Favourable and unfavourable effects on long-term survival of radiotherapy for early breast cancer: an overview of the randomised trials

New paradigms to break barriers in early cancer detection for improved prognosis and treatment outcomes

The uncontrolled growth and spread of cancerous cells beyond their usual boundaries into surrounding tissues characterizes cancer. In developed countries, cancer is the leading cause of death, while in underdeveloped nations, it ranks second. Using existing cancer diagnostic tools has increased early detection rates, which is crucial for effective cancer treatment. In recent decades, there has been significant progress in cancer-specific survival rates owing to advances in cancer detection and treatment. The ability to accurately identify precursor lesions is a crucial aspect of effective cancer screening programs, as it enables early treatment initiation, leading to lower long-term incidence of invasive cancer and improved overall prognosis. However, these diagnostic methods have limitations, such as high costs and technical challenges, which can make accurate diagnosis of certain deep-seated tumors difficult. To achieve accurate cancer diagnosis and prognosis, it is essential to continue developing cutting-edge technologies in molecular biology and cancer imaging.

Assessment of Postmastectomy Radiation Therapy Receipt by Age and Association With Outcomes in Women With Breast Cancer

PURPOSE

Postmastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) and improves overall survival (OS) in patients with breast cancer. Young age has been recognized as a risk factor for LRR. The primary objective of this study was to determine if recommendations for PMRT differed among patients younger than 50 years as compared to women aged 50 years or older.

METHODS

We reviewed medical records of patients with breast cancer who underwent mastectomy with or without PMRT from 2010 through 2018. Univariable and multivariable models were used to estimate the association of age with PMRT.

RESULTS

Of 2471 patients, 839 (34%) were <50 years; 1632 (66%) were ≥50 years. Patients <50 years had a higher percentage of grade 3 tumors, hormone receptor (HR) negative and/or Her-2/neu positive tumors, clinical stage T2/T3 tumors, and nodal involvement. Compared with patients ≥50 years, patients <50 years were more likely to undergo PMRT (OR 1.57; P = .001) and regional node irradiation (RNI) to the internal mammary nodes. Advanced clinical and pathologic stage, invasive tumor histology, the presence of lymphovascular invasion, and treatment with systemic chemotherapy were predictors of PMRT receipt for patients <50 years (P < .05). PMRT was associated with improved OS and recurrence free survival (RFS) among all patients (P < .01).

CONCLUSION

Patients <50 years were more likely to undergo PMRT and to receive RNI to the internal mammary nodes but were also more likely to have other risk factors for recurrence that would warrant a PMRT recommendation. PMRT improved OS and RFS for all patients.

Competing risk analysis of cardiovascular disease risk in breast cancer patients receiving a radiation boost

BACKGROUND

Thoracic radiotherapy may damage the myocardium and arteries, increasing cardiovascular disease (CVD) risk. Women with a high local breast cancer (BC) recurrence risk may receive an additional radiation boost to the tumor bed.

OBJECTIVE

We aimed to evaluate the CVD risk and specifically ischemic heart disease (IHD) in BC patients treated with a radiation boost, and investigated whether this was modified by age.

METHODS

We identified 5260 BC patients receiving radiotherapy between 2005 and 2016 without a history of CVD. Boost data were derived from hospital records and the national cancer registry. Follow-up data on CVD events were obtained from Statistics Netherlands until December 31, 2018. The relation between CVD and boost was evaluated with competing risk survival analysis.

RESULTS

1917 (36.4%) received a boost. Mean follow-up was 80.3 months (SD37.1) and the mean age 57.8 years (SD10.7). Interaction between boost and age was observed for IHD: a boost was significantly associated with IHD incidence in patients younger than 40 years but not in patients over 40 years. The subdistribution hazard ratio (sHR) was calculated for ages from 25 to 75 years, showing a sHR range from 5.1 (95%CI 1.2-22.6) for 25-year old patients to sHR 0.5 (95%CI 0.2-1.02) for 75-year old patients.

CONCLUSION

In patients younger than 40, a radiation boost is significantly associated with an increased risk of CVD. In absolute terms, the increased risk was low. In older patients, there was no association between boost and CVD risk, which is likely a reflection of appropriate patient selection.

Omission of radiation therapy post breast conserving surgery

Radiation therapy (RT) after breast conserving surgery decreases the risks of local recurrence and breast cancer mortality in the multidisciplinary management of patients with breast cancer. However, breast cancer is a heterogeneous disease, and the absolute benefit of post-operative RT in individual patients varies substantially. Clinical trials aiming to identify patients with low-risk early breast cancer in whom post-operative RT may be safely omitted, based on conventional clinical-pathologic variables alone, have not provided sufficiently tailored information on local recurrence risk assessment to guide treatment decisions. The majority of patients with early breast cancer continue to be routinely treated with RT after breast conserving surgery. This approach may represent over-treatment for a substantial proportion of the patients. The clinical impact of genomic signatures on local therapy decisions for early breast cancer has been remarkably modest due to the lack of high-level evidence supporting their clinical validity for assessment of the risk of local recurrence. Efforts to personalise breast cancer care must be supported by high level evidence to enable balanced, informed treatment decisions. These considerations underpin the importance of ongoing biomarker-directed clinical trials to generate the high-level evidence necessary for setting the future standard of care in personalised local therapy for patients with early breast cancer.

Chronic inflammatory effects of in vivo irradiation of the murine heart on endothelial cells mimic mechanisms involved in atherosclerosis

PURPOSE

Radiotherapy is a major pillar in the treatment of solid tumors including breast cancer. However, epidemiological studies have revealed an increase in cardiac diseases approximately a decade after exposure of the thorax to ionizing irradiation, which might be related to vascular inflammation. Therefore, chronic inflammatory effects were examined in primary heart and lung endothelial cells (ECs) of mice after local heart irradiation.

METHODS

Long-lasting effects on primary ECs of the heart and lung were studied 20-50 weeks after local irradiation of the heart of mice (8 and 16 Gy) in vivo by multiparameter flow cytometry using antibodies directed against cell surface markers related to proliferation, stemness, lipid metabolism, and inflammation, and compared to those induced by occlusion of the left anterior descending coronary artery.

RESULTS

In vivo irradiation of the complete heart caused long-lasting persistent upregulation of inflammatory (HCAM, ICAM‑1, VCAM-1), proliferation (CD105), and lipid (CD36) markers on primary heart ECs and an upregulation of ICAM‑1 and VCAM‑1 on primary ECs of the partially irradiated lung lobe. An artificially induced heart infarction induces similar effects with respect to inflammatory markers, albeit in a shorter time period.

CONCLUSION

The long-lasting upregulation of prominent inflammatory markers on primary heart and lung ECs suggests that local heart irradiation induces chronic inflammation in the microvasculature of the heart and partially irradiated lung that leads to cardiac injury which might be related to altered lipid metabolism in the heart.

Breast Cancer: An Overview of Current Therapeutic Strategies, Challenge, and Perspectives

Breast cancer is the most commonly diagnosed cancer and the leading cause of death among female patients, which seriously threatens the health of women in the whole world. The treatments of breast cancer require the cooperation of a multidisciplinary setting and taking tumor load and molecular makers into account. For early breast cancer, breast-conserving surgery with radiotherapy or mastectomy alone remains the standard management, and the administration of adjuvant systemic therapy is decided by the status of lymph nodes, hormone receptors, and human epidermal growth factor receptor-2. For metastatic breast cancer, the goal of treatments is to prolong survival and maintain quality of life. This review will present the current advances and controversies of surgery, chemotherapy, radiotherapy, endocrine therapy, targeted therapy, immunotherapy, gene therapy, and other innovative treatment strategies in early-stage and metastatic breast cancer.

Recent advances progress in radiotherapy for breast cancer after breast-conserving surgery: a review

Adjuvant radiotherapy after breast-conserving surgery has become an integral part of the treatment of breast cancer. In recent years, the development of radiotherapy technology has made great progress in this field, including the comparison of the curative effects of various radiotherapy techniques and the performance of the segmentation times. The choice of radiotherapy technology needs to be co-determined by clinical evidence practice and evaluated for each individual patient to achieve precision radiotherapy. This article discusses the treatment effects of different radiotherapy, techniques, the risk of second cancers and short-range radiation therapy techniques after breast-conserving surgery such as hypo fractionated whole breast irradiation and accelerated partial breast irradiation. The choice of radiotherapy regimen needs to be based on the individual condition of the patient, and the general principle is to focus on the target area and reduce the irradiation of the normal tissues and organs. Short-range radiotherapy and hypofractionated are superior to conventional radiotherapy and are expected to become the mainstream treatment after breast-conserving surgery.

