Safety of the Breast Cancer Adjuvant Radiotherapy in Ataxia-Telangiectasia Mutated Variant Carriers.

The Ataxia-Telangiectasia Mutated (ATM) gene is implicated in DNA double-strand break repair. Controversies in clinical radiosensitivity remain known for monoallelic carriers of the ATM pathogenic variant (PV). An evaluation of the single-nucleotide polymorphism (SNP) rs1801516 (G-A) showed different results regarding late subcutaneous fibrosis after breast radiation therapy (RT). The main objective of this study was to evaluate acute and late toxicities in carriers of a rare ATM PV or predicted PV and in carriers of minor allele A of rs1801516 facing breast RT. Fifty women with localized breast cancer treated with adjuvant RT between 2000 and 2014 at Institut Curie were selected. Acute and late toxicities in carriers of a rare PV or predicted PV (n= 9), in noncarriers (n = 41) and in carriers of SNP rs1801516 (G-A) (n = 8), were examined. The median age at diagnosis was 53 years old and 82% of patients had an invasive ductal carcinoma and 84% were at clinical stage I-IIB. With a median follow-up of 13 years, no significant difference between carriers and noncarriers was found for acute toxicities (p > 0.05). The same results were observed for late toxicities without an effect from the rs1801516 genotype on toxicities. No significant difference in acute or late toxicities was observed between rare ATM variant carriers and noncarriers after breast RT for localized breast cancer.

Radiation Exposure of Cardiac Conduction Nodes During Breast Proton Therapy.

Purpose: The exposition of cardiac conduction system during breast radiation therapy has never been studied, despite the increasing use of intensity-modulated radiation therapy, which exposes larger volume to low-dose bath. We evaluated conduction node exposure during breast irradiation with volumetric modulated arc therapy and estimated the potential dosimetric benefit with intensity-modulated proton therapy. Materials and Methods: Atrioventricular (AVN) and sinoatrial (SAN) nodes were retrospectively delineated according to published guidelines on the simulation computed tomography scans of 12 breast cancer patients having undergone conserving surgery and adjuvant locoregional volumetric modulated arc therapy. Intensity-modulated proton therapy treatment was replanned on the simulation computed tomography scans for all breast cancer patients. Mean and maximum doses delivered to the SAN and the AVN were retrieved and compared. Correlation coefficients were calculated between doses to the SAN or the AVN and the whole heart. Results: Average mean doses delivered to the SAN and AVN were 2.8 and 2.3 Gy, respectively, for left-sided irradiation and 9.6 and 3.6 Gy, respectively, for right-sided irradiation. Average maximum doses to the SAN and AVN were 3.5 Gy and 2.8 Gy, respectively, for left-sided irradiation and 13.1 and 4.6 Gy, respectively, for right-sided irradiation. Intensity-modulated proton therapy significantly reduced mean and maximum doses to the SAN and AVN. Correlations between doses to the SAN or AVN and whole heart were usually significant. Conclusion: SAN and AVN can be substantially exposed during breast volumetric modulated arc therapy, especially for right-sided irradiation. Cardiotoxicity studies evaluating conduction node exposure might define dose constraints and criteria for additional cardiac-sparing techniques, such as respiratory techniques or proton therapy, which could benefit patients with underlying rhythmic or conduction disorders.

Large scale experience of two ultrahypofractionated 5 fractions regimes after breast conserving surgery from a single centre.

