Radiation therapy to the primary tumor for de novo metastatic breast cancer and overall survival in a retrospective multicenter cohort analysis

Radiation therapy of the primary tumour and oligometastatic sites in patients with breast cancer with synchronous metastases: A literature review

De novo metastatic breast cancer represents 5 to 8% of all breast cancers (2500 new cases per year in France). Systemic treatment is the cornerstone of treatment, whereas radiation therapy usually has a palliative intent. Advances in systemic and local treatments (surgery and radiation therapy) have substantially improved overall survival. In the recent breast cancer statistics in the United States, the 5-year relative survival for patients diagnosed during 2012-2018 was 29% for stage IV (Breast Cancer Statistics). Thus, an increasing proportion of metastatic breast cancers present a prolonged complete response to systemic therapy, which raises the question of the impact of local treatment on patient survival. Radiation therapy has shown its value for early breast cancer, but its place in the local management of the primary tumour or oligometastatic sites for de novo metastatic breast cancer remains under debate. This article is a literature review assessing the role of radiation therapy directed to the primary tumour and oligometastatic sites of breast cancer in patients with synchronous metastases, in order to highlight clinicians in their therapeutic decision.

Recommandations francophones pour la pratique clinique concernant la prise en charge des cancers du sein de Saint-Paul-de-Vence 2022-2023

With more than 60,000 new cases of breast cancer in mainland France in 2023 and 8% of all cancer deaths, breast cancer is the leading cancer in women in terms of incidence and mortality. While the number of new cases has almost doubled in 30 years, the percentage of patients at all stages alive at 5 years (87%) and 10 years (76%) testifies to the major progress made in terms of screening, characterisation and treatment. However, this progress, rapid as it is, needs to be evaluated and integrated into an overall strategy, taking into account the characteristics of the disease (stage and biology), as well as those of the patients being treated. These are the objectives of the St Paul-de-Vence recommendations for clinical practice. We report here the summary of the votes, discussions and conclusions of the Saint-Paul-de-Vence 2022-2023 RPCs.

Impact of high dose radiotherapy for breast tumor in locoregionally uncontrolled stage IV breast cancer: a need for a risk-stratified approach

AIM

Patients with locoregionally uncontrolled breast tumors are frequently referred for breast palliative radiotherapy (PRT) to mitigate symptoms. We analyzed the outcomes following breast PRT to optimize PRT according to risk groups.

METHODS

We reviewed 133 patients who underwent breast PRT. A median total dose of 45 Gy was prescribed with an equivalent dose in 2 Gy fractions (EQD2, α/β = 3.5) of 53 Gy. The Cox proportional hazards model was used to analyze the prognostic factors of local control (LC).

RESULTS

Most (90.2%) had polymetastatic disease (> 5 lesions), and 48.9% had bone metastasis. With a median follow-up of 17.2 months, the 2-year LC and overall survival (OS) rates were 49.4%, and 48.3%, respectively. Multivariable analyses demonstrated progressive or mixed responses outside the breast and > 2 lines of previous therapy as adverse features for clinical outcomes. Group 1 (0 risk factors) showed favorable 2-year LC and OS of 63.9%, and 72.8%, respectively, whereas group 3 (2 risk factors) showed the worst outcomes of 0%, and 6.8%, respectively. Breast PRT with EQD2 ≥ 63 Gy showed a significant benefit in LC for group 1 and marginal benefit (p = 0.055) for group 2, but no improvement for group 3 (p = 0.300).

CONCLUSION

Breast PRT showed favorable LC outcomes in patients with stable disease outside the breast and treated with ≤ 2 lines of systemic treatment. Our findings warrant future clinical trials investigating the role of higher than palliative dose and early intervention of PRT in stage IV patients.

