Cardiotoxicity of breast cancer radiotherapy - overview of current results

Clinical benefits of deep inspiration breath-hold in postoperative radiotherapy for right-sided breast cancer: a meta-analysis

OBJECTIVES

The study aims to emphasize the clinical importance of the Deep Inspiration Breath Hold (DIBH) technique by quantifying its dosimetric advantages over Free Breathing (FB) in reducing radiation exposure to the heart, liver, and lungs for right-sided breast cancer patients. This evidence supports its potential for routine clinical use to mitigate radiation-induced toxicity.

METHODS

A systematic retrieval of controlled trials comparing DIBH and FB techniques in postoperative radiotherapy for right-sided breast cancer was conducted utilizing the PubMed, Embase, Cochrane Library, and Web of Science databases. The primary outcomes assessed included the doses of adjacent normal tissues (heart, liver, and lungs). Summary standardized mean differences (SMD) along with 95% confidence intervals (CI) were computed, respectively. StataMP 17 software was selected to perform data analysis.

RESULTS

The study encompassed an analysis of 313 patients derived from seven online studies, comprising 168 individuals in the DIBH group and 269 individuals in the FB group. The findings indicated that the DIBH group received significantly lower irradiation doses to the heart, liver, and lungs in comparison to the FB group, with statistical significance (heart dose: SMD = -0.63, 95% CI -0.85 to -0.41, P < 0.05; liver dose: SMD = -1.15, 95% CI -1.91 to -0.38, P < 0.05; lung dose: SMD = -0.79, 95% CI -1.23 to -0.35, P < 0.05).

CONCLUSION

This meta-analysis indicated that the application of DIBH during postoperative radiotherapy for right-sided breast cancer markedly decreases radiation exposure to the heart, liver, and lungs, while maintaining consistent tumor dose coverage.

CLINICAL TRIAL NUMBER

Not applicable.

Impact of Proton Irradiation Depending on Breast Cancer Subtype in Patient-Derived Cell Lines

Research on different types of ionizing radiation's effects has been ongoing for years, revealing its efficacy in damaging cancer cells. Solid tumors comprise diverse cell types, each being able to respond differently to radiation. This study evaluated the radiobiological response of established (MDA-MB-231 (Triple negative breast cancer, TNBC), MCF-7 (Luminal A)) and patient-derived malignant cell lines, cancer-associated fibroblasts, and skin fibroblasts following proton IRR. All cell line types were irradiated with the proton dose of 2, 4, and 6 Gy. The radiobiological response was assessed using clonogenic assay, γH2AX, and p53 staining. It was noticeable that breast cancer lines of different molecular subtypes displayed no significant variations in their response to proton IRR. In terms of cancer-associated fibroblasts extracted from the tumor tissue, the line derived from a TNBC subtype tumor demonstrated higher resistance to ionizing radiation compared to lines isolated from luminal A tumors. Fibroblasts extracted from patients' skin responded identically to all doses of proton radiation. This study emphasizes that tumor response is not exclusively determined by the elimination of breast cancer cells, but also takes into account tumor microenvironmental variables and skin reactions.

Targeting interleukin-17 in radiation-induced toxicity and cancer progression

Recent strategies to combine chemoradiation with immunotherapy to treat locally advanced lung cancer have improved five-year survival outcomes. However, collateral toxicity to healthy lungs, esophagus, cardiac, and vascular tissue continues to limit the effectiveness of curative-intent thoracic radiation (tRT). It is necessary to gain a deeper comprehension of the fundamental mechanisms underlying inflammation-mediated radiation-induced damage to normal cells. Several cells have been linked in published studies to the release of cytokines and chemokines after radiation therapy. Several inflammatory mediators, such as IL-1, IL-6, TNF-α, and TGF-β, also cause the production of Interleukin-17 (IL-17), a cytokine that is essential for maintaining immunological homeostasis and plays a role in the toxicity caused by radiation therapy. However, currently, the role of IL-17 in RT-induced toxicity in conjunction with cancer progression remains poorly understood. This review provides an overview of the most recent data from the literature implicating IL-17 in radiation-mediated tissue injuries and the efficacy of tRT in lung cancer, as well as its potential as a therapeutic target for interventions to reduce the side effects of tRT with curative intent and to boost an anti-tumor immune response to improve treatment outcomes. IL-17 may also act as a biomarker for predicting the effectiveness of a given treatment as well as the toxicity caused by tRT.

