Omission of Radiotherapy After Breast-Conserving Surgery for Women With Breast Cancer With Low Clinical and Genomic Risk: 5-Year Outcomes of IDEA.

PURPOSE: Multiple studies have shown a low risk of ipsilateral breast events (IBEs) or other recurrences for selected patients age 65-70 years or older with stage I breast cancers treated with breast-conserving surgery (BCS) and endocrine therapy (ET) without adjuvant radiotherapy. We sought to evaluate whether younger postmenopausal patients could also be successfully treated without radiation therapy, adding a genomic assay to classic selection factors. METHODS: Postmenopausal patients age 50-69 years with pT1N0 unifocal invasive breast cancer with margins ≥2 mm after BCS whose tumors were estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor 2-negative with Oncotype DX 21-gene recurrence score ≤18 were prospectively enrolled in a single-arm trial of radiotherapy omission if they consented to take at least 5 years of ET. The primary end point was the rate of locoregional recurrence 5 years after BCS. RESULTS: Between June 2015 and October 2018, 200 eligible patients were enrolled. Among the 186 patients with clinical follow-up of at least 56 months, overall and breast cancer-specific survival rates at 5 years were both 100%. The 5-year freedom from any recurrence was 99% (95% CI, 96 to 100). Crude rates of IBEs for the entire follow-up period for patients age 50-59 years and age 60-69 years were 3.3% (2/60) and 3.6% (5/140), respectively; crude rates of overall recurrence were 5.0% (3/60) and 3.6% (5/140), respectively. CONCLUSION: This trial achieved a very low risk of recurrence using a genomic assay in combination with classic clinical and biologic features for treatment selection, including postmenopausal patients younger than 60 years. Long-term follow-up of this trial and others will help determine whether the option of avoiding initial radiotherapy can be offered to a broader group of women than current guidelines recommend.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2023.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer address all aspects of management for breast cancer. The treatment landscape of metastatic breast cancer is evolving constantly. The therapeutic strategy takes into consideration tumor biology, biomarkers, and other clinical factors. Due to the growing number of treatment options, if one option fails, there is usually another line of therapy available, providing meaningful improvements in survival. This NCCN Guidelines Insights report focuses on recent updates specific to systemic therapy recommendations for patients with stage IV (M1) disease.

Radiation Therapy for Low-Risk Breast Cancer: Whole, Partial, or None?

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.The following case represents a relatively common clinical scenario of a postmenopausal female patient who presents with low-risk, estrogen receptor-positive/progesterone receptor-positive/human epidermal growth factor receptor 2-negative, early-stage, left-sided breast cancer to discuss the role of postoperative radiation (RT) following wide local excision (WLE) and sentinel node biopsy. The spectrum of choices, ranging from omission of RT, accelerated partial breast irradiation (PBI), whole-breast radiation therapy, and the nuances of various dose/fractionation regimens for each option, are discussed in the context of the Danish Breast Cancer Study Group (DBCSG) PBI trial published in this issue, with additional review of other key trials that inform these treatment recommendations. After consideration of the clinical-pathologic features in the framework of the existing data and an in-depth discussion taking into consideration the patient's preferences/goals, the decision was made to deliver moderately hypofractionated RT (40 Gy/15 fractions) to a PBI volume, in concordance with the DBCSG-PBI trial.

DCIS: Risk Assessment in the Molecular Era.

Ductal carcinoma in situ (DCIS) represents 20% of all breast cancers. The treatment paradigm for the majority of patients with DCIS consists of breast-conserving surgery (BCS) and radiotherapy (RT), with adjuvant endocrine therapy offered for hormone-receptor positive disease. RT after BCS reduces the risk of in-breast recurrence, decreasing subsequent in-situ and invasive cancers by ≥50%, with 10-year breast-cancer specific survival outcomes approaching 98%. As local control rates are high, treatment efforts have focused on selective de-escalation of care. Traditionally, clinicians have used clinical-pathologic features (ie, grade, age, size, margin width) to guide selection of low-risk DCIS patients in whom postoperative RT may be omitted. More recently, genomic molecular assays including the Oncotype DX Breast DCIS Score and DCISionRT have been developed to provide individualized assessment of predicting RT benefit after BCS. These molecular assays have the potential for personalized risk assessment, particularly when used in combination with existing clinical-pathologic features for risk assessment. This article reviews the current status and existing published literature on DCIS molecular-risk assessment tools and their potential for guiding postoperative RT recommendations in the BCT setting. In addition, current trials studying omission of definitive surgery for low-risk DCIS are discussed.