Outcomes and toxicity of concurrent CDK4/6 inhibitor and locoregional radiotherapy for patients with de novo metastatic breast cancer

The objective of the present study was to assess the outcomes and toxicity of patients treated with concurrent administration of CDK4/6 inhibitors (CDK4/6i) and locoregional radiation therapy (RT), including the breast with a boost or the thoracic wall after mastectomy and the regional lymph node areas. We retrospectively analyzed data from 27 patients with hormone receptor-positive, HER2-negative de novo metastatic breast cancer treated with CDK4/6i and concomitant locoregional RT in 2017/2022. Survival rates were calculated by Kaplan-Meier method. Prognostic factors were tested with log-rank test. CDK4/6i was used as the first systemic metastatic treatment for all the patients, and the median overall treatment time was 26 months. The median time from initiation of CDK4/6i to the start of RT was 10 months (IQR: 7-14 months). The median duration of concomitant CDK4/6i and RT administration was 21 days (IQR: 14.5-23 days). After a median follow-up of 19 months (IQR: 14-36 months), 1 patient died, 11/27 had distant metastases and 1 patient had local recurrence, respectively. The 1- and 3-years progression-free survival (PFS) were 61.4% (95% CI: 45.1%-83.7%) and 53.7% (35.8%-80.5%), respectively. The acute toxicities most observed during RT were neutropenia (44%) and dermatitis (37%). Dermatitis was significantly more frequent in patients with large target volumes (CTV > 911 cc and PTV > 1285 cc). CDK4/6i had to be discontinued in five patients during RT (due to toxicity in three cases and disease progression in two cases). One patient has developed grade 2 late pulmonary fibrosis. Finally, our study demonstrated that concurrent administration of locoregional RT and CDK4/6i did not induce severe late toxicity for most patients.

Radiotherapy of the Primary Disease for Synchronous Metastatic Cancer: A Systematic Review

In the case of synchronous metastatic disease, the local treatment of primary tumors by radiotherapy has long been reserved for palliative indications. The emergence of the concept of oligometastatic and oligopersistent diseases, the advent of new systemic therapies enabling longer overall survival with an enhanced quality of life, a better understanding of the biologic history of metastatic spread, and technical advances in radiation therapy are revolutionizing the management of patients with de novo metastatic cancer. The prognosis of these patients has been markedly improved and many studies have investigated the survival benefits from the local treatment of various primary tumors in cases of advanced disease at the time of diagnosis or in the case of oligopersistence. This article provides an update on the place of irradiation of the primary tumor in cancer with synchronous metastases, and discusses its interest through published or ongoing trials.

Stereotactic Body Radiation Therapy in Patients with Oligometastatic Disease: Clinical State of the Art and Perspectives

Stereotactic body radiation therapy (SBRT) is a form of radiation therapy (RT) in which a small number of high doses of radiation are delivered to a target volume using highly sophisticated equipment. Stereotactic body radiation therapy is crucial in two cancer stages: early primary cancer and oligometastatic disease, with the goal of inducing complete cancer remission in both. This treatment method is commonly used to treat a variety of disease types. Over the years, a growing body of clinical evidence on the use of SBRT for the treatment of primary and metastatic tumors has accumulated, with efficacy and safety demonstrated in randomized clinical trials. This article will review the technical and clinical aspects of SBRT according to disease type and clinical indication.

Retrospective comparative effectiveness research: will changing the analytical methods change the results?

In medicine, retrospective cohort studies are used to compare treatments to one another. We hypothesize that the outcomes of retrospective comparative effectiveness research studies can be heavily influenced by biostatistical analytic choices, thereby leading to inconsistent conclusions. We selected a clinical scenario currently under investigation: survival in metastatic prostate, breast, or lung cancer after systemic vs systemic + definitive local therapy. We ran >300 000 regression models (each representing a publishable study). Each model had various forms of analytic choices (to account for bias): propensity score matching, left truncation adjustment, landmark analysis, and covariate combinations. There were 72 549 lung, 14 904 prostate, and 13 857 breast cancer patients included. In the most basic analysis, which omitted propensity score matching, left truncation adjustment, and landmark analysis, all of the HRs were < 1 (generally, 0.60-0.95, favoring addition of local therapy), with all P-values < 0.001. Left truncation adjustment landmark analysis produced results with non-significant P-values. The combination of propensity score matching, left truncation adjustment, landmark analysis, and covariate combinations generally produced P-values that were > 0.05 and/or HRs that were > 1 (favoring systemic therapy alone). The use of more statistical methods to reduce the selection bias caused reported HR ranges to approach 1.0. By varying analytic choices in comparative effectiveness research, we generated contrary outcomes. Our results suggest that some retrospective observational studies may find a treatment improves outcomes for patients, while another similar study may find it does not, simply based on analytical choices. This article is protected by copyright. All rights reserved.

