Tucatinib Combination Treatment After Trastuzumab-Deruxtecan in Patients With ERBB2-Positive Metastatic Breast Cancer

Importance

Little is known regarding the outcomes associated with tucatinib combined with trastuzumab and capecitabine (TTC) after trastuzumab-deruxtecan exposure among patients with ERBB2 (previously HER2)-positive metastatic breast cancer (MBC).

Objective

To investigate outcomes following TTC treatment in patients with ERBB2-positive MBC who had previously received trastuzumab-deruxtecan.

Design, Setting, and Participants

This cohort study included all patients with MBC who were treated in 12 French comprehensive cancer centers between August 1, 2020, and December 31, 2022.

Exposure

Tucatinib combined with trastuzumab and capecitabine administered at the recommended dose.

Main Outcomes and Measures

Clinical end points included progression-free survival (PFS), time to next treatment (TTNT), overall survival (OS), and overall response rate (ORR).

Results

A total of 101 patients with MBC were included (median age, 56 [range, 31-85] years). The median number of prior treatment lines for metastatic disease at TTC treatment initiation was 4 (range, 2-15), including 82 patients (81.2%) with previous trastuzumab and/or pertuzumab and 94 (93.1%) with previous ado-trastuzumab-emtansine) exposure. The median duration of trastuzumab-deruxtecan treatment was 8.9 (range, 1.4-25.8) months, and 82 patients (81.2%) had disease progression during trastuzumab-deruxtecan treatment, whereas 18 (17.8%) had stopped trastuzumab-deruxtecan for toxic effects and 1 (1.0%) for other reasons. Tucatinib combined with trastuzumab and capecitabine was provided as a third- or fourth-line treatment in 37 patients (36.6%) and was the immediate treatment after trastuzumab-deruxtecan in 86 (85.1%). With a median follow-up of 11.6 (95% CI, 10.5-13.4) months, 76 of 101 patients (75.2%) stopped TTC treatment due to disease progression. The median PFS was 4.7 (95% CI, 3.9-5.6) months; median TTNT, 5.2 (95% CI, 4.5-7.0) months; and median OS, 13.4 (95% CI, 11.1 to not reached [NR]) months. Patients who received TTC immediately after trastuzumab-deruxtecan had a median PFS of 5.0 (95% CI, 4.2-6.0) months; median TTNT of 5.5 (95% CI, 4.8-7.2) months, and median OS of 13.4 (95% CI, 11.9-NR) months. Those who received TTC due to trastuzumab-deruxtecan toxicity-related discontinuation had a median PFS of 7.3 (95% CI, 3.0-NR) months. Best ORR was 29 of 89 patients (32.6%). Sixteen patients with active brain metastasis had a median PFS of 4.7 (95% CI, 3.0-7.3) months, median TTNT of 5.6 (95% CI, 4.4 to NR), and median OS of 12.4 (95% CI, 8.3-NR) months.

Conclusions and Relevance

In this study, TTC therapy was associated with clinically meaningful outcomes in patients with ERBB2-positive MBC after previous trastuzumab-deruxtecan treatment, including those with brain metastases. Prospective data on optimal drug sequencing in this rapidly changing therapeutic landscape are needed.

p4EBP1 staining predicts outcome in ER-positive endocrine-resistant metastatic breast cancer patients treated with everolimus and exemestane

BACKGROUND

To identify patients most likely to respond to everolimus, a mammalian target of rapamycin (mTOR) inhibitor, a prospective biomarker study was conducted in hormone receptor-positive endocrine-resistant metastatic breast cancer patients treated with exemestane-everolimus therapy.

METHODS

Metastatic tumor biopsies were processed for immunohistochemical staining (p4EBP1, PTEN, pAKT, LKB1, and pS6K). ESR1, PIK3CA and AKT1 gene mutations were detected by NGS. The primary endpoint was the association between the p4EBP1 expression and clinical benefit rate (CBR) at 6 months of everolimus plus exemestane treatment.

RESULTS

Of 150 patients included, 107 were evaluable for the primary endpoint. p4EBP1 staining above the median (Allred score ≥6) was associated with a higher CBR at 6 months (62% versus 40% in high-p4EBP1 versus low-p4EBP1, χ2 test, p = 0.026) and a longer progression-free survival (PFS) (median PFS of 9.2 versus 5.8 months in high-p4EBP1 versus low-p4EBP1; p = 0.02). When tested with other biomarkers, only p4EBP1 remained a significant predictive marker of PFS in multivariate analysis (hazard ratio, 0.591; p = 0.01).

CONCLUSIONS

This study identified a subset of patients with hormone receptor-positive endocrine-resistant metastatic breast cancer and poor outcome who would derive less benefit from everolimus and exemestane. p4EBP1 may be a useful predictive biomarker in routine clinical practice.

CLINICAL TRIAL REGISTRATION

NCT02444390.

First-line real-world treatment patterns and survival outcomes in women younger or older than 40 years with metastatic breast cancer in the real-life multicenter French ESME cohort

AIM

To describe first-line treatment patterns, overall survival (OS) and real-world progression-free survival (rwPFS) in young women (<40) with metastatic breast cancer (mBC), as compared to women aged 40-69.

MATERIALS AND METHODS

Data on adult women diagnosed with mBC (2008-2017) were extracted from the ESME mBC database (NCT03275311) which includes consecutive patients starting first-line metastatic treatment in one of the 18 French Comprehensive cancer centers. We reported first-line therapeutic strategy and prognostic factors of OS and rwPFS for women aged < 40 and 40-69.

RESULTS

In total, 14,897 mBC women were included (1512 aged <40). HR+ /HER2- mBC was the most frequent subtype. First-line treatment differed between young patients and older ones for HR+ /HER2- and Triple Negative (TN) mBC. Median OS for women aged < 40 and 40-69, respectively, was 46.9 and 46.2 months for HR+ /HER2- mBC; 13.5 and 15.2 for TN mBC; and, 60.7 and 55.1 for HER2 + mBC. Median rwPFS under first line treatment was 11.6 and 11.9 months for HR+ /HER2- in women aged < 40 and 40-69, respectively; 5.5 and 5.9 for TN, and, 13.3 and 12.9 for HER2 + . Factors associated with shorter OS and rwPFS were similar for both women aged < 40 and 40-69 and included ≥ 3 metastatic sites, visceral metastases, and longer MFI, with time-varying effects observed for several prognostic factors.

CONCLUSION

Young women presented more frequently with TN and HER2 + subtypes and aggressive mBC than women aged 40-69 did. Prognostic factors of OS and rwPFS were quite similar between age groups and mBC subtypes.

Intrathecal Catheter for Chemotherapy in Leptomeningeal Carcinomatosis From HER2-Negative Metastatic Breast Cancer

PURPOSE

Most oncological treatments for leptomeningeal metastasis (LM) do not cross the blood-brain barrier (BBB). One therapeutic option is intrathecal (IT) chemotherapy. Both the brain-implanted Omaya reservoir and lumbar puncture (LP) are classic routes for IT chemotherapy delivery. An intrathecal catheter (IC) connected to a subcutaneous port is a recently developed option for the management of chemotherapy infusions. It is essential to evaluate the efficacy and safety of chemotherapy infusion using such device.

METHODS

We conducted a retrospective monocentric study within Institut de cancerologie de l'Ouest at Angers, including all patients with advanced breast cancer (aBC) with LM implanted with an IT device for IT chemotherapy between January 2013 and May 2020. The primary endpoint was overall survival (OS) and secondary endpoints included surgical feasibility, patient safety, and progression-free survival (PFS). The catheter was inserted through an LP, the tip was positioned at the right level and connected to a subcutaneous port implanted under the skin of the anterior thoracic wall. IT chemotherapy is painless and easy for qualified nurses to administer on an outpatient basis.

RESULTS

Thirty women underwent the implantation. No failures occurred during the procedure. A total of 77% of patients reported no complications after implantation. Only three complications required surgical treatment. The median number of IT chemotherapy courses per patient was 8 (range, 2-27). The tolerance profile for iterative IT chemotherapy was manageable in ambulatory care. With a median follow-up of 76.5 months (95% confidence interval [CI], 11.6-not available), the median OS was 158 days (95% CI, 87-235), and the median PFS was 116 days (95% CI, 58-174).

CONCLUSION

Infusing chemotherapy using an implanted catheter is an efficient option for managing IT chemotherapy with a good tolerance profile. Patient-reported outcomes for the evaluation of IT chemotherapy toxicity are currently being developed.

Atezolizumab and paclitaxel as first line therapy in advanced triple-negative breast cancer patients included in the French early access program

Following the results of the IMpassion130 trial, an early access program (EAP) was opened in France, allowing patients with PD-L1-positive advanced triple negative breast cancer (aTNBC) to receive a combination of paclitaxel and atezolizumab as first line therapy. This EAP was later discontinued when the IMpassion131 trial read out with negative results. We performed a retrospective multicentric analysis in patients who were prospectively enrolled in the French EAP. Efficacy and toxicity data were obtained on 64 patients treated from August 2019 to August 2020 in 10 French cancer centers. Median progression-free survival (PFS) and overall survival (OS) were 4.1 months (95% CI [3.0-5.8]) and 17.9 months (95% CI [12.4-NR]), respectively. The 6-months PFS rate was 28% (95% CI [16-40%]) (N = 18/64), while N = 33/64 patients (52%, 95% CI [38-63%]) experienced a tumor response. Exploratory subgroup analyses retrieved that corticosteroid use at inclusion in the EAP, before treatment initiation, was the only independent unfavorable prognostic factor for PFS (HR 2.7, 95% CI [1.3-5.6]). No new safety signal was observed. This real-life study, unique by its setting (EAP granted by anticipation and later withdrawn), suggests atezolizumab and paclitaxel has a limited efficacy in PD-L1-positive aTNBC, especially in patients receiving corticosteroids as comedication before treatment start.