Breast Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology.

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. These NCCN Clinical Practice Guidelines for Breast Cancer include recommendations for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, and management of breast cancer during pregnancy. The content featured in this issue focuses on the recommendations for overall management of ductal carcinoma in situ and the workup and locoregional management of early stage invasive breast cancer. For the full version of the NCCN Guidelines for Breast Cancer, visit NCCN.org.

Cancer Misinformation and Harmful Information on Facebook and Other Social Media: A Brief Report.

There are few data on the quality of cancer treatment information available on social media. Here, we quantify the accuracy of cancer treatment information on social media and its potential for harm. Two cancer experts reviewed 50 of the most popular social media articles on each of the 4 most common cancers. The proportion of misinformation and potential for harm were reported for all 200 articles and their association with the number of social media engagements using a 2-sample Wilcoxon rank-sum test. All statistical tests were 2-sided. Of 200 total articles, 32.5% (n = 65) contained misinformation and 30.5% (n = 61) contained harmful information. Among articles containing misinformation, 76.9% (50 of 65) contained harmful information. The median number of engagements for articles with misinformation was greater than factual articles (median [interquartile range] = 2300 [1200-4700] vs 1600 [819-4700], P = .05). The median number of engagements for articles with harmful information was statistically significantly greater than safe articles (median [interquartile range] = 2300 [1400-4700] vs 1500 [810-4700], P = .007).

The Impact of Radiotherapy Delay in Breast Conservation Patients Not Receiving Chemotherapy and the Rationale for Dichotomizing the Radiation Oncology Time-Dependent Standard into Two Quality Measures.

INTRODUCTION: The Commission on Cancer/National Quality Forum breast radiotherapy quality measure establishes that for women < 70 years, adjuvant radiotherapy after breast conserving surgery (BCS) should be started < 1 year from diagnosis. This was intended to prevent accidental radiotherapy omission or delay due to a long interval between surgery and chemotherapy completion, when radiation is delivered. However, the impact on patients not receiving chemotherapy, who proceed from surgery directly to radiotherapy, remains unknown. PATIENTS AND METHODS: Patients aged 18-69, diagnosed with stage I-III breast cancer as their first and only cancer diagnosis (2004-2016), having BCS, for whom this measure would be applicable, were reviewed from the National Cancer Database. RESULTS: Among 308,521 patients, the median age was 57.0 years, and > 99% of all patients were compliant with the measure. The cohort of interest included 186,650 (60.5%) patients not receiving chemotherapy, with a mean age of 57.9 years. Of these, 90.5% received external beam radiotherapy (EBRT) and 9.5% brachytherapy. Among them, 24.9% started radiotherapy > 8 weeks after surgery. In a multivariable model, delay from surgery to radiotherapy increased the hazard ratios for overall survival to 9.0% (EBRT) per month and 3.0% (brachytherapy) per week. CONCLUSION: While 99.9% of patients undergoing BCS without chemotherapy remain compliant with the current quality measure, 25% have delays > 8 weeks to start radiation, which is associated with impaired survival. These data suggest that the current quality measure should be dichotomized into two, with or without chemotherapy, in order to impel prompt radiotherapy initiation and maximize outcomes in all patients.

Benefit of Deep Inspiratory Breath Hold for Right Breast Cancer When Regional Lymph Nodes Are Irradiated.