Locoregional Therapy in De novo Metastatic Breast Cancer: A Retrospective Cohort Study

Objective: Whether locoregional therapy (LRT) should be performed in patients with de novo metastatic breast cancer (dnMBC) has been debated. Here we report the survival outcomes of LRT in patients with dnMBC, focusing on the association of surgical timings and surgical margins with survival in this patient population. Methods: The retrospective study included patients with dnMBC in our hospital, between March 1, 2007 and December 31, 2017. Overall survival (OS) was evaluated by means of a stratified log-rank test and summarized with the use of Kaplan–Meier methods. Results: A total of 153 patients were included, of whom 87 underwent LRT and 66 systemic therapy alone (STA). LRT showed a significant OS benefit over STA (HR, 0.62; 95% CI, 0.39 to 0.99; P  =  .043). The OS of LRT group and STA group were 39 months (95% CI, 33.6 to 44.4 months) and 24.6 months (95% CI, 20.6 to 28.6 months), respectively. The benefit was consistent across most subgroups. The OS of patients undergoing surgery was better than that of patients without surgery (HR, 0.58; 95% CI, 0.35 to 0.94; P  =  .0001), and there was difference in survival improvement at different surgical timings (surgery before chemotherapy, during chemotherapy, and after chemotherapy) (P  =  .0001). The survival benefit of surgery after chemotherapy was significantly greater than that of the other 2 options (HR, 0.77; 95% CI, 0.63 to 0.94). Moreover, compared with patients with positive margins, the OS of patients with negative margins was significantly improved (HR, 0.22; 95% CI, 0.13 to 0.37; P < .001). Conclusions: Our results suggest that LRT is associated with improved OS in women with dnMBC, and patients who had surgery after systemic chemotherapy with negative surgical margins, are expected to benefit more.

De novo metastatic breast cancer in patients with a small locoregional tumour (T1-T2/N0): Characteristics and prognosis

INTRODUCTION

The estimated rate of de novo metastatic breast cancer (dnMBC) at the time of diagnosis is between 5 to 12%. International guidelines recommend metastatic work-up (MWU) only in women with advanced breast cancer. The purpose of this study was to describe the characteristics and prognosis of patients with dnMBC diagnosed without an initial indication for MWU.

METHODS

We conducted a retrospective, comparative study in dnMBC patients selected from the ESME-MBC cohort. Patients were treated in France between 2008 and 2016. We compared two populations: patients in whom dnMBC was diagnosed by staging although not indicated by guidelines (non-guideline staging [NGS]) and those in whom dnMBC was diagnosed by guideline staging (GS).

RESULTS

During the study period, 22,463 patients with MBC were included in the ESME cohort. Among them, 6698 were dnMBC patients. In 247 of these patients (6% of dnMBC and 1% of the overall population), dnMBC was diagnosed by non-guideline staging. Women in this group were significantly younger (57 vs. 59 years, p = 0.02) and had fewer metastatic sites at diagnosis than dnMBC-GS patients. The two groups were not significantly different in terms of the other characteristics. Overall survival (OS) and progression-free survival (PFS) were better in the dnMBC-NGS group than in the dnMBC-GS group. The impact on survival was confirmed by univariate and multivariate analysis (HR 1.83 [1.31-2.57], p < 0.01).

CONCLUSION

This study provides the first description of a very specific population. These patients with dnMBC-NGS were younger and more likely to have oligometastatic disease with a better prognosis.

Pertuzumab and Trastuzumab Combination with Concomitant Locoregional Radiotherapy for the Treatment of Breast Cancers with HER2 Receptor Overexpression

Simple Summary

This retrospective study demonstrates that the combination of locoregional breast RT with dual HER2 blockade by pertuzumab/trastuzumab was very well tolerated, suggesting that RT can be safely administered to patients with HER2-positive breast cancer during dual HER2 blockade. Excellent locoregional control was achieved in irradiated patients.