Efficacy of front-line treatment for hormone receptor-positive HER2-negative metastatic breast cancer with germline BRCA1/2 mutation

BACKGROUND

Efficacy of endocrine therapy in HR+/HER2- metastatic breast cancer could differ depending on the presence of BRCA1/2 germline mutation.

METHODS

The ESME metastatic breast cancer platform (NCT03275311) is a French real world database. Multivariable models including a time-varying approach and landmark analyses assessed the association between time-dependent gBRCA status (categorised as gBRCAm, gBRCAwt (wild type), and untested), overall survival (OS), and first-line progression-free survival (PFS1).

RESULTS

A total of 170 patients were gBRCAm carriers, 676 gBRCAwt, and 12,930 were untested at baseline. In the multivariable analysis, gBRCAm carriers overall had a lower OS compared to gBRCAwt (adjusted HR [95% CI] 1.26 [1.03-1.55]). gBRCAm patients treated with front-line endocrine therapy had lower adjusted OS (adjusted HR [95% CI] = 1.54 [1.03-2.32]) and PFS1 (adjusted HR [95% CI] 1.58 [1.17-2.12]) compared to gBRCAwt patients. However, for patients who received frontline chemotherapy, neither OS nor PFS1 differed between gBRCAm carriers and the other groups (HR versus gBRCAwt for OS: 1.12 [0.88-1.41], p = 0.350; PFS1: 1.09 [0.90-1.31], p = 0.379).

CONCLUSION

In this large cohort of HR+/HER2- MBC patients treated in a pre-CDK4/6 inhibitors era, gBRCAm status was associated with a lower OS and lower PFS following first-line endocrine therapy, but not following first-line chemotherapy.

Evaluating everolimus for the treatment of breast cancer

INTRODUCTION

Everolimus is an oral drug that inhibits mTOR with immunosuppressive and antiproliferative characteristics. It is commonly used in association with exemestane in hormone receptor (HR)-positive advanced breast cancer (ABC).

AREAS COVERED

The current review summarizes the publications relating to everolimus from clinical research in breast cancer. Everolimus showed treatment efficacy and an acceptable safety tolerance with prevention of side effects in Phase II/III studies. BOLERO-2 study showed a progression-free survival improvement in patients with HR-positive ABC previously treated with aromatase inhibitors (AI) and leading to its acceptance in this indication. The absence of a post CDK4/6 inhibitor (CDK4/6i.) study and the arrival of new drugs may raise questions about its current place in the therapeutic strategy.

EXPERT OPINION

Everolimus is relevant in the management of HR-positive ABC. Because of its efficacy, acceptable tolerability and the absence of drugs that have shown a greater benefit, it remains a second-line treatment option in HR-positive, HER2 negative (score 0) patients without BRCA mutation or visceral crisis and can be discuss with fulvestrant in second line after CDK4-6i. It is likely that within 5 years this treatment will be replaced in second line HR-positive breast cancer by new emerging treatments: drug-conjugated antibodies, tyrosine kinase inhibitors or immunotherapy in combination with chemotherapy.

Abstract P3-11-09: Extracellular vesicle-based biomarker assay for the monitoring of the efficacy of frontline endocrine therapy + CDK4-6 inhibitors in metastatic breast cancer

CONTEXT: Endocrine therapy combined with CDK4/6 inhibitor is the standard frontline treatment for the vast majority of HR+/HER2- metastatic breast cancer (MBC) patients. Despite an overall survival benefit, patients eventually progress and mechanisms of resistance to this combination are not well identified. Non-invasive monitoring of the efficacy of treatment could help into tailoring therapeutic regimen. Extracellular vesicles (EVs) are a group of heterogeneous nanosized bioparticles (30-1000nm), released by almost all cell types - including tumor, platelets, and immune cells – carrying informative biological material emanating from the mother cell and circulating in the blood stream. In this project, we ambition to assess whether the vesiclemia, i.e. plasmatic extracellular vesicle concentration can be used as a clinic-biological parameter to assist in the monitoring of patients. METHODS: EPICURE is an ongoing pilot prospective cohort study of heterogeneous and massive data integration, i.e. multi-omics approaches in MBC patients. The present study focused on patients with HR+/HER2- MBC receiving frontline endocrine therapy+iCDK4/6. Plasma samples were drawn every 3 months during the treatment until progression. The workflow for the enrichment of circulating EVs was developed from frozen plasma. A semi-automatized isolation procedure using size exclusion chromatography combined with the newly developed interference light microscopy apparatus Videodrop allowed to routinely separate plasmatic EVs and quantify vesiclemia in a fast and reliable manner for a large number of samples (longitudinal follow-up of MBC patients). RESULTS: 26 patients were included and monitored for vesiclemia. Median age was 58.5y (±13.7). Metastatic disease sites were distributed as follows: bone metastases (21; 84%), liver (21; 84%), thoracic (10; 40%), node (2; 8%), brain (1; 4%), others (2; 8%). Endocrine therapy included aromatase inhibitors (20; 77%), fulvestrant (6; 29%), GnRH agonists (5; 19%) and CDK4/6 inhibitors palbocilib (15; 57%), abemaciclib (8; 31%) and ribociclib (3; 11%). With a median follow-up time of 22.1 months (95%CI 21.2 - not reached), median progression free survival was 21.8 months (95%CI 18.1 - not reached). Median time on treatment was 19.4 months (IQR 11.6 - 22.1). Objective response rate was confirmed in 12 patients (6 with complete response). Out of the 26 patients, 12 stopped the frontline treatment due to disease progression. 135 longitudinal follow-up samples were analyzed for EVs. All patients who progressed rapidly after treatment initiation (i.e median PFS&lt; 6 months) had an increased vesiclemia at the months 2 and 6 after inclusion. Conversely, patients who had a median PFS &gt;18m had a stable vesiclemia during this period. CONCLUSION This study aims to use circulating EVs as a therapeutic companion to anticipate treatment resistance and tumor progression in MBC patients. Our preliminary data suggest that the vesiclemia could be used as a predictive tool to anticipate treatment failure, and thus might be used to tailor treatments in time.

Citation Format: Mathilde Richard, Jean Sebastien FRENEL, Laurent Mathiot, Mario Campone, Mathilde Colombie, Marie Robert, Anne Patsouris, Frederic Bigot, Julie Gavard, Gwennan André-Grégoire, Laetitia Guevel. Extracellular vesicle-based biomarker assay for the monitoring of the efficacy of frontline endocrine therapy + CDK4-6 inhibitors in metastatic breast cancer. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-11-09.

Abstract P5-02-37: Multi-omics approach to identify markers of resistance to endocrine therapy + CDK4/6 inhibitors in first line HR+/HER2- metastatic breast cancer (MBC) patients

CONTEXT: Endocrine therapy combined with CDK4/6 inhibitor is the standard frontline treatment for the vast majority of HR+/HER2- MBC patients. Despite an overall survival benefit, patients eventually progress and mechanisms of resistance to this combination are not well identified. METHODS: EPICURE is an ongoing pilot prospective cohort study of heterogeneous and massive data integration, ie. multi-omics approach in MBC patients. The present study aims at identifying progression markers in patients with HR+/HER2- MBC receiving frontline endocrine therapy+iCDK4/6 by means of transcriptomics, genomics and proteomics data. All patients had a tumor biopsy at the entry in the study (B1) and a biopsy was repeated at progression if feasible (B2). Transcriptomic (RNAseq: NextSeq550, Illumina), genomic (whole exome sequencing: NextSeq550, Illumina) and proteomic (DIA mass spectrometry: TimsTOFPro2, Bruker) were performed on B1 and B2 according to available tumor tissue. RESULTS: Fifty-one patients matching inclusion criteria were included. B1 was done at inclusion for all patients (B1) (n = 51) and B2 was performed in 8 patients. (B2) (n = 8). Eight metastatic sites were biopsied: node (n = 17); liver (n = 16); bone (n = 8); breast local recurrence (n = 5); chest wall (n = 5); skin (n = 4); pleural (n = 3); ovary (n = 1). Transcriptomic, genomic and proteomic analysis of paired biopsies (B1 and B2) was performed in parallel and separately for 8, 7 and 2 patients, respectively. Exploratory data analysis of transcriptomic and proteomic data showed that liver biopsies clustered together. In order to eliminate this anatomic bias, specific genes and proteins of liver metastases were identified by means of DESeq2 analysis (12 liver vs 39 other sites) for transcriptomic data (n = 2654) and LIMMA (4 liver vs 14 other sites) for proteomic data (n = 227), and excluded for the rest of the analysis. Differential analyses (ie. gene expression, non-synonymous mutations and protein expression) between B1 and B2 were performed for each patient. These three kind of lists were finally submitted to ToppGene, DAVID and GOrilla for Gene Ontology terms enrichment analyses. Transcriptomic analyses of the 8 paired biopsies highlighted immune response (IR) in seven B1, IR in four B2 and neurogenesis in three B2. Genomics data evaluation between B1 and B2 pointed out “transposon integration” as an important pathway. Proteomic data of the 2 paired biopsies analysed underlined high immune response in B1, and muscle development/contraction and response to tumor necrosis factor in B2 for one patient. For the second one, liver metabolism in B1 and extracellular matrix and p38 MAPK cascade were emphasised. CONCLUSION: This preliminary study based on transcriptomic, genomic and proteomic data represents an encouraging first step of the EPICURE project. In a near future, additional paired biopsies and other kinds of omics data (epigenetics, radiomics, microbiomics, exposomics) will be available. Furthermore, omics data will be analysed in an integrated manner (ie. artificial intelligence), which will make it possible to detect synergies across the different omics data.

