True recurrence vs. new primary ipsilateral breast tumor relapse: an analysis of clinical and pathologic differences and their implications in natural history, prognoses, and therapeutic management

Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: a Kaplan-Meier-derived patient data meta-analysis

PURPOSE

Partial breast irradiation (PBI) and intraoperative radiation (IORT) represent alternatives to whole breast irradiation (WBI) following breast conserving surgery. However, data is mixed regarding outcomes. We therefore performed a pooled analysis of Kaplan-Meier-derived patient data from randomized trials to evaluate the hypothesis that PBI and IORT have comparable long-term rates of ipsilateral breast tumor recurrence as WBI.

METHODS

In February, 2023, PubMed, EMBASE and Cochrane Central were systematically searched for randomized phase 3 trials of early-stage breast cancer patients undergoing breast-conserving surgery with PBI or IORT as compared to WBI. Time-to-event outcomes of interest included ipsilateral breast tumor recurrence (IBTR), overall survival (OS) and distant disease-free survival (DDFS). Statistical analysis was performed with R Statistical Software.

RESULTS

Eleven randomized trials comprising 15,460 patients were included; 7,675 (49.6%) patients were treated with standard or moderately hypofractionated WBI, 5,413 (35%) with PBI and 2,372 (15.3%) with IORT. Median follow-up was 9 years. PBI demonstrated comparable IBTR risk compared with WBI (HR 1.20; 95% CI 0.95-1.52; p = 0.12) with no differences in OS (HR 1.02; 95% CI 0.90-1.16; p = 0.70) or DDFS (HR 1.15; 95% CI 0.81-1.64; p = 0.43). In contrast, patients treated with IORT had a higher IBTR risk (HR 1.46; 95% CI 1.23-1.72; p < 0.01) compared with WBI with no difference in OS (HR 0.98; 95% CI 0.84-1.14; p = 0.81) or DDFS (HR 0.91; 95% CI 0.76-1.09; p = 0.31).

CONCLUSION

For patients with early-stage breast cancer following breast-conserving surgery, PBI demonstrated no difference in IBTR as compared to WBI while IORT was inferior to WBI with respect to IBTR.

Residual Risk of Ipsilateral Tumor Recurrence in Patients Who Achieved Clear Lumpectomy Margins After Repeated Resection

PURPOSE

Patients with breast cancer with positive lumpectomy margins have a two-fold increased risk of ipsilateral breast tumor recurrence (IBTR). This can be the result of either technically incomplete resection or the biological characteristics of the tumor that lead to a positive margin. We hypothesized that if achieving negative margins by re-excision nullifies the IBTR risk, then the increased risk is mainly attributed to the technical incompleteness of the initial surgeries. Thus, we investigated IBTR rates in patients with breast cancer who achieved clear margins after re-excision.

METHODS

We retrospectively reviewed patients who underwent breast lumpectomy for invasive breast cancer between 2004 and 2018 at a single institution, and investigated IBTR events.

RESULTS

Among 5,598 patients, 793 achieved clear margins after re-excision of their initial positive margins. During the median follow-up period of 76.4 months, 121 (2.2%) patients experienced IBTR. Patients who underwent re-excision to achieve negative margin experienced significantly higher IBTR rates compared to those achieving clear margin at first lumpectomy (10-year IBTR rate: 5.3% vs. 2.6% [25 vs. 84 events]; unadjusted p = 0.031, hazard ratio, 1.61, 95% confidence interval [CI], 1.04-2.48; adjusted p = 0.030, hazard ratio, 1.69, 95% CI, 1.05-2.72). This difference was more evident in patients aged < 50 years and those with delayed IBTR. Additionally, no statistically significant differences were observed in the spatial distribution of IBTR locations.

CONCLUSION

Patients who underwent re-excision for initial positive margins had an increased risk of IBTR, even after achieving a final negative margin, compared to patients with negative margins initially. This increased risk of IBTR is mostly observed in young patients and delayed cases.

Predictors and outcomes of recurrent retroperitoneal liposarcoma: new insights into its recurrence patterns

BACKGROUND

The clinical profiles of recurrent retroperitoneal liposarcoma (RLS) need to be explored. The recurrence patterns of RLS are controversial and ambiguous.

METHODS

A total of 138 patients with recurrent RLS were finally recruited in the study. The analysis of overall survival (OS) and recurrence-free survival (RFS) was performed by Kaplan‒Meier analysis. To identify independent prognostic factors, all significant variables on univariate Cox regression analysis (P ≤ 0.05) were subjected to multivariate Cox regression analysis. The corresponding nomogram model was further built to predict the survival status of patients.

RESULTS

Among patients, the 1-, 3-, and 5-year OS rates were 70.7%, 35.9% and 30.9%, respectively. The 1-, 3- and 5-year RFS rates of the 55 patients who underwent R0 resection were 76.1%, 50.8% and 34.4%, respectively. The multivariate analysis revealed that resection method, tumor size, status of pathological differentiation, pathological subtypes and recurrence pattern were independent risk factors for OS or RFS. Patients with distant recurrence (DR) pattern usually had multifocal tumors (90.5% vs. 74.7%, P < 0.05); they were prone to experience changes of pathological differentiation (69.9% vs. 33.3%, P < 0.05) and had a better prognosis than those with local recurrence (LR) pattern. R0 resection and combined organ resection favored the survival of patients with DR pattern in some cases.

CONCLUSIONS

Patients with DR pattern had better prognosis, and they may benefit more from aggressive combined resection than those with LR pattern. Classifying the recurrence patterns of RLS provides guidance for individualized clinical management of recurrent RLS.

Locoregional Recurrence Patterns in Patients With Different Molecular Subtypes of Breast Cancer

IMPORTANCE

While numerous studies have consistently reported that the molecular subtypes of breast cancer (BC) are associated with different patterns of distant metastasis, few studies have investigated the association of tumor subtypes with locoregional recurrence.

OBJECTIVE

To investigate the patterns of ipsilateral breast tumor recurrence (IBTR), regional recurrence (RR), and contralateral BC (CBC) according to tumor subtypes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used the clinical records of patients who underwent BC surgery at a single institution in South Korea between January 2000 and December 2018. Data were analyzed from May 1, 2019, to February 20, 2023.

EXPOSURES

Ipsilateral breast tumor recurrence, RR, and CBC events.

MAIN OUTCOMES AND MEASURES

The primary outcome was differences in annual incidence patterns of IBTR, RR, and CBC according to tumor subtypes. Hormone receptor (HR) status was assessed by immunohistochemical staining assay, and ERBB2 status was evaluated according to American Society of Clinical Oncology and College of American Pathologists guidelines.

RESULTS

A total of 16 462 female patients were included in the analysis (median age at time of operation, 49.0 years [IQR, 43.0-57.0 years]). The 10-year IBTR-, RR-, and CBC-free survival rates were 95.9%, 96.1%, and 96.5%, respectively. On univariate analysis, HR-/ERBB2+ tumors had the worst IBTR-free survival (vs HR+/ERBB2- subtype: adjusted hazard ratio, 2.95; 95% CI, 2.15-4.06), while the HR-/ERBB2- subtype had the worst RR- and CBC-free survival among all subtypes (vs HR+/ERBB2- subtype, RR: adjusted hazard ratio, 2.95; 95% CI, 2.37-3.67; CBC: adjusted hazard ratio, 2.12; 95% CI, 1.64-2.75). Subtype remained significantly associated with recurrence events in Cox proportional hazards regression analysis. Regarding the annual recurrence pattern, the IBTR patterns of HR-/ERBB2+ and HR-/ERBB2- subtypes showed double peaks, while HR+/ERBB2- tumors showed a steadily increasing pattern without distinguishable peaks. Additionally, the HR+/ERBB2- subtype seemed to have a steady RR pattern, but other subtypes showed the highest RR incidence at 1 year following surgery, which then gradually decreased. The annual recurrence incidence of CBC gradually increased among all subtypes, and patients with the HR-/ERBB2- subtype had a higher incidence than patients with other subtypes over 10 years. Younger patients (age ≤40 years) had greater differences in IBTR, RR, and CBC patterns between subtypes than did older patients.

CONCLUSIONS AND RELEVANCE

In this study, locoregional recurrence occurred with different patterns according to BC subtypes, with younger patients having greater differences in patterns among subtypes than older patients. The findings suggest that tailoring surveillance should be recommended regarding differences in locoregional recurrence patterns according to tumor subtypes, particularly for younger patients.

Locoregional recurrence in triple negative breast cancer: past, present, and future

INTRODUCTION

Triple negative breast cancer (TNBC) is a rare but aggressive biological subtype of breast cancer associated with higher locoregional and distant recurrence rates and lower overall survival despite advancements in diagnostic and treatment strategies.

AREAS COVERED

This review explores the evolving landscape of locoregional recurrence (LRR) in TNBC with improved surgical and radiation therapy delivery techniques including salvage breast conserving surgery (SBCS), re-irradiation, and thermo-radiation. We review current retrospective and prospective, albeit limited, clinical data highlighting the optimal management of locoregionally recurrent TNBC. We also discuss tumor genomic profiling and transcriptome analysis and review potential investigational directions.