Noncancer Effects of Ionizing Radiation Exposure on the Eye, the Circulatory System and beyond: Developments made since the 2011 ICRP Statement on Tissue Reactions

For radiation protection purposes, noncancer effects with a threshold-type dose-response relationship have been classified as tissue reactions (formerly called nonstochastic or deterministic effects), and equivalent dose limits aim to prevent occurrence of such tissue reactions. Accumulating evidence demonstrates increased risks for several late occurring noncancer effects at doses and dose rates much lower than previously considered. In 2011, the International Commission on Radiological Protection (ICRP) issued a statement on tissue reactions to recommend a threshold of 0.5 Gy to the lens of the eye for cataracts and to the heart and brain for diseases of the circulatory system (DCS), independent of dose rate. Literature published thereafter continues to provide updated knowledge. Increased risks for cataracts below 0.5 Gy have been reported in several cohorts (e.g., including in those receiving protracted or chronic exposures). A dose threshold for cataracts is less evident with longer follow-up, with limited evidence available for risk of cataract removal surgery. There is emerging evidence for risk of normal-tension glaucoma and diabetic retinopathy, but the long-held tenet that the lens represents among the most radiosensitive tissues in the eye and in the body seems to remain unchanged. For DCS, increased risks have been reported in various cohorts, but the existence or otherwise of a dose threshold is unclear. The level of risk is less uncertain at lower dose and lower dose rate, with the possibility that risk per unit dose is greater at lower doses and dose rates. Target organs and tissues for DCS are also unknown, but may include heart, large blood vessels and kidneys. Identification of potential factors (e.g., sex, age, lifestyle factors, coexposures, comorbidities, genetics and epigenetics) that may modify radiation risk of cataracts and DCS would be important. Other noncancer effects on the radar include neurological effects (e.g., Parkinson's disease, Alzheimer's disease and dementia) of which elevated risk has increasingly been reported. These late occurring noncancer effects tend to deviate from the definition of tissue reactions, necessitating more scientific developments to reconsider the radiation effect classification system and risk management. This paper gives an overview of historical developments made in ICRP prior to the 2011 statement and an update on relevant developments made since the 2011 ICRP statement.

Post-mastectomy radiotherapy for women with early breast cancer and one to three positive lymph nodes

BACKGROUND

Continual improvement in adjuvant therapies has resulted in a better prognosis for women diagnosed with breast cancer. A surrogate marker used to detect the spread of disease after treatment of breast cancer is local and regional recurrence. The risk of local and regional recurrence after mastectomy increases with the number of axillary lymph nodes affected by cancer. There is a consensus to use radiotherapy as an adjuvant treatment after mastectomy (postmastectomy radiotherapy (PMRT)) in women diagnosed with breast cancer and found to have disease in four or more positive axillary lymph nodes. Despite data showing almost double the risk of local and regional recurrence in women treated with mastectomy and found to have one to three positive lymph nodes, there is a lack of international consensus on the use of PMRT in this group.

OBJECTIVES

To assess the effects of PMRT in women diagnosed with early breast cancer and found to have one to three positive axillary lymph nodes.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov up to 24 September 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs). The inclusion criteria included women diagnosed with breast cancer treated with simple or modified radical mastectomy and axillary surgery (sentinel lymph node biopsy (SLNB) alone or those undergoing axillary lymph node clearance with or without prior SLNB). We included only women receiving PMRT using X-rays (electron and photon radiation), and we defined the radiotherapy dose to reflect what is currently being recommended (i.e. 40 Gray (Gy) to 50 Gy in 15 to 25/28 fractions in 3 to 5 weeks. The included studies did not administer any boost to the tumour bed. In this review, we excluded studies using neoadjuvant chemotherapy as a supportive treatment before surgery.

DATA COLLECTION AND ANALYSIS

We used Covidence to screen records. We collected data on tumour characteristics, adjuvant treatments and the outcomes of local and regional recurrence, overall survival, disease-free survival, time to progression, short- and long-term adverse events and quality of life. We reported on time-to-event outcome measures using the hazard ratio (HR) and subdistribution HR. We used Cochrane's risk of bias tool (RoB 1), and we presented overall certainty of the evidence using the GRADE approach.

MAIN RESULTS

The RCTs included in this review were subgroup analyses of original RCTs conducted in the 1980s to assess the effectiveness of PMRT. Hence, the type and duration of adjuvant systemic treatments used in the studies included in this review were suboptimal compared to the current standard of care. The review involved three RCTs with a total of 829 women diagnosed with breast cancer and low-volume axillary disease. Amongst the included studies, only a single study pertained to the modern-day radiotherapy practice. The results from this one study showed a reduction of local and regional recurrence (HR 0.20, 95% confidence interval (CI) 0.13 to 0.33, 1 study, 522 women; low-certainty evidence) and improvement in overall survival with PMRT (HR 0.76, 95% CI 0.60 to 0.97, 1 study, 522 women; moderate-certainty evidence). One of the other studies using radiotherapy techniques that do not reflect modern-day practice reported on disease-free survival in women with low-volume axillary disease (subdistribution HR 0.63, 95% CI 0.41 to 0.96, 1 study, 173 women). None of the included studies reported on PMRT side effects or quality-of-life outcome measures.

AUTHORS' CONCLUSIONS

Based on one study, the use of PMRT in women diagnosed with breast cancer and low-volume axillary disease indicated a reduction in locoregional recurrence and an improvement in survival. There is a need for more research to be conducted using modern-day radiotherapy equipment and methods to support and supplement the review findings.

A comparison of cardiovascular and pulmonary morbidities and risk factors in breast cancer survivors compared to an age-matched female control group in the Lifelines prospective population cohort

PURPOSE

To provide more insight into late treatment-related toxicities among breast cancer (BC) survivors by comparing morbidities and risk factors between BC survivors and age-matched controls.

MATERIALS AND METHODS

All female participants diagnosed with BC before inclusion in Lifelines, a population-based cohort in the Netherlands, were selected and matched 1:4 to female controls without any oncological history on birth year. Baseline was defined as the age at BC diagnosis. Outcomes were obtained from questionnaires and functional analyses performed at entry to Lifelines (follow-up 1; FU1) and several years later (FU2). Cardiovascular and pulmonary events were defined as morbidities that were absent at baseline but present at FU1 or FU2.

RESULTS

The study consisted of 1,325 BC survivors and 5,300 controls. The median period from baseline (i.e., BC treatment) to FU1 and FU2 was 7 and 10 years, respectively. Among BC survivors more events of heart failure (OR: 1.72 [1.10-2.68]) and less events of hypertension (OR: 0.79 [0.66-0.94]) were observed. At FU2, more electrocardiographic abnormalities were found among BC survivors compared to controls (4.1% vs. 2.7%, respectively; p = 0.027) and Framingham scores for the 10-year risk of coronary heart disease were lower (difference: 0.37%; 95% CI [-0.70 to -0.03%]). At FU2, BC survivors had more frequently a forced vital capacity below the lower limit of normal than controls (5.4% vs. 2.9%, respectively; p = 0.040).

CONCLUSION

BC survivors are at risk of late treatment-related toxicities despite a more favourable cardiovascular risk profile compared to age-matched female controls.

Impact of de-escalating systemic therapy guided by 21-gene assay on locoregional recurrence after partial-breast irradiation

PURPOSE

Partial-breast irradiation (PBI) has been performed as alternative to whole-breast irradiation (WBI) in breast-conserving therapy (BCT). Recently, the 21-gene recurrence score (RS) was introduced to determine the adjuvant therapy for estrogen receptor (ER)-positive, and human epidermal growth factor receptor 2 (HER2)-negative diseases. However, the impact of RS-based systemic therapy on locoregional recurrence (LRR) following BCT with PBI remains uninvestigated.

METHODS AND MATERIALS

Patients with ER-positive, HER2-negative, and node-negative breast cancer who underwent BCT with PBI were examined during May 2012-March 2022. In addition to immunohistochemistry (IHC), RS was available to decide on adjuvant therapy.

RESULTS

In total, 431 patients were evaluated with a median followup of 48.6 months. The 4-year LRR-free survival rates were 97.3% and 96.4% in the IHC and RS cohorts, respectively (p = 0.50). Ki67 of >20% was significantly associated with LRR in the multivariate analysis (HR 4.39, p < 0.05). For patients with Ki67 > 20%, 29 of 71 (40.8%) and 46 of 59 (78.0%) patients received only endocrine therapy in the IHC and RS cohorts, respectively (p < 0.0001). For patients with Ki67 >20% who received only endocrine therapy, the 4-year LRR-free survival rates were 91.8% in the IHC cohort and 94.6% in the RS cohort (p = 0.29) CONCLUSIONS: Although the introduction of RS increased the number of patients receiving endocrine therapy alone for Ki67 >20% of disease by two times, the LRR-free survival after BCT with PBI could be maintained. However, further studies from multiple institutions with longer followup data are required.

Cardiac dose in the treatment of synchronous bilateral breast cancer patients between three different radiotherapy techniques (VMAT, IMRT, and 3D CRT)

PURPOSE

Synchronous bilateral irradiation of both mammary glands and chest wall is a challenging task due to technical difficulties and limited evidence supporting an optimal technique to improve treatment outcomes. We studied and compared the dosimetry data of three radiotherapy techniques to select the most optimal one.