Abstract

Background: The combination of pertuzumab and trastuzumab dual HER2 blockade with concomitant curative dose locoregional breast radiotherapy in patients with metastatic breast cancer is an important part of treatment strategy. Methods: This was a retrospective study conducted at the Institut Curie on all patients treated concomitantly with pertuzumab/trastuzumab and locoregional breast radiotherapy. Toxicity was evaluated according to the NCICTCAEv4.0. Overall survival, progression-free survival and locoregional recurrence-free survival were evaluated in metastatic patients who were initially well controlled by chemotherapy, for whom local treatment was decided by the multidisciplinary team. Results: Fifty-five patients treated between October 2013 and December 2019 were included, with a median follow-up of 4.1 years. The median age was 53 years (range: 28–81). All patients received curative dose radiotherapy (RT) concomitantly with pertuzumab and trastuzumab (Pertu/Trastu). The median radiation dose was 50 Gy. Safety evaluation did not reveal any significant adverse effects, with 3 cases of grade 3 radiodermatitis (5.4%), but no significant gastrointestinal or cardiac toxicity. The mean difference in LVEF before any chemotherapy and after radiotherapy was −2.43% (p < 0.01). Conclusions: This study demonstrates that the combination of locoregional breast RT with dual HER2 blockade by Pertu/Trastu was very well tolerated, suggesting that RT can be safely administered to patients with HER2-positive breast cancer.

Combination of Olaparib with radiotherapy for triple-negative breast cancers: One-year toxicity report of the RADIOPARP Phase I trial

Triple-negative breast cancer (TNBC) cells are sensitive to PARP1 inhibitors in vitro. The combination of Olaparib and radiotherapy for TNBC is currently evaluated in the Phase I RADIOPARP trial. RADIOPARP is a monocentric prospective open-label Phase I dose-escalation trial evaluating the combination of breast radiotherapy and Olaparib in TNBC patients with inflammatory, locoregionally advanced or metastatic disease, or with residual disease after neoadjuvant chemotherapy. Olaparib was orally given at increasing dose levels (50, 100, 150 or 200 mg twice a day [BID]); radiotherapy consisted of 50 Gy to the breast or chest wall with or without lymph node irradiation. Twenty-four TNBC patients were enrolled between September 2017 and November 2019. Olaparib was escalated to 200 mg BID without dose-limiting toxicities. At 1-year follow-up, no treatment-related grade ≥3 toxicity was observed. One patient (4.2%) had persistent grade 2 adverse events (breast pain, fibrosis and deformity). There was no cardiac, pulmonary or digestive toxicity related to treatment. The 1-year follow-up report of the RADIOPARP Phase I trial, evaluating Olaparib associated with breast radiotherapy in TNBC patients, consequently demonstrated an excellent toxicity profile of this combination with few low-grade adverse events.

Effect of Postoperative Radiotherapy after Primary Tumor Resection in De Novo Stage IV Breast Cancer: A Multicenter Retrospective Study (KROG 19-02)

Purpose

To investigate the impact of postoperative radiotherapy (PORT) in de novo metastatic breast cancer (dnMBC) patients undergoing planned primary tumor resection (PTR) and to identify the subgroup of patients who would most benefit from PORT.

Materials and Methods

This study enrolled 426 patients with dnMBC administered PTR alone or with PORT. The primary and secondary outcomes were overall and progression-free survival (OS and PFS), respectively.

Results

The median follow-up time was 53.7 months (range, 3.1-194.4). The 5-year OS and PFS rates were 73.2% and 32.0%, respectively. For OS, clinical T3/4 stage, triple-negative breast cancer (TNBC), postoperative chemotherapy alone were significantly poor prognostic factors, and administration of PORT failed to show its significance. Regarding PFS, PORT was a favorable prognostic factor (hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.50-0.82, p <0.001), in addition to T1/2 stage, ≤5 metastases, and non-TNBC. According to the multivariate analyses of OS in the PORT group, we divided the patients into three groups [Group 1, T1/2 and non-TNBC (n=193); Group 2, T3/4 and non-TNBC (n=171); and Group 3, TNBC (n=49)], and evaluated the effect of PORT. Although PORT had no significance for OS in all subgroups, it was a significant factor for good prognosis regardingPFS in Group 1 and 2, not in Group 3.

Conclusion

PORT was associated with a significantly better PFS in patients with dnMBC who underwent PTR. Patients with clinical T1/2 stage and non-TNBC benefited most from PORT, while those with TNBC showed little benefit.

Impact of loco-regional treatment including radiotherapy in patients presenting with metastatic breast cancer

Background:

The impact of loco-regional treatment (LRT) with radiotherapy (RT) in patients presenting with metastatic breast cancer (MBC) has not been widely studied. The aim of this study was to review the treatment outcomes of LRT including RT in patients with MBC.