PURPOSE: Ultra-hypofractionation breast radiotherapy is a safe alternative to moderate hypofractionation. This study reports the results of two ultrahypofractionated regimens used in clinical practice in a high-volume radiotherapy center in terms of efficacy and of tolerance. METHODS: we included all patients treated in an adjuvant setting with five fractions after breast conserving surgery (BCS), for a histologically-confirmed invasive or in situ breast carcinoma. Radiotherapy regimens after BCS were either a 5-week schedule with 5 weekly fractions of 5,7 Gy or a one-week schedule with 5 daily fractions of 5,2 Gy. Adverse events were recorded and local-relapse free survival (LRFS), locoregional-relapse free survival (LRRFS), metastasis-free survival (MFS), for breast-cancer specific survival (BCSS) and overall survival (OS) were evaluated. RESULTS: Between December 2014 and December 2022, 396 patients (400 breasts) were treated with ultrahypofractionated radiotherapy. Five-year LRFS was 98.8% (95% confidence interval: 97.1%-100%), and 5-year OS was 96.0% (95%CI: 92.6-99.5%). Age was statistically associated with OS in univariate analysis (HR: 1.16, 95%CI: 1.04-1.42, p = .01). Four patients (1.0%) experienced acute grade 3 radiation-induced adverse events, and 8 patients (2.3%) acute grade 2 toxicities. Twenty-three patients (5.8%) experienced late toxicity, all of them being graded as grade 1. The use of the 5.7 Gy-weekly-fraction regimen and the delivery of a tumor bed boost were significantly associated with acute radiodermatitis (p < .01; p = .02; respectively) and late fibrosis (p < .01; p = .049; respectively). CONCLUSIONS: ultrahypofractionated radiotherapy was associated with an excellent tumor control rate in our 'real-life' cohort with low-risk breast cancer patients. However, delivery of a tumor bed boost and using weekly 5.7-Gy fractions were associated with an increased risk of acute and late cutaneous toxicities.

Tolerance and Oncological Outcomes of In-Field Reirradiation for Locally Recurrent Breast Cancer: A Long-Term Single-Center Experience.

BACKGROUND: The management of cancer relapse in previously irradiated tissues is a challenging therapeutic issue. The aim of this work was to report our experience with breast reirradiation for locoregionally recurrent breast cancer. METHODS: All patients who underwent breast or chest wall in-field reirradiation at the Institut Curie, Paris, France, between 2003 and 2019, were identified. Efficacy outcomes and physician-reported toxicities were retrospectively assessed. RESULTS: A total of 21,372 patients underwent breast irradiation in our institution. Of these, 28 received a second course of radiotherapy to the homolateral breast/chest wall. A total of 18 (64%) patients were treated with a curative intent, and 10 (36%) were treated for palliative purposes. Only one acute and one late grade 3 adverse events were reported. One patient with major cardiovascular risk factors died of myocardial infarction 13 months after left breast reirradiation. The 2-year LRFS, OS, DSS, PFS and MFS were 59%, 79%, 82%, 46% and 75%, respectively, in the whole cohort. The 2-year LRFS (72% vs. 31%, p = 0.02), OS (94% vs. 50%, p < 0.01), DSS (94% vs. 56%, p < 0.01) and PFS (61% vs. 20%, p = 0.02) differed significantly between patients treated with curative or palliative intent but not the MFS (78% vs. 69%, p = 0.77). Among the patients, eight (29%) remained relapse-free 5 years after reirradiation. CONCLUSION: Breast/chest wall reirradiation appears to be feasible with good disease control, especially in patients treated with a curative intent, and presents acceptable toxicity rates.

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.

Mapping the location of local and regional recurrences according to breast cancer surgery and radiation therapy: Results from EORTC 22922/10925.

The purpose of this study is to evaluate the influence of the extent of surgery and radiation therapy (RT) on the rates and sites of local (LR) and regional recurrences (RR) in the EORTC 22922/10925 trial. PATIENTS AND METHODS: All data were extracted from the trial's individual patients' case report forms (CRF) and analysed with a median follow-up of 15.7 years. Cumulative incidence curves were produced for LR and RR accounting for competing risks: an exploratory analysis of the effect of the extent of surgical and radiation treatments on LR rate was conducted using the Fine & Gray model accounting for competing risks and adjusted for baseline patient and disease characteristics. The significance level was set at 5%, 2-sided. Frequency tables were used to describe the spatial location of LR and RR. RESULTS: Out of 4004 patients included in the trial, 282 (7%) patients experienced LR and 165 (4.1%) RR, respectively. Cumulative incidence rate of LR at 15 years was lower after mastectomy (3.1%) compared to BCS + RT (7.3%) (F&G: HR (Hazard Ratio) = 0.421, 95%CI = 0.282-0.628, p-value < 0.0001). LR were similar up to 3 years for both mastectomy and BCS but continued to occur at a steady rate for BCS + RT, only. The spatial location of the recurrence was related to the locoregional therapy applied and the absolute gain of RT correlated to stage of disease and extent of surgery. CONCLUSIONS: The extent of locoregional therapies impacts significantly on LR and RR rates and spatial location.