METHODS

We compared three-dimensional conformal radiation treatment (3D CRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT) during irradiation of synchronous bilateral breast cancer in nine patients followed by examination of dose distribution to the cardiac conduction system (SA node, AV node and Bundle of His), myocardium, lungs, left anterior descending artery (LADA) and right coronary artery (RCA) .

RESULTS

VMAT is the most sparing technique for SBBC treatment. Even though doses to the SA node, AV node and Bundle of His were higher with VMAT (D_mean were 3.75 ± 0.62, 2.58 ± 0.83 and 3.03 ± 1.18 Gy respectively) compared with 3D CRT (D_mean were 2.61 ± 0.66, 1.52 ± 0.38 and 1.88 ± 0.70 Gy respectively), this difference is statistically insignificant. Doses to the right and left lung (average D_mean = 12.65 ± 3.20 Gy, V_20Gy = 24.12 ± 6.25%), myocardium (D_mean = 5.33 ± 1.51 Gy, V_10Gy = 9.80 ± 3.83%, V_20Gy = 7.19 ± 3.15%, V_25Gy = 6.20 ± 2.93%), and LADA (D_mean = 10.04 ± 4.92 Gy, V_20Gy = 18.17 ± 13.24% and V_25Gy = 15.41 ± 12.19%) were highest with 3D CRT. The highest  D_mean in the cardiac conduction system (5.30 ± 2.23, 3.15 ± 1.61 and 3.89 ± 1.85 Gy respectively) was observed with IMRT, and a similar effect was noted in RCA (D_mean = 7.48 ± 2.11 Gy).

CONCLUSION

VMAT is the optimal and satisfactory radiation therapy technique for sparing organs at risk (OARs). With VMAT, a lower D_mean value was noted in the myocardium, LADA, and lungs. The use of 3D CRT significantly increases the dose of radiation reaching the lungs, myocardium, and LADA, which can subsequently cause cardiovascular and lung complications, but not in the cardiac conduction system.

Women's experiences of age-related discontinuation from mammography screening: A qualitative interview study

INTRODUCTION

In Denmark, women are discontinued from mammography screening at age 69 due to decreased likelihood of benefits and increased likelihood of harm. The risk of harm increases with age and includes false positives, overdiagnosis and overtreatment. In a questionnaire survey, 24 women expressed unsolicited concerns about being discontinued from mammography screening due to age. This calls for further investigation of experiences related to discontinuation from screening.

METHODS

We invited the women, who had left comments on the questionnaire, to participate in in-depth interviews with the purpose to explore their reactions, preferences, and conceptions about mammography screening and discontinuation. The interviews lasted 1-4 h and were followed up with a telephone interview 2 weeks after the initial interview.

RESULTS

The women had high expectations of the benefits of mammography screening and felt that participation was a moral obligation. Following that, they perceived the screening discontinuation as a result of societal age discrimination and consequently felt devalued. Further, the women perceived the discontinuation as a health threat, felt more susceptible to late diagnosis and death, and therefore sought out new ways to control their risk of breast cancer.

CONCLUSION

Our findings indicate that the age-related discontinuation from mammography screening might be of more importance than previously assumed. This study raises important questions about screening ethics, and we encourage research to explore this in other settings.

PATIENT AND PUBLIC CONTRIBUTION

This study was conducted as a result of the women's unsolicited concerns about being discontinued from screening. This particular group contributed to the study with their own statements, interpretations and perspectives on the discontinuation of screening, and the initial analysis of data was discussed with the women during follow-up interviews.

Whole Breast Irradiation Versus Intraoperative Electron Radiation Therapy for Breast Conserving Therapy: A Large Mature Single Institution Matched-Pair Evaluation of True Local Relapse, Progression Free Survival, and Overall Survival

PURPOSE

Comparative outcome data after intraoperative radiation therapy and whole breast irradiation (WBI) for breast cancer at >10 years median follow-up are rare. We present a mature, single-institution, matched-pair comparison reporting survival and relapse rates in patients treated with either modality.

METHODS AND MATERIALS

Complete data sets for 258 intraoperative electron radiation therapy (IOERT) patients treated between 2000 and 2010 were matched with 258 patients postoperatively treated with WBI by age/histology/tumor size, grading/lymph-node-status/hormone receptors/type of adjuvant therapy/surgical margins, and treatment date. Relapse at surgical intervention site was classified as true local recurrence (LR). All recurrences in the treated breast (any quadrant) were classified as ipsilateral recurrence (IR).

RESULTS

Median follow-up was 157 months (12-251) for the IOERT group and 154 months (31-246) for the WBI group. Cumulative incidence of IR at 5, 10, and 15 years was 2.4%, 7.9%, and 12.7% for IOERT and 1.2%, 4.1%, and 5.0% for WBI (P = .02). Cumulative incidence of LR at 5, 10, and 15 years was 1.6%, 5.1%, and 8.3% for IOERT and 0.4%, 2.1%, and 2.5% for WBI (P = .02). No differences in overall survival, disease-free survival, second cancer incidence, or cardiac events were recorded in either treatment group. Outcome was better in the accelerated partial breast irradiation (APBI)-suitable group than in the APBI-unsuitable group (2009 criteria) (cumulative incidence of IR at 5, 10, and 15 years was 0% vs 7.3%, 6.1% vs 13.3%, and 7.3% vs 19.9% for IOERT and 0% vs 1.8%, 2.0% vs 3.9%, and 3.1% vs 3.9% for WBI) and in the revised APBI-suitable group than in the APBI-cautionary group (2017 criteria) (cumulative incidence of IR at 5, 10, and 15 years was 1.1% vs 6.4%, 6.2% vs 13.3%, and 7.8% vs 27.5% for IOERT and 1.7% vs 0%, 4.1% vs 4.4%, and 5.4% vs 4.4% for WBI).

CONCLUSIONS

The IR and LR rate were higher after IOERT than after WBI for the American Society for Radiation Oncology suitable patient group, although without reaching statistical significance. Thus, IOERT could be an alternative to WBI upon stringent patient selection, but patients should be counseled carefully about the potential for increased IR rate with IOERT. Second cancer incidence and cardiac events did not differ between IOERT and WBI.

[The place of radiotherapy]

Radiation therapy (RT) is a key component of the management of elderly breast cancer patients. However, level I evidence in elderly patients is limited. Patient selection should include comorbidities and geriatric assessment. Advances in radiation planning and delivery are improving target coverage, reducing toxicity, and expanding treatment eligibility. Some alternative techniques, such as treatment in the lateral or prone position, may reduce the risk of toxicity. Shorter cycles of hypofractionated whole breast RT are safe and effective. In some cases, partial breast irradiation may be an option.

A Nomogram Based on Hematological Parameters and Clinicopathological Characteristics for Predicting Local–Regional Recurrence After Breast-Conserving Therapy

Objectives

The aim of this study was to identify the factors for local–regional recurrence (LRR) after breast-conserving therapy (BCT). We established a practical nomogram to predict the likelihood of LRR after BCT based on hematological parameters and clinicopathological features.

Methods

A retrospective analysis was performed on 2,085 consecutive breast cancer patients who received BCT in Shandong Cancer Hospital from 2006 to 2016, including 1,460 patients in the training cohort and 625 patients in the validation cohort. Univariate and multivariate analyses were performed based on hematological parameters (fibrinogen, platelets, mean platelet volume, neutrophils, monocytes, and lymphocytes) and clinicopathological characteristics to identify the independent factors for LRR. Subsequently, a nomogram for predicting LRR was established by logistic regression analysis. The nomogram was validated in 625 patients in the validation cohort.

Results

During the median follow-up period of 66 months, 44 (3.01%) patients in the training cohort and 19 (3.04%) patients in the validation cohort suffered from LRR. Multivariate analysis showed six independent factors related to LRR, including molecular subtype, pathological N stage, re-resection, radiotherapy or not, platelet count*MPV*fibrinogen (PMF), and neutrophil count/lymphocyte count ratio (NLR). Six variables were entered into logistic regression to establish the nomogram for predicting LRR. The nomogram of LRR showed excellent discrimination and prediction accuracy. The area under the receiver operating characteristic curve (AUC) was 0.89 (p < 0.001, 95% CI = 0.83, 0.95) in the training cohort and 0.88 (p < 0.001, 95% CI = 0.8, 0.96) in the validation cohort. Calibration curves for the prediction model in the training and validation cohorts both demonstrated satisfactory consistency between the nomogram-predicted and actual LRR.

Conclusion

The combination of hematological parameters and clinicopathological characteristics can predict LRR after BCT. The predictive nomogram based on preoperative and postoperative indicators of BCT might serve as a practical tool for individualized prognostication. More prospective studies should be performed to verify the model.