Materials and methods:

Patients who presented with MBC were included in this retrospective study. Analysis was undertaken to determine the difference in local disease control, overall survival (OS) and progression-free survival (PFS) with systemic treatment alone, surgery alone, surgery plus RT and RT alone with long-rank test. Multivariate analysis was done, using the cox regression for factors affecting PFS and OS.

Results:

From 2007 to 2014, data of 257 patients with MBC were collected. Totally, 185 patients received LRT and 72 did not. LRT was surgery plus RT, surgery only and RT only in 113, 47 and 25 patients, respectively. Cytotoxic chemotherapy and hormone therapy were received by 205 and 166 patients, respectively. Median follow-up was 36 months (6–120 months). PFS and OS at 3 years with and without LRT were 31% versus 6% (p < 0·001) and 41% versus 17% (p < 0·001), respectively. PFS at 3 years with surgery plus RT, RT alone and surgery was 40, 33 and 6%, respectively. OS at 3 years with surgery plus RT, RT alone and surgery was 50, 38 and 17%, respectively. Patients without LRT had worse PFS and OS, 6 and 17%, respectively. RT had significant impact on PFS and OS along with chemotherapy and hormone treatment.

Conclusion:

In patients with MBC, improved local control, PFS and OS were achieved with loco-regional RT. Loco-regional RT along with chemotherapy and hormones were significant factors for PFS and OS irrespective of surgery.

Breast cancer

Breast cancer is still the most common cancer worldwide. But the way breast cancer is viewed has changed drastically since its molecular hallmarks were extensively characterised, now including immunohistochemical markers (eg, ER, PR, HER2 [ERBB2], and proliferation marker protein Ki-67 [MKI67]), genomic markers (eg, BRCA1, BRCA2, and PIK3CA), and immunomarkers (eg, tumour-infiltrating lymphocytes and PD-L1). New biomarker combinations are the basis for increasingly complex diagnostic algorithms. Neoadjuvant combination therapy, often including targeted agents, is a standard of care (especially in HER2-positive and triple-negative breast cancer), and the basis for de-escalation of surgery in the breast and axilla and for risk-adapted post-neoadjuvant strategies. Radiotherapy remains an important cornerstone of breast cancer therapy, but de-escalation schemes have become the standard of care. ER-positive tumours are treated with 5-10 years of endocrine therapy and chemotherapy, based on an individual risk assessment. For metastatic breast cancer, standard therapy options include targeted approaches such as CDK4 and CDK6 inhibitors, PI3K inhibitors, PARP inhibitors, and anti-PD-L1 immunotherapy, depending on tumour type and molecular profile. This range of treatment options reflects the complexity of breast cancer therapy today.

[Concurrent radiation therapy and dual HER2 blockade in breast cancer: Assessment of toxicity]

PURPOSE

The tolerance of the concurrent use of radiotherapy, pertuzumab and trastuzumab is unknown. The purpose of this study was to evaluate the toxicity of this association in patients treated for HER2 positive metastatic and/or locally recurrent unrespectable breast cancer.

MATERIAL AND METHODS

A retrospective study was performed in our institution for all consecutive patients treated with concurrent irradiation, pertuzumab and trastuzumab. The radiotherapy was performed while pertuzumab and trastuzumab were administrated as a maintenance treatment at the dose of 420mg (total dose) and 6mg/kg respectively every 3 weeks without chemotherapy. Toxicity was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Left ventricular ejection fraction (LVEF) was measured at baseline and then every 3-4 months.

RESULTS

We studied 77 patients. treated in between 2013 and 2019 with median follow-up of 38 months (range 0-264 months). Median age was 53 years (33-86). There were 50 patients (64.9%) with metastatic and 27 patients (35.1%) with recurrent disease. All patients received docetaxel followed by P-T as first line treatment and they received 34 cycles (10-85) of pertuzumab and trastuzumab. All patients experienced partial or complete response according to RECIST criteria. Irradiation volumes were whole breast (41 patients, 53.2%) and chest wall (29 patients, 37.7%) at a dose of 50Gy with a median duration of 39 days. Radiotherapy of lymph nodes was performed in 53 patients (68.8%) as following: supraclavicular-infraclavicular and axillary lymph nodes in 52 patients (67.5%), and internal mammary nodes in 31 patients (40.3%). For 20 patients. (26.0%) radiotherapy was palliative: bone irradiation (12 patients, 15.6%), whole-brain radiotherapy (2 patients, 2.6%), cerebral metastasis irradiation (6 patients). As early toxicity we observed: radio dermatitis as following: 36 patients (46.8%) presented grade I, 17 patients (22.1%) presented grade II, and 3 patients (3.9%) presented grade III. One patient (1.3%) presented grade II esophagitis. One patient (1.3%) presented asymptomatic decrease of LVEF during treatment and 6 patients (7.7%) presented a decrease of LVEF. There was no radiation-induced pneumonitis. As late toxicity, we observed 1 (1.3%) case of grade I and 1 (1.3%) with grade II telangiectasia. There was 1 case (1.3%) of grade III cardiac toxicity, 8 months after the concurrent treatment.