EXPERT OPINION

Significant progress has been made in the prevention of LRR but rates remain suboptimal, particularly in the TNBC population, and outcomes following LRR are poor. Further prospective studies are needed to identify the most effective and safest systemic therapy regimens and to whom it should be offered. There has been growing interest in the role of molecular markers, genomic signatures, and tumor microenvironment in predicting outcomes and guiding LRR treatment. Transcriptome analyses and biomarker-driven investigations are currently being studied and represent a promising era of development in the management of LRR.

The 2022 Assisi Think Tank Meeting: White paper on optimising radiation therapy for breast cancer

The present white paper, referring to the 4th Assisi Think Tank Meeting on breast cancer, reviews state-of-the-art data, on-going studies and research proposals. < 70% agreement in an online questionnaire identified the following clinical challenges: 1: Nodal RT in patients who have a) 1-2 positive sentinel nodes without ALND (axillary lymph node dissection); b) cN1 disease transformed into ypN0 by primary systemic therapy and c) 1-3 positive nodes after mastectomy and ALND. 2. The optimal combination of RT and immunotherapy (IT), patient selection, IT-RT timing, and RT optimal dose, fractionation and target volume. Most experts agreed that RT- IT combination does not enhance toxicity. 3: Re-irradiation for local relapse converged on the use of partial breast irradiation after second breast conserving surgery. Hyperthermia aroused support but is not widely available. Further studies are required to finetune best practice, especially given the increasing use of re-irradiation.

Locoregional relapse after sparing mastectomies and immediate reconstruction in women with breast cancer

INTRODUCTION

In recent years, cultural changes in today's society and improved risk assessment have increased the indication for mastectomies in women with breast cancer. Various studies have confirmed the oncological safety of sparing mastectomies and immediate reconstruction. The objective of this study is to analyze the incidence of locoregional relapses of this procedure and its impact on reconstruction and overall survival.

PATIENTS AND METHODS

Prospective study of patients with breast carcinoma who underwent a sparing mastectomy and immediate reconstruction. Locoregional relapses and their treatment and their impact on survival were analyzed.

RESULTS

The study group is made up of 271 women with breast carcinoma treated with a skin-sparing mastectomy and immediate reconstruction. The mean follow-up was 7.98 years and during the same 18 locoregional relapses (6.6%) were diagnosed: 72.2% in the mastectomy flap and 27.8% lymph node. There were no significant differences in the pathological characteristics of the primary tumor between patients with and without locoregional relapse, although the percentage of women with hormone-sensitive tumors was higher in the group without relapse. Patients with lymph node relapse had larger tumors (80% T2-T3) and 60% had axillary metastases at diagnosis, compared to 7.7% of women with skin relapse (p = 0.047). All patients operated on for locoregional relapse preserved their reconstruction. The incidence of metastases and deaths was significantly higher in patients with a relapse, causing a non-significant decrease in overall survival.

CONCLUSION

Locoregional relapses are a rare event in women with a sparing mastectomy and immediate reconstruction. Most patients with locoregional relapse can preserve their initial reconstruction through local resection of the tumor and adjuvant and / or neoadjuvant therapies.

Prognosis of local invasive relapses after carcinoma in situ of the breast: a retrospective study from a population-based registry

PURPOSE

The prognosis of local invasive recurrence (LIR) after prior carcinoma in situ (CIS) of the breast has not been widely studied and existing data are conflicting, especially considering the specific prognosis of this entity, compared to de novo invasive breast cancer (de novo IBC) and with LIR after primary IBC.

METHODS

We designed a retrospective study using data from the specialized Côte d'Or Breast and Gynecological cancer registry, between 1998 and 2015, to compare outcomes between 3 matched groups of patients with localized IBC: patients with LIR following CIS (CIS-LIR), patients with de novo IBC (de novo IBC), and patients with LIR following a first IBC (IBC-LIR). Distant relapse-free (D-RFS), overall survival (OS), clinical, and treatment features between the 3 groups were studied.

RESULTS

Among 8186 women initially diagnosed with IBC during our study period, we retrieved and matched 49 CIS-LIR to 49 IBC, and 46 IBC-LIR patients. At diagnosis, IBC/LIR in the 3 groups were mainly stage I, grade II, estrogen receptor-positive, and HER2 negative. Metastatic diseases at diagnosis were higher in CIS-LIR group. A majority of patients received adjuvant systemic treatment, with no statistically significant differences between the 3 groups. There was no significant difference between the 3 groups in terms of OS or D-RFS.

CONCLUSION

LIR after CIS does not appear to impact per se on survival of IBC.

Breast cancer: emerging principles of metastasis, adjuvant and neoadjuvant treatment from cancer registry data

PURPOSE

Growing primary breast cancers (PT) can initiate local recurrences (LR), regional lymph nodes (pLN) and distant metastases (MET). Components of these progressions are initiation, frequency, growth duration, and survival. These characteristics describe principles which proposed molecular concepts and hypotheses must align with.

METHODS

In a population-based retrospective modeling approach using data from the Munich Cancer Registry key steps and factors associated with metastasis were identified and quantified. Analysis of 66.800 patient datasets over four time periods since 1978, reliable evidence is obtained even in small subgroups. Together with results of clinical trials on prevention and adjuvant treatment (AT) principles for the MET process and AT are derived.

RESULTS

The median growth periods for PT/MET/LR/pLN comes to 12.5/8.8/5/3.5 years, respectively. Even if 30% of METs only appear after 10 years, a pre-diagnosis MET initiation principle not a delayed one should be true. The growth times of PTs and METs vary by a factor of 10 or more but their ratio is robust at about 1.4. Principles of AT are 50% PT eradication, the selective and partial eradication of bone and lung METs. This cannot be improved by extending the duration of the previously known ATs.

CONCLUSION

A paradigm of ten principles for the MET process and ATs is derived from real world data and clinical trials indicates that there is no rationale for the long-term application of endocrine ATs, risk of PTs by hormone replacement therapies, or cascading initiation of METs. The principles show limits and opportunities for innovation also through alternative interpretations of well-known studies. The outlined MET process should be generalizable to all solid tumors.

Optimal radiotherapy after breast-conserving surgery for early breast cancer: A network meta-analysis of 23,418 patients

PURPOSE

In order to explore whether partial breast irradiation can replace hypofractionated whole breast irradiation and whether the former two are superior to conventional fractionated whole breast irradiation, we conducted a network meta-analysis based on the data from the latest randomized controlled trials to evaluate the efficacy of these radiotherapy modalities.

MATERIAL AND METHODS

Data from eligible studies were analyzed to determine the published events for ipsilateral breast tumor recurrence, distant metastasis, total deaths, and non-breast cancer-related deaths. In the case of low or high heterogeneity, the fixed-effect or random-effect model was used for statistical analysis respectively. NMA was performed by using the node-splitting model for two-category data among three radiotherapies based on a Bayesian method.

RESULTS

A total of 23,418 patients were included in 16 studies. For ipsilateral breast tumor recurrence, both pairwise (OR=1.9; CI95%: 1.2 -2.8; p<0.05) and indirect (OR=1.7; CI95%: 1.2 -2.4; p<0.05) comparison of three radiotherapies by network meta-analysis showed that conventional fractionated whole breast irradiation was significantly better than partial breast irradiation. Indirect comparison of three radiotherapies by network meta-analysis showed that hypofractionated whole breast irradiation was significantly better than partial breast irradiation (OR=1.6; CI95%: 1.0 -2.5; p<0.05). Network and paired meta-analyses found no significant differences in other endpoints among the three radiotherapies.

CONCLUSION

Overall, this network meta-analysis showed that partial breast irradiation was related to the increase of ipsilateral breast tumor recurrence compared with hypofractionated or conventional fractionated whole breast irradiation in patients with early-stage breast cancer.

Repeat Breast-Conserving Surgery Versus Salvage Mastectomy for Ipsilateral Breast Tumour Recurrence After Breast-Conserving Surgery in Breast Cancer Patients: A Meta-Analysis

Background

Salvage mastectomy (SM) is the standard surgery for ipsilateral breast tumour recurrence (IBTR). However, whether repeat breast-conserving surgery (RBCS) is an alternative method remains unclear. We performed a meta-analysis to compare the effects of RBCS and SM after IBTR for breast-conserving surgery (BCS).

Methods

We searched PubMed, Cochrane, Wiley Online and Embase for controlled studies comparing RBCS and SM after IBTR for BCS (published between 1993 and 2019, published in English). Our main endpoints were the secondary local recurrence rate (SLRR), distant metastasis rate (DMR) and overall survival (OS). We used a random-effects model or fixed-effects model for data pooling.