Heart Sparing Radiotherapy Techniques in Breast Cancer: A Focus on Deep Inspiration Breath Hold

Adjuvant radiation therapy is a critical component of breast cancer management. However, when breast cancer patients receive incidental radiation to the heart, there is an increased risk of cardiac disease and mortality. This is most common for patients with left-sided breast cancers and those receiving nodal irradiation as part of treatment. The overall risk of cardiac toxicity increases 4–16% with each Gray increase in mean heart radiation dose, with data suggesting that no lower limit exists which would eliminate cardiac risk entirely. Radiation techniques have improved over time, leading to lower cardiac radiation exposure than in the past. This decline is expected to reduce the incidence of radiation-induced heart dysfunction in patients. Deep inspiration breath hold (DIBH) is one such technique that was developed to reduce the risk of cardiac death and coronary events. DIBH is a non-invasive approach that capitalizes on the natural physiology of the respiratory cycle to increase the distance between the heart and the therapeutic target throughout the course of radiation therapy. DIBH has been shown to decrease the mean incidental radiation doses to the heart and left anterior descending coronary artery by approximately 20–70%. In this review, we summarize different techniques for DIBH and discuss recent data on this technique.

Effect of radiotherapy sequence on long-term outcome in patients with node-positive breast cancer: a retrospective study

The optimal sequence of chemotherapy (CT) and radiotherapy (RT) after surgery in breast cancer patients is unclear. There is a lack of literature on RT given between anthracycline and taxane administration. We evaluated the effect of RT sequence on long-term outcome in breast cancer. Two hundred patients who underwent surgery between January 2009 and December 2012 for node-positive breast cancers were evaluated retrospectively. All patients were treated with doxorubicin and cyclophosphamide (AC) followed by taxane. Sandwich RT group that received RT between AC and taxane was compared to the group that received RT after CT. The mean follow-up period was 105.4 months. The locoregional recurrence (LRR) rate was lower in sandwich RT group (P = 0.012) and there was no significant difference in distant metastasis between the two groups. The RT sequence was an important predictor for LRR in multivariable analysis (P = 0.017). For luminal A subtype, disease-free survival (DFS) was better in sandwich RT group than in CT followed by RT group (P = 0.001). The overall survival did not correlated with RT sequence regardless of subtype. Sandwich RT can offer DFS benefit in luminal A subtype breast cancer. A tailored approach of sequencing chemotherapy and radiotherapy would be needed considering the factors that can influence outcome.

Deep inspiratory breath-hold radiotherapy for left-sided breast cancer: Initial experience with Active Breathing Coordinator™ in a regional hospital

INTRODUCTION

Deep inspiratory breath-hold (DIBH) has become standard in radiotherapy for left-sided breast cancer to reduce the heart dose. This study evaluated breath-hold stability and reproducibility using Elekta's Active Breathing Coordinator™ (ABC) and its effectiveness and feasibility in left-sided breast cancer patients undergoing radiotherapy.

METHODS

Eligible patients were planned with free breathing (FB) and DIBH protocols. DIBH treatment was considered if the mean heart dose (MHD) was ≥2 Gy on the FB plan. Those who proceeded with DIBH treatment were enrolled for the pilot study. Electronic portal images of DIBH treatment beams were taken using the movie-exposure mode for breath-hold stability and reproducibility analysis. DIBH effectiveness in heart dose reduction and impact on simulation and treatment durations were compared with FB protocol.

RESULTS

Out of 56 eligible patients, 15 proceeded with DIBH treatment. The mean difference of patient setup within a single breath-hold was 0.4 mm; between different breath-holds of the same beam 1.1 mm and between different days 2.6 mm. DIBH reduced the MHD by 47% and the mean left anterior descending artery (LAD) dose by 35%. DIBH took longer time than FB in simulation and treatment. At least 14% of the eligible patients did not tolerate DIBH during simulation.

CONCLUSIONS

ABC leads to stable and reproducible breath-holds and results in significant heart dose reductions. It may not be tolerated by all patients and has resource implications.

Quantifying Societal Burden of Radiation-Induced Cardiovascular Events in Breast Cancer Survivors

Background and Purpose

Radiation-induced cardiotoxicity is an important health concern for clinicians during treatment of breast cancer (BC) patients. Underlying mechanisms are well-documented, whereas little is known about the societal impact of this long-term effect. This study aimed to quantify the additional burden of radiation-induced cardiovascular (CV) diseases in BC survivors.

Materials and Methods

Conventional health economic modelling techniques were applied to estimate attributed CV-related costs and disutility in a hypothetical cohort of BC survivors. A situation in which radiotherapy caused an additional CV risk was compared with a situation in which this risk was not taken into account. Uncertainty was assessed via deterministic and probabilistic sensitivity analyses. Analyses were performed from a broad societal perspective up until 20 years after BC treatment.

Results

Radiation-induced cardiotoxicity evokes a mean incremental cost of €275.10 per woman over a time horizon of 20 years after BC treatment. An additional decrement of 0.017 QALYs (per woman) might be expected when taking the radiation-induced cardiotoxic risk into account in BC survivors. Incremental costs and disutility increased with age. A scenario analysis showed that these results were more profound in women with more advanced staging.

Conclusion

Our analyses suggest that with current radiation techniques, rather minor costs and disutility are to be expected from radiation-induced cardiotoxicity in BC survivors. The cost of past investments in order to achieve current mean heart dose (MHD) seems justified when considering the gains from cost and disutility reduction resulting from radiation-induced cardiovascular events. The question we might consider is whether future opportunity costs associated with investments on further technological advancements offset the expected marginal benefit from further reducing the MHD.

Transparency in quality of radiotherapy for breast cancer in the Netherlands: a national registration of radiotherapy-parameters

Background

Radiotherapy (RT) is part of the curative treatment of approximately 70% of breast cancer (BC) patients. Wide practice variation has been reported in RT dose, fractionation and its treatment planning for BC. To decrease this practice variation, it is essential to first gain insight into the current variation in RT treatment between institutes. This paper describes the development of the NABON Breast Cancer Audit-Radiotherapy (NBCA-R), a structural nationwide registry of BC RT data of all BC patients treated with at least surgery and RT.

Methods

A working group consisting of representatives of the BC Platform of the Dutch Radiotherapy Society selected a set of dose volume parameters deemed to be surrogate outcome parameters, both for tumour control and toxicity. Two pilot studies were carried out in six RT institutes. In the first pilot study, data were manually entered into a secured web-based system. In the second pilot study, an automatic Digital Imaging and Communications in Medicine (DICOM) RT upload module was created and tested.

Results

The NBCA-R dataset was created by selecting RT parameters describing given dose, target volumes, coverage and homogeneity, and dose to organs at risk (OAR). Entering the data was made mandatory for all Dutch RT departments. In the first pilot study (N = 1093), quite some variation was already detected. Application of partial breast irradiation varied from 0 to 17% between the 6 institutes and boost to the tumour bed from 26.5 to 70.2%. For patients treated to the left breast or chest wall only, the average mean heart dose (MHD) varied from 0.80 to 1.82 Gy; for patients treated to the breast/chest wall only, the average mean lung dose (MLD) varied from 2.06 to 3.3 Gy. In the second pilot study 6 departments implemented the DICOM-RT upload module in daily practice. Anonymised data will be available for researchers via a FAIR (Findable, Accessible, Interoperable, Reusable) framework.

Conclusions

We have developed a set of RT parameters and implemented registration for all Dutch BC patients. With the use of an automated upload module registration burden will be minimized. Based on the data in the NBCA-R analyses of the practice variation will be done, with the ultimate aim to improve quality of BC RT.

Trial registration Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02043-0.

Risk of coronary stenosis after adjuvant radiotherapy for breast cancer

Purpose

Adjuvant radiotherapy (RT) for breast cancer is associated with an increased risk of ischemic heart disease. We examined the risk of coronary artery stenosis in a large cohort of women with breast cancer receiving adjuvant RT.

Methods

A cohort of women diagnosed with breast cancer between 1992 and 2012 in three Swedish health care regions (n = 57,066) were linked to the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) to identify women receiving RT who subsequently underwent a percutaneous coronary intervention (PCI) due to coronary stenosis. Cox regression analyses were performed to examine risk of a coronary intervention and competing risk analyses were performed to calculate cumulative incidence.

Results

A total of 649 women with left-sided breast cancer and 494 women with right-sided breast cancer underwent a PCI. Women who received left-sided RT had a significantly higher risk of a PCI in the left anterior descending artery (LAD) compared to women who received right-sided RT, hazard ratio (HR) 1.44 (95% confidence interval [CI] 1.21–1.77, p < 0.001). For the proximal, mid, and distal LAD, the HRs were 1.60 (95% CI 1.22–2.10), 1.38 (95% CI 1.07–1.78), and 2.43 (95% CI 1.33–4.41), respectively. The cumulative incidence of coronary events at 25 years from breast cancer diagnosis were 7.0% in women receiving left-sided RT and 4.4% in women receiving right-sided RT.

