The heart's exposure to radiation increases the risk of cardiac toxicity after chemoradiotherapy for superficial esophageal cancer: a retrospective cohort study

Dosimetric advantages for cardiac substructures in radiotherapy of esophageal cancer in deep-inspiration breath hold

BACKGROUND

Radiotherapy is one of the main treatment options for patients with esophageal cancer; however, it has been linked with an increased risk of cardiac toxicities. In the current study, we evaluated the effect of planning the radiation in deep-inspiration breath hold (DIBH) on the dose sparing of cardiac substructures and lung.

MATERIALS AND METHODS

In this study, we analyzed 30 radiation therapy plans from 15 patients diagnosed with esophageal cancer planned for neoadjuvant radiotherapy. Radiation plans were generated for 41.4 Gy and delivered in 1.8 Gy per fraction for free-breathing (FB) and DIBH techniques. We then conducted a comparative dosimetric analysis, evaluating target volume coverage, the impact on cardiac substructures, and lung doses across the two planning techniques for each patient.

RESULTS

There was no significant disparity in target volume dose coverage between DIBH and FB plans. However, the Dmean, D2%, and V30% of the heart experienced substantial reductions in DIBH relative to FB, with values of 6.21 versus 7.02 Gy (p = 0.011), 35.28 versus 35.84 Gy (p = 0.047), and 5% versus 5.8% (p = 0.048), respectively. The Dmean of the left ventricle was notably lower in DIBH compared to FB (4.27 vs. 5.12 Gy, p = 0.0018), accompanied by significant improvements in V10. Additionally, the Dmean and D2% of the left coronary artery, as well as the D2% of the right coronary artery, were significantly lower in DIBH. The dosimetric impact of DIBH on cardiac substructures proved more advantageous for middle esophageal (ME) than distal esophageal (DE) tumors.

CONCLUSION

Radiotherapy in DIBH could provide a method to reduce the radiation dose to the left ventricle and coronaries, which could reduce the cardiac toxicity of the modality.

High Incidence of Cardiovascular Disease in Patients With Oesophageal Cancer-A Registry-Based Cohort Study

BACKGROUND

The cardiovascular disease (CVD) burden among patients with oesophageal cancer (EC) treated with curative intent is unclear.

AIM

To determine CVD incidence and all-cause mortality in patients with EC.

METHOD

Danish national health registries were used to identify patients diagnosed with primary EC between 2008 and 2018. Each EC patient was matched with 10 individuals from the general population. The primary endpoint was a CVD hospital contact (CVD-HC), either admission or outpatient contact. Cox proportional hazard regression models were used to compare the risk of incident CVD-HCs between the cohorts.

RESULTS

The study included 1,525 patients with EC and 15,250 individuals from the general population. Patients with EC had a post-diagnosis one-year adjusted hazard ratio (HR) of CVD-HC of 6.1 (95% confidence intervals [CIs] 5.6-6.8) compared with the general population. During the next nine years, the risk of CVD-HC was comparable between the two cohorts, with an adjusted HR of 1.0 (95% CI 0.9-1.3). Patients with EC, and particularly those with prevalent CVD, had a high risk of atrial fibrillation, ischaemic heart disease, and venous thromboembolism within the first year after EC diagnosis. Prevalent CVD among patients with EC was not associated with higher mortality.

CONCLUSIONS

CVD morbidity was transiently increased in the first year following EC diagnosis compared with the general population. All-cause mortality risks were high but did not appear to be affected by prevalent CVD. The very high risk of CVD in patients with primary EC to be treated with curative intent calls for healthcare initiatives to advance preventive and post-treatment strategies.

Correlation between morphological parameters and dosimetric parameters of the heart and spinal cord in the intermediate- and advanced-stage esophageal cancer

BACKGROUND

Radiation therapy plays a pivotal role as the primary adjuvant treatment for esophageal cancer (EPC), emphasizing the critical importance of carefully balancing radiation doses to the target area and organs at risk in the radiotherapeutic management of esophageal cancer.

AIMS

This study aimed to explore the correlation between morphological parameters and dosimetric parameters of the heart and spinal cord in intermediate- and advanced-stage esophagus cancer to provide a reference for clinical treatment.