Citation Format: Jean Sebastien FRENEL, Fadoua Ben Azzouz, Frederic Bigot, Jonathan Dauve, Marie Francoise Heymann, Wilfried Gouraud, Catherine Guette, Hamza Lasla, Bertrand Michel, Alain Morel, Anne Patsouris, Marie Robert, Grégoire Siekaniec, Mathilde Colombie, Pascal Jézéquel, Mario Campone. Multi-omics approach to identify markers of resistance to endocrine therapy + CDK4/6 inhibitors in first line HR+/HER2- metastatic breast cancer (MBC) patients. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-02-37.

Real-World Data on Olaparib in Relapsed BRCA-mutated Ovarian Cancer: A Multicenter GINECO RETROLA Cohort Study

BACKGROUND/AIM

Olaparib was approved in 2014 by the European Medicines Agency (EMA) as maintenance treatment for patients with breast cancer gene (BRCA)-mutated platinum-sensitive relapsed high-grade epithelial ovarian cancer (EOC) following the results of the Study 19. We present the results of a national real-world study on the effectiveness of olaparib in relapsed BRCA-mutated EOC patients.

PATIENTS AND METHODS

Patients with EOC, peritoneal, and/or fallopian-tube cancer treated with olaparib in a French Center between May 2014 and March 2017 were included. The primary end-point of the study was progression-free survival.

RESULTS

Of the 128 patients analyzed, 89 were treated according to the EMA label. The median progression-free survival was 17.0 months. The most common treatment-related toxicity was fatigue. Treatment-related myelodysplastic syndrome (n=5) and a second cancer (n=1) were diagnosed.

CONCLUSION

In this real-life setting, olaparib confirmed its efficacy and safety profile, as previously shown in clinical trials.

Outcomes of patients with HER2-negative metastatic breast cancer after platinum- and non-platinum-based first-line chemotherapy among patients with and without pathogenic germline BRCA1/2 mutations

BACKGROUND

The efficacy and added benefit of platinum-based chemotherapy (PtCT) for metastatic breast cancer (MBC) remain unclear in patients with and without germline BRCA1 or BRCA2 mutations (gBRCA1/2m and gBRCA1/2wt, respectively).

METHODS

We selected from the French national real-world multicentre ESME cohort (2008-2016) all patients with HER2-negative MBC with known gBRCA1/2 status at first-line chemotherapy initiation. Using multivariable Cox models, we compared the outcome (progression-free (PFS) and overall survival (OS)) of first-line PtCT and non-PtCT regimens based on the patients' gBRCA1/2 status and tumour subtype.

RESULTS

Patients who received PtCT had more aggressive tumour features. In the multivariable analysis, first-line PtCT was associated with better adjusted PFS and OS in gBRCA1/2m carriers (N = 300), compared with non-PtCT (HR 0.54, 95% CI 0.4-0.73, P < 0.001, and HR 0.70, 95% CI 0.49-0.99, P = 0.047, respectively). Conversely, outcomes were similar in gBRCA1/2wt patients (N = 922) treated with PtCT and non-PtCT, whatever the tumour subtype. Landmark analyses at months 3 and 6 post treatment initiation supported these results.

CONCLUSIONS

In this pre-PARP inhibitor real-world cohort, PFS and OS were better after PtCT than non-PtCT in patients with gBRCA1/2m, but not in those with gBRCA1/2wt. These results emphasise the need of early gBRCA1/2 testing in patients with MBC.

CLINICAL TRIAL NUMBER

NCT03275311.

Comparison of Management and Outcomes in ERBB2-Low vs ERBB2-Zero Metastatic Breast Cancer in France

IMPORTANCE

ERBB2-low (ie, ERBB2 immunohistochemistry score of 1+ or 2+ in the absence of ERBB2 gene amplification) breast cancer (BC) is a new entity, with emerging dedicated treatments. Little is known about its prognosis and response to conventional therapy compared with ERBB2-zero breast tumors (ie, those with an immunohistochemistry score of 0).

OBJECTIVE

To compare the outcomes for patients with ERBB2-low metastatic BC (MBC) with those of patients with ERBB2-zero MBC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted from the Epidemiological Strategy and Medical Economics MBC platform and included patients with MBC treated between 2008 and 2016 in 18 French comprehensive cancer centers. The data analysis was conducted from July 16, 2020, to April 1, 2022.

MAIN OUTCOMES AND MEASURES

The main outcome was overall survival (OS), and the secondary outcome was progression-free survival under first-line treatments (PFS1).

RESULTS

The median (range) age was 60.0 (22.0-103.0) years. Among 15 054 patients with MBC, 4671 (31%) had ERBB2-low MBC and 10 383 (69%) had ERBB2-zero MBC. The proportion of ERBB2-low cancers was higher among patients with hormone receptor-positive MBC than those with hormone receptor-negative disease (4083 patients [33.0%] vs 588 patients [21.0%]). With a median follow-up of 49.5 months (95% CI, 48.6-50.4 months), the median OS of the ERBB2-low group was 38.0 months (95% CI, 36.4-40.5 months) compared with 33.9 months (95% CI, 32.9-34.9 months) for the ERBB2-zero group (P < .001). After adjustment for age, visceral metastases, number of metastatic sites, de novo disease, period of care, and hormone receptor status, patients with ERBB2-low MBC had slightly better OS compared with patients with ERBB2-zero MBC (adjusted hazard ratio, 0.95; 95% CI, 0.91-0.99; P = .02). In contrast, PFS1 did not differ by ERBB2 status (adjusted hazard ratio, 0.99; 95% CI, 0.95-1.02; P = .45). No significant differences in OS and PFS1 were observed in multivariate analyses by hormone receptor status and types of frontline treatment.

CONCLUSIONS AND RELEVANCE

In this large cohort study, patients with ERBB2-low MBC had a slightly better OS than those with completely ERBB2-zero tumors, but identical PFS1, which could help guide treatment selection.

Efficacy of trastuzumab emtansine (T-DM1) and lapatinib after dual HER2 inhibition with trastuzumab and pertuzumab in patient with metastatic breast cancer: Retrospective data from a French multicenter real-life cohort

Purpose

Trastuzumab-emtansine (T-DM1), as well as lapatinib plus capecitabine were proven effective in two Phase III studies, following first-line trastuzumab plus a taxane. The introduction of dual HER2 blockade by trastuzumab and pertuzumab as first-line has positioned T-DM1 into second-line, and lapatinib plus capecitabine beyond, without formal evaluation of these strategies.

Methods

ESME Data Platform (NCT03275311) included individual data from all patients aged ≥18 years, in whom first-line treatment for metastatic breast cancer (MBC) was initiated between January 1, 2008 and December 31, 2016 in one of the 18 French Comprehensive Cancer Centers. The efficacy of T-DM1 and lapatinib plus capecitabine combination, following double blockade associating trastuzumab and pertuzumab were evaluated in this national real-life database. Eligibility criteria were: female, MBC, HER2+ tumor, first-line taxane-based chemotherapy and dual HER2-blockage by trastuzumab plus pertuzumab. Cohort A received second-line T-DM1, and Cohort B second-line T-DM1 and third or fourth-line lapatinib plus capecitabine.

Results

Cohort A comprised 233 patients, and Cohort B 47 patients. Median progression-free survival (PFS) was 7.1 months in Cohort A and 4.6 months in Cohort B. Median overall survival were 36.7 months and 12.9 months, respectively. PFS was significantly dependent on the preceding treatment line's duration. In cohort A, HER2 expression status was a significant predictive factor of PFS.

Conclusion

First-line trastuzumab plus pertuzumab do not markedly diminish T-DM1's efficacy in second-line. Similarly, sequential treatment with trastuzumab plus pertuzumab then T-DM1 does not noticeably modify the efficacy of lapatinib plus capecitabine.

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French real-life cohort.

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Dual blockade HER2 does not markedly diminish T-DM1's activity in second-line and lapatinib's activity in third or fourth line.

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The second-line (T-DM1) PFS was significantly longer when the first-line treatment with trastuzumab plus pertuzumab was ≥12 months.

Impact of HER2 Status on Pathological Response after Neoadjuvant Chemotherapy in Early Triple-Negative Breast Cancer

PURPOSE

Investigates the link between HER2 status and histological response after neoadjuvant chemotherapy in patients with early TNBC.