Conclusion

Implementing and further developing techniques that lower cardiac doses is important in order to reduce the risk of long-term side effects of adjuvant RT for breast cancer.

Supplementary Information

The online version of this article (10.1007/s00066-022-01927-0) contains supplementary material, which is available to authorized users.

Can We Successfully De-Escalate Axillary Surgery in Women Aged ≥ 70 Years with Ductal Carcinoma in Situ or Early-Stage Breast Cancer Undergoing Mastectomy?

BACKGROUND

Omission of sentinel lymph node biopsy (SLNB) in older women with clinically node-negative, hormone receptor-positive (HR+) early-stage breast cancer undergoing lumpectomy is accepted, given established low rates of regional recurrence. The safety of omitting SLNB in women undergoing mastectomy is unknown and may differ depending on extent of breast disease and variation in radiotherapy use.

PATIENTS AND METHODS

From 2006 to 2018, 123 cTis and 328 cT1-2 HR+/HER2- tumors from 410 women aged ≥ 70 years who underwent mastectomy and SLNB were included (41 bilateral cases). The rate of nodal positivity and effect of nodal positivity on adjuvant therapy use were examined.

RESULTS

Median age was 74 years; 21% of patients had positive sentinel lymph nodes, 7% had micrometastases, and 14% had macrometastases. Of cases of cTis tumors, 31% were upstaged to invasive carcinoma; 1% had macrometastases. Fewer cases of cT1 than cT2 tumors had macrometastases [13% (26/200) versus 29% (37/128); p < 0.001]. Eight percent of patients with pT1 tumors (18/228) and 27% of patients with pT2 tumors (30/113) received chemotherapy. Most patients with pT1, pN1 disease (78%; 25/32) did not receive chemotherapy. Rates of locoregional recurrence were similar between patients with cT1 or cT2 tumors with and without nodal metastases (median follow-up, 4.5 years).

CONCLUSIONS

Women aged ≥ 70 years with cTis and cT1N0 HR+/HER2- tumors who underwent mastectomy had low rates of nodal positivity, similar to rates reported for lumpectomy. Given this and the RxPONDER results, omission of SLNB may be considered, as findings are unlikely to alter adjuvant therapy recommendations.

A Japanese prospective multi-institutional feasibility study on accelerated partial breast irradiation using multicatheter interstitial brachytherapy: clinical results with a median follow-up of 60 months

BACKGROUND

We carried out the first multi-institutional prospective study on accelerated partial breast irradiation (APBI) via multicatheter interstitial brachytherapy in a shorter period for early breast cancer in Japan.

METHODS

Patient eligibility criteria included positive hormone receptors, tumors ≤ 3 cm and TNM stage pN0M0. After breast-conserving surgery (Japanese cylindrical resection) and histological confirmation of negative surgical margins and the absence of lymph node metastasis, applicator implantation was performed either postoperatively or intraoperatively. High-dose-rate brachytherapy of 36 Gy in 6 fractions was delivered.

RESULTS

Forty-six patients from six institutions received this treatment regimen, and the median follow-up time was 60 months (range 57-67 months). The median resected breast tissue volume was 81 cm³ (range 28-260 cm³). No Grade 4 late sequela, local recurrence nor death due to breast cancer were observed. Grade 2-3 sequelae such as rib fracture (2%), soft tissue necrosis (9%), fibrosis (20%), and breast pain (9%) were observed. The resected breast tissue volumes of the patients who had Grade ≥ 2 fibrosis and Grade < 2 fibrosis were 105.9 ± 32.3 cm³ and 76.3 ± 45.6 cm³, respectively, p = 0.02. The overall cosmetic outcome score of Excellent/Good was 74% at 60 months after APBI. Grade ≥ 1 fibrosis was observed in 44% and 92% of patients who scored Excellent/Good and Fair/Poor, respectively, p = 0.004.

CONCLUSIONS

This study showed excellent local control and survival results with minimal late sequelae.

A How-To Compendium for GammaPod Treatments, Clinical Workflow, and Clinical Program at an Early Adopting Institution

Breast irradiation following breast-conserving surgery is an integral part of breast conserving therapy for curative treatment of early-stage breast cancer^1-7. With the recognition that the majority of ipsilateral local relapses following breast-conserving therapy occur at the site of the tumor bed, several trials have since investigated the efficacy of accelerated partial-breast irradiation (APBI)^8-10 as an alternative to the established but less convenient option of daily whole breast irradiation over several weeks. However, the setup uncertainty and inter-fraction movement expected with 3-dimensional conformal radiation therapy (3D-CRT) APBI has generally required the use of larger planning target volume margin expansions, which ultimately results in a larger dose to normal tissues, as well as an association with worsened cosmesis^11-13. A stereotactic partial breast irradiation (S-PBI) approach is needed to allow more precise radiation therapy to the region of the primary tumor. As the GammaPod uses a vacuum assisted breast cup and pump, it allows for smaller CTV margins than 3D-CRT. Here, we describe our methods and workflow for efficient GammaPod S-PBI, as the second institution in the world to go live with GammaPod.

Hypofractionated proton therapy in breast cancer: where are we? A critical review of the literature

PURPOSE

To critically review available literature on hypofractionated (≥ 3 Gy/fraction) proton therapy (PT) for breast cancer (BCa).

METHODS

A systematic screening of the literature was performed in April 2021 in compliance with the preferred reporting items for systematic reviews and meta-analyses recommendations. All full-text publication written in English were considered eligible. Acute and late toxicities, oncological outcomes and dosimetric features were considered for the analysis.

RESULTS

Twelve publications met the inclusion criteria; all studies but one focused on accelerated partial breast irradiation (APBI). Eleven works considered post-operative patients, one referred to ABPI as a curative-intent modality. The dosimetric profile of PT compared favorably with both photon-based 3D conformal and intensity-modulated techniques, while a more extended follow-up is warranted to fully assess both the long-term toxicities and the non-inferiority of oncological outcomes.

CONCLUSION

Our work shows that results on PT for BCa are currently only available for APBI applications, with dosimetric analyses demonstrating a clear advantage over both 3D conformal and intensity modulated X-rays techniques, especially when ≥ 2 treatment fields were used. However, further evidence is needed to define whether such theoretical benefit translates into clinical improvements, especially in the long-term.

A patient decision aid for breast cancer patients deciding on their radiation treatment, no change in decisional conflict but better informed choices

BACKGROUND AND PURPOSE

In selected breast cancer patients, radiation treatment (RT) lowers the recurrence risk, with minor or no improvement of survival. In these patients, the choice to undergo RT is considered a preference-sensitive decision. To facilitate shared decision-making (SDM) for this choice, a patient decision aid was made. We aimed to evaluate the effect of the PtDA on decisional conflict.

MATERIAL AND METHODS

We performed a multi-center pre- and post-intervention study (BRASA-trial). The first 214 patients made a choice without support of the PtDA; the subsequent 189 patients received a link to the PtDA. The primary endpoint was decisional conflict; secondary endpoints were perceived SDM and knowledge on treatment options. Patients filled out questionnaires immediately after, and three months after their decision. Data were analyzed with multi-level regression analysis.

RESULTS

After correcting for the difference in age and educational level, the mean (±SD) decisional conflict for the intervention group (27.3 ± 11.4) was similar to the control group (26.8 ± 11.4; difference = 0.86, 95 %CI 1.67,3.36) three months after their decision. This also applied to perceived SDM. Patients exposed to the PtDA pursued additional treatment less often (45% vs 56%, odds ratio 0.59, 95 %CI 0.37,0.95) and scored significantly higher on the knowledge test (7.4 ± 2.5 vs 6.1 ± 2.7, corrected difference = 1.0, 95 %CI 0.50,1.49). There was no significant increase in consultation time.

CONCLUSIONS

Handing out the PtDA was not associated with improved scores in decisional conflict or perceived SDM, but it was associated with a choice for less additional treatment and better knowledge about the treatment options.

Cardiac inflammation and fibrosis following chemo/radiation therapy: mechanisms and therapeutic agents

The incidence of cardiovascular disorders is one of the most concerns among people who underwent cancer therapy. The heart side effects of cancer therapy may occur during treatment to some years after the end of treatment. Some epidemiological studies confirm that heart diseases are one of the most common reasons for mortality among patients that were received treatment for cancer. Experimental studies and also clinical investigations indicate that inflammatory changes such as pericarditis, myocarditis, and also fibrosis are key mechanisms of cardiac diseases following chemotherapy/radiotherapy. It seems that chronic oxidative stress, massive cell death, and chronic overproduction of pro-inflammatory and pro-fibrosis cytokines are the key mechanisms of cardiovascular diseases following cancer therapy. Furthermore, infiltration of inflammatory cells and upregulation of some enzymes such as NADPH Oxidases are a hallmark of heart diseases after cancer therapy. In the current review, we aim to explain how radiation or chemotherapy can induce inflammatory and fibrosis-related diseases in the heart. We will explain the cellular and molecular mechanisms of cardiac inflammation and fibrosis following chemo/radiation therapy, and then review some adjuvants to reduce the risk of inflammation and fibrosis in the heart.