Dosimetric evaluation of the benefit of deep inspiration breath hold (DIBH) for locoregional irradiation of right breast cancer with volumetric modulated arctherapy (VMAT).

INTRODUCTION: Right-lateralized cardiac substructures can be substantially exposed during right breast cancer (R-BC) radiotherapy. The cardiac benefit of deep inspiration breath hold (DIBH) is established in combination with volumetric modulated arctherapy (VMAT) for left breast cancer with regional node irradiation but is unknown for R-BC. This study evaluated the dosimetric benefit of DIBH for locoregional irradiation of R-BC with VMAT. MATERIAL AND METHODS: All patients treated for R-BC with adjuvant locoregional DIBH-VMAT in the Department of Radiation Oncology of the Institut Curie (Paris, France) until December 2022 were included, corresponding to 15 patients. FB- and DIBH-VMAT plans were compared both for a normofractionated regimen (50 Gy/25fx) used for treatment and a replanned hypofractionated regimen (40 Gy/15fx). Dose to the heart, cardiac substructures (sinoatrial node (SAN), atrio-ventricular node (AVN), right coronary artery, left anterior descending coronary artery, left ventricle), ipsilateral lung and liver were retrieved and compared. RESULTS: Mean heart dose (MHD) was 3.33 Gy with FB vs. 3.10 Gy with DIBH on normofractionated plans (p = 0.489), and 2.58 Gy with FB vs. 2.41 Gy with DIBH on hypofractionated plan (p = 0.489). The benefit of DIBH was not significant for any cardiac substructure. The most exposed cardiac substructure were the SAN (mean dose of 6.62 Gy for FB- and 5.64 Gy for DIBH-VMAT on normofractionated plans) and the RCA (mean dose of 4.21 Gy for FB- and 4.06 Gy for DIBH-VMAT on normofractionated plans). The maximum benefit was observed for the RCA with a median individual dose reduction of 0.84 Gy on normofractionated plans (p = 0.599). No significant dosimetric difference were observed for right lung. Liver mean dose was significantly lower with DIBH with median values decreasing from 2.54 Gy to 0.87 Gy (p = 0.01). CONCLUSION: Adding DIBH to efficient cardiac-sparing radiotherapy techniques, such as VMAT, is not justified in the general case for locoregional R-BC irradiation. Specific R-BC patient subpopulations who could benefit from additional DIBH combination with locoregional VMAT are yet to be identified.

Clinical outcomes of curative-intent multimodal management of chemorefractory nonmetastatic inflammatory breast cancer.