Results

Fifteen of the 424 eligible studies were ultimately included, and all studies were retrospective cohort studies (n=2532 participants). 1) SLRR: The SLRR of RBCS was higher than SM (pooled relative rate (pRR) = 1.87, 95% CI 1.22 - 2.86, P=0.004). Stratified analysis was performed according to whether radiotherapy was performed after salvage surgery (radiotherapy group: 2ndRT, no radiotherapy group: no-2ndRT), and the following results were revealed: pRR=0.43 (95% CI 0.20-0.95, P=0.04) for group 2ndRT; and pRR=2.30 (95% CI 1.72-3.06, P<0.00001) for group no-2ndRT. These results showed that the main cause of heterogeneity was salvage radiotherapy. 2) DMR: No significant difference in the DMR was observed between RBCS and SM (pRR = 0.61, 95% CI 0.37 - 1.01, P=0.05). 3) OS: No significant difference in OS was observed between RBCS and SM (pRR=0.65, 95% CI 0.39 - 1.08, P=0.10).

Conclusions

The SLRR of RBCS was higher than SM for ITBR after BCS, but survival was not affected. RBCS may be used as an alternative for IBTR patients after BCS with strict control for several indications, such as tumor size, recurrence interval and biological behavior, and attaching importance to subsequent salvage radiotherapy and systematic therapy.

Prognostic Factors and Surgery for Breast Cancer Patients With Locoregional Recurrence: An Analysis of 5,202 Consecutive Patients

Purpose

With the application of “less extensive surgery” in breast cancer treatment, the pattern of locoregional recurrence (LRR) has significantly changed. This study aims to evaluate the risk and prognostic factors of LRR in a recent large breast cancer cohort.

Methods

Consecutive early breast cancer patients who received surgery from January 2009 to March 2018 in Shanghai Ruijin Hospital were retrospectively analyzed. LRR was defined as recurrence at the ipsilateral breast (IBTR), chest wall, or regional lymph nodes and without concurrent distant metastasis (DM). Patients’ characteristics and survival were compared among these groups.

Results

Among 5,202 patients included, 87 (1.7%) and 265 (5.1%) experienced LRR and DM as first event after a median 47.0 (3.0–122.5) months’ follow-up. LRR was significantly associated with large tumor size and positive lymph node status (p < 0.05). Forty (46.0%) patients received further salvage surgery after LRR and had a significantly better 3-year post-recurrence overall survival than those who did not (94.7% vs. 60.7%, p = 0.012). Multivariate analysis showed that salvage surgery for LRR was independently associated with better survival (HR = 0.12, 95% CI 0.02–0.93, p = 0.043) along with estrogen receptor (ER) positivity (HR = 0.33, 95% CI 0.12–0.91, p = 0.033).

Conclusion

LRR rate was relatively low in recent era of breast cancer treatment. Tumor size and lymph node status were associated with risk of LRR, and salvage surgery for selected LRR patients achieved an excellent outcome.

Spatiotemporal Patterns of Loco-Regional Recurrence After Breast-Conserving Surgery

Background

Loco-regional recurrences (LRR) following breast-conserving surgery (BCS) remain a heterogeneous class of disease that has significant variation in its biological behavior and prognosis.

Methods

To delineate the spatiotemporal patterns of LRR after BCS, we analyzed the data of 4325 patients treated with BCS from 2006 to 2016. Clinico-pathological and treatment specific factors were analyzed using the Cox proportional hazards model to identify factors predictive for LRR events. Recurrence patterns were scrutinized based on recurrence type and recurrence-free interval (RFI). Annual recurrence rates (ARR) were compared according to recurrence type and molecular subtype.

Results

With a median follow-up of 66 months, 120 (2.8%) LRRs were recorded as the first site of failure. Age, pathologic stage, and molecular subtype were identified as predictors of LRR. The major recurrence type was ipsilateral breast tumor recurrence, which mainly (83.6%) occurred ≤5y post surgery. In the overall population, ARR curves showed that relapse peaked in the first 2.5 years. Patients with regional nodal recurrence, shorter RFI, and synchronous distant metastasis were associated with a poorer prognosis. HER2-positive disease had a higher rate of LRR events, more likely to have in-breast recurrence, and had an earlier relapse peak in the first 2 years after surgery.

Conclusions

LRR risk following BCS is generally low in Chinese ethnicity. Different recurrence patterns after BCS were related to distinct clinical outcomes. Management of LRR should be largely individualized and tailored to the extent of disease, the molecular profile of the recurrence, and to baseline clinical variables.

Increased Risk for Ipsilateral Breast Tumor Recurrence in Invasive Lobular Carcinoma after Accelerated Partial Breast Irradiation Brachytherapy

BACKGROUND

The suitability criteria for accelerated partial breast irradiation (APBI) from the American Brachytherapy Society (ABS), American Society for Radiation Oncology (ASTRO), and The Groupe Européende Curiethérapie European SocieTy for Radiotherapy & Oncology (GEC-ESTRO) have significant differences.

MATERIALS AND METHODS

This is a single institution retrospective review of 946 consecutive patients with invasive breast cancer who underwent lumpectomy and APBI intracavitary brachytherapy from 2003 to 2018. Overall survival (OS), breast cancer-specific survival (BCSS), relapse-free survival (RFS), and ipsilateral breast tumor recurrence (IBTR) were estimated with Kaplan-Meier method.

RESULTS

Median follow-up time was 60.2 months. Median age was 68 years (46-94 years). The majority of patients had estrogen receptor (ER)-positive disease (94%). There were 821 (87%) cases of invasive ductal carcinoma and 68 cases (7%) of invasive lobular carcinoma (ILC). The 5-year OS, BCSS, RFS, and IBTR were 93%, 99%, 90%, and 1.5%, respectively. Upon univariate analysis, ILC (hazard ratio [HR], 4.6; p = .008) and lack of nodal evaluation (HR, 6.9; p = .01) were risk factors for IBTR. The 10-year IBTR was 2.5% for IDC and 14% for ILC. While the ABS and ASTRO criteria could not predict IBTR, the GEC-ESTRO intermediate risk group was associated with inferior IBTR (p = .04) when compared to both low risk and high risk groups. None of the suitability criteria was able to predict RFS.

CONCLUSION

These results show that APBI is an effective treatment for patients with invasive breast cancer. Expansion of the current eligibility criteria should be considered, although prospective validation is needed. Caution is required when considering APBI for patients with ILC.

IMPLICATIONS FOR PRACTICE

In a large retrospective review of 946 patients with early breast cancer treated with partial mastectomy and accelerated partial breast irradiation (APBI) intracavitary brachytherapy, this study demonstrates durable local control. Patients deemed unsuitable or high risk by the American Brachytherapy Society, American Society for Radiation Oncology, and European Society for Radiotherapy and Oncology guidelines were not at increased risk for ipsilateral breast tumor recurrence (IBTR), suggesting that expansion of the current criteria should be considered. Importantly, however, these results demonstrate that caution should be taken when considering APBI for patients with invasive lobular carcinoma, as these patients had relatively high risk for IBTR (10-year IBTR, 14%).

Partial breast irradiation versus whole breast radiotherapy for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane Review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypofractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

On 27 August 2020, we searched the Cochrane Breast Cancer Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and three trial databases. We searched for grey literature: OpenGrey (September 2020), reference lists of articles, conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction, used Cochrane's risk of bias tool and resolved any disagreements through discussion, and assessed the certainty of the evidence for main outcomes using GRADE. Main outcomes were local recurrence-free survival, cosmesis, overall survival, toxicity (subcutaneous fibrosis), cause-specific survival, distant metastasis-free survival and subsequent mastectomy. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included nine RCTs that enrolled 15,187 women who had invasive breast cancer or ductal carcinoma in-situ (6.3%) with T1-2N0-1M0 Grade I or II unifocal tumours (less than 2 cm or 3 cm or less) treated with breast-conserving therapy with negative margins. This is the second update of the review and includes two new studies and 4432 more participants. Local recurrence-free survival is probably slightly reduced (by 3/1000, 95% CI 6 fewer to 0 fewer) with the use of PBI/APBI compared to WBRT (hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.03 to 1.42; 8 studies, 13,168 participants; moderate-certainty evidence). Cosmesis (physician/nurse-reported) is probably worse (by 63/1000, 95% CI 35 more to 92 more) with the use of PBI/APBI (odds ratio (OR) 1.57, 95% CI 1.31 to 1.87; 6 studies, 3652 participants; moderate-certainty evidence). Overall survival is similar (0/1000 fewer, 95% CI 6 fewer to 6 more) with PBI/APBI and WBRT (HR 0.99, 95% CI 0.88 to 1.12; 8 studies, 13,175 participants; high-certainty evidence). Late radiation toxicity (subcutaneous fibrosis) is probably increased (by 14/1000 more, 95% CI 102 more to 188 more) with PBI/APBI (OR 5.07, 95% CI 3.81 to 6.74; 2 studies, 3011 participants; moderate-certainty evidence). The use of PBI/APBI probably makes little difference (1/1000 less, 95% CI 6 fewer to 3 more) to cause-specific survival (HR 1.06, 95% CI 0.83 to 1.36; 7 studies, 9865 participants; moderate-certainty evidence). We found the use of PBI/APBI compared with WBRT probably makes little or no difference (1/1000 fewer (95% CI 4 fewer to 6 more)) to distant metastasis-free survival (HR 0.95, 95% CI 0.80 to 1.13; 7 studies, 11,033 participants; moderate-certainty evidence). We found the use of PBI/APBI in comparison with WBRT makes little or no difference (2/1000 fewer, 95% CI 20 fewer to 20 more) to mastectomy rates (OR 0.98, 95% CI 0.78 to 1.23; 3 studies, 3740 participants, high-certainty evidence).