Improved breast cancer histological grading using deep learning

BACKGROUND

The Nottingham histological grade (NHG) is a well-established prognostic factor for breast cancer that is broadly used in clinical decision making. However, ∼50% of patients are classified as grade 2, an intermediate risk group with low clinical value. To improve risk stratification of NHG 2 breast cancer patients, we developed and validated a novel histological grade model (DeepGrade) based on digital whole-slide histopathology images (WSIs) and deep learning.

PATIENTS AND METHODS

In this observational retrospective study, routine WSIs stained with haematoxylin and eosin from 1567 patients were utilised for model optimisation and validation. Model generalisability was further evaluated in an external test set with 1262 patients. NHG 2 cases were stratified into two groups, DG2-high and DG2-low, and the prognostic value was assessed. The main outcome was recurrence-free survival.

RESULTS

DeepGrade provides independent prognostic information for stratification of NHG 2 cases in the internal test set, where DG2-high showed an increased risk for recurrence (hazard ratio [HR] 2.94, 95% confidence interval [CI] 1.24-6.97, P = 0.015) compared with the DG2-low group after adjusting for established risk factors (independent test data). DG2-low also shared phenotypic similarities with NHG 1, and DG2-high with NHG 3, suggesting that the model identifies morphological patterns in NHG 2 that are associated with more aggressive tumours. The prognostic value of DeepGrade was further assessed in the external test set, confirming an increased risk for recurrence in DG2-high (HR 1.91, 95% CI 1.11-3.29, P = 0.019).

CONCLUSIONS

The proposed model-based stratification of patients with NHG 2 tumours is prognostic and adds clinically relevant information over routine histological grading. The methodology offers a cost-effective alternative to molecular profiling to extract information relevant for clinical decisions.

Speckle-Tracking Echocardiography in Cardio-Oncology and Beyond

Speckle-tracking echocardiography has enabled clinicians to detect changes in myocardial function with more sensitivity than that afforded by traditional diastolic and systolic functional measurements, including left ventricular ejection fraction. Speckle-tracking echocardiography enables evaluation of myocardial strain in terms of strain (percent change in length of a myocardial segment relative to its length at baseline) and strain rate (strain per unit of time). Both measurements have potential for use in diagnosing and monitoring the cardiovascular side effects of cancer therapy. Regional and global strain measurements can independently predict outcomes not only in patients who experience cardiovascular complications of cancer and cancer therapy, but also in patients with a variety of other clinical conditions. This review and case series examine the clinical applications and overall usefulness of speckle-tracking echocardiography in cardio-oncology and, more broadly, in clinical cardiology.

An injectable and biodegradable nano-photothermal DNA hydrogel enhances penetration and efficacy of tumor therapy

The biological barrier of solid tumors hinders deep penetration of nanomedicine, constraining anticancer treatment. Moreover, the inherent multidrug resistance (MDR) of cancer tissues may further limit the efficacy of anti-tumor nanomedicine. We synthesized highly permeable, photothermal, injectable, and positively charged biodegradable nucleic acid hydrogel (DNA-gel) nanoparticles to deliver cancer drugs. The nanoparticles are derived from photothermal materials containing black phosphorus quantum dots (BPQDs). The intra-tumoral BPQDs improve the sensitivity of tumor cells to photothermal therapy (PTT) and photodynamic treatment (PDT). Tumor cells take up the positively charged and controllable size DNA-gel nanoparticles, facilitating easy penetration and translocation of the particles across and within the cells. Mouse models demonstrated the anti-tumor activity of the DNA gel nanoparticles in vivo. In particular, the DNA gel nanoparticles enhanced clearance of both small and large tumor masses. Just 20 days after treatment, the tumor masses had been cleared. Compared to DOX chemotherapy alone, the DNA-gel treatment also significantly reduced drug resistance and improved the overall survival of mice with orthotopic breast tumors (83.3%, 78 d). Therefore, DNA gel nanoparticles are safe and efficient supplements for cancer therapy.

Contralateral breast dose with electronic compensators and conventional tangential fields - A clinical dosimetric study

Dose to the contralateral breast (CLB) from radiotherapy treatment has the potential to induce secondary breast cancer. Electronic tissue compensation (eComp) for breast cancer patients is one of the alternative methods to conventional 3D-conformal radiotherapy that eliminates the use of wedges. Several studies have investigated dose to the CLB using tangential fields involving wedges, intensity-modulated radiation therapy and volumetric modulated arc radiation therapy and various other techniques via treatment planning system calculations, Monte Carlo methods and phantoms. However, there are limited data published in assessing the actual dose received by the CLB from treatment with eComp-based tangential fields. In this study, the CLB dose for patients undergoing tangential field radiotherapy with eComp and enhanced dynamic wedged (standard) tangential fields was measured and compared to assess the CLB dose between the two methods. Measurements were conducted on a randomised trial of 40 patients, 20 of them had undergone standard planning, and the remaining 20 were treated with eComp. The mean surface dose measured with TLDs at 3cm from the medial tangential border for eComp and standard techniques was 10.04±1.37% and 10.14±2.05%, respectively for a prescription dose of 2.65Gy/fraction. The estimated dose at 1cm depth in tissue, measured with the use of perspex domes placed over the TLD at the same location, was 5.12±0.87% and 6.29±2.01% for eComp and standard, respectively. The CLB dose is dependent on the proximity of the medial tangential field edge to the contralateral breast and is patient-specific. The results of this study show that at 1cm depth, eComp technique delivers significantly less dose (p<0.05) to the CLB as compared to standard tangential fields. Furthermore, the surface dose measured for both eComp and standard are comparable indicating that the eComp-based tangential field technique does not contribute any excess dose to CLB when compared to standard tangential fields. The excess relative risk (ERR) for radiation-induced cancers for eComp was found to be 0.08, compared to 0.11 for standard tangential fields.

Prone position versus supine position in postoperative radiotherapy for breast cancer: A meta-analysis

BACKGROUND

This meta-analysis evaluates the difference of sparing organs at risk (OAR) in different position (Prone position and Supine position) with different breathing patterns (Free breathing, FB/Deep inspiration breath hold, DIBH) for breast cancer patients receiving postoperative radiotherapy and provides a useful reference for clinical practice.

METHOD

The relevant controlled trials of prone position versus supine position in postoperative radiotherapy for breast cancer were retrieved from the sources of PubMed, Cochrane Library, Embase, Web of Science and ClinicalTrails.gov. The principal outcome of interest was OAR doses (heart dose, left anterior descending coronary artery dose and ipsilateral lung dose) and target coverage. We mainly compared the effects of P-FB (Prone position FB) and S-FB (Supine position FB) and discussed the effects of DIBH combined with different positions on OAR dose in postoperative radiotherapy. We calculated summary standardized mean difference (SMD) and 95% confidence intervals (CI). The meta-analysis was performed using RevMan 5.4 software.

RESULTS

The analysis included 751 patients from 19 observational studies. Compared with the S-FB, the P-FB can have lower heart dose, left anterior descending coronary artery (LADCA) dose, and ipsilateral lung dose (ILL) more effectively, and the difference was statistically significant (heart dose, SMD = - 0.51, 95% CI - 0.66 ∼ - 0.36, P < .00001. LADCA dose, SMD = - 0.58, 95% CI - 0.85 ∼ - 0.31, P < .0001. ILL dose, SMD = - 2.84, 95% CI - 3.2 ∼ - 2.48, P < .00001). And there was no significant difference in target coverage between the S-FB and P-FB groups (SMD = - 0.1, 95% CI - 0.57 ∼ 0.36, P = .66). Moreover, through descriptive analysis, we found that P-DIBH (Prone position DIBH) has better sparing OAR than P-FB and S-DIBH (Supine position DIBH).

CONCLUSION

By this meta-analysis, compared with the S-FB we found that implementation of P-FB in postoperative radiotherapy for breast cancer can reduce irradiation of heart dose, LADCA dose and ILL dose, without compromising mean dose of target coverage. Moreover, P-DIBH might become the most promising way for breast cancer patients to undergo radiotherapy.

Optimizing Breast Reconstruction through Integration of Plastic Surgery and Radiation Oncology

Post-mastectomy radiation therapy (PMRT) is an important adjunct to improve oncologic outcomes and survival in select breast cancer patients at increased risk for local recurrence. As recommendations for PMRT broaden, an increasing number of patients will have it included as part of their breast cancer treatment plan.