METHODS AND RESULTS

A total of 105 patients with intermediate- and advanced-stage EPC, who received treatment in our hospital from 2019 to 2021, were included. The morphological parameters were calculated by imaging. Intensity-modulated radiation therapy plan was executed at Raystation4.7. The PTV-G stood for the externally expanded planning target volume (PTV) of the gross tumor volume (GTV) and PTV-C for the externally expanded volume of the clinical target volume (CTV). The prescription dose of PTV-G and PTV-C was set as 60Gy/30F and 54Gy/30F, respectively. The linear regression model was used to analyze the correlation between morphologic parameters of EPC and dosimetric parameters of the heart and spinal cord. In 105 cases, the total lung length was correlated with the spinal cord maximum dose (D2 ). The heart mean doses (Dmean ) and heart V40 (the relative volume that receives 40 Gy or more) was correlated with PTV-G volume, PTV-G length; In middle- and upper-segment EPC cases, only the total lung volume was correlated with the spinal cord Dmean , spinal cord D2 , heart Dmean , and heart V40 ; In middle-stage EPC cases, the heart Dmean was correlated with the PTV-G volume, PTV-G length. The total lung length was correlated with the spinal cord D2 ; In middle- and lower-segment EPC, only the PTV-G volume and PTV-G length were correlated with the heart Dmean . All the aforementioned values were statistically significant.

CONCLUSIONS

Combined with the unsegmented tumor and different locations, the organ at risk dose was comprehensively considered.

Incident Atrial Fibrillation and Survival Outcomes in Esophageal Cancer following Radiotherapy

PURPOSE

Radiation therapy (RT) associates with long-term cardiotoxicity. In preclinical models, RT exposure induces early cardiotoxic arrhythmias including atrial fibrillation (AF). Yet, whether this occurs in patients is unknown.

METHODS AND MATERIALS

Leveraging a large cohort of consecutive patients with esophageal cancer treated with thoracic RT from 2007 to 2019, we assessed incidence and outcomes of incident AF. Secondary outcomes included major adverse cardiovascular events (MACE), defined as AF, heart failure, ventricular arrhythmias, and sudden death, by cardiac RT dose. We also assessed the relationship between AF development and progression-free and overall survival. Observed incident AF rates were compared with Framingham predicted rates, and absolute excess risks were estimated. Multivariate regression was used to define the relationship between clinical and RT measures, and outcomes. Differences in outcomes, by AF status, were also evaluated via 30-day landmark analysis. Furthermore, we assessed the effect of cardiac substructure RT dose (eg, left atrium, LA) on the risk of post RT-related outcomes.

RESULTS

Overall, from 238 RT treated patients with esophageal cancer, 21.4% developed incident AF, and 33% developed MACE with the majority (84%) of events occurring ≤2 years of RT initiation (median time to AF, 4.1 months). Cumulative incidence of AF and MACE at 1 year was 19.5%, and 25.7%, respectively; translating into an observed incident AF rate of 824 per 10,000 person-years, compared with the Framingham predicted rate of 92 (relative risk, 8.96; P < .001, absolute excess risk 732). Increasing LA dose strongly associated with incident AF (P = .001); and those with AF saw worse disease progression (hazard ratio, 1.54; P = .03). In multivariate models, outside of traditional cancer-related factors, increasing RT dose to the LA remained associated with worse overall survival.

CONCLUSIONS

Among patients with esophageal cancer, radiation therapy increases AF risk, and associates with worse long-term outcomes.

Development and validation of a nomogram to predict cardiac death after radiotherapy for esophageal cancer

Background

Patients frequently die from cardiac causes after radiotherapy for esophageal cancer. Early detection of cardiac death risk in these patients is crucial to improve clinical decision-making and prognosis. Thus, we modeled the risk of cardiac death after irradiation for esophageal cancer.

Methods

A retrospective analysis of 37,599 esophageal cancer cases treated with radiotherapy in the SEER database between 2000 and 2018 was performed. The selected cases were randomly assigned to the model development group (n = 26,320) and model validation group (n = 11,279) at a ratio of 7:3. We identified the risk factors most commonly associated with cardiac death by least absolute shrinkage and selection operator regression analysis (LASSO). The endpoints for model development and validation were 5- and 10-year survival rates. The net clinical benefit of the models was evaluated by decision curve analysis (DCA) and concordance index (C-index). The performance of the models was further assessed by creating a receiver operating characteristic curve (ROC) and calculating the area under the curve (AUC). Kaplan-Meier (K-M) survival analysis was performed on the probability of death. Patients were classified according to death probability thresholds. Five- and ten-year survival rates for the two groups were shown using K-M curves.

Results

The major risk factors for cardiac death were age, surgery, year of diagnosis, sequence of surgery and radiotherapy, chemotherapy and a number of tumors, which were used to create the nomogram. The C-indexes of the nomograms were 0.708 and 0.679 for the development and validation groups, respectively. DCA showed the good net clinical benefit of nomograms in predicting 5- and 10-year risk of cardiac death. The model exhibited moderate predictive power for 5- and 10-year cardiac mortality (AUC: 0.833 and 0.854, respectively), and for the development and validation cohorts (AUC: 0.76 and 0.813, respectively).

Conclusions

Our nomogram may assist clinicians in making clinical decisions about patients undergoing radiotherapy for esophageal cancer based on early detection of cardiac death risk.