AUTHORS' CONCLUSIONS

It appeared that local recurrence-free survival is probably worse with PBI/APBI; however, the difference was small and nearly all women remain free of local recurrence. Overall survival is similar with PBI/APBI and WBRT, and we found little to no difference in other oncological outcomes. Some late effects (subcutaneous fibrosis) may be worse with PBI/APBI and its use is probably associated with worse cosmetic outcomes. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver PBI/APBI. We await completion of ongoing trials.

Modern radiation techniques in early stage breast cancer for the breast radiologist

Partial breast irradiation (PBI) and ultra-hypofractionated whole breast irradiation (uWBI) are contemporary alternatives to conventional and standard hypofractionated whole breast irradiation (WBI), which shorten treatment from 3 to 6 weeks to 1-2 weeks for select patients. PBI and accelerated PBI (APBI) can be delivered with external beam radiation (3D conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT)), intraoperative radiation (IORT), or brachytherapy. These new radiation techniques offer the advantage of convenience and lower cost, which ultimately improves access to care. Globally, the COVID 19 pandemic has accelerated APBI/PBI and ultra-hypofractionated regimens into routine practice for carefully selected patients. Recent long-term data from randomized controlled trials (RCTs) have demonstrated these techniques are safe and effective in suitable patients demonstrating equivalent or improved local recurrence, acute/late toxicity, and cosmesis. PBI and APBI should be limited to low risk unifocal invasive ductal carcinoma and ductal carcinoma in situ with tumor size < 2 cm, clear margins (≥2 mm), ER+, and negative nodes. Based on the results from UK Fast-Forward and UK FAST ultra-hypofractionated breast radiation can be safely employed for early stage node negative patients, but is not yet considered an international standard of care. In this review, authors will appraise recent data for these shorter course radiation treatment regimens, as well as, considerations for breast radiologists including surveillance imaging and radiographic findings.

Intraoperative irradiation for early breast cancer (ELIOT): long-term recurrence and survival outcomes from a single-centre, randomised, phase 3 equivalence trial

BACKGROUND

In the randomised, phase 3 equivalence trial on electron intraoperative radiotherapy (ELIOT), accelerated partial breast irradiation (APBI) with the use of intraoperative radiotherapy was associated with a higher rate of ipsilateral breast tumour recurrence (IBTR) than whole-breast irradiation (WBI) in patients with early-stage breast cancer. Here, we aimed to examine the planned long-term recurrence and survival outcomes from the ELIOT trial.

METHODS

This single-centre, randomised, phase 3 equivalence trial was done at the European Institute of Oncology (Milan, Italy). Eligible women, aged 48-75 years with a clinical diagnosis of a unicentric breast carcinoma with an ultrasound diameter not exceeding 25 mm, clinically negative axillary lymph nodes, and who were suitable for breast-conserving surgery, were randomly assigned (1:1) via a web-based system, with a random permuted block design (block size of 16) and stratified by clinical tumour size, to receive post-operative WBI with conventional fractionation (50 Gy given as 25 fractions of 2 Gy, plus a 10 Gy boost), or 21 Gy intraoperative radiotherapy with electrons (ELIOT) in a single dose to the tumour bed during surgery. The trial was open label and no-one was masked to treatment group assignment. The primary endpoint was the occurrence of IBTR. The trial was designed assuming a 5-year IBTR rate of 3% in the WBI group and equivalence of the two groups, if the 5-year IBTR rate in the ELIOT group did not exceed a 2·5 times excess, corresponding to 7·5%. Overall survival was the secondary endpoint. The main analysis was done by intention to treat. The cumulative incidence of IBTR events and overall survival were assessed at 5, 10, and 15 years of follow-up. This trial is registered with ClinicalTrials.gov, NCT01849133.

FINDINGS

Between Nov 20, 2000, and Dec 27, 2007, 1305 women were enrolled and randomly assigned: 654 to the WBI group and 651 to the ELIOT group. After a median follow-up of 12·4 years (IQR 9·7-14·7), 86 (7%) patients developed IBTR, with 70 (11%) cases in the ELIOT group and 16 (2%) in the WBI group, corresponding to an absolute excess of 54 IBTRs in the ELIOT group (HR 4·62, 95% CI 2·68-7·95, p<0·0001). In the ELIOT group, the 5-year IBTR rate was 4·2% (95% CI 2·8-5·9), the 10-year rate was 8·1% (6·1-10·3), and the 15-year rate was 12·6% (9·8-15·9). In the WBI group, the 5-year IBTR rate was 0·5% (95% CI 0·1-1·3), the 10-year rate was 1·1% (0·5-2·2), and the 15-year rate was 2·4% (1·4-4·0). At final follow-up on March 11, 2019, 193 (15%) women had died from any cause, with no difference between the two groups (98 deaths in the ELIOT group vs 95 in the WBI group; HR 1·03, 95% CI 0·77-1·36, p=0·85). In the ELIOT group, the overall survival rate was 96·8% (95% CI 95·1-97·9) at 5 years, 90·7% (88·2-92·7) at 10 years, and 83·4% (79·7-86·4) at 15 years; and in the WBI group, the overall survival rate was 96·8% (95·1-97·9) at 5 years, 92·7% (90·4-94·4) at 10 years, and 82·4% (78·5-85·6) at 15 years. We did not collect long-term data on adverse events.

INTERPRETATION

The long-term results of this trial confirmed the higher rate of IBTR in the ELIOT group than in the WBI group, without any differences in overall survival. ELIOT should be offered to selected patients at low-risk of IBTR.

FUNDING

Italian Association for Cancer Research, Jacqueline Seroussi Memorial Foundation for Cancer Research, Umberto Veronesi Foundation, American Italian Cancer Foundation, The Lombardy Region, and Italian Ministry of Health.

Management of ductal carcinoma in situ with accelerated partial breast irradiation brachytherapy: Implications for guideline expansion

PURPOSE

Accelerated partial breast irradiation (APBI) for patients with ductal carcinoma in situ (DCIS) is controversial, and the suitability criteria from the American Brachytherapy Society (ABS), American Society of Therapeutic Radiology and Oncology (ASTRO), and the European Society for Radiotherapy and Oncology (GEC-ESTRO) have important differences.

METHODS AND MATERIALS

This is a single-institution retrospective review of 169 consecutive patients with DCIS who underwent lumpectomy followed by APBI intracavitary brachytherapy from 2003 to 2018. Outcomes, including overall survival, recurrence-free survival (RFS), ipsilateral breast tumor recurrence, and distant metastasis, were estimated with the Kaplan-Meier method.

RESULTS

The median followup time was 62.5 months. Median age was 66 years (47-89 years). The majority of patients had estrogen receptor-positive disease (89%). Fifty patients (30%) had Grade 3 disease. Of the 142 patients with adequate pathology interpretation, 91 and 108 cases had margins ≥ 3 mm and ≥2 mm, respectively. Most patients (72%) were prescribed and started endocrine therapy. Of the patients evaluable for ABS criteria (N = 130), 97 met the suitability criteria. Of the patients evaluable for ASTRO criteria (N = 129), 42 were deemed cautionary and 33 were deemed unsuitable. Of the patients evaluable for GEC-ESTRO criteria (N = 143), 141 cases were at intermediate risk and two were at high risk. Five-year ipsilateral breast tumor recurrence, RFS, and overall survival were 0.6%, 97.7%, and 97.2%, respectively. The ABS, ASTRO, and GEC-ESTRO criteria failed to significantly predict for RFS.

CONCLUSIONS

These results, although limited by short-term followup, indicate that expansion of the eligibility criteria of APBI for patients with DCIS should be considered.

Prognosis of Surgical Treatment After Ipsilateral Breast Tumor Recurrence

BACKGROUND

Ipsilateral breast tumor recurrence (IBTR) was determined to be a powerful independent risk factor of distant disease and increased mortality. Although mastectomy is the standard salvage treatment for IBTR after breast conserving treatment, there is evidence that repeat breast conserving surgery (rBCS) might be a feasible alternative treatment.

MATERIALS AND METHODS

The data of patients who were diagnosed with IBTR between 1998 and 2013 were obtained from the Surveillance, Epidemiology, and End Results database. Breast cancer-specific survival (BCSS) and overall survival (OS) were calculated using the Kaplan-Meier method. The Cox proportional hazards model was used for multivariate analysis, and propensity score matching analysis was applied to compensate for the differences in some baseline characteristics.

RESULTS

A total of 475 patients (22.9%) who underwent rBCS and 1600 (77.1%) who underwent mastectomy after IBTR were included in the study. During a median follow-up of 130 mo, no significant differences were observed in BCSS and OS between the rBCS and mastectomy groups of patients before and after propensity score matching. Multivariate analysis revealed that race, the American Joint Committee on Cancer stage of the recurrent tumor, and reirradiation were independent prognostic factors for both BCSS and OS.