The dosimetric benefit of in-advance respiratory training for deep inspiration breath holding is realized during daily treatment in left breast radiotherapy: A comparative retrospective study of serial surface motion tracking

Introduction

A novel approach of in‐advancepreparatory respiratory training and practice for deep inspiration breath holding (DIBH) has been shown to further reduce cardiac dose in breast cancer radiotherapy patients, enabled by deeper (extended) DIBH. Here we investigated the consistency and stability of such training‐induced extended DIBH after training completion and throughout the daily radiotherapy course.

Methods

Daily chestwall motion from real‐time surface tracking transponder data was analysed in 67 left breast radiotherapy patients treated in DIBH. Twenty‐seven received preparatory DIBH training/practice (_prepTrn) 1–2 weeks prior to CT simulation, resulting in an extended DIBH (_extDIBH) and reduced cardiac dose at simulation. Forty had only conventional immediate pre‐procedure DIBH instruction without _prepTrn and without extended DIBH (non‐Trn group). Day‐to‐day variability in chestwall excursion pattern during radiotherapy was compared among the groups.

Results

The average of daily maximum chestwall excursions was overall similar, 2.5 ± 0.6 mm for _prepTrn/_extDIBH vs. 2.9 ± 0.8 mm for non‐Trn patients (P = 0.24). Chestwall excursions beyond the 3‐mm tolerance threshold were less common in the _prepTrn/_extDIBH group (18.8% vs. 37.5% of all fractions within the respective groups, P = 0.038). Among patients with cardiopulmonary disease those with _prepTrn/_extDIBH had fewer chestwall excursions beyond 3 mm (9.4% vs. 46.7%, P = 0.023) and smaller average maximum excursions than non‐Trn patients (2.4 ± 0.3 vs. 3.0 ± 0.6 mm, P = 0.047, respectively).

Conclusion

Similar stability of daily DIBH among patients with and without preparatory training/practice suggests that the training‐induced extended DIBH and cardiac dose reductions were effectively sustained throughout the radiotherapy course. Training further reduced beyond‐tolerance chestwall excursions, particularly in patients with cardiopulmonary disease.

Local Recurrence in Young Women with Breast Cancer: Breast Conserving Therapy vs. Mastectomy Alone

Simple Summary

To date, breast conserving therapy has equivalent local control to mastectomy alone. However, it is not clear whether this finding is equally applied to young women because of the lack of large scale prospective randomized studies. In this study, we compared the local control between breast conserving therapy and mastectomy alone for young women with breast cancer. We found that young women who underwent breast conserving therapy had an approximately 2.5-fold increased risk of local recurrence compared with those receiving mastectomy alone. The prognosis of young women who had local recurrence after breast conserving therapy were poor despite the aggressive salvage treatments. Therefore, the development of more effective novel systemic treatments is required to improve treatment outcomes in young women with breast cancer receiving breast conserving therapy.

Abstract

We compared the cumulative incidence of local recurrence in young patients (≤40 years) with breast cancer between breast conserving therapy (BCT) and mastectomy alone. Among 428 women with early-stage breast cancer who were treated between 2001 and 2012, 311 underwent BCT and 117 underwent mastectomy alone. Adjuvant systemic treatments were administered to 409 patients (95.6%). We compared the cumulative incidence of LR and survival rates between two groups. During a median follow-up period of 91 months, the 10-year cumulative incidence of LR was 9.3% (median interval of 36.5 months from surgery). Patients treated with BCT tended to have a higher risk for local recurrence (11.1% for BCT vs. 4.1% for mastectomy alone, p = 0.078). All patients with isolated LR after BCT (n = 23) underwent salvage mastectomy followed by systemic treatments. The 5-year distant metastasis-free survival and overall survival of patients with isolated LR after BCT were 44.2% and 82.2%, respectively. The BCT group exhibited an approximately 2.5-fold higher risk of LR than mastectomy alone group. Patients with isolated LR after BCT showed poor prognosis despite undergoing aggressive salvage treatments. The development of novel treatments should be investigated to reduce LR for improving prognosis and preserving cosmetic outcomes in young women.

Factors Associated With a Delay in Postmastectomy Radiation Therapy

BACKGROUND

While the optimal time interval between mastectomy and postmastectomy radiation therapy (PMRT) has not been well-elucidated, a delay in PMRT has been associated with increased local recurrence. We sought to determine factors associated with a delay in PMRT beyond 12 weeks in patients not undergoing adjuvant chemotherapy.

METHODS

Medical records of breast cancer patients who underwent mastectomy at our institution between January 2010 and December 2017 who subsequently received PMRT were retrospectively reviewed. As adjuvant chemotherapy can delay PMRT, patients receiving adjuvant chemotherapy were excluded. Factors associated with a delay in PMRT (defined as > 12 weeks from the time of mastectomy) were analyzed.

RESULTS

Among the 89 patients who met our inclusion criteria, the mean time from mastectomy to PMRT was 11.4 weeks. 24 patients (27.0%) had PMRT > 12 weeks after mastectomy. Factors associated with a delay in PMRT included black race (P = 0.031), younger age (P = 0.047), higher body mass index (P = 0.015), contralateral prophylactic mastectomy (P = 0.033), longer initial hospital length of stay (P = 0.001), and more complications (P = 0.025). On multivariable analysis controlling for all of these factors, only initial hospital length of stay (OR 1.63; 95% CI: 1.07-2.49; P = 0.024) was associated with a delay in PMRT.

CONCLUSION

Over a quarter of patients not undergoing adjuvant chemotherapy have a delay in PMRT beyond 12 weeks from the time of mastectomy. Length of initial hospital stay is the key driver in delaying PMRT.

Growth differentiation factor 11 mitigates cardiac radiotoxicity via activating AMPKα

Cardiac radiotoxicity largely impedes the therapeutic benefits of radiotherapy to malignancies. Growth differentiation factor 11 (GDF11) is implicated in the pathogenesis of cardiac diseases under different pathological conditions. This study aims to investigate the role and underlying mechanisms of GDF11 on cardiac radiotoxicity. Mice were injected with cardiotropic adeno-associated virus 9 carrying the full-length mouse GDF11 gene or negative control under a cTnT promoter from the tail vein, and then received a single dose of 20 Gray (Gy) whole-heart irradiation (WHI) for 16 weeks to imitate cardiac radiotoxicity. Compound C (CC, 20 mg/kg) was intraperitoneally injected every two days at 1 week before WHI stimulation to inhibit 5' AMP-activated protein kinase α (AMPKα). Cardiac GDF11 expression was significantly suppressed at both the protein and mRNA levels. GDF11 overexpression decreased oxidative stress, apoptosis, and fibrosis in radiated hearts, thereby mitigating cardiac radiotoxicity, and dysfunction. Further detection revealed that GDF11 activated AMPKα to reduce radiation-induced oxidative damage and that AMPKα inhibition by CC offset the cardioprotective effects by GDF11. GDF11 mitigates cardiac radiotoxicity via activating AMPKα and it is a promising candidate to treat cardiac radiotoxicity.

Breast-conserving Surgery Without Radiation Therapy for Invasive Cancer

Radiotherapy (RT) after breast-conserving surgery (BCS) halves the risk of local recurrence, and it is considered the standard of care for the vast majority of patients with early invasive breast cancer. However, the majority of patients treated with BCS will not recur locally, even in the absence of RT. Over the past several decades, the improved and widespread use of systemic therapy has significantly decreased the rate of local recurrence. This has stimulated interest in identifying favorable patient subsets not requiring RT. Randomized controlled trials have shown in women aged ≥ 70 years with stage I estrogen receptor-positive (ER⁺) tumors, RT can be safely omitted. To better identify patients with favorable prognosis, ongoing trials have incorporated biological markers and genomic assays. Despite great research efforts to de-escalate locoregional treatment, real-world data indicate that omission of RT in low-risk patients is inconsistent. Better decision-making is warranted to reduce overtreatment and financial toxicity.

Proton versus Photon Breath-Hold Radiation for Left-Sided Breast Cancer after Breast-Conserving Surgery: A Dosimetric Comparison

PURPOSE

Radiation to breast, chest wall, and/or regional nodes is an integral component of breast cancer management in many situations. Irradiating left-sided breast and/or regional nodes may be technically challenging because of cardiac tolerance and subsequent risk of long-term cardiac complications. Deep inspiratory breath-hold (DIBH) technique physically separates cardiac structures away from radiation target volume, thus reducing cardiac dose with either photon (Ph) or proton beam therapy (PBT). The utility of combining PBT with DIBH is less well understood.

METHODS AND MATERIALS

We compared photon-DIBH (Ph-DIBH) versus proton DIBH (Pr-DIBH) for different planning parameters, including target coverage and organ at risk (OAR) sparing. Necessary ethical permission was obtained from the institutional review board. Ten previous patients with irradiated, intact, left-sided breast and Ph-DIBH were replanned with PBT for dosimetric comparison. Clinically relevant normal OARs were contoured, and Ph plans were generated with parallel, opposed tangent beams and direct fields for supraclavicular and/or axillae whenever required. For proton planning, all targets were delineated individually and best possible coverage of planning target volume was achieved. Dose-volume histogram was analyzed to determine the difference in doses received by different OARs. Minimum and maximum dose (Dmin and Dmax ) as well as dose received by a specific volume of OAR were compared. Each patient's initial plan (Ph-DIBH) was used as a control for comparing newly devised PBT plan (Pr-DIBH). Matched, paired t tests were applied to determine any significant differences between the 2 plans.