Recent death early warning value of ECG changes in patients with NSCLC

We aimed to explore the predictive value of abnormal electrocardiogram (ECG) changes in non-small-cell lung carcinoma non-small cell lung cancer (NSCLC) patients for near-term mortality. Seventy-eight NSCLC patients hospitalized in Chaohu Hospital Affiliated to Anhui Medical University from October 2017 to August 2021 were selected as the observation group. Baseline medical history and type of ECG abnormalities were the same. Seventy-eight patients were included in the control group. To compare the difference in mortality within 3 months between the observation group and the control group after the occurrence of the same type of electrocardiogram abnormalities, and to explore the value of electrocardiogram abnormalities in the early warning of NSCLC patients recent death. When the average ventricular rate of patients in the observation group was ≥100 beats/minute, ST-segment depression ≥0.05 mm, QRS voltage decrease ≥0.5 mm, new atrial fibrillation and other electrocardiogram changes, all patients died within 3 months. The control group with the same abnormal ECG had no death within 3 months (P < .05). In the resting 12-lead synchronous ECG in NSCLC patients, when the average ventricular rate ≥100 beats/minute, QRS wave voltage significantly decreased ≥0.5 mm, ST segment depression ≥0.05 mm, new atrial fibrillation appeared, it suggested that the patients' cardiac function decreased and the potential for near-term adverse outcomes is high.

Performance of physical, cardiovascular, and psychological functions in middle-aged women with and without breast cancer

PURPOSE

To compare the physical performance, including upper-limb motor and cardiovascular functions, and psychological functions, including anxiety and depression, sleep, and fatigue, between women with and without breast cancer.

METHODS

Thirty-two women with breast cancer and 32 healthy counterparts were recruited for the study. Upper-limb muscle strength, shoulder range of motion, and upper-limb function were assessed using a handheld dynamometer, a goniometer, and the short form of the Disabilities of Arm-Shoulder-Hand Questionnaire, respectively. Exercise endurance and cardiovascular functions were assessed using the 6-min walk test and blood pressure and heart rate variability, respectively. The Hospital Anxiety and Depression Scale, the Pittsburgh Sleep Quality Index, and the Fatigue Assessment Scale were used to assess the symptoms of anxiety and depression, sleep quality, and fatigue, respectively.

RESULTS

Breast cancer participants' body-weight-adjusted upper-limb strength of both the affected and unaffected sides (0.11-0.14) was only 61.1-77.8% of those of the healthy participants (0.18). Their shoulder mobility of the affected side (flexion: 161.64°; abduction: 157.01°) were 94.2% (flexion) and 92.5% (abduction) of those of the healthy participants (flexion: 171.56°; abduction: 169.68°), respectively. Breast cancer participants had higher quickDASH mean score (19.53), HADS-A mean score (6.78), HADS-D mean score (4.72), global PSQI mean score (7.22) and FAS mean score (25.97) as well as shorter mean distance covered by 6 MWT (496.66 m) than those of the healthy participants.

CONCLUSIONS

Rehabilitative interventions, such as mind-body interventions and exercise training, target physical fitness and promote the psychological health of women with breast cancer are necessary.

Breast cancer treatment planning using a novel spherical fuzzy CRITIC-REGIME

Breast cancer is the leading cause of cancer-related deaths, and choosing a suitable treatment plan for this disease has proved difficult for oncologists owing to the variety of criteria and alternatives that must be considered during the decision-making process. Since prospective treatment options influence patients’ health-related quality of life in a variety of ways, a methodology that can completely and objectively evaluate alternative treatments has become an essential issue. This paper proposes a novel multi-criteria decision-making (MCDM) methodology by integrating the CRiteria Importance Through Intercriteria Correlation (CRITIC) and the REGIME techniques and handles the problem of breast cancer treatment selection problem. CRITIC enables the determination of objective criterion weights based on the decision matrix, while REGIME ranks the options without the need for lengthy computations or normalization procedures. The suggested methodology is demonstrated in a spherical fuzzy atmosphere, which allows decision experts to independently express their degrees of membership, non-membership, and hesitancy in a broad three-dimensional spherical space. In the numerical example provided, three oncologists evaluate four breast cancer treatment alternatives, namely, surgery, radiotherapy, chemotherapy, and hormone therapy, with respect to five criteria, which are disease or tumor type, stage of disease, patient type, side effects, and financial status of the patient. The tumor type is determined to be the most important assessment criterion, and surgery is selected as the best course of action. The stability and validity of the proposed methodology are verified through sensitivity and comparative studies. The discussions, limitations, and future research avenues are also given within the study.