CONCLUSIONS

The results of our study indicate that rBCS can be a feasible alternative treatment option for patients with IBTR. Nevertheless, further studies should be conducted to identify the prognosis of patients after rBCS as well as the best candidates for a second breast conserving surgery.

No Difference in Overall Survival and Non-Breast Cancer Deaths after Partial Breast Radiotherapy Compared to Whole Breast Radiotherapy-A Meta-Analysis of Randomized Trials

Purpose/objective: Adjuvant radiotherapy after breast conserving surgery is the standard approach in early stage breast cancer. However, the extent of breast tissue that has to be targeted with radiation has not been determined yet. Traditionally, the whole breast was covered by two opposing tangential beams. Several randomized trials have tested partial breast irradiation (PBI) compared to whole breast irradiation (WBI) using different radiation techniques. There is evidence from randomized trials that PBI might result in lower mortality rates compared to WBI. We aimed to reassess this question using current data from randomized trials. Material/methods: We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect sizes for overall survival (OS), breast cancer-specific survival (BCSS), and non-breast cancer death (NBCD) as investigated endpoints. Analysis of subgroups using different radiation techniques was intended. We used hazard ratios (HR) and risk differences (RD) to estimate pooled effect sizes. Statistical analysis was performed using the inverse variance heterogeneity model. Results: We identified eleven studies randomizing between PBI and WBI. We did not find significant differences in OS (n = 14,070; HR = 1.02; CI-95%: 0.89–1.16; p = 0.810, and n = 15,203; RD = −0.001; CI-95%: −0.008–0.006; p = 0.785) and BCSS (n = 15,203; RD = 0.001; CI-95%: −0.002–0.005; p = 0.463). PBI also did not result in a significant decrease of NBCD (n = 15,203; RD = −0.003; CI-95%: −0.010–0.003; p = 0.349). A subgroup analysis by radiation technique also did not point to any detectable differences. Conclusion: In contrast to a previous assessment of mortality, we could not find a detrimental effect of WBI on OS or NBCD. A longer follow-up might be necessary to fully assess the long-term mortality effects of PBI compared to WBI.

Local staging of ipsilateral breast tumor recurrence: mammography, ultrasound, or MRI?

BACKGROUND

Despite increasingly effective curative breast-conserving treatment (BCT) regimens for primary breast cancer, patients remain at risk for an ipsilateral breast tumor recurrence (IBTR). With increasing interest for repeat BCT in selected patients with IBTR, a reliable assessment of the size of IBTR is important for surgical planning.

AIM

The primary aim of this study is to establish the performance in size estimation of XMG, US, and breast MRI in patients with IBTR. The secondary aim is to compare the detection of multifocality and contralateral lesions between XMG and MRI.

PATIENTS AND METHODS

The sizes of IBTR on mammography (XMG), ultrasound (US), and magnetic resonance imaging (MRI) in 159 patients were compared to the sizes at final histopathology. The accuracy of the size estimates was addressed using Pearson's coefficient and Bland-Altman plots. Secondary outcomes were the detection of multifocality and contralateral lesions between XMG and MRI.

RESULTS

Both XMG and US significantly underestimated the tumor size by 3.5 and 4.8 mm, respectively, while MRI provided accurate tumor size estimation with a mean underestimation of 1.1 mm. The sensitivity for the detection of multifocality was significantly higher for MRI compared to XMG (25.5% vs. 5.5%). A contralateral malignancy was found in 4.4% of patients, and in 1.9%, it was detected by MRI only.

CONCLUSION

The addition of breast MRI to XMG and US in the preoperative workup of IBTR allows for more accurate size estimation. MRI provides a higher sensitivity for the detection of multifocality compared to XMG.

Comparison of postoperative CT- and preoperative MRI-based breast tumor bed contours in prone position for radiotherapy after breast-conserving surgery

Objectives

To compare the target volume of tumor bed defined by postoperative computed tomography (post-CT) in prone position registered with or without preoperative magnetic resonance imaging (pre-MRI).

Methods

A total of 22 patients were included with early-stage breast invasive ductal cancer, who have undergone breast-conservative surgery and received the pre-MRI and post-CT in prone position. The MRI sequences (T1W, T2W, T2W-SPAIR, DWI, dyn-eTHRIVE, sdyn-eTHRIVE) were delineated and manually registered to CT, respectively. The clinical target volumes (CTVs) and planning target volumes (PTVs) were contoured on CT and different MRI sequences, respectively. Differences were measured in terms of consistence index (CI), dice coefficient (DC), geographical miss index (GMI), and normal tissue index (NTI).

Results

The differences of delineation volumes among CT and MRIs were significant, both in the CTVs (p = 0.035) and PTVs (p < 0.001). The values of CI and DC for sdyn-eTHRIVE registration to CT were the largest among all MRI sequences, but GMI and NTI were the smallest. No obvious linear correlation (p > 0.05) between the CI derived from the registration of CT and sdyn-eTHRIVE of CTV with the breast volume, the cavity visualization score (CVS) of CT, time interval from surgery to CT simulation, the maximum diameter of the intraoperative mass, and the number of titanium clips, respectively.

Conclusions

The CTVs and PTVs in MRI sequences were all smaller than those in CT. The pre-MRI, especially the sdyn-eTHRIVE, could be used to optimize the post-CT-based target delineation of breast cancer.

Key Points

• Registered pre-MRI to post-CT in order to improve the accuracy of target volume delineation of breast cancer.

• The CTVs and PTVs in MRI sequences were all smaller than those in CT.

• The sdyn-eTHRIVE of pre-MRIs may be a better choice to improve the delineation of CT-based CTV and PTV.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07085-0) contains supplementary material, which is available to authorized users.

Accelerated partial breast irradiation by brachytherapy: present evidence and future developments

Accelerated partial breast irradiation (APBI) delivers a short course of adjuvant RT after breast conserving surgery to only a limited part of the breast where the tumor was located. This procedure requires expertise, good communication, and close collaboration between specialized surgeons and attending radiation oncologists with adequate intraoperative tumor bed clip marking. However, APBI offers several intrinsic benefits when compared with whole breast irradiation (WBIR) including reduced treatment time (1 versus 4-6 weeks) and better sparing of surrounding healthy tissues. The present publication reviews the APBI level 1-evidence provided with various radiation techniques supplemented by long-term experience obtained from large multi-institutional phase II studies. Additionally, it offers an outlook on recent research with ultra-short or single-fraction APBI courses and new brachytherapy sources. Mature data from three randomized controlled trials (RCTs) clearly prove the noninferiority of APBI with 'only two techniques-1/MIBT (multicatheter interstitial brachytherapy) (two trials) and 2/intensity modulated radiotherapy (one trial)'-in terms of equivalent local control/overall survival to the previous standard 'conventionally fractionated WBIR'. However, MIBT-APBI techniques were superior in both toxicity and patient-reported outcomes (PROs) versus WBIR at long-term follow-up. Currently, in RCT-setting, alternative APBI techniques such as intraoperative electrons, 50-kV x-rays and three-dimensional conformal external beam radiotherapy (3D-CRT) failed to demonstrate noninferiority to conventionally fractionated WBIR. However, 3D-CRT-APBI compared noninferior to hypo-fractionated WBIR in preventing ipsilateral breast tumor recurrence (randomized RAPID-trial) but was associated with a higher rate of late radiation toxicity. Ultimately, MIBT remains the only APBI modality with noninferior survival/superior toxicity/PROs at 10-years and therefore should be prioritized over alternative methods in patients with breast cancer considered at low-risk for local recurrence according to recent international guidelines.

Breast-conserving therapy is safe both within BRCA1/2 mutation carriers and noncarriers with breast cancer in the Chinese population

Background

BRCA1/2 mutation is associated with a high risk of breast cancer, which may preclude breast cancer patients with BRCA1/2 mutation from breast-conserving therapy (BCT) [breast-conserving surgery (BCS), followed by radiotherapy, BCT]. It is debatable whether BCT could be a rational choice for Chinese breast cancer patients with a BRCA1/2 mutation.

Methods

The study comprised a cohort of women with invasive breast cancer either receiving BCT or mastectomy following the criteria for the germline BRCA1/2 mutation test. Germline DNA for BRCA1/2 testing was derived from blood samples. Survival analyses were performed. The correlations were analyzed between survival and distinct types of surgery. To compare the survival between different surgical management, Kaplan-Meier univariate analysis and multivariate Cox regression was used.

