Concurrent Versus Sequential Radiation Dose Escalation to the Surgical Cavity for Conservative Treatment of High-Risk Early Breast Cancer: NRG/RTOG 1005 Phase III Trial
PURPOSE For patients with breast cancer undergoing breast conservation, escalating the dose (boost) of radiation to the lumpectomy cavity after whole-breast irradiation (WBI) reduces ipsilateral breast recurrence (IBR) but extends treatment duration. This phase III trial investigated whether boost delivery during WBI versus after WBI provides noninferior IBR and preserves cosmetic appearance. METHODS NRG/RTOG 1005 randomly assigned patients at higher risk for IBR after lumpectomy and axillary surgery to either a sequential boost of 12 Gy in six fractions(F) or 14 Gy in 7F after WBI of 50 Gy in 25F or 42.7 Gy in 16F (sequential arm) or a concurrent boost of 8 Gy in 15F of 0.53 Gy per day with WBI of 40 Gy in 15F (concurrent arm) using 3-dimensional conformal radiation therapy (RT) or intensity-modulated RT. Based on 1.59% 5-year IBR for the sequential arm, defining the noninferiority margin as a hazard ratio upper limit on the 90% CI of 2.12, 2,312 patients provide 80% power for noninferiority of IBR as first recurrence for the concurrent arm. Secondary end points included disease-free survival and overall survival, adverse events (AEs), and cosmetic outcomes. RESULTS Between May 24, 2011, and June 20, 2014, 2,354 patients were randomly assigned, with 2,255 eligible for analysis (sequential arm, n = 1,118; concurrent arm, n = 1,137). With median follow-up of 7.3 years, there were 56 IBR events; 5- and 7-year IBR were 2.1% and 2.2% on the sequential arm and 1.9% and 2.6% on the concurrent arm, respectively. The noninferiority criterion was met: HR (90% CI): 1.31 (0.84 to 2.04), P = .037. No differences were observed in AEs, cosmetic outcomes, or survival between arms. CONCLUSION Concurrent boost during WBI results in noninferior IBR compared with sequential boost without worsening toxicity or cosmetic outcomes and reduces overall treatment time.
Pathologic Exploration of the Axillary Soft Tissue Microenvironment and Its Impact on Axillary Management and Breast Cancer Outcomes
PURPOSE Axillary soft tissue (AXT) involvement with tumor cells extending beyond the positive lymph node (LN+) and extracapsular extension (ECE) has been overlooked in breast pathology specimen analysis. MATERIALS AND METHODS We analyzed 2,162 LN+ patients, dividing them into four groups on the basis of axillary pathology: (1) LN+ only, (2) LN+ and ECE only, (3) LN+ and AXT without ECE, and (4) LN+ with both AXT and ECE. The primary end points were 10-year locoregional failure (LRF), the 10-year axillary failure, and 10-year distant metastasis rates. Multivariable Cox models, accounting for clinical factors, were fitted using the entire cohort, and subgroups analyses were conducted. RESULTS The median follow-up was 9.4 years. The 10-year distant metastasis incidence was 42% for LN + AXT + ECE, 23% for both LN + AXT and LN + ECE only, and 13% for LN+ only. The 10-year axillary failure rates were 4.5% for LN + AXT + ECE, 4.6% for LN + AXT, 0.8% for LN + ECE only, and 1.6% for LN+ only. The 10-year LRF rates were 14% for LN + AXT + ECE, 10% for LN + AXT, 5.7% for LN + ECE only, and 6.2% for LN+ only. Multivariable analysis revealed that AXT was significantly associated with distant metastasis (hazard ratio [HR], 1.6; P < .001), locoregional failure (HR, 2.3; P < .001), and axillary failure (HR, 3.3; P = .003). Subgroup analyses showed that regional LN radiation (RLNR) improved locoregional tumor outcomes with AXT, ECE, or both (HR, 0.5; P = .03). Delivering ≤50 Gy to the axilla in the presence of AXT/ECE increased axillary failure (HR, 3.0; P = .04). Moreover, when delivering RLNR, axillary LN dissection could be de-escalated to sentinel node biopsy even in the presence of features such as AXT or ECE without significantly increasing any failure outcome: (HR, 1.0; P = .92) for LRF, (HR, 1.1; P = .94) axillary failure, and (HR, 0.4; P = .01) distant metastasis. CONCLUSION Routine reporting of axillary tissue involvement, beyond LNs and ECE, is crucial in predicting breast cancer outcomes. Ruling out the presence of AXT is imperative before any form of axillary de-escalation, especially RLNR omission.
Looking Back: International Practice Patterns in Breast Radiation Oncology From a Case-Based Survey Across 54 Countries During the First Surge of the COVID-19 Pandemic
PURPOSE The COVID-19 pandemic has profoundly affected cancer care worldwide, including radiation therapy (RT) for breast cancer (BC), because of risk-based resource allocation. We report the evolution of international breast RT practices during the beginning of the pandemic, focusing on differences in treatment recommendations between countries. MATERIALS AND METHODS Between July and November 2020, a 58-question survey was distributed to radiation oncologists (ROs) through international professional societies. Changes in RT decision making during the first surge of the pandemic were evaluated across six hypothetical scenarios, including the management of ductal carcinoma in situ (DCIS), early-stage, locally advanced, and metastatic BC. The significance of changes in responses before and during the pandemic was examined using chi-square and McNemar-Bowker tests. RESULTS One thousand one hundred three ROs from 54 countries completed the survey. Incomplete responses (254) were excluded from the analysis. Most respondents were from the United States (285), Japan (117), Italy (63), Canada (58), and Brazil (56). Twenty-one percent (230) of respondents reported treating at least one patient with BC who was COVID-19–positive. Approximately 60% of respondents reported no change in treatment recommendation during the pandemic, except for patients with metastatic disease, for which 57.7% (636/1,103; P < .0005) changed their palliative practice. Among respondents who noted a change in their recommendation during the first surge of the pandemic, omitting, delaying, and adopting short-course RT were the most frequent changes, with most transitioning to moderate hypofractionation for DCIS and early-stage BC. CONCLUSION Early in the COVID-19 pandemic, significant changes in global RT practice patterns for BC were introduced. The impact of published results from the FAST FORWARD trial supporting ultrahypofractionation likely confounded the interpretation of the pandemic's independent influence on RT delivery.
Breast Cancer–Related Lymphedema: Risk Factors, Screening, Management, and the Impact of Locoregional Treatment