INTRODUCTION: Chemorefractory nonmetastatic inflammatory breast cancer (IBC) which progresses under neoadjuvant chemotherapy poses specific therapeutic challenges: either pursuing a curative-intent treatment with a salvage combination of radiotherapy and surgery or switching to second-line systemic treatments despite the absence of metastasis. Due to the rarity of this situation, no specific management guidelines exist and the outcomes of these patients remain uncertain. In this retrospective observational study, we aimed to report the clinical outcomes of patients treated in a curative intent for chemorefractory nonmetastatic IBC, with a multimodal salvage treatment combining radiotherapy and surgery. MATERIALS AND METHODS: This single-center retrospective observational study included all chemorefractory nonmetastatic IBC treated at the Institut Curie (Paris, France). Overall survival (OS), disease-free survival (DFS), and locoregional relapse-free survival (LRRFS) were calculated from the time of diagnosis and from the time of neoadjuvant chemotherapy interruption. RESULTS: Between January 2010 and January 2018, 7 patients presented with chemorefractory nonmetastatic IBC with a progressive disease during neoadjuvant chemotherapy. Overall, chemorefractory IBC patients were young (median age of 50 years), had a good performance status, and usually presented with node-positive tumors characterized by a combination of adverse histological factors such as triple-negative breast cancer (TNBC), grade III, and high proliferation index. From the date of pathological diagnosis, 1­year OS, DFS, and LRRFS were 64.3%, 53.6%, and 71.4%, respectively. From the date of neoadjuvant chemotherapy interruption, 1­year OS, DFS, and LRRFS were 47.6%, 19.0%, and 45.7%, respectively, and median OS, DFS, and LRRFS were 8.3, 5.0, and 5.0 months, respectively. CONCLUSION: The prognosis of chemorefractory nonmetastatic IBC treated with a multimodal approach combining surgery and radiotherapy is particularly reserved, despite the curative intent of the salvage treatment and the lack of distant metastasis at the time of treatment. Optimal treatment modalities are still to be defined in this rare but critical presentation of IBC.

Concurrent Olaparib and Radiotherapy in Patients With Triple-Negative Breast Cancer: The Phase 1 Olaparib and Radiation Therapy for Triple-Negative Breast Cancer Trial.

Importance: Triple-negative breast cancer (TNBC) cells are sensitive to poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors used as radiosensitizers. Whether combining PARP inhibitors with radiotherapy in patients with TNBC would enhance the biological effectiveness of the irradiation and improve locoregional control is unclear. Objective: To assess the safety and tolerability of PARP inhibition with olaparib used concurrently with radiotherapy in patients with TNBC with residual disease after neoadjuvant chemotherapy. Design, Setting, and Participants: This phase 1 prospective dose-escalation trial (Olaparib and Radiation Therapy for TNBC [RadioPARP] trial) using a time-to-event continual reassessment method was performed from September 2017 to November 2019, with follow-up until November 2021. Participants had an incomplete pathologic response after neoadjuvant chemotherapy or unresectable TNBC despite previous neoadjuvant chemotherapy, an Eastern Cooperative Oncology Group Performance Status score of 0 or 1, and adequate organ functions. Interventions: Olaparib was administered orally in the form of tablets and given at increasing doses (50 mg, 100 mg, 150 mg, or 200 mg twice daily). Olaparib therapy was started 1 week before radiotherapy and was continued concomitantly with radiotherapy. After breast-conserving surgery, a total dose of 50.4 Gy was delivered to the whole breast, with a 63-Gy simultaneously integrated boost to the tumor bed for patients younger than 60 years. After radical mastectomy or for unresectable tumors despite neoadjuvant chemotherapy, a total dose of 50.0 Gy was delivered to the chest wall (after mastectomy) or to the whole breast (for unresectable tumors). Regional lymph node stations could be treated with a total dose of 50.0 Gy to 50.4 Gy in cases of node-positive disease. Main Outcomes and Measures: Main outcomes were the safety and tolerability of PARP inhibition with radiotherapy for early-stage, high-risk TNBC. Secondary outcomes included overall survival (OS) and event-free survival (EFS). Results: Among the 24 patients included in the trial (100% female; median age, 46 years [range, 25-74 years]), no dose-limiting toxic effects were observed, and olaparib was escalated to 200 mg twice daily without reaching the maximum tolerated dose. No late treatment-related grade 3 or greater toxic effect was observed, and the maximum observed treatment-related toxic effects at the 2-year follow-up were grade 2 breast pain, fibrosis, and deformity in 1 patient (4.2%). Three-year OS and EFS were 83% (95% CI, 70%-100%) and 65% (95% CI, 48%-88%), respectively. Homologous recombination status was not associated with OS or EFS. Conclusions and Relevance: The findings of this phase 1 dose-escalation trial suggest that PARP inhibition with olaparib concurrently with radiotherapy for early-stage, high-risk TNBC is well tolerated and should continue to be evaluated in further clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT03109080.