BACKGROUND: Although deep inspiratory breath-hold (DIBH) is routinely used for left-sided breast cancers, its benefits for right-sided breast cancer (rBC) have yet to be established. We compared free-breathing (FB) and DIBH treatment plans for a cohort of rBC undergoing regional nodal irradiation (RNI) to determine its potential benefits. METHODS AND MATERIALS: rBC patients considered for RNI (internal mammary nodal chains, supraclavicular field, with or without axilla) from October 2017 to May 2020 were included in this analysis. For each patient, FB versus DIBH plans were generated and dose volume histograms evaluated the following parameters: mean lung dose, ipsilateral lung V20/V5 (volumes of lung receiving 20 Gy and 5 Gy, respectively); mean heart dose and heart V5 (volumes of heart receiving 5 Gy); liver V20 absolute /V30 absolute (absolute volume of liver receiving 20 Gy and 30 Gy, respectively), liver Dmax, and total liver volume irradiated (TVIliver). The dosimetric parameters were compared using Wilcoxon signed-rank testing. RESULTS: Fifty-four patients were eligible for analysis, comparing 108 FB and DIBH plans. DIBH significantly decreased all lung and liver parameters: mean lung dose (19.7 Gy-16.2 Gy, P < .001), lung V20 (40.7%-31.7%, P < .001), lung V5 (61.2%-54.5%, P < .001), TVIliver (1446 cc vs 1264 cc; P = .006) liver Dmax (50.2 Gy vs 48.9 Gy; P = .023), liver V20 (78.8-23.9 cc, P < .001), and liver V30 (58.1-14.6 cc, P < .001) compared with FB. DIBH use did not significantly improve heart parameters, although the V5Heart trended on significance (1.25-0.6, P = .067). CONCLUSIONS: This is the largest cohort to date analyzing DIBH for RNI-rBC. Our findings demonstrate significant improvement in all lung and liver parameters with DIBH, supporting its routine consideration for rBC patients undergoing comprehensive RNI.

Decreasing the Interval Wait Times for Screening Mammogram Results Using the "Reflex Testing" Algorithm.

OBJECTIVE: The purpose of this analysis was to determine whether our "reflex testing" (RefT) intervention, implemented to address barriers in scheduling, communication, and diagnostic order placement for resolving BI-RADS 0 screening mammograms, resulted in decreased interval wait times (IWT) for patients with abnormal screening mammograms (abSM). METHODS: All BI-RADS 0 cases over two six-month periods (pre-RefT and post-RefT) were analyzed. Timelines were generated for each BI-RADS 0 case. Elapsed days were computed from date of BI-RADS 0 report to the date of biopsy, additional diagnostic testing, and final resolution. The means of each endpoint within the pre-RefT and post-RefT cohorts were statistically analyzed using Pearson chi-square analysis to assess whether IWT differed significantly after RefT implementation. RESULTS: The analytic cohort consisted of 1523 BI-RADS 0 cases (n(pre-RefT) = 647, n(post-RefT) = 876). Reflex testing decreased the overall mean IWT from 23.5 to 8.2 days (P < 0.001). For patients not requiring biopsy (1190/1523, 78.1%), the mean IWT from the BI-RADS 0 designation to first diagnostic test or resolution decreased from 29.7 to 10.8 days (P < 0.010). For patients who had biopsy (333/1523, 21.9%), RefT significantly decreased the IWT from BI-RADS 0 to first diagnostic test from 31.4 to 7.7 days (P < 0.001) and also significantly decreased the IWT from first diagnostic test to biopsy (20.9 to 17.7 days; P < 0.013). CONCLUSION: Reflex testing intervention streamlines the workflow and significantly decreases IWT for resolving BI-RADS 0 abSM. The RefT intervention could be considered to improve efficiency at other breast centers.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2021.

The NCCN Guidelines for Breast Cancer include up-to-date guidelines for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, male breast cancer, and breast cancer during pregnancy. These guidelines are developed by a multidisciplinary panel of representatives from NCCN Member Institutions with breast cancer-focused expertise in the fields of medical oncology, surgical oncology, radiation oncology, pathology, reconstructive surgery, and patient advocacy. These NCCN Guidelines Insights focus on the most recent updates to recommendations for adjuvant systemic therapy in patients with nonmetastatic, early-stage, hormone receptor-positive, HER2-negative breast cancer.

A Delphi study and International Consensus Recommendations: The use of bolus in the setting of postmastectomy radiation therapy for early breast cancer.

Bolus serves as a tissue equivalent material that shifts the 95-100% isodose line towards the skin and subcutaneous tissue. The need for bolus for all breast cancer patients planned for postmastectomy radiation therapy (PMRT) has been questioned. The work was initiated by the faculty of the European SocieTy for Radiotherapy & Oncology (ESTRO) breast cancer courses and represents a multidisciplinary international breast cancer expert collaboration to optimize PMRT. Due to the lack of randomised trials evaluating the benefits of bolus, we designed a stepwise project to evaluate the existing evidence about the use of bolus in the setting of PMRT to achieve an international consensus for the indications of bolus in PMRT, based on the Delphi method.