Results

In BRCA1/2 mutation carriers (N=176) and noncarriers (N=293), 25% and 27.3% of the patients received BCT, respectively (P=0.675). Patients receiving mastectomy (without radiotherapy or followed by radiotherapy) have larger tumor size (P<0.05 both in BRCA1/2 mutation carriers and noncarriers), prognostically worse tumor characteristics including significantly more advanced TNM stage (P=0.017 and P<0.0001 respectively) and more positive lymph nodes (P=0.008 and P<0.0001, respectively) both in BRCA1/2 mutation carriers and noncarriers. Still, more often received systemic therapy has also been observed. After adjustment for clinical-pathological characteristics and systemic treatment, patients who received BCT had a similar breast cancer disease-free survival compared with patients who received mastectomy, both in BRCA1/2 mutation carriers and noncarriers [HR _BRCA1/2 =1.17, confidence interval (CI): 0.57-2.39, P=0.68; HR_noncarriers =0.91, CI: 0.47-1.77, P=0.79, respectively). The recurrence free survival after BCT did not differ from mastectomy in BRCA1/2 mutation carriers [BCT, 5-year cumulative recurrence-free survival (RFS) =0.95, CI: 0.89-1.00; mastectomy, 5-year cumulative RFS =0.93, CI: 0.85-1.00], even better for BCT in noncarriers (BCT, 5-year cumulative RFS =0.67, CI: 0.42-0.89; mastectomy, 5-year cumulative RFS =0.83, CI: 0.71-0.95).

Conclusions

Thus, BCT may be a safe and rational choice for Chinese female breast cancer patients with a BRCA1/2 mutation. However, tumor size, the TNM stage, the number of positive lymph nodes, might be taken into consideration when choosing surgical management.

Multifocality in ipsilateral breast tumor recurrence - A study in ablative specimens

BACKGROUND

The incidence and clinical significance of multifocality in ipsilateral breast tumor recurrence (IBTR) after breast-conserving therapy (BCT) are unclear. With growing interest in repeat BCT, this information has become of importance. This study aimed to gain insight in the incidence of multifocality in IBTR, to identify patient- and tumor-related predicting factors and to investigate the prognostic significance of multifocality.

METHODS

Two hundred and fifteen patients were included in this analysis. All had an IBTR after BCT and were treated by salvage mastectomy and appropriate adjuvant therapy. Predictive tumor- and patient-related factors for multifocality in IBTR were identified using X2 test and univariate logistic regression analyses. Prognostic outcomes were calculated using Kaplan Meier analysis and compared using the log rank test.

RESULTS

Multifocality was present in 50 (22.9%) of IBTR mastectomy specimens. Axillary positivity in IBTR was significantly associated with multifocality in IBTR. Chest wall re-recurrences occurred more often after multifocal IBTR (14% versus 7% after unifocal IBTR, p = 0.120). Regional re-recurrences did not differ significantly between unifocal and multifocal IBTR (8% vs. 6%, p = 0.773). Distant metastasis after salvage surgery occurred more frequently after multifocal IBTR (15% vs. 24%, p = 0.122). Overall survival was 132 months after unifocal IBTR and 112 months after multifocal IBTR (p = 0.197).

CONCLUSION

The prevalence of multifocality in IBTR is higher than in primary breast cancer. Axillary positivity in IBTR was associated with a multifocal IBTR. Chest wall re-recurrences and distant metastasis were, although not statistically significant, more prevalent after multifocal IBTR.

Surgical Clips in Breast-conserving Surgery: Do they Represent the Tumour Bed Accurately?

INTRODUCTION

Radiotherapy after Breast-Conserving Surgery (BCS) is a standard treatment for breast cancer. Currently, surgical clips are used to determine the tumour bed before radiotherapy planning. This study aimed to evaluate the migration of these clips on mammograms.

METHODS

The study was conducted on 121 females who were treated with radiotherapy after BCS at their first radiologic control examination 6 months after the end of treatment. MLO and CC views of all cases were evaluated regarding the clips. The distance between the surgical scar centre and the centre of the area covered by the clips was measured on both MLO and CC projections and recorded separately. This distance was determined as the clip displacement. A displacement ≤10 mm was recorded as no displacement.

RESULTS

The clips were out of the images and were not evaluated in 45 cases (37.2%) on CC and in 9 cases (7.4%) on MLO projections. There were no clip displacements in 37 (30.6%) cases on CC and in 43 (35.5%) cases on MLO views. The amount of displacement ranged from 11 to 56 mm with a mean of 24.38 mm on CC views, while on MLO projections, displacement ranged from 11 to 66 mm with a mean of 24.42 mm.

CONCLUSION

A clip displacement of greater than 10 mm was found in 64.5% of cases on MLO views. Therefore, we believe that the reliability of these clips for accurate delineation of the tumour bed in radiotherapy planning is controversial and other methods must be added.

Ipsilateral breast tumor recurrence in early stage breast cancer patients treated with breast conserving surgery and adjuvant radiation therapy: Concordance of biomarkers and tumor location from primary tumor to in-breast tumor recurrence

BACKGROUND

Patients with an in-breast tumor recurrence (IBTR) after breast-conserving therapy have a high risk of distant metastasis and disease-related mortality. Classifying clinical parameters that increase risk for recurrence after IBTR remains a challenge.

AIM

To describe primary and recurrent tumor characteristics in patients who experience an IBTR and understand the relationship between these characteristics and disease outcomes.

METHODS

Patients with stage 0-II breast cancer treated with lumpectomy and adjuvant radiation were identified from institutional databases of patients treated from 2003-2017 at our institution. Overall survival (OS), disease-free survival, and local recurrence-free survival (LRFS) were estimated using the Kaplan Meier method. We identified patients who experienced an isolated IBTR. Concordance of hormone receptor status and location of tumor from primary to recurrence was evaluated. The effect of clinical and treatment parameters on disease outcomes was also evaluated.

RESULTS

We identified 2164 patients who met the eligibility criteria. The median follow-up for all patients was 3.73 [interquartile range (IQR) 2.27-6.07] years. Five-year OS was 97.7% (95%CI: 96.8%-98.6%) with 28 deaths; 5-year LRFS was 98.0% (97.2-98.8) with 31 IBTRs. We identified 37 patients with isolated IBTR, 19 (51.4%) as ductal carcinoma in situ and 18 (48.6%) as invasive disease, of whom 83.3% had an in situ component. Median time from initial diagnosis to IBTR was 1.97 (IQR: 1.03-3.5) years. Radiotherapy information was available for 30 of 37 patients. Median whole-breast dose was 40.5 Gy and 23 patients received a boost to the tumor bed. Twenty-five of thirty-two (78.1%) patients had concordant hormone receptor status, HER-2 receptor status, and estrogen receptor (ER) (P = 0.006) and progesterone receptor (PR) (P = 0.001) status from primary to IBTR were significantly associated. There were no observed changes in HER-2 status from primary to IBTR. The concordance between quadrant of primary to IBTR was 10/19 [(62.2%), P = 0.008]. Tumor size greater than 1.5 cm (HR = 0.44, 95%CI: 0.22-0.90, P = 0.02) and use of endocrine therapy upfront (HR = 0.36, 95%CI: 0.18-0.73, P = 0.004) decreased the risk of IBTR.

CONCLUSION

Among patients with early stage breast cancer who had breast conserving surgery treated with adjuvant RT, ER/PR status and quadrant were highly concordant from primary to IBTR. Tumor size greater than 1.5 cm and use of adjuvant endocrine therapy were significantly associated with decreased risk of IBTR.

Prognostic impact of repeat sentinel lymph node biopsy in patients with ipsilateral breast tumour recurrence

BACKGROUND

Ipsilateral breast tumour recurrence (IBTR) has an unfavourable prognosis, with a significant subsequent risk of distant recurrence. Repeat sentinel lymph node biopsy (rSLNB) has recently been demonstrated to be technically feasible and useful in tailoring adjuvant treatment plans in patients with IBTR. The prognostic impact of rSLNB in patients with IBTR remains unclear. This study analysed the risk of distant recurrence after IBTR, and evaluated the prognostic impact of rSLNB and other patient and tumour characteristics on distant recurrence-free survival.

METHODS

Data were obtained from the SNARB (Sentinel Node and Recurrent Breast Cancer) study. Cox proportional hazards analyses were performed to assess the prognostic effect of tumour, patient and treatment factors on distant recurrence-free survival.

RESULTS

Of the 515 included patients, 230 (44·7 per cent) had a tumour-negative rSLNB and 46 (8·9 per cent) a tumour-positive rSLNB. In 239 patients (46·4 per cent) the rSLNB procedure was unsuccessful. After a median follow-up of 5·1 years, 115 patients (22·3 per cent) had developed a recurrence. The overall 5-year distant recurrence-free survival rate was 84·2 (95 per cent c.i. 80·7 to 87·7) per cent. An interval of less than 2 years between primary breast cancer treatment and ipsilateral recurrence (P = 0·018), triple-negative IBTR (P = 0·045) and absence of adjuvant chemotherapy after IBTR (P = 0·010) were independently associated with poor distant recurrence-free survival. The association between the outcome of rSLNB and distant recurrence-free survival was not statistically significant (P = 0·682).

CONCLUSION

The outcome of rSLNB is not an important prognostic factor for distant recurrence, and its value as a staging tool in patients with IBTR seems disputable.

Race and risk of subsequent aggressive breast cancer following ductal carcinoma in situ

BACKGROUND

General populations of black women have a higher risk of developing breast cancer negative for both estrogen receptor (ER) and progesterone receptor (PR) in comparison with white counterparts. Racial differences remain unknown in the risk of developing aggressive invasive breast cancer (IBC) that is characterized by negativity for both ER and PR (ER-PR-) or higher 21-gene recurrence scores after ductal carcinoma in situ (DCIS).