The association of internal mammary and medial supraclavicular lymph node radiation technique with clinical outcomes: Results from the EORTC 22922/10925 randomised trial.

BACKGROUND AND PURPOSE: The multicentre EORTC 22922/10925 trial (ClinicalTrials.gov, NCT00002851) was conducted between 1996 and 2004. The trial evaluated the effect of irradiation of the internal mammary and medial supraclavicular lymph node chains (IM-MS) vs no further radiation therapy (RT) on survival and cause of death in breast cancer stage I-III patients. At 15.7 years of median follow-up, a significant reduction of breast cancer specific mortality (BCSM) and any recurrence, not translating in improved overall survival (OS), and low absolute rates of side effects were found. The aim of the current analysis was to evaluate the association of RT techniques of IM-MS lymph node irradiation with long-term outcomes. PATIENTS AND METHODS: Three RT techniques were used for IM-MS: a standard technique using a fixed set-up combining photon/electron beams to the IM and tangential fields to the breast or chest wall vs a standard-modified technique with minor adaptation for beam settings vs a more individualised technique based on individual localisation of the IM. Techniques used were fixed per institution over the duration of the trial. We performed an exploratory and descriptive analysis of the outcomes after 15 years follow-up for the three RT techniques. RESULTS: Between July 1996 and January 2004, 46 radiation oncology departments from 13 countries accrued 4004 patients. Median follow-up was 15.7 years. The number of patients treated by each technique was 2440 (61%) by standard vs 635 (16%) by standard-modified vs 929 (23%) patients by individualised technique. The absolute improvements of oncological outcomes in terms of disease-free survival (DFS), OS and BCSM with IM-MS RT compared to no IM-MS RT were 6.8%, 4.9% and -5.8% for the individualised technique, vs 1.6%, 2.9% and -4.3% for modified standard and -1.4%, 1.1% and -3% for standard technique, respectively. The increase in 15-year rates of side effects due to IM-MS RT, both scored longitudinally and cross-sectionally, were similar among the techniques. CONCLUSION: Even though a straightforward comparison by technique is not possible because of variations in baseline characteristics between institutions, our findings suggest that the use of more individualised RT techniques is associated with higher rates of oncological improvements without increased risks for late side effects.

The place of the boost in the breast cancer treatment: State of art.

Several randomized controlled trials have demonstrated the benefit of a boost to the tumor bed (TB) to reduce the risk of ipsilateral breast tumor recurrence. Recent technological progress has facilitated improved conformation of isodoses around the target volume. The accuracy and reproducibility of TB delineation have become even more essential. The purpose of this study is to review the extant knowledge on the boost delineation in breast cancer, focusing on interobserver variability (IOV) and the influence of various factors, such as the presence of clips or different imaging modalities to improve IOV. Most studies investigating IOV for boost delineation have shown poor reproducibility (with comparison indices such as the dice similarity index around 0.5). Clips in the lumpectomy cavity (LC), postoperative fluid accumulation in the LC and/or high cavity visualization score appeared to be associated with improved IOV. Likewise, the use of preoperative imaging (CT and/or MRI) may also be useful in improving the accuracy of TB definition but without any real gain in terms of IOV. Moreover, the delineation of boost has become even more challenging since the development of oncoplastic surgery. To improve the reproducibility and the accuracy of boost delineation, this review suggests that within each center, a group of multidisciplinary experts, including surgeons, radiation oncologists, pathologists, and radiologists, should convene to develop local guidelines, which may include the choice of preoperative imaging, the number and location of surgical clips, pathological margins, and orientation. The elaboration of contouring atlas is certainly of great assistance.

