovascular disease (CVD), and age.

RESULTS

In all, 91,473 women with breast cancer and 454,197 without breast cancer were included. Women with breast cancer had lower baseline prevalence of all CVDs. Compared with cancer-free controls, breast cancer survivors had substantially increased risks of deep vein thrombosis (adjusted HR, 1.67; 95% CI, 1.62-1.73; 386,484 person-years of follow-up) and pericarditis (HR, 1.43; 95% CI, 1.38-1.49; 390,776 person-years of follow-up); evidence of smaller increased risks of sudden cardiac arrest, arrhythmia, heart failure, and valvular heart disease (adjusted HRs ranging from 1.05-1.09, lower CI limits all ≥1); and evidence of lower risk of incident angina, myocardial infarction, revascularization, peripheral vascular disease, and stroke (adjusted HRs ranging from 0.89-0.98, upper CI limits all ≤1). Increased risks of arrhythmia, heart failure, pericarditis, and deep vein thrombosis persisted >5 years after cancer diagnosis.

CONCLUSIONS

Women with a history of breast cancer were at increased risk of several CVDs, persisting into survivorship. Monitoring and managing cardiovascular risk throughout the long-term follow-up of women diagnosed with breast cancer should be a priority.

The impact of smoking on adjuvant breast cancer radiation treatment: A systematic review

BACKGROUND

The influence of cigarette smoking on cancer risk has been well-studied. Similarly, exposure to ionizing radiation from radiotherapy (RT) can produce detrimental effects on an individual's health. In patients administered RT, there has been an observed relationship in other primary carcinomas. The purpose of this systematic review was to summarize the influence of cigarette smoking on outcomes post adjuvant RT in breast cancer patients.

METHODS

OVID Medline, Cochrane and Embase were searched and 1893 articles were identified. A total of 71 articles were included in the review. Study type, published year and sample size, age, systemic therapies, RT techniques and treatment side effects were collected if available.

RESULTS

The review found 198 different outcomes which fell into 7 categories and similar outcomes were recorded. 40% of skin reaction outcomes, 50% of cardiovascular outcomes, 71% of reconstruction outcomes, 29% of pulmonary function outcomes, 33% of mortality outcomes and 42% of secondary recurrence outcomes reported significant differences between smokers and non-smokers. None of the articles reported non-smokers to have a higher risk than smokers.

CONCLUSION

Cigarette smoking can pose a higher risk of post-treatment complications that can influence an individual's quality of life, survival rate and/or recurrence risk. This review further assessed the impact of smoking on various patient outcomes and side-effects in the adjuvant breast RT setting. The information provided in this review suggest that smoking cessation programs would help educate patients to understand their risks of being a current or former smoker when undergoing RT.