METHODS

This study identified 163,892 women (10.5% black, 9.8% Asian, and 8.6% Hispanic) with incident DCIS between 1990 and 2015 from the Surveillance, Epidemiology, and End Results data sets. Cox proportional hazards regression was used to estimate hazards ratios (HRs) of subsequent IBC classified by the hormone receptor status and 21-gene recurrence scores.

RESULTS

During a median follow-up of 90 months, 8333 women developed IBC. In comparison with white women, the adjusted HR of subsequent ER-PR- breast cancer was 1.86 (95% confidence interval [CI], 1.57-2.20) for black women (absolute 10-year difference, 2.2%) and 1.40 (95% CI, 1.14-1.71) for Asian women (absolute 10-year difference, 0.4%); this was stronger than the associations for ER+ and/or PR+ subtypes (Pheterogeneity  = .0004). The 21-gene recurrence scores of subsequent early-stage, ER+ IBCs varied by race/ethnicity (Pheterogeneity  = .057); black women were more likely than white women to have a recurrence score of 26 or higher (HR, 1.38; 95% CI, 1.00-1.92). No significant difference was observed in the risks of subsequent IBC subtypes for Hispanic women.

CONCLUSIONS

Black and Asian women with DCIS had higher risks of developing biologically aggressive IBC than white counterparts. This should be considered in treatment decisions for black and Asian patients with DCIS.

Patterns of Recurrence Among Higher-Risk Patients Receiving Daily External Beam Accelerated Partial-Breast Irradiation to 40 Gy in 10 Fractions

Purpose

The 2016 American Society for Radiation Oncology consensus guidelines for the use of accelerated partial-breast irradiation (APBI) define “suitable,” “cautionary,” and “unsuitable” populations for this adjuvant breast radiation therapy technique. We sought to determine whether patients in the cautionary group exhibited adverse outcomes after APBI compared with their suitable counterparts.

Methods and Materials

We identified 252 consecutively treated patients from a single institution with in situ or early-stage invasive breast cancer who underwent APBI between 2008 and 2017. Treatment technique was uniform throughout the population, consisting of 3-dimensional conformal radiation therapy to 40 Gy administered in 10 daily fractions.

Results

One hundred seventy-eight patients (70%) were classified as suitable, 69 (27%) as cautionary, and 5 (2.0%) as unsuitable. Because unsuitable patients were few and had no recurrences, they were excluded from analysis. At a median follow-up time of 3.9 years, 97.2% of patients were free of recurrence. Four patients (1.5% overall; 3 suitable and 1 cautionary) experienced ipsilateral in-breast recurrences, and 1 cautionary patient developed an ipsilateral regional recurrence in an axillary lymph node. There was no significant difference in the rate of ipsilateral breast recurrence (2.4% vs 1.0%) between cautionary and suitable groups.

Conclusions

Local recurrences are rare among guideline-defined cautionary patients with in situ or invasive breast cancer treated with APBI delivered via daily 3-dimensional conformal radiation therapy to 40 Gy. At a median follow-up of 3.9 years, no significant differences in local control were noted between cautionary and suitable patient groups. Further study is needed to characterize long-term disease outcomes among various risk groups.

Évaluation d’un second traitement chirurgical conservateur pour récidive locale d’un cancer du sein

Objectif : Évaluation d’un deuxième traitement conservateur (T) [n = 41] par rapport à une mastectomie totale (M) [n = 93]. Étude rétrospective unicentrique de 134 patientes ayant présenté une récidive mammaire homolatérale isolée et opérable.

Résultats : La survie globale à cinq ans est de 82,5 % dans les deux groupes. Pas de différence significative pour la survie spécifique et la survie sans métastase dans les deux groupes. Le contrôle local à cinq ans est de 92,9 % dans le groupe Met de 66,2 % dans le groupe T (RR de nouvelle récidive de 4,48). La présence d’emboles, le caractère multifocal et la révélation clinique de la récidive sont des facteurs pronostiques péjoratifs de survie. Sur l’ensemble de la série (n = 134), 25 (18,6 %) ont conservé leur sein.

Conclusion : Pour minimiser le risque de récidive après un second traitement conservateur, on peut envisager cette chirurgie si la récidive est isolée, de petite taille, de bas grade, sans embole, et strictement unifocale. L’acte chirurgical doit assurer des marges saines et un résultat esthétique satisfaisant. La patiente participe au choix du traitement.

Management of In-Breast Tumor Recurrence

The management of isolated in-breast tumor recurrence is complex, requiring careful consideration of prior local therapies to plan future multimodality treatment. Options for surgical management have evolved from standard salvage mastectomy with axillary clearance and now include repeat breast conservation with axillary staging in select patients. Reattempting sentinel lymph node biopsy may avoid the morbidity of extensive axillary surgery and has been shown to be feasible in clinically node-negative patients with oncologically safe outcomes. In the adjuvant setting, partial breast irradiation has emerged as a valuable means to improve local control rates with limited associated toxicity and acceptable overall cosmesis. Furthermore, results from prospective trials are now available to support the use of chemotherapy in hormone-receptor negative subgroups, which is associated with improvements in long-term, disease-free, and overall survival.

Advancements and Personalization of Breast Cancer Treatment Strategies in Radiation Therapy

Significant technologic advances in radiation treatment delivery now allow for more personalized delivery considerations which incorporate individual patient characteristics (such as tumor location and patient anatomy) and more precise delivery in the breast conservation or post-mastectomy setting. The combined advancements with other treatment modalities (i.e., systemic therapy, surgical management) have had direct effects on local-regional management and outcomes such that currently, local-regional relapses after definitive treatment for localized disease are now rarely experienced. Recent advances in the radiation therapy field have come from careful patient selection for a variety of three-dimensional treatment delivery techniques and alternatives to conventional tangential radiation. These advances have been demonstrated to diminished acute/long-term toxicity, minimized dose to surrounding normal tissue structures such as the heart and lung, and ultimately result in an improvement in the therapeutic ratio for radiation treatment. This chapter discusses recent radiation innovations and appropriate patient selection for their application, for a more personalized approach to radiation therapy for breast cancer patients.

Impact of an In Situ Component on Outcome After In-Breast Tumor Recurrence in Patients Treated with Breast-Conserving Therapy

BACKGROUND

Among all in-breast tumor recurrences (IBTR) following breast-conserving therapy (BCT), some comprise metachronous new primaries (NPs) while others are true recurrences (TRs). Establishing this distinction remains a challenge.

METHODS

We studied 3932 women who underwent BCT for stage I-III breast cancer from 1998 to 2008. Of these, 115 (2.9%) had an IBTR. Excluding patients with inoperable/unresectable recurrences or simultaneous distant metastases, 81 patients with isolated IBTR comprised the study population. An IBTR was categorized as an NP rather than a TR if it included an in situ component. The log-rank test and Kaplan-Meier method were used to evaluate disease-free survival (DFS) and overall survival (OS), and univariate and multivariate analyses were performed using Cox proportional hazards regression models.

RESULTS

At a median of 64.5 months from IBTR diagnosis, 28 of 81 patients had DFS events. Five-year DFS was 43.1% in the TR group (p = 0.0001) versus 80.3% in the NP group, while 5-year OS was 59.7% in the TR group versus 91.7% among those with NPs (p = 0.0011). On univariate analysis, increasing tumor size, high grade, positive margins, lymphovascular invasion, node involvement, lack of axillary surgery, chemotherapy, radiation therapy, and IBTR type (TR vs. NP) were significantly associated with worse DFS. Controlling for tumor size and margin status, TRs remained significantly associated with lower DFS (hazard ratio 3.717, 95% confidence interval 1.607-8.595, p = 0.002).

CONCLUSION

The presence of an in situ component is associated with prognosis among patients with IBTR following BCT and may be useful in differentiating TRs and NPs.

Can Locoregionally Recurrent Breast Cancer Be Cured?

Locoregional recurrence (LRR) of breast cancer can occur after multidisciplinary treatment of a primary breast cancer. With modern multidisciplinary breast cancer treatment, the incidence of isolated LRR is decreasing. Improvements in systemic therapy are driving the decrease in LRR. LRR does still occur, however. LRR reflects biology of the cancer, as does systemic recurrence. LRR of breast cancer is frequently associated with systemic disease recurrence and poor prognosis. Given this associated poor prognosis, historically, it has been unclear whether patients with LRR would benefit from aggressive therapy with curative intent. Findings in retrospective studies suggest that prognosis for patients with LRR is not universally poor, and some patients may benefit from aggressive locoregional and systemic therapy. The challenge remains to assess prognosis and appropriately treat patients with locoregional breast cancer recurrence.