Development of Simplified Auto-Segmentable Functional Cardiac Atlas.

PURPOSE: There is increasing evidence that radiation doses to cardiac substructures are associated with cardiac adverse events. Manual delineation of cardiac substructures is time-consuming, and auto-segmentation of cardiac substructure atlases has consequently been evaluated. However, proper automatic delineation of small substructures, such as the left anterior descending coronary artery, is challenging, and auto-segmentation of cardiac conduction system substructures has never been evaluated, despite multiple reports of radiation-induced arrhythmia after thoracic irradiations. The aim of this study was to propose and evaluate a simplified auto-segmentable functional cardiac atlas. METHODS AND MATERIALS: We created a cardiac substructure atlas based on 20 computed tomography scans from patients with breast cancer comprising the 4 cardiac cavities, a high-risk cardiac zone as a left anterior descending coronary artery surrogate, and the 2 cardiac conduction nodes. Automatic delineation of this atlas by an atlas-based auto-segmentation algorithm was evaluated on a validation data set, consisting of 20 additional computed tomography scans. Dice similarity coefficients were used to evaluate the concordance level between the manual and the automatic contours; a dosimetric comparison between mean and maximum doses to the manual and to the auto-segmented substructures was additionally performed, based on intensity modulated radiation therapy treatment plans of the patients of the validation set. RESULTS: Average dice similarity coefficient values were 0.78 for the 4 cardiac cavities, 0.65 for the high-risk cardiac zones, 0.56 for the sinoatrial node, and 0.15 for the atrioventricular node. Compared with manual contours, auto-segmented substructures were slightly smaller but the dosimetric parameters were similar. CONCLUSIONS: We proposed a simplified functional cardiac atlas that included the cardiac conduction system and circumvented coronary delineation difficulties by using a surrogate high-risk cardiac zone. Most cardiac substructures were associated with acceptable atlas-based auto-segmentation properties. Such an atlas could be used for epidemiologic studies and for clinical practice.

Combination of Modern Radiotherapy and New Targeted Treatments for Breast Cancer Management.

BACKGROUND: The objective of the present study was to review the essential knowledge about the combinations of the most commonly used or under development targeted treatments and radiation therapy (RT). METHODS: Preclinical and clinical studies investigating this combination were extensively reviewed. RESULTS: Several studies showed that the combination of RT and tamoxifen increased the risk of radiation-induced pulmonary toxicity; therefore, both modalities should not be given concomitantly. The combination of HER2 inhibitors (trastuzumab, pertuzumab) and RT seems to be safe. However, trastuzumab emtansine (T-DM1) should not be administered concurrently with brain RT since this combination could increase the risk of brain radionecrosis. The combination of RT and other new target treatments such as selective estrogen receptor degradants, lapatinib, cell cycle inhibitors, immune checkpoint inhibitors, or molecules acting on DNA damage repair seems feasible but was essentially evaluated on retrospective or prospective studies with a small number of patients. Furthermore, there is considerable heterogeneity among these studies regarding the dose and fractionation of radiation, the dosage of drugs, and the sequence of treatments used. CONCLUSIONS: The combination of RT with most targeted therapies for BC appears to be well-tolerated, but these results need to be confirmed in prospective randomized studies.

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

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.

Neoadjuvant Concurrent Radiotherapy and Chemotherapy in Early Breast Cancer Patients: Long-Term Results of a Prospective Phase II Trial.