RESULTS

Both the plans were adequate in target coverage. Dose to cardiac structure subunits and ipsilateral lung were significantly reduced with the proton breath-hold technique. Significant dose reduction with Pr-DIBH was observed in comparison to Ph-DIBH for mean dose (D mean) to the heart (0.23 Gy versus 1.19 Gy; P < .001); D mean to the left ventricle (0.25 Gy versus 1.7 Gy; P < .001); D mean, D max, and the half-maximal dose to the left anterior descending artery (1.15 Gy versus 5.54 Gy; P < .003; 7.7 Gy versus 22.15 Gy; P < .007; 1.61 Gy versus 4.42 Gy, P < .049); D max of the left circumflex coronary artery (0.13 Gy versus 1.35 Gy; P < .001) and D mean, the volume to the ipsilateral lung receiving 20 Gy and 5 Gy (2.28 Gy versus 8.04 Gy; P < .001; 2.36 Gy versus 15.54 Gy, P < .001; 13.9 Gy versus 30.28 Gy; P = .002). However, skin dose and contralateral breast dose were not significantly improved with proton.

CONCLUSION

This comparative dosimetric study showed significant benefit of Pr-DIBH technique compared with Ph-DIBH in terms of cardiopulmonary sparing and may be the area of future clinical research.

RADIOTHERAPY-ASSOCIATED CARDIOVASCULAR COMPLICATIONS IN CANCER (review)

The review is devoted to the current issues of radiation-induced cardiovascular complications, their diagnostics andincidence depending on the radiation doses and exposure regimens, potential efficiency of the screening strategiesfor cardiotoxicity monitoring after radiotherapy in cancer patients by analyzing the data from literature and clinical trials, based on recommendations of European Society of Cardiology and European Society of Medical Oncology.

Risk-Adapted Postmastectomy Radiotherapy Decision Based on Prognostic Nomogram for pT1-2N1M0 Breast Cancer: A Multicenter Study

PURPOSE

The aim of this study was to develop a widely accepted prognostic nomogram and establish a risk-adapted PMRT strategy based on locoregional recurrence for pT1-2N1M0 breast cancer.

METHODS AND MATERIALS

A total of 3,033 patients with pT1-2N1M0 breast cancer treated at 6 participating institutions between 2000 and 2016 were retrospectively reviewed. A nomogram was developed to predicted locoregional recurrence-free survival (LRFS). A propensity score-matched (PSM) analyses was performed in risk-adapted model.

RESULTS

With the median follow-up of 65.0 months, the 5-year overall survival (OS), disease free survival (DFS) and LRFS were 93.0, 84.8, and 93.6%, respectively. There was no significant difference between patients who received PMRT or not for the entire group. A nomogram was developed and validated to estimate the probability of 5-year LRFS based on five independent factors including age, primary tumor site, positive lymph nodes number, pathological T stage, and molecular subtype that were selected by a multivariate analysis of patients who did not receive PMRT in the primary cohort. According to the total nomogram risk scores, the entire patients were classified into low- (40.0%), moderate- (42.4%), and high-risk group (17.6%). The 5-year outcomes were significantly different among these three groups (P<0.001). In low-risk group, patients who received PMRT or not both achieved a favorable OS, DFS, and LRFS. In moderate-risk group, no differences in OS, DFS, and LRFS were observed between PMRT and no PMRT patients. In high-risk group, compared with no PMRT, PMRT resulted in significantly different OS (86.8 vs 83.9%, P = 0.050), DFS (77.2 vs 70.9%, P = 0.049), and LRFS (90.8 vs. 81.6%, P = 0.003). After PSM adjustment, there were no significant differences in OS, DFS, and LRFS in low-risk and moderate-risk groups. However, in the high-risk group, PMRT still resulted in significantly better OS, DFS and improved LRFS.

CONCLUSIONS

The proposed nomogram provides an individualized risk estimate of LRFS in patients with pT1-2N1M0 breast cancer. Risk-adapted PMRT for high-risk patients is a viable effective strategy.

Targeted Intraoperative Radiotherapy Is Non-inferior to Conventional External Beam Radiotherapy in Chinese Patients With Breast Cancer: A Propensity Score Matching Study

Purpose: To investigate the efficacy of targeted intraoperative radiotherapy (TARGIT) vs. conventional external beam radiotherapy (EBRT) in Chinese patients with breast cancer. Methods: We retrospectively analyzed breast cancer patients who underwent breast-conserving surgery (BCS) at our hospital between April 2009 and October 2017. Patients were divided into TARGIT group and EBRT group according to different radiotherapy methods. TARGIT was performed with low-energy X-rays emitted by the Intrabeam system to deliver a single dose of 20 Gy to the applicator surface. Propensity score matching was performed at 1:1. The Kaplan-Meier method was used to calculate the locoregional recurrence (LR), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) of the two groups, and the log-rank test was run to analyse between-group difference before and after matching. Results: A total of 281 patients were included, with a median follow-up of 43 months. Of them, 82 were included in the TARGIT group and 199 in the EBRT group. Using the risk-adapted approach, 6.1% of patients received supplemental EBRT in the TARGIT group. The 5-year LR rate was 3.2% in the TARGIT group and 3.1% in the EBRT group (P = 0.694), the 5-year DMFS rates were 100 and 96.7%, respectively (P = 0.157); the 5-year DFS rates were 96.8 and 94.2% (P = 0.604); and the 5-year OS rates were 97.6 and 97.8% (P = 0.862). After matching which eliminated interference from imbalanced baseline factors, 128 matched patients were analyzed by the Kaplan-Meier method. The 5-year LR rate was 2.3% in the TARGIT group and 1.6% in the EBRT group; the 5-year DMFS rates were 100 and 98.4%, respectively; the 5-year DFS rates were 97.7 and 98.4%; and the 5-year OS rates were 98.4 and 98.4% (P = 0.659, 0.313, 0.659, 0.987). There was no significant difference in efficacy between TARGIT group and EBRT group. Conclusion: TARGIT and EBRT have similar 5-year outcomes in selected Chinese breast cancer patients undergoing BCS, and it can be used as an effective alternative to standard therapy, with substantial benefits to patients. The results need to be further confirmed by extending the follow-up time.

A Pilot Study of Cardiac MRI in Breast Cancer Survivors After Cardiotoxic Chemotherapy and Three-Dimensional Conformal Radiotherapy

PURPOSE/OBJECTIVES

Node-positive breast cancer patients often receive chemotherapy and regional nodal irradiation. The cardiotoxic effects of these treatments, however, may offset some of the survival benefit. Cardiac magnetic resonance (CMR) is an emerging modality to assess cardiac injury. This is a pilot trial assessing cardiac damage using CMR in patients who received anthracycline-based chemotherapy and three-dimensional conformal radiotherapy (3DCRT) regional nodal irradiation using heart constraints.

MATERIALS AND METHODS

Node-positive breast cancer patients (2000-2008) treated with anthracycline-based chemotherapy and 3DCRT regional nodal irradiation (including the internal mammary chain nodes) with heart ventricular constraints (V25 < 10%) were invited to participate. Cardiac tissues were contoured and analyzed separately for whole heart (pericardium) and for combined ventricles and left atrium (myocardium). CMR obtained ventricular function/dimensions, late gadolinium enhancement (LGE), global longitudinal strain (GLS), and extracellular volume fraction (ECV) as measures of cardiac injury and/or early fibrosis. CMR parameters were correlated with dose-volume constraints using Spearman correlations.

RESULTS

Fifteen left-sided and five right-sided patients underwent CMR. Median diagnosis age was 50 (32-77). No patients had baseline cardiac disease before regional nodal irradiation. Median time after 3DCRT was 8.3 years (5.2-14.4). Median left-sided mean heart dose (MHD) was 4.8 Gy (1.1-11.2) and V25 was 5.7% (0-12%). Median left ventricular ejection fraction (LVEF) was 63%. No abnormal LGE was observed. No correlations were seen between whole heart doses and LVEF, LV mass, GLS, or LV dimensions. Increasing ECV did not correlate with increased heart or ventricular doses. However, correlations between higher LV mass and ventricular mean dose, V10, and V25 were seen.

CONCLUSION

At a median follow-up of 8.3 years, this cohort of node-positive breast cancer patients who received anthracycline-based chemotherapy and regional nodal irradiation had no clinically abnormal CMR findings. However, correlations between ventricular mean dose, V10, and V25 and LV mass were seen. Larger corroborating studies that include advanced techniques for measuring regional heart mechanics are warranted.