Recommendations for breast imaging follow-up of women with a previous history of breast cancer: position paper from the Italian Group for Mammography Screening (GISMa) and the Italian College of Breast Radiologists (ICBR) by SIRM

Women who were previously treated for breast cancer (BC) are an important particular subgroup of women at intermediate BC risk. Their breast follow-up should be planned taking in consideration a 1.0-1.5 % annual rate of loco-regional recurrences and new ipsilateral or contralateral BCs during 15-20 years, and be based on a regional/district invitation system. This activity should be carried out by a Department of Radiology integrating screening and diagnostics in the context of a Breast Unit. We recommend the adoption of protocols dedicated to women previously treated for BC, with a clear definition of responsibilities, methods for invitation, site(s) of visits, methods for clinical and radiological evaluation, follow-up duration, role and function of family doctors and specialists. These women will be invited to get a mammogram in dedicated sessions starting from the year after the end of treatment. The planned follow-up duration will be at least 10 years and will be defined on the basis of patient's age and preferences, taking into consideration organizational matters. Special agreements can be defined in the case of women who have their follow-up planned at other qualified centers. Dedicated screening sessions should include: evaluation of familial/personal history (if previously not done) for identifying high-risk conditions which could indicate a different screening strategy; immediate evaluation of mammograms by one or, when possible, two breast radiologists with possible addition of supplemental mammographic views, digital breast tomosynthesis, clinical breast examination, breast ultrasound; and prompt planning of possible further workup. Results of these screening sessions should be set apart from those of general female population screening and presented in dedicated reports. The following research issues are suggested: further risk stratification and effectiveness of follow-up protocols differentiated also for BC pathologic subtype and molecular classification, and evaluation of different models of survivorship care, also in terms of cost-effectiveness.

Accelerated partial breast irradiation: Past, present, and future

Accelerated partial breast irradiation (APBI) focuses higher doses of radiation during a shorter interval to the lumpectomy cavity, in the setting of breast conserving therapy for early stage breast cancer. The utilization of APBI has increased in the past decade because of the shorter treatment schedule and a growing body of outcome data showing positive cosmetic outcomes and high local control rates in selected patients undergoing breast conserving therapy. Technological advances in various APBI modalities, including intracavitary and interstitial brachytherapy, intraoperative radiation therapy, and external beam radiation therapy, have made APBI more accessible in the community. Results of early APBI trials served as the basis for the current consensus guidelines, and multiple prospective randomized clinical trials are currently ongoing. The pending long term results of these trials will help us identify optimal candidates that can benefit from ABPI. Here we provide an overview of the clinical and cosmetic outcomes of various APBI techniques and review the current guidelines for selecting suitable breast cancer patients. We also discuss the impact of APBI on the economics of cancer care and patient reported quality of life.

Clinicopathological Features and Prognostic Factors Affecting Survival Outcomes in Isolated Locoregional Recurrence of Breast Cancer: Single-Institutional Series

Purpose

The purpose of this study was to investigate the clinicopathologic features and prognostic factors affecting outcome in patients with isolated locoregional recurrence of breast cancer (ILRR).

Methods

We retrospectively analyzed the medical records of 104 patients who were diagnosed with ILRR and underwent curative surgery from January 2000 to December 2010 at Samsung Medical Center.

Results

Among 104 patients, 43 (41%) underwent total mastectomy and 61 (59%) underwent breast-conserving surgery for primary breast cancer. The median time from initial operation to ILRR was 35.7 months (4.5–132.3 months). After diagnosis of ILRR, 45 (43%) patients were treated with mastectomy, 41 (39%) with excision of recurred lesion, and 18 (17%) with node dissection. During a median follow-up of 8.9 years, the 5-year overall survival was 77% and 5-year distant metastasis-free survival (DMFS) was 54%. On multivariate analysis, younger age (< 35 years), higher stage, early onset of elapse (≤ 24 months), lymph node recurrences, and subtype of triple negative breast cancer (TNBC) were found to be independently associated with DMFS. Patients in the no chemotherapy group showed a longer DMFS after surgery for ILRR than those treated with chemotherapy (median 101.5 vs. 48.0 months, p = 0.072) but without statistical significance.

Conclusion

Our analysis showed that younger age (< 35 years), higher stage, early onset of relapse (≤ 24 months), lymph node recurrence, and subtype of TNBC are the worst prognostic factors for ILRR.

Prognostic Impact of Time to Ipsilateral Breast Tumor Recurrence after Breast Conserving Surgery

Background

The poor prognosis of patients who experience ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery (BCS) is established. A short time between primary cancer and IBTR is a prognostic factor but no clinically relevant threshold was determined. Classification of IBTR may help tailor treatment strategies.

Purpose

We determined a specific time frame, which differentiates IBTR into early and late recurrence, and identified prognostic factors for patients with IBTR at time of the recurrence.

Methods

We analyzed 2209 patients with IBTR after BCS. We applied the optimal cut-points method for survival data to determine the cut-off times to IBTR. A subgroup analysis was performed by hormone receptor (HR) status. Survival analyses were performed using a Cox proportional hazard model to determine clinical features associated with distant-disease-free survival (DDFS) after IBTR. We therefor built decision trees.

Results

On the 828 metastatic events observed, the majority occurred within the first 3 months after IBTR: 157 in the HR positive group, 98 in the HR negative group. We found different prognostic times to IBTR: 49 months in the HR positive group, 33 in the HR negative group. After multivariate analysis, time to IBTR was the first discriminant prognostic factor in both groups (HR 0.65 CI95% [0.54–0.79] and 0.42 [0.30–0.57] respectively). The other following variables were significantly correlated with the DDFS: the initial number of positive lymph nodes for both groups, the initial tumor size and grade for HR positive tumors.

Conclusion

A short interval time to IBTR is the strongest factor of poor prognosis and reflects occult distant disease. It would appear that prognosis after IBTR depends more on clinical and histological parameters than on surgical treatment. A prospective trial in a low-risk group of patients to validate the safety of salvage BCS instead of mastectomy in IBTR is needed.

Partial breast irradiation for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). RT is given to sterilize tumour cells that may remain after surgery to decrease the risk of local tumour recurrence. Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypo-fractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialized Register (4 May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 5), MEDLINE (January 1966 to 4 May 2015), EMBASE (1980 to 4 May 2015), CINAHL (4 May 2015) and Current Contents (4 May 2015). We searched the International Standard Randomised Controlled Trial Number Register (5 May 2015), the World Health Organization's International Clinical Trials Registry Platform (4 May 2015) and ClinicalTrials.gov (17 June 2015). We searched for grey literature: OpenGrey (17 June 2015), reference lists of articles, several conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomized controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction and used Cochrane's 'Risk of bias' tool, and resolved any disagreements through discussion. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included seven RCTs and studied 7586 women of the 8955 enrolled.Local recurrence-free survival appeared worse for women receiving PBI/APBI compared to WBRT (hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.11 to 2.35; six studies, 6820 participants, low-quality evidence). Cosmesis (physician-reported) appeared worse with PBI/APBI (odds ratio (OR) 1.51, 95% CI 1.17 to 1.95, five studies, 1720 participants, low-quality evidence). Overall survival did not differ with PBI/APBI (HR 0.90, 95% CI 0.74 to 1.09, five studies, 6718 participants, high-quality evidence).Late radiation toxicity (subcutaneous fibrosis) appeared worse with PBI/APBI (OR 6.58, 95% CI 3.08 to 14.06, one study, 766 participants, moderate-quality evidence). Acute skin toxicity appeared reduced with PBI/APBI (OR 0.04, 95% CI 0.02 to 0.09, two studies, 608 participants). Telangiectasia (OR 26.56, 95% CI 3.59 to 196.51, 1 study, 766 participants) and radiological fat necrosis (OR 1.58, 95% CI 1.02 to 2.43, three studies, 1319 participants) appeared worse with PBI/APBI. Late skin toxicity (OR 0.21, 95% CI 0.01 to 4.39, two studies, 608 participants) and breast pain (OR 2.17, 95% CI 0.56 to 8.44, one study, 766 participants) appeared not to differ with PBI/APBI.'Elsewhere primaries' (new primaries in the ipsilateral breast) appeared more frequent with PBI/APBI (OR 3.97, 95% CI 1.51 to 10.41, three studies, 3009 participants).We found no clear evidence of a difference for the comparison of PBI/APBI with WBRT for the outcomes of: cause-specific survival (HR 1.08, 95% CI 0.73 to 1.58, five studies, 6718 participants, moderate-quality evidence), distant metastasis-free survival (HR 0.94, 95% CI 0.65 to 1.37, four studies, 3267 participants, moderate-quality evidence), relapse-free survival (HR 1.36, 95% CI 0.88 to 2.09, three studies, 3811 participants), loco-regional recurrence-free survival (HR 1.80, 95% CI 1.00 to 3.25, two studies, 3553 participants) or mastectomy rates (OR 1.20, 95% CI 0.77 to 1.87, three studies, 4817 participants, low-quality evidence). Compliance was met: more than 90% of the women in all studies received the RT they were assigned to receive. We found no data for the outcomes of costs, quality of life or consumer preference.

AUTHORS' CONCLUSIONS

It appeared that local recurrence and 'elsewhere primaries' (new primaries in the ipsilateral breast) are increased with PBI/APBI (the difference was small), but we found no evidence of detriment to other oncological outcomes. It appeared that cosmetic outcomes and some late effects were worse with PBI/APBI but its use was associated with less acute skin toxicity. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver of PBI/APBI. We await completion of ongoing trials.