Background: Neoadjuvant concurrent radiochemotherapy makes it possible to increase the breast conservation rate. This study reports the long term outcome of this treatment. Methods: From 2001 to 2003, 59 women with T2-3 N0-2 M0 invasive breast cancer (BC) not amenable to upfront breast conserving treatment (BCS) were included in this prospective, non-randomized phase II study. Chemotherapy (CT) consisted of four cycles of continuous 5-FU infusion and Vinorelbine. Starting concurrently with the second CT cycle, normofractionated RT was delivered to the breast and LN. Breast surgery was then performed. Results: Median follow-up (FU) was 13 years [3-18]. BCS was performed in 41 (69%) patients and mastectomy in 18 patients, with pathological complete response rate of 27%. Overall and distant-disease free survivals rates at 13 years were 70.9% [95% CI 59.6-84.2] and 71.5% [95% CI 60.5-84.5] respectively. Loco regional and local controls rates were 83.4% [95% CI 73.2-95.0] and 92.1% [95% CI 83.7-100], respectively. Late toxicity (CTCAE-V3) was assessed in 51 patients (86%) with a median follow-up of 13 years. Fifteen presented grade 2 fibrosis (29.4%), 8 (15.7%) had telangiectasia, and 1 had radiodermatitis. Conclusions: This combined treatment provided high long-term local control rates with limited side-effects.

The impact of isolated local recurrence on long-term outcome in early-breast cancer patients after breast-conserving therapy.

PURPOSE: To analyse the prognostic impact of isolated local recurrence (ILR) on long-term outcome for early-breast cancer patients treated with breast-conserving therapy. MATERIAL AND METHODS: The data of the EORTC 22881-10882 'boost-no boost' and 22922-10925 'IM-MS' trials were used to analyse the prevalence and outcome following ILR. A multistate model described the impact of intermediate events on long-term outcomes, taking into account various prognostic factors. This model was used to predict long-term outcomes after ILR. RESULTS: Of the 8367 patients included, 726 experienced an ILR, 11.6% of them within the first 2 years and 30.0% after 10 years. Ten-year cumulative breast cancer mortality rates after ILR were 58.2% in patients with an ILR within 2 years, 31.0% for ILR between 2 and 4 years, 17.6% in patients with an ILR between 4 and 10 years, and 29.7% for ILR after year 10 (p < 0.001). The multistate model showed that when tumour-free, younger breast cancer patients had a higher probability of developing ILR compared to older patients. Shorter time to ILR was associated with a higher chance to develop distant metastases (DM), and a shorter time to development of DM were associated with an increased hazard of breast cancer-related death. The multistate model enabled prediction of long-term outcome based on individual patient covariates, length of follow-up without recurrence and timing of ILR since randomisation. CONCLUSIONS: Outcome of early-breast cancer changed not only according to baseline risk factors but also according to the presence of intermediate events, time to these events, and subsequent follow-up without any further events.

Evaluation of the early adverse effects of radiotherapy in breast cancer patients with COVID-19: Prospective single institutional study.

The COVID-19 caused by the SARS-CoV-2 coronavirus is at the origin of a global pandemic. This pandemic has prompted the current health system to reorganize and rethink the care offered by health establishments. We report the early toxicity in patients infected with COVID-19 treated at the same time for early-stage breast cancer (BC). This is a monocentric prospective study of patients treated in our hospital between March 2020 and June 2020 and were diagnosed with COVID-19 infection. The inclusion criteria were to be irradiated for early-stage BC and to have a positive COVID-19 diagnosis on a PCR test and/or a lung computed tomography (CT) scan and/or suggestive clinical symptoms. Radiotherapy (RT) consisted of breast or chest wall irradiation with or without lymph node irradiation, with protocols adapted to pandemic situation. The treatment-related toxicity was graded according to the CTCAE (version 4.03). All 350 patients treated for early-stage BC were studied. Of them, 16 were presented with clinical symptoms of COVID-19 infection and of them, 12 had clinical, CT scan, and PCR confirmation. This entire cohort of 12 pts with median age of 56 (42-72) underwent their RT. During the radiotherapy, there were 9 pts presented radiation dermatitis, 8 (66%) were grade 1 and one was (8%) grade 2. Two patients with lymph nodes irradiation presented esophagitis grade 2. This prospective COVID-19 cohort, treated for early-stage BC demonstrated an acceptable toxicity profile with few low-grade adverse events. Longer follow-up is needed to confirm these findings.

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.