The use of bolus in postmastectomy radiation therapy for breast cancer: A systematic review.

PURPOSE: Post mastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) and breast cancer mortality for selected patients. Bolus overcomes the skin-sparing effect of external-beam radiotherapy, ensuring adequate dose to superficial regions at risk of local recurrence (LR). This systematic review summarizes the current evidence regarding the impact of bolus on LR and acute toxicity in the setting of PMRT. RESULTS: 27 studies were included. The use of bolus led to higher rates of acute grade 3 radiation dermatitis (pooled rates of 9.6% with bolus vs. 1.2% without). Pooled crude LR rates from thirteen studies (n = 3756) were similar with (3.5%) and without (3.6%) bolus. CONCLUSIONS: Bolus may be indicated in cases with a high risk of LR in the skin, but seems not to be necessary for all patients. Further work is needed to define the role of bolus in PMRT.

Special subtypes with favorable prognosis in breast cancer: A registry-based cohort study and network meta-analysis.

BACKGROUND: We aimed to explore whether cribriform and adenoid cystic carcinoma had comparable prognoses to mucinous, tubular and papillary carcinoma, which were long recognized as favorable histologies by NCCN guidelines. METHODS: A retrospective analysis based on the Surveillance, Epidemiology, and End Results Study (SEER) database (1994-2014) was conducted. The prognostic significance of all clinicopathological factors was calculated using univariate and multivariate analyses. A systematic review based on PubMed and network meta-analysis was conducted. RESULTS: From the SEER database, the histologic subtypes of breast cancer (tubular, cribriform, adenoid cystic, mucinous, and papillary) were sorted by overall survival (OS) (94.4%, 91.6%, 90.8%, 87.6%, and 84.2%, respectively) and tubular, cribriform, mucinous, papillary, and adenoid cystic carcinoma by breast cancer-specific survival (BCSS) (99.4%, 98.4%, 97.7%, 95.2%, and 94.9%, respectively). A network meta-analysis combining 11 studies (886,649 patients) was conducted, which demonstrated consistent outcomes. SEER-based analyses revealed that, among the favorable subtypes, systemic chemotherapy did not improve OS or BCSS in hormone receptor-positive, node-negative patients, validating that these subtypes are generally associated with excellent outcomes, for which systemic chemotherapy may not be warranted. CONCLUSIONS: Our data are consistent with guidelines suggesting that the mucinous, tubular, and papillary subtypes of breast cancer have favorable histologies. SEER data and meta-analysis supports this favorable category to include adenoid cystic and cribriform carcinoma, whose OS and BCSS outcomes are comparable to the former three. These findings add to the body of data, suggesting that patients with these histologic subtypes confer excellent prognosis, which may guide optimal therapeutic management strategies.

Recommendations for prioritization, treatment, and triage of breast cancer patients during the COVID-19 pandemic. the COVID-19 pandemic breast cancer consortium.

The COVID-19 pandemic presents clinicians a unique set of challenges in managing breast cancer (BC) patients. As hospital resources and staff become more limited during the COVID-19 pandemic, it becomes critically important to define which BC patients require more urgent care and which patients can wait for treatment until the pandemic is over. In this Special Communication, we use expert opinion of representatives from multiple cancer care organizations to categorize BC patients into priority levels (A, B, C) for urgency of care across all specialties. Additionally, we provide treatment recommendations for each of these patient scenarios. Priority A patients have conditions that are immediately life threatening or symptomatic requiring urgent treatment. Priority B patients have conditions that do not require immediate treatment but should start treatment before the pandemic is over. Priority C patients have conditions that can be safely deferred until the pandemic is over. The implementation of these recommendations for patient triage, which are based on the highest level available evidence, must be adapted to current availability of hospital resources and severity of the COVID-19 pandemic in each region of the country. Additionally, the risk of disease progression and worse outcomes for patients need to be weighed against the risk of patient and staff exposure to SARS CoV-2 (virus associated with the COVID-19 pandemic). Physicians should use these recommendations to prioritize care for their BC patients and adapt treatment recommendations to the local context at their hospital.