METHODS

We retrieved clinical and anatomopathological data retrospectively from 449 patients treated for the first time with standard neoadjuvant chemotherapy for early unilateral BC between 2005 and 2020. The primary endpoint was pathological complete response (pCR, i.e., ypT0 ypN0), according to HER2 status. Secondary endpoints included invasive disease-free survival (I-DFS) and overall survival (OS).

RESULTS

437 patients were included, and 121 (27.7%) patients had HER2-low tumours. The pCR rate was not significantly different between the HER2-low group vs. the HER2-0 group (35.7% versus 41.8%, p = 0.284) in either univariate analysis or multivariate analysis adjusted for TNM classification and grade (odds ratio [OR] = 0.70, confidence interval [CI] 95% 0.45-1.08). With a median follow-up of 72.9 months, no significant survival differences were observed between patients with HER2-low tumours vs. patients with HER2-0 tumours in terms of I-DFS (p = 0.487) and OS (p = 0.329).

CONCLUSIONS

In our cohort, HER2 status was not significantly associated with pCR in a manner consistent with data published recently on TNBC. However, the prognostic impact of HER2-low expression among TNBC patients warrants further evaluation.

Clinicopathological characteristics and prognosis of breast cancer patients with isolated central nervous system metastases in the multicentre ESME database

Background:

As a result of progress in diagnosis and treatment, there is a growing prevalence of metastatic breast cancer (MBC) with isolated CNS metastases. This study describes the largest-to-date real-life cohort of this clinical setting and compares it to other clinical presentations.

Methods:

We retrospectively analysed the French Epidemiological Strategy and Medical Economics (ESME) MBC database including patients who initiated treatment for MBC between 2008 and 2016. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Descriptive statistics and multivariate Cox model were used.

Results:

Of 22,266 patients, 647 (2.9%) and 929 (4.2%) patients had isolated first-site CNS metastases or combined with extra-CNS metastases, with longer OS for the group with isolated CNS metastases (16.9 versus 13.9 months, adjusted HR = 1.69 (95% CI: 1.50–1.91), p < 0.001). Among the 541 (2.4%) patients with isolated CNS metastases and no intrathecal therapy (excluding leptomeningeal metastases), HER2+ cases were preponderant over TN or HR+ /HER2− cases (41.6% versus 26.1% versus 28.5%, respectively, p < 0.01). The treatment strategy consisted of a combination of local treatment and systemic therapy (49.2%), local treatment only (35.5%) or systemic therapy only (11.4%), or symptomatic therapy only (3.9%). Median PFS was 6.1 months (95% CI: 5.7–6.8). Median OS was 20.7 months (95% CI: 17.3–24.3), reaching 37.9 months (95% CI: 25.9–47.6) in the HR+ /HER2+ subgroup. Older age, TN subtype, MBC-free interval of 6–12 months, lower performance status, and WBRT were associated with poorer survival. Patients who received systemic therapy within 3 months from MBC diagnosis had longer OS (24.1 versus 16.1 months, p = 0.031), but this was not significant on multivariate analysis [HR = 1.0 (95% CI: 0.7–1.3), p = 0.806].

Conclusions:

Patients with isolated CNS metastases at MBC diagnosis represent a distinct population for which the role of systemic therapy needs to be further investigated in prospective studies.

Prognostic Value of Metabolic, Volumetric and Textural Parameters of Baseline [18F]FDG PET/CT in Early Triple-Negative Breast Cancer

Simple Summary

The aim of this study was to evaluate PET/CT parameters to determine different prognostic groups in TNBC, in order to select patients with a high risk of relapse, for whom therapeutic escalation can be considered. We have demonstrated that the MTV, TLG and entropy of the primary breast lesion could be of interest to predict the prognostic outcome of TNBC patients.

Abstract

(1) Background: triple-negative breast cancer (TNBC) remains a clinical and therapeutic challenge primarily affecting young women with poor prognosis. TNBC is currently treated as a single entity but presents a very diverse profile in terms of prognosis and response to treatment. Positron emission tomography/computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) is gaining importance for the staging of breast cancers. TNBCs often show high [¹⁸F]FDG uptake and some studies have suggested a prognostic value for metabolic and volumetric parameters, but no study to our knowledge has examined textural features in TNBC. The objective of this study was to evaluate the association between metabolic, volumetric and textural parameters measured at the initial [¹⁸F]FDG PET/CT and disease-free survival (DFS) and overall survival (OS) in patients with nonmetastatic TBNC. (2) Methods: all consecutive nonmetastatic TNBC patients who underwent a [¹⁸F]FDG PET/CT examination upon diagnosis between 2012 and 2018 were retrospectively included. The metabolic and volumetric parameters (SUV_max, SUV_mean, SUV_peak, MTV, and TLG) and the textural features (entropy, homogeneity, SRE, LRE, LGZE, and HGZE) of the primary tumor were collected. (3) Results: 111 patients were enrolled (median follow-up: 53.6 months). In the univariate analysis, high TLG, MTV and entropy values of the primary tumor were associated with lower DFS (p = 0.008, p = 0.006 and p = 0.025, respectively) and lower OS (p = 0.002, p = 0.001 and p = 0.046, respectively). The discriminating thresholds for two-year DFS were calculated as 7.5 for MTV, 55.8 for TLG and 2.6 for entropy. The discriminating thresholds for two-year OS were calculated as 9.3 for MTV, 57.4 for TLG and 2.67 for entropy. In the multivariate analysis, lymph node involvement in PET/CT was associated with lower DFS (p = 0.036), and the high MTV of the primary tumor was correlated with lower OS (p = 0.014). (4) Conclusions: textural features associated with metabolic and volumetric parameters of baseline [¹⁸F]FDG PET/CT have a prognostic value for identifying high-relapse-risk groups in early TNBC patients.

Real-world evidence of the management and prognosis of young women (⩽40 years) with de novo metastatic breast cancer

Background:

Breast cancer (BC) in young women merits a specific approach given the associated fertility, genetic and psychosocial issues. De novo metastatic breast cancer (MBC) in young women is an even more serious condition, with limited data available.

Methods:

We evaluated management of women aged ⩽40 years with de novo MBC in a real-life national multicentre cohort of 22,463 patients treated between 2008 and 2016 (NCT0327531). Our primary objective was to compare overall survival (OS) in young women versus women aged 41–69 years. The secondary objectives were to compare first-line progression-free survival (PFS1) and to describe treatment patterns.

Results:

Of the 4524 women included, 598 (13%) were ⩽40 years. Median age at MBC diagnosis was 36 years (range = 20–40). Compared with women aged 41–69 years, young women had more grade III tumours (49% versus 35.7%, p < 0.0001), human epidermal growth factor receptor 2 amplified (HER2+) disease (34.6% versus 26.4%, p < 0.0001) and HR–/HER2– disease known as “triple negative breast cancer” (TNBC) (17.1% versus 12.7%, p < 0.0001). BRCA testing was performed for 260 young women, with a BRCA1/2 mutation in 44 (17% of those tested) In young HR+/HER2– patients, chemotherapy (CT) was given as the frontline treatment more frequently compared with older ones (89.6% versus 68.8%, respectively, p < 0.0001). After median follow-up of 49.7 months (95% confidence interval, CI = 48.0–51.7), the median OS of young women was 58.5 months, 20.7 months and not attained in HR+/HER2–, TNBC and HER2+ subgroups, respectively. After adjustment for histological subtype, tumour grade, and number and type of metastasis, young women had significantly better OS compared with older ones, except for the TNBC subgroup, for which the outcome was similar. PFS1 was statistically different only in the TNBC subgroup, with 7.8 months for young women and 6.3 months for older women ( p = 0.0015).

Conclusion:

De novo MBC affects a significant proportion of young women. A subgroup of these patients achieves long OS and merits multidisciplinary care.

Multicenter evaluation of breast cancer patients' satisfaction and experience with oncology telemedicine visits during the COVID-19 pandemic

INTRODUCTION

During the COVID-19 pandemic, teleconsultation was implemented in clinical practice to limit patient exposure to COVID-19 while monitoring their treatment and follow-up. We sought to examine the satisfaction of patients with breast cancer (BC) who underwent teleconsultations during this period.

METHODS

Eighteen centres in France and Italy invited patients with BC who had at least one teleconsultation during the first wave of the COVID-19 pandemic to participate in a web-based survey that evaluated their satisfaction (EORTC OUT-PATSAT 35 and Telemedicine Satisfaction Questionnaire [TSQ] scores) with teleconsultation.

RESULTS

Among the 1299 participants eligible for this analysis, 53% of participants were undergoing standard post-treatment follow-up while 22 and 17% were currently receiving active anticancer therapy for metastatic and localised cancers, respectively. The mean satisfaction scores were 77.4 and 73.3 for the EORTC OUT-PATSAT 35 and TSQ scores, respectively. In all, 52.6% of participants had low/no anxiety. Multivariable analysis showed that the EORTC OUT-PATSAT 35 score correlated to age, anxiety score and teleconsultation modality. The TSQ score correlated to disease status and anxiety score.