Cardiac late effects after modern 3D-conformal radiotherapy in breast cancer patients: a retrospective cohort study in Germany (ESCaRa)

PURPOSE

Radiotherapy (RT) was identified as a risk factor for long-term cardiac effects in breast cancer patients treated until the 1990s. However, modern techniques reduce radiation exposure of the heart, but some exposure remains unavoidable. In a retrospective cohort study, we investigated cardiac mortality and morbidity of breast cancer survivors treated with recent RT in Germany.

METHODS

A total of 11,982 breast cancer patients treated between 1998 and 2008 were included. A mortality follow-up was conducted until 06/2018. In order to assess cardiac morbidity occurring after breast cancer treatment, a questionnaire was sent out in 2014 and 2019. The effect of breast cancer laterality on cardiac mortality and morbidity was investigated as a proxy for radiation exposure. We used Cox Proportional Hazards regression analysis, taking potential confounders into account.

RESULTS

After a median follow-up time of 11.1 years, there was no significant association of tumor laterality with cardiac mortality in irradiated patients (hazard ratio (HR) for left-sided versus right-sided tumor 1.09; 95% confidence interval (CI) 0.85-1.41). Furthermore, tumor laterality was not identified as a significant risk factor for cardiac morbidity (HR = 1.05; 95%CI 0.88-1.25).

CONCLUSIONS

Even though RT for left-sided breast cancer on average incurs higher radiation dose to the heart than RT for right-sided tumors, we found no evidence that laterality is a strong risk factor for cardiac disease after contemporary RT. However, larger sample sizes, longer follow-up, detailed information on individual risk factors and heart dose are needed to assess clinically manifest late effects of current cancer therapy.

Application of an automatic segmentation method for evaluating cardiac structure doses received by breast radiotherapy patients

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Atlas-based method for contouring heart substructures on breast radiotherapy CT.

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Excellent agreement between automatic and manual contours for most patients.

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Dice similarity coefficient for LAD was low (0.06) because a narrow, long structure.

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Doses derived from automatic and manual contours agree within observer variability.

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For left breast treatment, right ventricle and LAD dose most senstive to contour shift.

Background and purpose

Quantifying radiation dose to cardiac substructures is important for research on the etiology and prevention of complications following radiotherapy; however, segmentation of substructures is challenging. In this study we demonstrate the application of our atlas-based automatic segmentation method to breast cancer radiotherapy plans for generating radiation doses in support of late effects research.

Material and methods

We applied our segmentation method to contour heart substructures on the computed tomography (CT) images of 70 breast cancer patients who received external photon radiotherapy. Two cardiologists provided manual segmentation of the whole heart (WH), left/right atria, left/right ventricles, and left anterior descending artery (LAD). The automatically contours were compared with manual delineations to evaluate similarity in terms of geometry and dose.

Results

The mean Dice similarity coefficient between manual and automatic segmentations was 0.96 for the WH, 0.65 to 0.82 for the atria and ventricles, and 0.06 for the LAD. The mean average surface distance was 1.2 mm for the WH, 3.4 to 4.1 mm for the atria and ventricles, and 6.4 mm for the LAD. We found the dose to the cardiac substructures based on our automatic segmentation agrees with manual segmentation within expected observer variability. For left breast patients, the mean absolute difference in mean dose was 0.1 Gy for the WH, 0.2 to 0.7 Gy for the atria and ventricles, and 1.8 Gy for the LAD. For right breast patients, these values were 0.0 Gy, 0.1 to 0.4 Gy, and 0.4 Gy, respectively.

Conclusion

Our automatic segmentation method will facilitate the development of radiotherapy prescriptive criteria for mitigating cardiovascular complications.

Future Perspectives of Proton Therapy in Minimizing the Toxicity of Breast Cancer Radiotherapy

The toxicity of radiotherapy is a key issue when analyzing the eligibility criteria for patients with breast cancer. In order to obtain better results, proton therapy is proposed because of the more favorable distribution of the dose in the patient’s body compared with photon radiotherapy. Scientific groups have conducted extensive research into the improved efficacy and lower toxicity of proton therapy for breast cancer. Unfortunately, there is no complete insight into the potential reasons and prospects for avoiding undesirable results. Cardiotoxicity is considered challenging; however, researchers have not presented any realistic prospects for preventing them. We compared the clinical evidence collected over the last 20 years, providing the rationale for the consideration of proton therapy as an effective solution to reduce cardiotoxicity. We analyzed the parameters of the dose distribution (mean dose, Dmax, V5, and V20) in organs at risk, such as the heart, blood vessels, and lungs, using the following two irradiation techniques: whole breast irradiation and accelerated partial breast irradiation. Moreover, we presented the possible causes of side effects, taking into account biological and technical issues. Finally, we collected potential improvements in higher quality predictions of toxic cardiac effects, like biomarkers, and model-based approaches to give the full background of this complex issue.