Progression of coronary artery calcification after radiation therapy for esophageal cancer

BACKGROUND

Advances in cancer treatment have resulted in increased attention toward potential cardiac complications, especially following treatment for esophageal cancer, which is associated with a risk of coronary artery disease. As the heart is directly irradiated during radiotherapy, coronary artery calcification (CAC) may progress in the short term. Therefore, we aimed to investigate the characteristics of patients with esophageal cancer that predispose them to coronary artery disease, CAC progression on PET-computed tomography and the associated factors, and the impact of CAC progression on clinical outcomes.

METHODS

We retrospectively screened 517 consecutive patients who received radiation therapy for esophageal cancer from our institutional cancer treatment database between May 2007 and August 2019. CAC scores were analyzed clinically for 187 patients who remained by exclusion criteria.

RESULTS

A significant increase in the Agatston score was observed in all patients (1 year: P  = 0.001*, 2 years: P  < 0.001*). Specifically for patients receiving middle-lower chest irradiation (1 year: P  = 0.001*, 2 years: P  < 0.001*) and those with CAC at baseline (1 year: P  = 0.001*, 2 years: P  < 0.001*), a significant increase in the Agatston score was observed. There was a trend for a difference in all-cause mortality between patients who had irradiation of the middle-lower chest ( P  = 0.053) and those who did not.

CONCLUSION

CAC can progress within 2 years after the initiation of radiotherapy to the middle or lower chest for esophageal cancer, particularly in patients with detectable CAC before radiotherapy initiation.

Radiation-associated Arrhythmias: Putative Pathophysiological Mechanisms, Prevalence, Screening and Management Strategies

Radiation-associated cardiovascular disease, an increasingly recognised disease process, is a significant adverse effect of radiation therapy for common malignancies that involve the chest, and include lymphomas, lung, mediastinal and breast cancers. Two factors contribute to the increasing incidence of radiation-associated cardiovascular disease: advances in malignancy detection and the improved survival of cancer patients, by which many symptoms of radiation-associated cardiovascular disease, specifically radiation-associated arrhythmias, present years and/or decades following initial radiotherapy. We present a focused overview of the currently understood pathophysiology, prevalence and management strategies of radiation-associated arrhythmias, which include bradyarrhythmias, tachyarrhythmias and autonomic dysfunction.

Atrial fibrillation in cancer survivors - a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is a common cardiac complication during cancer treatment. It is unclear if cancer survivors have increased AF risk when compared to the population. AF screening is now recommended in patients ≥65 years, however there are no specific recommendations in the oncology population. We sought to compare the AF detection rate of cancer survivors compared to the general population.

METHODS

We searched the Pubmed, Embase and Web of Science databases using search terms related to AF and cancer mapped to subject headings. We included English language studies, limited to adults > 18 years who were > 12 months post completion of cancer treatment. Using a random-effects model we calculated the overall AF detection rate. Meta-regression analysis was performed to assess for potential causes for study heterogeneity.

RESULTS

Sixteen studies were included in the study. The combined AF detection rate amongst all the studies was 4.7% (95% C.I 4.0-5.4%), which equated to a combined annualised AF rate of 0.7% (95% C.I 0.1-0.98%). There was significant heterogeneity between studies (I² = 99.8%, p < 0.001). In the breast cancer cohort (n = 6 studies), the combined annualised AF rate was 0.9% (95% C.I 0.1-2.3%), with significant heterogeneity (I² = 99.9%, p < 0.001).

CONCLUSION

Whilst the results should be interpreted with caution due to study heterogeneity, AF rates in patients with cancer survival >12 months were not significantly increased compared to the general population.

STUDY REGISTRATION

Open Science Framework - DOI: https://doi.org/10.17605/OSF.IO/APSYG .

Redefining the Incidence and Profile of Fluoropyrimidine-Associated Cardiotoxicity in Cancer Patients: A Systematic Review and Meta-Analysis