CONCLUSION

Patients with BC were satisfied with oncology teleconsultations during the COVID-19 pandemic. Teleconsultation may be an acceptable alternative follow-up modality in specific circumstances.

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.

Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer

Elevated plasma vitamin B12 has been associated with solid cancers, based on a single B12 measurement. We evaluated the incidence of solid cancers following B12 measurement in patients with persistent elevated B12, compared to patients without elevated B12 and to patients with non-persistent elevated B12. The study population included patients with at least two plasma B12 measurements without already known elevated-B12-related causes. Patients with elevated plasma B12 (≥ 1000 ng/L) at first measurement (n = 344) were matched for age and sex with patients having 2 normal B12 measurements (< 1000 ng/L) (NN group, n = 344). The patients with elevated plasma B12 at first measurement were split into 2 groups, according to the presence (EE group, n = 144) or the absence (EN group, n = 200) of persistent elevated plasma B12 at second measurement. We compared the cancer-free survival during 60 months between the groups after adjustment for the other elevated-B12-related causes in a survival competing risk model. Compared to the NN group, a persistent elevated plasma B12 ≥ 1000 ng/mL was strongly associated with the occurrence of solid cancer (HR 5.90 [95% CI 2.79-12.45], p < 0.001), contrary to non-persistent plasma B12 elevation (p = 0.29). These results could help to select patients in whom the screening for solid cancers would be of interest.

Abstract PS3-19: Prognostic value of textural associated with metabolic parameters of baseline 18FDG-PET/CT in early triple-negative breast cancer (TNBC)

Background : Triple negative breast cancer (TNBC) represents 10-17 % of all diagnosed early breast cancers, occurs more frequently in young women (&lt; 50 years old) and has a poor prognosis. TNBC remains a clinical and therapeutic challenge dealing with a paradox: a high-risk of metastatic relapse despite a high rate of clinical and histological response after neoadjuvant chemotherapy with contrasting but disappointing results of targeted therapies. However, TNBCs are treated as a single entity and due to their phenotypic heterogeneity and various molecular pathogenesis, this subtype has a very different profile in terms of prognosis and response to treatment. Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18FDG) is gaining importance for the staging of patients with large or locally advanced breast cancer. TNBCs often show high 18FDG uptake and several studies demonstrate correlations between standard uptake value (SUV) and histoprognostic factors such as grade or KI67%. Recently, a new approach is growing interest in medical imaging: textural analysis. Some studies have shown correlations between metabolic parameters with overall survival (OS) and disease free survival (DFS) in other carcinoma, such as lung and head-and-neck cancers. Few studies analyzed textural features with potentially promising prognostic value that has to be confirmed. The objective of this study is to evaluate the association between metabolic and textural parameters measured at the initial 18FDG-PET/CT, disease-free survival (DFS) and overall survival (OS) in patients with non-metastatic TBNC. Patients and Methods: All consecutive non-metastatic TNBC women who underwent 18FDG-PET/CT at diagnosis between 2012 and 2018 were retrospectively included. Metabolic parameters (SUVmax, SUVmean, SUVpeak, MTV, TLG) in the primary tumor and lymph nodes and textural features (entropy, homogeneity, SRE, LRE, LGZE, HGZE) in the primary tumor were collected. Regression models were used to assess the correlations between PET parameters and histoprognostic factors. Cox regression models were computed to identify association with DFS and OS. Results : One hundred and eleven patients were enrolled. The median follow-up was 53.6 months. Thirty-six patients experienced relapse and 20 died. Homogeneity was associated with no axillary lymph node involvement and lower grade. Entropy was associated with higher grade, lymph node involvement and inflammatory tumors. SRE was only associated with higher grade. TLG and MTV were highly correlated (r =0.98, 95%CI = 0.97-0.99). TLG, MTV and Entropy of the primary tumor were associated with lower DFS (p = 0.008, p = 0.006, and p = 0.025, respectively) and lower OS (p = 0.002, p = 0.001 and p = 0.046, respectively). In the 50 patients with positive PET axillary lymph nodes, all metabolic parameters except SUVmean were correlated with DFS whereas no correlation was seen with OS. Conclusion: Textural associated with metabolic features of baseline 18FDG-PET/CT add prognosis value interesting to identify high risk group of relapse in early TNBC patients.

Citation Format: Clément Bouron, Clara Mathie, Valérie Seegers, Camille Guillerminet, Mario Campone, Olivier Morel, Pascal Jézéquel, Anne Patsouris, Aude Testard. Prognostic value of textural associated with metabolic parameters of baseline 18FDG-PET/CT in early triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-19.

Abstract PS7-46: Enrollment of older metastatic breast cancer patients in clinical trials

Background: About 40% of breast cancer cases occur in women 65 years old (yo) or older and 20% in women over 75 yo. These numbers are expected to increase in the near future. Ironically, older patients remain underrepresented in clinical trials with no improvement in the past decade, although they may present different efficacy/toxicity profiles compared with younger adults. In this context, real life cohorts may bring valuable insight to identify potential barriers to recruitment of older patients with metastatic breast cancer (MBC) in clinical trials. Methods: We used the national Epidemio-Strategy and Medical Economics (ESME) MBC Data Platform, a multi-center real life database using a retrospective data collection process in 18 French Cancer Centers. Cases selected were adult patients with MBC whose first metastasis was treated between January 1st, 2008 and December 31st, 2016. We selected MBC women over 70 yo at the time of MBC diagnosis, with at least one line of systemic treatment and no other cancer in the 5 years before MBC. The primary objective was to describe factors associated with enrollment in clinical trials in older patients, using a multivariable Cox model. Factors included in this model were age (continuous, and by class), period (2008-2011 vs 2012-2016), phenotype (ER+, HER2+, or ER- HER2-), ECOG Performance Status (PS), treatment, metastatic sites (brain, visceral, nodes/bone only) and number, and volume of hospital activity. No geriatric description could be extracted from the database. Results: There were 5846 patients ≥70yo (median age 77) and 15892 patients &lt; 70 yo. Of the older ones, 245 (4.2%) were enrolled in a clinical trial in first line compared with 1602 (10%) for younger ones. Most of the older patients in this cohort (66%) had ER+ HER2+ disease, half had visceral metastases (&lt; 3 metastatic sites in 82%). Median follow-up of older patients was 46.3 months; 95%CI 44.8-49.0. Cause of death was related to disease in 1155 (33.9%) older patients, and related to another cause or unknown in 2156 (63.3%), data were missing for 2441 patients. Median overall survival (OS) was 34.1 months in the older population, 95%CI 32.9-35.4, and specific overall survival was 70.8 months, 95%CI 66.3-80.0. Significant factors identified in the multivariable analysis for enrollment in 1st line treatment clinical trial ≥70 are shown in table. Volume of activity was not identified as one.

By multivariate analysis, participation of older patients to a clinical trial was associated with an increased OS (HR 0.7; 95% CI 0.6-0.8) but not with a better breast cancer specific survival (HR 0.94; 95%CI 0.68-1.29). Conclusions: In this large real-life database, few older MBC patients were enrolled in a trial compared with younger ones. Factors associated with such participation to clinical research were younger age (&lt; 80 yo), good PS, HER2+ disease, and investigational treatment consisting of chemotherapy or targeted therapy. There was a small improvement in accruing older patients between 2007-2011 and 2012-2016 (2.6% versus 5.5%). Most of these factors raise questions on drug availability and perceived potential benefits by investigators and medical teams. Accrual of older patients with cancer in other disease types should be more encouraged.

VariableOR95%CIAge vs 70-75 75-80 80-85 85+0.74 0.47 0.170.54-1 0.31-0.71 0.06-0.37MBC diagnosis period vs 2008-2011 2012-20161.671.23-2.27Phenotype vs Others HER2+1.761.26-2.45PS vs 0 1 2-40.71 0.150.5-1 0.08-0.26Treatment4.88 5.253.08-7.9 3.48-8.14Chemotherapy vs others4.883.08-7.9Targeted treatment vs others5.253.48-8.14

Citation Format: Michael Bringuier, Matthieu Carton, Christelle Levy, Anne Patsouris, David Pasquier, Marc Debled, Olivier Rigal, William Jacot, Anthony Gonçalves, Isabelle Desmoulins, Thibault De La Motte Rouge, Thomas Bachelot, Jean-Marc Ferrero, Jean-Christophe Eymard, Florence Dalenc, Marie-Ange Mouret-Reynier, Thierry Petit, Michael Chevrot, Coralie Courtinard, Lionel Uwer, Jean-Sebastien Frenel, Capucine Baldini. Enrollment of older metastatic breast cancer patients in clinical trials [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-46.