Comparison of Nodal Target Volume Definition in Breast Cancer Radiation Therapy According to RTOG Versus ESTRO Atlases: A Practical Review From the TransAtlantic Radiation Oncology Network (TRONE).

Regional nodal irradiation has gained interest in recent years with the publication of several important randomized trials and the availability of more conformal techniques. Target volume delineation represents a critical step in the radiation planning process. Adequate coverage of the microscopic tumor spread to regional lymph nodes must be weighed against exposure of critical structures such as the heart and lungs. Among available guidelines for delineating the clinical target volume for the breast/chest wall and regional nodes, the Radiation Therapy Oncology Group and European Society for Radiotherapy and Oncology guidelines are the most widely used internationally. These guidelines have been formulated based on anatomic boundaries of areas historically covered in 2-dimensional field-based radiation therapy but have not been validated by patterns-of-failure studies. In recent years, an important body of data has emerged from mapping studies documenting patterns of local and regional recurrence. We aim to review, discuss, and compare contouring guidelines for breast cancer radiation therapy in the context of contemporary data on locoregional relapse to improve their implementation in modern practice.

Breast Cancer, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology.

Several new systemic therapy options have become available for patients with metastatic breast cancer, which have led to improvements in survival. In addition to patient and clinical factors, the treatment selection primarily depends on the tumor biology (hormone-receptor status and HER2-status). The NCCN Guidelines specific to the workup and treatment of patients with recurrent/stage IV breast cancer are discussed in this article.

Hypofractionated radiation treatment for breast cancer: The time is now.

While there is now Level I data with long-term follow-up supporting the routine use of hypofractionated (HF) whole-breast radiation therapy (WBRT) after breast-conserving surgery, its adoption has been slow and variable. This article will review the literature supporting the efficacy and safety of hypofractionated radiation for breast cancer, discuss the radiobiological rationale specific to breast tumors, and make an argument for justifying the routine adoption of shorter, HF-WBRT courses when delivering breast radiation. Data using HF with regional nodal irradiation and in the post-mastectomy setting will also be reviewed. The aim is to provide an in-depth understanding of the use of hypofractionated radiation therapy for breast cancer, its applicability, and topics warranting future research.

Standard Tangential Radiation Fields Do Not Provide Incidental Coverage to the Internal Mammary Nodes.

PURPOSE: The purpose of the study was to evaluate the incidental dose delivered to the internal mammary nodes (IMNs) in patients treated with tangential 3-dimensional conformal radiation therapy and to identify potential parameters that may affect the IMN mean dose. METHODS AND MATERIALS: The study cohort consisted of 362 consecutively treated patients with breast cancer in our center between January 2015 and July 2017 who had received adjuvant whole-breast radiation therapy or postmastectomy radiation with or without a supraclavicular ± axillary field and without intentional inclusion of the IMN chain. The clinical target volume (CTV) for the IMNs was contoured per the Radiation Therapy Oncology Group 3509/3510 protocol and was then divided into 3 subregions: upper, mid, and lower thirds. The planning target volume for the IMNs was generated by adding 5 mm to the CTV. The primary endpoint was to assess the V40 (volume receiving 40 Gy) to the IMN planning target volume and its potential influencing parameters using a linear regression model. RESULTS: The mean (±standard deviation) dose to the CTV IMN chain was 36% ± 28.7%. The Kruskal-Wallis test demonstrated significant differences in the median dose delivered to each level: upper third (7.2%), mid third (21.5%), and lower third (41.7%) (P < .001). The mean V40 IMN planning target volume was 14.2% (standard deviation, 18.7%). Presternal fat thickness (regression coefficient [RC] = -16.4; P < .001), postmastectomy radiation (RC = 24; P < .001), reconstruction after mastectomy (RC = -22.4; P < .001), and the addition of a supraclavicular field (RC = 8.8; P = .03) were all significantly associated with IMN mean dose. CONCLUSIONS: For patients receiving standard breast/chest wall tangential radiation fields, the IMN chain is not incidentally covered with therapeutic doses in the vast majority of cases. Therefore, if regional nodal radiation is intended to include the IMNs, contouring and careful plan review are necessary to ensure adequate therapeutic coverage.