Aim: The cardiac toxicity that occurs during administration of anti-tumor agents has attracted increasing concern. Fluoropyrimidines have been used for more than half a century, but their cardiotoxicity has not been well clarified. In this study, we aimed to assess the incidence and profile of fluoropyrimidine-associated cardiotoxicity (FAC) comprehensively based on literature data. Methods: A systematic literature search was performed using PubMed, Embase, Medline, Web of Science, and Cochrane library databases and clinical trials on studies investigating FAC. The main outcome was a pooled incidence of FAC, and the secondary outcome was specific treatment-related cardiac AEs. Random or fixed effects modeling was used for pooled meta-analyses according to the heterogeneity assessment. PROSPERO registration number: (CRD42021282155). Results: A total of 211 studies involving 63,186 patients were included, covering 31 countries or regions in the world. The pooled incidence of FAC, by meta-analytic, was 5.04% for all grades and 1.5% for grade 3 or higher. A total of 0.29% of patients died due to severe cardiotoxicities. More than 38 cardiac AEs were identified, with cardiac ischemia (2.24%) and arrhythmia (1.85%) being the most frequent. We further performed the subgroup analyses and meta-regression to explore the source of heterogeneity, and compare the cardiotoxicity among different study-level characteristics, finding that the incidence of FAC varied significantly among different publication decades, country/regions, and genders. Patients with esophagus cancer had the highest risk of FAC (10.53%), while breast cancer patients had the lowest (3.66%). The treatment attribute, regimen, and dosage were significantly related to FAC. When compared with chemotherapeutic drugs or targeted agents, such a risk was remarkably increased (χ2 = 10.15, p < 0.01; χ2 = 10.77, p < 0.01). The continuous 5-FU infusion for 3–5 consecutive days with a high dosage produced the highest FAC incidence (7.3%) compared with other low-dose administration patterns. Conclusions: Our study provides comprehensive global data on the incidence and profile of FAC. Different cancer types and treatment appear to have varying cardiotoxicities. Combination therapy, high cumulative dose, addition of anthracyclines, and pre-existing heart disease potentially increase the risk of FAC.

Cardiac Substructures Dosimetric Predictors for Cardiac Toxicity After Definitive Radiotherapy in Esophageal Cancer

PURPOSE

To investigate the predictive value of the cardiac substructures (CSs) dosimetric parameters for cardiac toxicity after definitive radiation therapy in locally advanced esophageal cancer.

METHODS AND MATERIALS

Between August 2010 and January 2016, 716 patients with stage 2-3 esophageal cancer receiving definitive radiation therapy at 2 institutions were divided into training (n = 432) and external validation (n = 284) cohorts. Dose-volume histogram parameters for the whole heart (WH) and CSs were extracted. Competing risks and Cox regressions analyses were performed. The predictive performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC) and the Brier score.

RESULTS

With a median follow-up of 93 months, 68 patients (15.7%) developed grade ≥3 cardiac events (G3+ CEs), with a median of 13.5 months to the first event. Multivariable analysis showed left ventricle, left anterior descending (LAD), and mean left circumflex (LCX) variables were significantly associated with G3+ CEs. The AUCs and Brier scores demonstrated favorable predictive accuracies of the models integrating these CS variables when predicting G3+ CEs in the training and validation cohorts. However, compared with the WH variables, the CS variables did not significantly improve the prediction of G3+ CEs. Nevertheless, when G3+ acute coronary syndrome and/or congestive heart failure (ACS/CHF) CE was the outcome of interest, models based on the LAD or LCX variables were superior to the WH variable models in training and validation cohorts.

CONCLUSIONS

Models based on CS variables showed favorable predictive accuracy for G3+ CEs. The LAD and LCX variables significantly improved the prediction of G3+ ACS/CHF events compared with the WH variables. Radiation doses to CSs, such as LCX and LAD, should be monitored to help reduce the occurrence of significant CEs in patients with esophageal cancer undergoing definitive radiation therapy.

Effects of Whole and Partial Heart Irradiation on Collagen, Mast Cells, and Toll-like Receptor 4 in the Mouse Heart

In radiation therapy of tumors in the chest, such as in lung or esophageal cancer, part of the heart may be situated in the radiation field. This can lead to the development of radiation-induced heart disease. The mechanisms by which radiation causes long-term injury to the heart are not fully understood, but investigations in pre-clinical research models can contribute to mechanistic insights. Recent developments in X-ray technology have enabled partial heart irradiation in mouse models. In this study, adult male and female C57BL/6J mice were exposed to whole heart (a single dose of 8 or 16 Gy) and partial heart irradiation (16 Gy to 40% of the heart). Plasma samples were collected at 5 days and 2 weeks after the irradiation for metabolomics analysis, and the cardiac collagen deposition, mast cell numbers, and left ventricular expression of Toll-like receptor 4 (TLR4) were examined in the irradiated and unirradiated parts of the heart at 6 months after the irradiation. Small differences were found in the plasma metabolite profiles between the groups. However, the collagen deposition did not differ between the irradiated and unirradiated parts of the heart, and radiation did not upregulate the mast cell numbers in either part of the heart. Lastly, an increase in the expression of TLR4 was seen only after a single dose of 8 Gy to the whole heart. These results suggest that adverse tissue remodeling was not different between the irradiated and unirradiated portions of the mouse heart. While there were no clear differences between male and female animals, additional work in larger cohorts may be required to confirm this result, and to test the inhibition of TLR4 as an intervention strategy in radiation-induced heart disease.