Abstract PD10-11: Efficacy of Platinum-based first-line chemotherapy among metastatic breast cancer (MBC) patients according to the germline BRCA1/2 mutational status: An analysis of the French ESME MBC database

Background: Platinum-based chemotherapy regimens (PtCT) have been shown to increase treatment efficacy when combined to neoadjuvant standard of care treatment of triple negative breast cancers (TNBC). In the metastatic breast cancer (MBC) setting, preclinical and clinical data suggest that PtCT could be more efficient than non-platinum based ones (non-PtCT) among patients (pts) with germline BRCA1/2 mutations (gBRCAm). However, published data remain controversial on this topic, particularly for MBC. We evaluated the progression-free (PFS) and overall survival (OS) under first-line PtCT and non-PtCT among gBRCAm carriers in ESME, a nationwide real-life MBC database. Methods: ESME MBC database (NCT03275311), is a unique national cohort of all consecutive pts who initiated a first-line treatment for MBC between 2008 and 2016 in one of the 18 French Comprehensive Cancer Centers. Women with HER2- MBC and known hormone receptors (HR) and gBRCA1/2 (before or in the 6 first months of metastatic disease, gBRCAm / wild type / not tested) status, who received a first-line MBC CT were selected. Patients with other germinal mutations were considered as wild type. Primary objectives were OS and PFS under first-line CT (PtCT vs. non-PtCT) in the TNBC gBRCA1/2m population.Secondary objectives were OS and PFS during first-line CT (PtCT vs. non-PtCT) in the TNBC wild-type and “not tested” population, as well as among the HR+/HER2- pts.To avoid guarantee time bias related to oncogenetic testing, analyses were performed at baseline (CT initiation) and different landmark time points (3-month or 6-month after CT initiation). Thus, BRCA status was defined according to oncogenetic testings performed before the landmark time, and patients who progressed or censored before the landmark time were excluded. Results: 10,164 pts (2,794 TNBC; 7,370 HR+/HER2-) were included in this analysis. Pts who received PtCT were significantly younger, affected by a gBRCA1/2m, had a high histological grade and/or TNBC tumor, with more frequent visceral and central nervous system spreading than non PtCT ones. Median follow-up was 51.1 months [95%CI 49.6; 52.6]. All reported results were based on the gBRCA status defined at CT initiation and on multivariable analysis adjusted on age at MBC diagnosis, de novo MBC status, type and number of metastases. In the gBRCA1/2m TNBC population (N=132), PtCT was independently associated with a better PFS compared to non-PtCT (HR=0.56, 95%CI 0.38-0.84, p=0.005), without significant difference in OS (HR=0.79, 95%CI 0.51-1.23, p=0.29).No difference was seen in wild-type BRCA1/2 TNBC pts (N=269) according to the CT regimen, while, in the larger population of untested TNBC (N=2,393), PtCT was associated with worse OS (HR=1.18, 95%CI 1.03-1.34, p=0.016) compared to non-PtCT regimens, without significant difference in PFS (HR=1.07, 95%CI 0.95-1.22, p=0.26). No significant difference was seen regarding PFS nor OS in gBRCA1/2m HR+/HER2- pts (N=124) and in the wild-type BRCA1/2 HR+/HER2- population.However, in the larger population of untested HR+/HER2- pts (N=6,836), PtCT was independently associated with worse OS (HR=2.15, 95%CI 1.79-2.59, p&lt;0.001) and PFS (HR=1.57, 95%CI 1.33-1.86, p&lt;0.001) compared to non-PtCT regimens. Results were similar in landmark analyses at 3-month or 6-month after CT initiation. Conclusions: This large-scale real-life analysis suggests higher efficacy of PtCT in term of PFS in gBRCA1/2m TNBC pts. The small sample size and post-1st line treatments may preclude observing a significant OS difference. PtCT appeared however associated with worse outcomes in untested TNBC and HR+/HER2- pts. These results emphasize the need for BRCA1/2 characterization before considering these regimens in the MBC setting.

Citation Format: William Jacot, Amélie Lusque, Audrey Mailliez, Thibault De la Motte Rouge, Luc Cabel, Christelle Levy, Anne Patsouris, Isabelle Desmoulins, Lionel Uwer, Marianne Leheurteur, Mathieu Robain, Olivier Caron, Thomas Bachelot, Thomas Filleron, Jean-Sébastien Frenel, Suzette Delaloge. Efficacy of Platinum-based first-line chemotherapy among metastatic breast cancer (MBC) patients according to the germline BRCA1/2 mutational status: An analysis of the French ESME MBC database [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD10-11.

Somatic mRNA Analysis of BRCA1 Splice Variants Provides a Direct Theranostic Impact on PARP Inhibitors

BACKGROUND

The identification of pretherapeutic somatic BRCA variants can have considerable clinical impact given that they affect response to the new poly (ADP-ribose) polymerase (PARP)-targeted therapy. One major issue with this type of testing is the identification of splicing variants of uncertain significance (VUS) on degraded somatic messenger RNA. It is therefore important to be able to quickly characterize these splice variants.

OBJECTIVE

As part of PARP inhibitor targeted therapy, we have investigated a method for the direct confirmation of potential pathogenic somatic splice variants of BRCA1 found in fixed tumor samples. Previously these VUS have commonly only been tested by in silico analysis.

METHODS

Five BRCA1 variants affecting splicing were characterized from formalin-fixed, paraffin-embedded (FFPE) ovarian carcinoma tissues by next-generation sequencing (NGS). Three patient samples had already been functionally characterized and were used as controls. Total somatic RNA from samples was extracted, reverse-transcribed, and amplified with several primer pairs encompassing the target exon. The polymerase chain reaction (PCR) products were analyzed by capillary gel electrophoresis to assess possible changes in size due to splicing alterations. Finally, we confirmed our results by cloning, followed by Sanger sequencing, and analyzed the expression of the aberrant forms.

RESULTS

Our molecular approach made it possible to visualize the splicing outcomes of three variants (c.5194-2A>G, c.5434C>G, and c.547+1G>A) already identified and present in databases and/or identified with prediction tools (ClinVar, UMD, ARUP Utah database, and Human Splice Finder splices sites prediction) and to confirm their exon skipping consequences, their expression in tumors, and thus their pathogenicity. The c.4484+5G>A variant was not found in databases and was predicted to have no impact on splicing, but was found to display altered processing in tumor tissue. This variant also had a major detrimental impact on transcriptional expression.

CONCLUSION

In a break from purely in silico approaches, we propose a simple and rapid pretherapeutic functional analysis of somatic BRCA1 variants potentially involved in splicing alterations. This approach will allow more ovarian cancer patients to benefit from new therapies targeting PARP.

Management and outcome of male metastatic breast cancer in the national multicenter observational research program Epidemiological Strategy and Medical Economics (ESME)

Background and Aims:

Because of its low prevalence, metastatic breast cancer (MBC) in males is managed based on clinical experience with women. Using a real-life database, we aim to provide a comprehensive analysis of male MBC characteristics, management and outcome.

Methods:

The Epidemiological Strategy and Medical Economics Data Platform collected data for all men and women ⩾18 years with MBC in 18 participating French Comprehensive Cancer Centers from January 2008 to November 2016. Demographic, clinical, and pathological characteristics were retrieved, as was treatment modality. Men were matched 1:1 to women with similar characteristics.

Results:

Of 16,701 evaluable patients, 149 (0.89%) men were identified. These men were older (median age 69 years) and predominantly had hormone receptor HR+/HER2– disease (78.3%). Median overall survival (OS) was 41.8 months [95% confidence interval (CI: 26.9–49.7)] and similar to women. Median progression-free survival (PFS) with first-line therapy was 9.3 months [95% CI (7.4–11.5)]. In the HR+/HER2– subpopulation, endocrine therapy (ET) alone was the frontline treatment for 43% of patients, including antiestrogens (n = 19), aromatase inhibitors (n = 15) with luteinizing hormone-releasing hormone (LHRH) analogs (n = 3), and various sequential treatments. Median PFS achieved by frontline ET alone was similar in men [9.8 months, 95% CI (6.9–17.4)] and in women [13 months, 95% CI (8.4–30.9)] (p = 0.80). PFS was similar for HR+/HER2– men receiving upfront ET or chemotherapy: 9.8 months [95% CI (6.9–17.4)] versus 9.5 months [95% CI (7.4–11.7)] (p = 0.22), respectively.

Conclusion:

MBC management in men and women leads to similar outcomes, especially in HR+/HER2– patients for whom ET should also be a cornerstone. Unsolved questions remain and successfully recruiting trials for men are still lacking.

Real-life prognosis of 5041 bone-only metastatic breast cancer patients in the multicenter national observational ESME program

BACKGROUND

Bone-only (BO) metastatic breast cancer (MBC) is considered a more favorable entity than other MBC presentations. However, only few retrospective series and data from selected randomized controlled trials have been reported so far.

METHODS

Using the French national multicenter ESME (Epidemiological Strategy and Medico Economics) Data Platform, the primary objective of our study was to compare the overall survival (OS) of patients with BO versus non-BO MBC at diagnosis, with adjustment on main prognostic factors using a propensity score. Secondary objectives were to compare first-line progression-free survival (PFS1), describe treatment patterns, and estimate factors associated with OS.

RESULTS

Out of 20,095 eligible women, 5041 (22.4%) patients had BO disease [hormone-receptor positive (HR+)/human epidermal growth-factor-receptor-2 negative (HER2-), n = 4 102/13,229 (31%); HER2+, n = 644/3909 (16.5%); HR-/HER2-, n = 295/2 957 (10%)]. BO MBC patients had a better adjusted OS compared with non-BO MBC [52.1 months (95% confidence interval (CI) 50.3-54.1) versus 34.7 months (95% CI 34.0-35.6) respectively]. The 5-year OS rate of BO MBC patients was 43.4% (95% CI 41.7-45.2). They also had a better PFS1 [13.1 months (95% CI 12.6-13.8) versus 8.5 months (95% CI 8.3-8.7), respectively]. This observation could be repeated in all subtypes. BO disease was an independent prognostic factor of OS [hazard ratio 0.68 (95% CI 0.65-0.72), p < 0.0001]. Results were concordant in all analyses.