CONCLUSION

The concurrent use of radiotherapy, pertuzumab and trastuzumab is feasible with good tolerance. Larger prospective data with longer follow-up is needed to confirm these results.

Impact of Postoperative Radiotherapy on Survival of Patients With de novo Stage IV Breast Cancer: A Population-Based Study From the SEER Database

Purpose: In our study, we aimed to evaluate the role of postoperative radiotherapy for patents with de novo stage IV breast cancer. Patients and Methods: Patients diagnosed with stage IV breast cancer from 2010 to 2016 were selected from the Surveillance, Epidemiology, and End Result (SEER) database. Those patients who received both chemotherapy and surgery and lived longer than 6 months were divided into radiotherapy and non-radiotherapy groups. Kaplan-Meier analysis and multivariate Cox proportional hazards models were used to estimate the survival outcomes before and after being 1:1 propensity score matched (PSM). Subgroup analyses stratified by age, subtype, status of distant metastasis, and surgery type were also performed. Results: Among 1,935 patients, 52% (1006) underwent radiotherapy while the non-radiotherapy group contained 48% (929). After PSM, a total of 1,520 patients in two groups of 760 patients were enrolled in this analysis. Kaplan-Meier and the multivariate survival analysis demonstrated that the radiotherapy group presented with a better prognosis compared to the non-radiotherapy group (after PSM, BCSS: Hazard Ratio, 0.697; 95% confidence interval, 0.59-0.823; P < 0.001; OS: Hazard Ratio, 0.707; 95% confidence interval, 0.601-0.831; P < 0.001). Further subgroup analyses showed the Luminal subtype (HR+/HER2-), triple-negative breast cancer (TNBC), and bone-only metastasis patients presented with the most promising survival in the radiotherapy group. Conclusions: Postoperative radiotherapy is associated with a significant survival advantages in BCSS and OS. It can be an optimal supplementary treatment for stage IV patients after surgery, especially for Luminal subtype, TNBC, and patients with a low metastatic burden.

Is there a role for locoregional treatment of the primary tumor in de novo metastatic breast cancer in the era of tailored therapies?: Evidences, unresolved questions and a practical algorithm

Improvements in systemic therapies have changed the face of de novo metastatic breast cancer (dnMBC), with a 5-year survival rate exceeding 25 %. Increasing evidence suggests that a subset of patients could benefit from a locoregional treatment (LRT) with prolonged survival, although the diversity of publications on the subject make it difficult to draw any conclusions. In this review, we summarize the available data on retrospective, prospective and current ongoing clinical trials. Since factors such as tumor biology, pattern of metastatic dissemination and the timing of the treatment are closely linked to the therapeutic strategy, we focus on papers which include these aspects. We discuss recent studies indicating that exclusive radiotherapy provides results comparable with those obtained by surgery. We will then discuss the biological rationale for LRT. Finally, we propose a decision-tree to select the optimal candidates for LRT in dnMBC patients.

[Treatment of primary disease with irradiation in case of de novo metastatic breast cancer]

Synchronous metastatic breast cancer accounts for 5 to 6% of all breast cancers in Western countries, which corresponds to nearly 2500 new cases per year in France. Irradiation of the primary tumour in cases of metastatic disease at diagnosis was historically reserved for palliative indications. However, progress in systemic treatments, a better understanding of the biological basis of metastatic dissemination, the genesis of the concept of oligometastatic disease and ablative treatments directed towards metastases are revolutionizing the management of patients with de novo stage IV breast cancer. Survival of these patients has improved markedly over the years, and several studies have investigated the carcinological benefit of local treatment of the breast tumour in patients with advanced diseases at diagnosis. This article provides an update on the role of irradiation of the primary tumour in breast cancer with synchronous metastases, and discusses its interest through published or ongoing trials.