CArdiac and REspiratory adaptive Computed Tomography (CARE-CT): a proof-of-concept digital phantom study

Current respiratory 4DCT imaging for high-dose rate thoracic radiotherapy treatments are negatively affected by the complex interaction of cardiac and respiratory motion. We propose an imaging method to reduce artifacts caused by thoracic motion, CArdiac and REspiratory adaptive CT (CARE-CT), that monitors respiratory motion and ECG signals in real-time, triggering CT acquisition during combined cardiac and respiratory bins. Using a digital phantom, conventional 4DCT and CARE-CT acquisitions for nineteen patient-measured physiological traces were simulated. Ten respiratory bins were acquired for conventional 4DCT scans and ten respiratory bins during cardiac diastole were acquired for CARE-CT scans. Image artifacts were quantified for 10 common thoracic organs at risk (OAR) substructures using the differential normalized cross correlation between axial slices (ΔNCC), mean squared error (MSE) and sensitivity. For all images, on average, CARE-CT improved the ΔNCC for 18/19 and the MSE and sensitivity for all patient traces. The ΔNCC was reduced for all cardiac OARs (mean reduction 21%). The MSE was reduced for all OARs (mean reduction 36%). In the digital phantom study, the average scan time was increased from 1.8 ± 0.4 min to 7.5 ± 2.2 min with a reduction in average beam on time from 98 ± 28 s to 45 s using CARE-CT compared to conventional 4DCT. The proof-of-concept study indicates the potential for CARE-CT to image the thorax in real-time during the cardiac and respiratory cycle simultaneously, to reduce image artifacts for common thoracic OARs.

Preclinical models of radiation-induced cardiac toxicity: Potential mechanisms and biomarkers

Radiation therapy (RT) is an important modality in cancer treatment with >50% of cancer patients undergoing RT for curative or palliative intent. In patients with breast, lung, and esophageal cancer, as well as mediastinal malignancies, incidental RT dose to heart or vascular structures has been linked to the development of Radiation-Induced Heart Disease (RIHD) which manifests as ischemic heart disease, cardiomyopathy, cardiac dysfunction, and heart failure. Despite the remarkable progress in the delivery of radiotherapy treatment, off-target cardiac toxicities are unavoidable. One of the best-studied pathological consequences of incidental exposure of the heart to RT is collagen deposition and fibrosis, leading to the development of radiation-induced myocardial fibrosis (RIMF). However, the pathogenesis of RIMF is still largely unknown. Moreover, there are no available clinical approaches to reverse RIMF once it occurs and it continues to impair the quality of life of long-term cancer survivors. Hence, there is an increasing need for more clinically relevant preclinical models to elucidate the molecular and cellular mechanisms involved in the development of RIMF. This review offers an insight into the existing preclinical models to study RIHD and the suggested mechanisms of RIMF, as well as available multi-modality treatments and outcomes. Moreover, we summarize the valuable detection methods of RIHD/RIMF, and the clinical use of sensitive radiographic and circulating biomarkers.

Proton Beam Therapy for Esophageal Cancer

Simple Summary

Early-stage esophageal cancer is managed surgically, with the addition of radiotherapy for locally advanced disease. Current photon-based radiotherapy results in a high treatment-related complications, due to proximal organ involvement. The anatomic location of the esophagus raises challenges due to the anatomical changes associated with diaphragmatic motion, weight loss, tumor changes, and set-up variability. These propelled the interest in proton beam therapy (PBT), which theoretically offers a reduction in the radiation exposure to healthy neighboring tissues with improvements in the therapeutic ratio. In this review, we present the role of PBT for esophageal cancer, including treatment planning, early clinical comparisons with photon-based techniques, ongoing trials, current challenges, toxicities, and issues of equity and health services.

Abstract

Early-stage esophageal cancer is often primarily managed surgically, with the addition of radiotherapy for locally advanced disease. However, current photon-based radiotherapy regimens and surgery results in a high incidence of treatment-related cardiac and pulmonary complications due to the involvement of proximal organs at risk. In addition, the anatomic location of the esophagus raises challenges for radiotherapy due to the anatomical changes associated with diaphragmatic motion, weight loss, tumor changes, and set-up variability. These challenges propelled the interest in proton beam therapy (PBT), which theoretically offers a reduction in the radiation exposure to healthy neighboring tissues with improvements in the therapeutic ratio. Several dosimetric studies support the potential advantages of PBT for esophageal cancer treatment however, translation of these results to improved clinical outcomes remains unclear with limited clinical data, especially in large populations. Studies on the effect on quality of life are likewise lacking. Here, we review the existing and emerging role of PBT for esophageal cancer, including treatment planning, early clinical comparisons of PBT with photon-based techniques, recently concluded and ongoing clinical trials, challenges and toxicities, effects on quality of life, and global inequities in the treatment of esophageal cancer.