Deep inspiration breath hold reduces the mean heart dose in left breast cancer radiotherapy

Background

Patients with left breast cancer who undergo radiotherapy have a non-negligible risk of developing radiation-induced cardiovascular disease (CVD). Cardioprotection can be achieved through better treatment planning protocols and through respiratory gating techniques, including deep inspiration breath hold (DIBH). Several dosimetric studies have shown that DIBH reduces the cardiac dose, but clinical data confirming this effect is limited. The aim of the study was to compare the mean heart dose (MHD) in patients with left breast cancer who underwent radiotherapy at our institution as we transitioned from non-gated free-breathing (FB) radiotherapy to gated radiotherapy (FB-GRT), and finally to DIBH.

Patients and methods

Retrospective study involving 2022 breast cancer patients who underwent radiotherapy at West Pomeranian Oncology Center in Szczecin from January 1, 2014 through December 31, 2017. We compared the MHD in these patients according to year of treatment and technique.

Results

Overall, the MHD for patients with left breast cancer in our cohort was 3.37 Gy. MHD values in the patients treated with DIBH were significantly lower than in patients treated with non-gated FB (2.1 vs. 3.48 Gy, p < 0.0001) and gated FB (3.28 Gy, p < 0.0001). The lowest MHD values over the four-year period were observed in 2017, when nearly 85% of left breast cancer patients were treated with DIBH. The proportion of patients exposed to high (> 4 Gy) MHD values decreased every year, from 40% in 2014 to 7.9% in 2017, while the percentage of patients receiving DIBH increased.

Conclusions

Compared to free-breathing techniques (both gated and non-gated), DIBH reduces the mean radiation dose to the heart in patients with left breast cancer. These findings support the use of DIBH in patients with left breast cancer treated with radiotherapy.

Cardiovascular Disease Amongst Women Treated for Breast Cancer: Traditional Cytotoxic Chemotherapy, Targeted Therapy, and Radiation Therapy

PURPOSE OF REVIEW

Cardiotoxicity can occur acutely during breast cancer treatment and impact the potential for the intended cancer treatment regime to be completed, or as a late effect affecting cancer survivorship. Indeed, the most common cause of mortality in females with early breast cancer is cardiovascular disease, especially in those over the age of 65. Optimal cancer care therefore needs to be delivered without jeopardising cardiovascular health. Understanding the different cardiotoxicities associated with breast cancer treatment is vital to this approach, and therefore, this article seeks to provide an overview of this.

RECENT FINDINGS

Tyrosine kinase inhibitors targeting human epidermal growth factor receptor (HER)-2, immune checkpoint inhibitors (ICI), and cyclin-dependent kinase (CDK) inhibitors are new targeted breast cancer treatments. In particular, ICI are associated with myocarditis that carries a significant mortality, whilst the CDK inhibitor ribociclib causes QT prolongation that requires cardiac surveillance and appropriate dose adjustment to prevent ventricular arrhythmias. The need has always been for strategies to mitigate the risks of cardiovascular toxicities, and new data is promising for the use of dexrazoxane in anthracyclines, and the role of beta blockers and angiotensin converting enzymes inhibitors in anthracyclines and HER-2 monoclonal antibodies such as trastuzumab. Significant headways in breast cancer treatment have resulted in reductions in disease recurrence and mortality, but cardiovascular complications continue to impact the ability to deliver some of these cancer treatments, and the period of cancer survivorship.

Harnessing genome-wide association studies to minimize adverse radiation-induced side effects

Radiotherapy is used as definitive treatment in approximately two-thirds of all cancers. However, like any treatment, radiation has significant acute and long-term side effects including secondary malignancies. Even when similar radiation parameters are used, 5%–10% of patients will experience adverse radiation side effects. Genomic susceptibility is thought to be responsible for approximately 40% of the clinical variability observed. In the era of precision medicine, the link between genetic susceptibility and radiation-induced side effects is further strengthening. Genome-wide association studies (GWAS) have begun to identify single-nucleotide polymorphisms (SNPs) attributed to overall and tissue-specific toxicity following radiation for treatment of breast cancer, prostate cancer, and other cancers. Here, we review the use of GWAS in identifying polymorphisms that are predictive of acute and long-term radiation-induced side effects with a focus on chest, pelvic, and head-and-neck irradiation. Integration of GWAS with “omic” data, patient characteristics, and clinical correlates into predictive models could decrease radiation-induced side effects while increasing therapeutic efficacy.