CONCLUSION

BO MBC patients have better outcomes compared with non-BO MBC, consistently, through all MBC subtypes.

Characteristics and outcome of breast cancer-related microangiopathic haemolytic anaemia: a multicentre study

BACKGROUND

Cancer-related microangiopathic haemolytic anaemia (MAHA) is a rare but life-threatening paraneoplastic syndrome. Only single cases or small series have been reported to date. We set up a retrospective multicentre study focusing on breast cancer-related MAHA.

METHODS

Main inclusion criteria were known diagnosis of breast cancer, presence of schistocytes and either low haptoglobin or cytopenia and absence of any causes of MAHA other than breast cancer, including gemcitabine- or bevacizumab-based treatment. Patient characteristics, treatments and outcome were retrieved from digital medical records.

RESULTS

Individual data from 54 patients with breast cancer-related MAHA were obtained from 7 centres. Twenty-three (44%) patients had a breast tumour with lobular features, and most primary tumours were low grade (grade I/II, N = 39, 75%). ER+/HER2-, HER2+ and triple-negative phenotypes accounted for N = 33 (69%), N = 7 (15%) and N = 8 (17%) cases, respectively. All patients had stage IV cancer at the time of MAHA diagnosis. Median overall survival (OS) was 28 days (range 0-1035; Q1:10, Q3:186). Independent prognostic factors for early death (≤ 28 days) were PS > 2 (OR = 7.0 [1.6; 31.8]), elevated bilirubin (OR = 6.9 [1.1; 42.6]), haemoglobin < 8.0 g/dL (OR = 3.7 [0.9; 16.7]) and prothrombin time < 50% (OR = 9.1 [1.2; 50.0]). A score to predict early death displayed a sensitivity of 86% (95% CI [0.67; 0.96]), a specificity of 73% (95% CI [0.52; 0.88]) and an area under the curve of 0.90 (95% CI [0.83; 0.97]).

CONCLUSIONS

Breast cancer-related MAHA appears to be a new feature of invasive lobular breast carcinoma. Prognostic factors and scores may guide clinical decision-making in this serious but not always fatal condition.

Evolution of plasma vitamin B12 in patients with solid cancers during curative versus supportive care

INTRODUCTION

The direction of the causal link between solid cancers and elevated plasma vitamin B₁₂ (B₁₂) remains uncertain.

METHODS

We retrospectively included patients having two B₁₂ measurements with a B₁₂ initially ≥ 1000 ng/l and a solid cancer diagnosed between the measurements. Patients were included in the Curative or Supportive group according to their treatments.

RESULTS

B₁₂ changes over time differed between groups (p = 0.001): +157.4 ng/l/month in the Supportive care group versus -171.6 ng/l/month in the Curative care group.

CONCLUSIONS

The decrease of plasma B₁₂ in cases of curative care could suggest that this B₁₂ elevation is secondary to solid cancers.

A pharmacokinetic evaluation of alpelisib for the treatment of HR+, HER2-negative, PIK3CA-mutated advanced or metastatic breast cancer

Introduction: In most cases, metastatic breast cancer remains an incurable disease. A PIK3CA mutation is detected in 30-40% of all hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancers. PIK3CA activating mutations have been linked to endocrine resistance. PI3K inhibitors therefore offer promising new therapeutic options for this disease. Areas covered: This review discusses the pharmacologic properties, preclinical development, clinical efficacy, and safety profile of alpelisib, a PI3K inhibitor indicated in HR+/HER2 - PIK3CA-mutated advanced breast cancer, describing current therapeutic indication and open questions. Expert opinion: Following results of the SOLAR-1 trial, alpelisib became the first PI3K inhibitor approved by the U.S. Food and Drug Administration, in combination with fulvestrant, for postmenopausal women and men with HR+/HER2 - PIK3CA-mutated advanced breast cancer following progression on or after an endocrine-based regimen. This trial showed a substantial improvement in progression-free survival. However, given the side effects of alpelisib, the treatment decision should follow a thorough benefit-risk assessment. The BYLieve trial suggests alpelisib-fulvestrant benefit after progression on CDK 4/6 inhibitors. The identification of patients that are likely to benefit the most from PI3K inhibitors is still eagerly sought.

Impact of body mass index on overall survival in patients with metastatic breast cancer

BACKGROUND

High Body mass index (BMI) is a risk factor for breast cancer among postmenopausal women and an adverse prognostic factor in early-stage. Little is known about its impact on clinical outcomes in patients with metastatic breast cancer (MBC).

METHODS

The National ESME-MBC observational cohort includes all consecutive patients newly diagnosed with MBC between Jan 2008 and Dec 2016 in the 18 French comprehensive cancer centers.

RESULTS

Of 22 463 patients in ESME-MBC, 12 999 women had BMI data available at MBC diagnosis. Median BMI was 24.9 kg/m² (range 12.1-66.5); 20% of women were obese and 5% underweight. Obesity was associated with more de novo MBC, while underweight patients had more aggressive cancer features. Median overall survival (OS) of the BMI cohort was 47.4 months (95% CI [46.2-48.5]) (median follow-up: 48.6 months). Underweight was independently associated with a worse OS (median OS 33 months; HR 1.14, 95%CI, 1.02-1.27) and first line progression-free survival (HR, 1.11; 95%CI, 1.01; 1.22), while overweight or obesity had no effect.

CONCLUSION

Overweight and obesity are not associated with poorer outcomes in women with metastatic disease, while underweight appears as an independent adverse prognostic factor.

Palliative care delivery according to age in 12,000 women with metastatic breast cancer: Analysis in the multicentre ESME-MBC cohort 2008-2016

INTRODUCTION

Patients with metastatic breast cancer (MBC) often require inpatient palliative care (IPC). However, mounting evidence suggests age-related disparities in palliative care delivery. This study aimed to assess the cumulative incidence function (CIF) of IPC delivery, as well as the influence of age.

METHODS

The national ESME (Epidemio-Strategy-Medical-Economical)-MBC cohort includes consecutive MBC patients treated in 18 French Comprehensive Cancer Centres. ICD-10 palliative care coding was used for IPC identification.

RESULTS

Our analysis included 12,375 patients, 5093 (41.2%) of whom were aged 65 or over. The median follow-up was 41.5 months (95% confidence interval [CI], 40.5-42.5). The CIF of IPC was 10.3% (95% CI, 10.2-10.4) and 24.8% (95% CI, 24.7-24.8) at 2 and 8 years, respectively. At 2 years, among triple-negative patients, young patients (<65 yo) had a higher CIF of IPC than older patients after adjusting for cancer characteristics, centre and period (65+/<65: β = -0.05; 95% CI, -0.08 to -0.01). Among other tumour sub-types, older patients received short-term IPC more frequently than young patients (65+/<65: β = 0.02; 95% CI, 0.01 to 0.03). At 8 years, outside large centres, IPC was delivered less frequently to older patients adjusted to cancer characteristics and period (65+/<65: β = -0.03; 95% CI, -0.06 to -0.01).

CONCLUSION

We found a relatively low CIF of IPC and that age influenced IPC delivery. Young triple-negative and older non-triple-negative patients needed more short-term IPCs. Older patients diagnosed outside large centres received less long-term IPC. These findings highlight the need for a wider implementation of IPC facilities and for more age-specific interventions.

Impact of age at diagnosis of metastatic breast cancer on overall survival in the real-life ESME metastatic breast cancer cohort

BACKGROUND

Young age is a poor prognostic factor in early stage breast cancer (BC) but its value is less established in metastatic BC (MBC). We evaluated the impact of age at MBC diagnosis on overall survival (OS) across three age groups (<40, 40 to 60 and > 60 years(y)).

METHODS

ESME MBC database is a national cohort, collecting retrospective data from 18 participating French cancer centers between January 01, 2008 and December 31, 2014.

RESULTS

Among 14 403 women included, 1077 (7.5%), 6436 (44.7%) and 6890 (47.8%) pts were <40, 40-60 and > 60 y respectively. Pts <40 had significantly more aggressive presentations than other age groups: more frequent HER2+ (25.7 vs 15.3% in >60y) and triple negative subtypes (27.4 vs 14.6% in >60y), and more frequent visceral involvement (36.3 vs 29.8% in >60y). At a median follow-up of 48 months, median OS differed across age groups: 38.8, 38.4 and 35.6 months for pts <40, 40-60 and > 60y, respectively (p < 0.0001). Compared to pts <40y, older pts had a statistically significant higher risk of death (all causes of death included), although of limited clinical value (HR = 1.1, IC 95%:1.01-1.20). There was a significant trend for better OS in pts <40y with HER2+ and luminal diseases. A possible explanation is a greater use of anti-Her2 therapies as first-line treatments: 86.6, 81.9 and 74.9% for pts <40, 40-60 and > 60y, respectively (p < 0.0001).

CONCLUSION

Although young age seems associated with more aggressive presentations at diagnosis of MBC, it has no deleterious effect on OS in this large series.