Treatment-Related Coronary Disorders of Fluoropyrimidine Administration: A Systematic Review and Meta-Analysis

Background: Coronary disorders are recognized as the most common manifestation of fluoropyrimidine-related cardiotoxicity in clinical practice. However, there are limited and conflicting data on the incidence and profiles of fluoropyrimidine-related coronary disorders. In this meta-analysis, we aimed to systematically assess the incidence of all-grade and grade 3 or higher fluoropyrimidine-related coronary disorders, and further explore the factors that influence its occurrence.

Methods: Studies reporting the fluoropyrimidine-related coronary disorders were retrieved from a systematic search of English literature in the PubMed, Web of Science, Medline, and Cochrane database from 1 Jan 2001, to 1 Jan 2022. The NIH assessment tool was used to evaluate the quality of each study. The data of basic study characteristics, treatment details, and results of coronary toxicities were extracted. According to the results of the heterogeneity test (I² and p-value statistic), a random-effect model or fixed-effect model was selected for the pooled analysis of the incidence of adverse coronary events. Subgroup analysis was conducted to further explore the risks influencing the occurrence of fluoropyrimidine-related coronary disorders. The stability and publication bias of our results were evaluated by sensitivity analysis and Egger test, respectively.

Results: A total of 63 studies were finally included in our pooled analysis, involving 25,577 patients. The pooled cumulative incidence of all-grade and grade 3 or higher coronary disorders was 2.75% (95% CI 1.89%–3.76%) and 1.00% (95% CI 0.62%–1.47%), respectively. The coronary disorders were most reported as myocardial ischemia (1.28%, 95% CI 0.42%–2.49%) and angina/chest pain (1.1%, 95% CI 0.54%–1.81%). Subgroup analysis revealed that studies in the female-only population seemed to have a lower incidence of fluoropyrimidine-related coronary disorders. The occurrence of adverse coronary events varied among different tumor types. Patients with esophageal cancer have the highest coronary toxicity (6.32%), while those with breast cancer have a relatively lower incidence (0.5%). Coronary disorders induced by 5-FU monotherapy are more frequent than that induced by capecitabine (3.31% vs. 1.21%, p < 0.01). Fluoropyrimidine combination therapy, whether combined with other chemotherapy drugs, targeted therapy drugs, or radiotherapy, significantly increased the incidence of coronary complications (p < 0.01).

Conclusion: This meta-analysis has defined the incidence of fluoropyrimidine-related coronary disorders and depicted its epidemiological profiles for the first time, which may provide a reference for clinical practice in cancer management.

Reduction in myocardial function and oxygen consumption after chemoradiotherapy in patients with esophageal cancer

BACKGROUND

Chemoradiotherapy (CRT) may induce myocardial dysfunction, congestive heart failure, and impaired physical performance in patients with esophageal cancer (EC). We aimed to investigate left ventricular (LV) function at rest and during stress, using echocardiography (echo) and a cardiopulmonary exercise (CPX) test both before and immediately after completing CRT.

MATERIAL AND METHODS

Consecutive EC patients referred for curative treatment were enrolled. Patients attended either definitive CRT or neoadjuvant CRT with subsequent surgery. The evaluation included cardiac biomarkers, electrocardiogram, echo, and CPX test. The primary endpoint was changes in left ventricular (LV) global longitudinal strain (GLS) at rest. Secondary endpoints were LV ejection fraction (LVEF), LV diastolic function, LVEF and GLS at peak exercise, and maximal oxygen consumption (VO_2max). The trial was registered with ClinicalTrials.gov (NCT03619317).

RESULTS

Among 47 patients enrolled (94% male; median age 67 years, range 50-86 years), cardiac examinations were performed a median of three days [Interquartile range (IQR (1-5))] before CRT and one day [IQR (0-6)] after CRT. At rest, GLS and LVEF decreased, 17.6 vs. 16.4% and 56.4 vs. 55.1%, respectively (p = 0.004; p = 0.030). Furthermore, an absolute decrease of at least 5% in LVEF and 2.5% in GLS was noted in 21% of the patients. Signs of LV diastolic dysfunction increased from 13 to 21% (p = ns). VO_2max significantly decreased; 21.2 ml/kg/min vs. 18.8 ml/kg/min (p < 0.001).

CONCLUSION

LV function and physical performance decreased in EC patients after CRT, and the LV systolic reserve capacity declined. This study highlighted that EC treatment was associated with early cardiac side effects, which may have clinical and prognostic implications.

Help or hindrance: The obesity paradox in cancer treatment response

Obesity is a rising epidemic, the influence of which on cancer development, progression as well as its impact on current standard of care cancer treatments is profound with many facets. Obesity is emerging as a modulating factor in many cancer therapies, such as chemotherapy, radiotherapy, immunotherapy and combination therapies. It has been reported to diminish the efficacy of some treatments but has also been alluded to being protective in terms of reduced treatment toxicities, thus the evolution of the obesity paradox. The obese tumour microenvironment influences treatment response through modulation of a series of aspects, including altered adipocyte secretome, angiogenesis, hypoxia, fibrosis, free fatty acid uptake as well as a modulated immune landscape. However, the influence of these underlying mechanisms on cancer treatment response and the biological action of adipose tissue is still largely unknown. Elucidation of these facets may lead to the enhanced efficacy of current treatment options or the identification of novel methods to combat cancer in the obese tumour microenvironment.

Risk Factors of Fluoropyrimidine Induced Cardiotoxicity among Cancer Patients: A Systematic Review and Meta-analysis

Cancer patients experienced an increased risk of cardiotoxicity during fluoropyrimidine-based chemotherapy (5-fluorouracil or capecitabine). We searched PubMed, PsycINFO, IPA, CINAHL, Web of Science, and ClinicalTrials.gov for studies published between January 1, 1990 and December 31, 2019, in English, examining risk factors for cardiotoxicity induced by fluoropyrimidine. Included study-level data were converted to risk ratios (RRs) and pooled RRs were calculated for meta-analyses using a random-effects method. Among 690 publications identified for abstract and title screening, 22 unique studies were included in the review, and 20 had sufficient data for meta-analyses. Results indicated that patients undergoing capecitabine-based combination therapy had a higher risk than those with monotherapy (pooled RR = 1.61). Patients with pre-existing cardiac disease (pooled RR = 3.26), hypertension (pooled RR = 1.52) or smoking (pooled RR = 2.22) also had higher risks than their counterparts. Developing risk assessment tools to mitigate the risk could be a viable strategy to improve outcomes for cancer patients undergoing fluoropyrimidine-based treatments.

Review of MR-Guided Radiotherapy for Esophageal Cancer

In this review, we outline the potential benefits and the future role of MRI and MR-guided radiotherapy (MRgRT) in the management of esophageal cancer. Although not currently used in most clinical practice settings, MRI is a useful non-invasive imaging modality that provides excellent soft tissue contrast and the ability to visualize cancer physiology. Chemoradiation therapy with or without surgery is essential for the management of locally advanced esophageal cancer. MRI can help stage esophageal cancer, delineate the gross tumor volume (GTV), and assess the response to chemoradiotherapy. Integrated MRgRT systems can help overcome the challenge of esophageal motion due to respiratory motion by using real-time imaging and tumor tracking with respiratory gating. With daily on-table MRI, shifts in tumor position and tumor regression can be taken into account for online-adaptation. The combination of accurate GTV visualization, respiratory gating, and online adaptive planning, allows for tighter treatment volumes and improved sparing of the surrounding normal organs. This could lead to a reduction in radiotherapy induced cardiac toxicity, pneumonitis and post-operative complications. Tumor physiology as seen on diffusion weighted imaging or dynamic contrast enhancement can help individualize treatments based on the response to chemoradiotherapy. Patients with a complete response on MRI can be considered for organ preservation while patients with no response can be offered an earlier resection. In patients with a partial response to chemoradiotherapy, areas of residual cancer can be targeted for dose escalation. The tighter and more accurate targeting enabled with MRgRT may enable hypofractionated treatment schedules.

Computed tomography-derived myocardial extracellular volume: an early biomarker of cardiotoxicity in esophageal cancer patients undergoing radiation therapy

Objectives

We aimed to assess extracellular volume (ECV) through non-gated, contrast-enhanced computed tomography (CT) before and after radiation therapy (RT) in patients with esophageal cancer (EC).

Materials and methods

EC patients who had undergone CT before and after RT were retrospectively assessed. Patients with preexisting cardiovascular disease or with heavily artifacted CT were excluded. ECV was calculated using density values for the myocardial septum and blood pool. Data were reported as mean and standard deviation or median and interquartile range according to their distribution; t test or Wilcoxon and Pearson r or Spearman ρ were subsequently used.

Results

Twenty-one patients with stage ≥ IB EC, aged 64 ± 18 years, were included. Mean and maximum RT doses were 21.2 Gy (16.9–24.1) and 42.5 Gy (41.8–49.2), respectively. At baseline (n = 21), hematocrit was 39% ± 4%, ECV 27.9% ± 3.5%; 35 days (30–38) after RT (n = 20), hematocrit was 36% ± 4%, lower than at baseline (p = 0.002), ECV 30.3% ± 8.3%, higher than at baseline (p = 0.081); at follow-up 420 days (244–624) after RT (n = 13), hematocrit was 36% ± 5%, lower than at baseline (p = 0.030), ECV 31.4% ± 4.5%, higher than at baseline (p = 0.011). No patients showed signs of overt cardiotoxicity. ECV early after RT was moderately positively correlated with maximum RT dose (ρ = 0.50, p = 0.036).

Conclusions

In EC patients, CT-derived myocardial ECV was increased after RT and may thus appear as a potential early biomarker of cardiotoxicity.

Cardiac radiation dose predicts survival in esophageal squamous cell carcinoma treated by definitive concurrent chemotherapy and intensity modulated radiotherapy

BACKGROUND

The prognostic significance of cardiac radiation dose in esophageal cancer after definitive concurrent chemoradiotherapy (CCRT) remains largely unknown. We aimed to investigate the association between cardiac dose-volume parameters and overall survival (OS) in esophageal squamous cell carcinoma (ESCC) after definitive CCRT.

METHODS

One hundred and twenty-one ESCC patients undergoing definitive CCRT with intensity modulated radiotherapy technique between 2008 and 2018 were reviewed. Cardiac dose-volume parameters were calculated. Survival of patients and cumulative incidence of adverse events were estimated by the Kaplan-Meier method and compared between groups by the log-rank test. The prognostic significance of cardiac dose-volume parameters was determined with multivariate Cox proportional hazards regression analysis.

RESULTS

Median follow-up was 16.2 months (range, 4.3-109.3). Median OS was 18.4 months. Heart V5, V10, and V20 were independent prognostic factors of OS. Median OS was longer for patients with heart V5 ≤ 94.3% (24.7 vs. 16.3 months, p = 0.0025), heart V10 ≤ 86.4% (24.8 vs. 16.9 months, p = 0.0041), and heart V20 ≤ 76.9% (20.0 vs. 17.2 months, p = 0.047). Lower cumulative incidence of symptomatic cardiac adverse events was observed among patients with heart V5 ≤ 94.3% (p = 0.017), heart V10 ≤ 86.4% (p = 0.02), and heart V20 ≤ 76.9% (p = 0.0057). Patients without symptomatic cardiac adverse events had a higher 3-year OS rate (33.8% vs. 0%, p = 0.03).

CONCLUSIONS

Cardiac radiation dose inversely correlated with survival in ESCC after definitive CCRT. Radiation dose to the heart should be minimized.

Pericardial effusion after definitive concurrent chemotherapy and intensity modulated radiotherapy for esophageal cancer

BACKGROUND

The literature regarding pericardial effusion after definitive concurrent chemotherapy and intensity modulated radiotherapy (IMRT) for esophageal cancer was lacking. This study aimed to investigate the risk factors of pericardial effusion in esophageal cancer patients undergoing definitive concurrent chemotherapy and IMRT.

METHODS

A total of 126 consecutive esophageal cancer patients treated with definitive concurrent chemotherapy and IMRT between 2008 and 2018 were reviewed. The pericardial effusion was determined on computed tomography scan of the chest and graded by the Common Terminology Criteria for Adverse Events, version 4.0. The cumulative incidence of pericardial effusion was estimated by the Kaplan-Meier method and compared between groups by the log-rank test. The risk factors of pericardial effusion were determined with multivariate Cox proportional hazards regression analysis.

RESULTS

The median follow-up time was 14.0 months. Thirty-seven (29.4%) patients had pericardial effusion after a median interval of 6.6 months since the end of IMRT. The cumulative incidence of pericardial effusion of any grade was higher in patients with mean heart dose > 23.45 Gy (p = 0.00018), heart V30 > 33.55% (p = 0.00015), mean pericardium dose > 20.33 Gy (p = 0.00027), and pericardium V20 > 42.55% (p = 0.00018). Furthermore, eight (6.3%) patients had symptoms related to pericardial effusion and were considered as cases with pericardial effusion ≥ grade 3. The cumulative incidence of pericardial effusion ≥ grade 3 was higher in patients with pericardium V30 > 65.80% (p = 0.00028), V40 > 55.35% (p < 0.0001), and V60 > 24.70% (p = 0.0021). Multivariate analyses showed the above dose-volume parameters predicted the risk of pericardial effusion in esophageal cancer.

CONCLUSIONS

Dose-volume parameters predicting the risk of pericardial effusion were identified in esophageal cancer treated with definitive concurrent chemotherapy and IMRT. They could be applied as constraints of IMRT for esophageal cancer.

Cardiotoxicity of radiation therapy in esophageal cancer

With a development of radiotherapeutic techniques, availability of radiotherapy data on cardiotoxicity, and slowly improving esophageal cancer outcomes, an increasing emphasis is placed on the heart protection in radiation treated esophageal cancer patients. Radiation induced heart complications encompass mainly pericardial disease, cardiomyopathy, coronary artery atherosclerosis, valvular heart disease, and arrhythmias. The most frequent toxicity is pericardial effusion which is usually asymptomatic in the majority of patients. The use of modern radiotherapy techniques is expected to reduce the risk of cardiotoxicity, although this expectation has to be confirmed by clinical data.