Contemporary outcomes of metastatic breast cancer among 22,000 women from the multicentre ESME cohort 2008-2016

AIM

Real-world data inform the outcome comparisons and help the development of new therapeutic strategies. To this end, we aimed to describe the full characteristics and outcomes in the Epidemiological Strategy and Medical Economics (ESME) cohort, a large national contemporary observational database of patients with metastatic breast cancer (MBC).

METHODS

Women aged ≥18 years with newly diagnosed MBC and who initiated MBC treatment between January 2008 and December 2016 in one of the 18 French Comprehensive Cancer Centers (N = 22,109) were included. We assessed the full patients' characteristics, first-line treatments, overall survival (OS) and first-line progression-free survival, as well as updated prognostic factors in the whole cohort and among the 3 major subtypes: hormone receptor positive and HER2-negative (HR+/HER2-, n = 13,656), HER2-positive (HER2+, n = 4017) and triple-negative (n = 2963) tumours.

RESULTS

The median OS of the whole cohort was 39.5 months (95% confidence interval [CI], 38.7-40.3). Five-year OS was 33.8%. OS differed significantly between the 3 subtypes (p < 0.0001) with a median OS of 43.3 (95% CI, 42.5-44.5) in HR+/HER2-; 50.1 (95% CI, 47.6-53.1) in HER2+; and 14.8 months (95% CI, 14.1-15.5) in triple-negative subgroups, respectively. Beyond performance status, the following variables had a constant significant negative prognostic impact on OS in the whole cohort and among subtypes: older age at diagnosis of metastases (except for the triple-negative subtype), metastasis-free interval between 6 and 24 months, presence of visceral metastases and number of metastatic sites ≥ 3.

CONCLUSIONS

The ESME program represents a unique large-scale real-life cohort on MBC. This study highlights important situations of high medical need within MBC patients. DATABASE REGISTRATION: clinicaltrials.gov Identifier NCT032753.

Abstract P4-06-11: High immune response identified as a good prognostic factor by proteomic SWATH-MS approach in 157 ER+/HER2- early breast cancer

Background: Estrogen positive/HER2 negative (ER+/HER2-) early (e) breast carcinoma (BC) is an heterogeneous entity, on the prognostic and predictive plan. Several prognostic multigene tests have been developed to identify patients in whom chemotherapy could be safely avoided. Proteomic is a complementary approach as variations in mRNA expression only account for ≈40% of the tumor-encoded protein range and it is taking into account, as other OMICs the tumoral microenvironment Sequential Windowed Acquisition of All Theoretical fragment (SWATH-MS) proteomic approach let an accurate and reproducible label-free quantification of large proteome. To our knowledge, no study has been conducted in a large cohort of luminal BC by SWATH-MS. The aim of this study was to establish a proteomic cartography of ER+/HER2- eBC and identify prognostic biomarkers. Methods: Frozen primary tumors were collected from 157 ER+/HER2- eBC treated in the ICO cancer center between 2006 and 2009. Patients were included if they fulfilled the following criteria: 1) ductal carcinoma; 2) unilateral; 3) first occurrence; 4) have received adjuvant chemotherapy. Clinicopathologic characteristics as outcomes were collected. Each sample was analyzed using SWATH-MS acquisition method as previously described (Aebersold et al, 2012). Peak extraction of the SWATH data was performed using either the Spectronaut software (ver 8.0, Biognosys, Switzerland). Peptide identification results were filtered with a q-value of &lt; 1%. We performed clustering analysis (fuzzy clustering method) based on the 15% of most variant proteins. Functional annotation of clusters based on GO biological process terms enrichment (GOEA) was performed by means of ToppGene and GORILLA web tools. Results: The median of follow-up was 8.34 years. Respectively 32, 4 and 7 patients presented a metastatic, locoregional and controlateral recurrence. 684 among 4555 proteins represented the 15% of most variants proteins.Two ER+/HER2- eBC clusters were identified (C1 [23%] and C2 [77%]) by means of fuzzy clustering and GOEA. Two significant clinicopathological differences were observed between the two subgroups: more unifocal tumors in C1 (P = 0.0415) and mostly a clear better outcome in term of Disease Free Survival (DFS), Distant DFS (DDFS) and Overall survival (OS) in patients belonging to C2 (cf table 1). Functional annotation found that C1 was characterized by mRNA processing and protein synthesis (GO:0006396: RNA processing; GO:0008380: RNA splicing; GO:0016071: mRNA metabolic process; GO:0022613: ribonucleoprotein complex biogenesis), and C2 by a high immune response (GO:0002757: immune response-activating signal transduction; GO:0050778: positive regulation of immune response; GO:0002253: activation of immune response; GO:0050776: regulation of immune response). Differential protein expression according to the C1-C2 clusters will be presented at the meeting. Conclusion: Proteomic cartography by SWATH-MS can clearly distinguish two ER+/HER2- eBC subgroups with clear different prognosis with a better outcome for C2 patients compared to C1 patients. High immune response observed in C2 could underlie this difference with results that must be confirmed on external cohort. Nevertheless this approach could be considered as a complementary approach, helpful for clinical decision for administration of adjuvant treatment.

All (n=157)Cluster 1 (n = 36)Cluster 2 (n = 121)PDisease-free survival72%55.5%77.6%0.0016Distant disease-free survival79.6%66.6%83.4%0.0063Overall survival81%61%87%0.0009Specific overall survival86%69%91%0.0012

Citation Format: Anne Patsouris, Hamza Lasla, Pascal Jézéquel, Philippe Juin, Alice Boissard, Cécile Henry, Mario Campone, Catherine Guette. High immune response identified as a good prognostic factor by proteomic SWATH-MS approach in 157 ER+/HER2- early breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-06-11.

Abstract P2-19-01: Impact of bone-only metastatic breast cancer on outcome in a real-life setting: A comprehensive analysis of 5,041 women from the ESME database

Background: Bone-only (BO) metastatic breast cancer (MBC), defined as bone as unique site of metastasis at MBC diagnosis, is thought to carry a better prognosis among MBC. However, only small retrospective series and data from selected randomized controlled trials have been reported so far. Based on a national database, we aimed at providing a large comprehensive analysis of BO MBC, and at evaluating its impact on clinical outcome.

Methods: The ESME MBC platform (NCT03275311) is a French multicenter retrospective real-life database using a clinical trial-like methodology to collect data from 18 French Comprehensive Cancer Centers. It includes data from each newly diagnosed MBC patient having initiated at least one treatment between 2008 and 2016. BO cases occurring in women were retrieved and compared to the overall non-BO population, regarding treatment effects and survival.

Results: Of the 22,463 women selected in the database, 5,041 (22.4%) patients with BO disease were identified. Most (N=4,102, 81.4%) had HR+/HER2- disease while 644 (12.8%) and 295 (5.9%) patients had HER2+ or HR-/HER2- disease, respectively. Compared to non-BO MBC, BO MBC patients were older in the global cohort and in HR-/HER2- patients (mean age 61.0y versus 59.5y, and 59.3y vs 56.4y, all p&lt;0.0001, respectively), and tumor histology was more frequently a lobular carcinoma in the global cohort, in HR+/HER2- and in HR-/HER2- patients (18.6% vs 10.8%, 20.6% vs 15.2%, 13.8% vs 3.2%, all p&lt;0.0001, respectively). In addition, metastatic disease occurred de novo more frequently in BO MBC patients (37.9% versus 29.2%) (p&lt;0.0001), and a statistically significant difference was also observed within each tumor subtype group. The management of bone disease included bisphosphonates or denosumab, radiotherapy, and invasive bone metastasis procedures in 3,913 (77.6%), 2,929 (58.1%), and 1,154 (22.9%) patients, respectively. Median follow up was 52.4 months (95% CI [50.8-54.2]) in BO population and 50.9 months (95% CI [49.7-51.8]) in non-BO population. BO MBC patients had improved median progression-free survival (PFS) 1, regarding first-line treatment, and overall survival (OS) compared to non-BO MBC, globally and within each tumor subtype group (Table). Indeed, 5-year OS rates reached up to 43%, 54% and 16% in HR+/HER2-, HER2+ and HR-/HER2- BO MBC groups, respectively. This suggests that a substantial number of these patients could be considered as long survivors. In the BO MBC cohort, de novo BO MBC patients had a higher 5-year OS rate than relapsed BO MBC patients. BO disease was an independent prognostic factor of OS (hazard ratio 0.68 (95% CI [0.65-0.72]), p&lt;0.0001) together with age, tumor subtype, grade, adjuvant treatment and metastatic-free interval.

Conclusion: This large comprehensive study is the largest cohort of BO MBC to date. BO MBC has a distinct presentation from non-BO MBC and carry a better prognosis compared to non-BO MBC. A significant proportion of BO MBC patients have a very long survival and may benefit from aggressive local therapy, as stereotactic radiotherapy. Dedicated studies are warranted to tailor the management of these patients.

Funding: This work was supported by UNICANCER. The ESME MBC database is supported by an industrial consortium (Roche, Pfizer, AstraZeneca, MSD, Eisai and Daiichi Sankyo). Data collection, analyses and publications are totally managed by R&D UNICANCER independently of the industrial consortium.

TableBOBOBOBOnon-BOnon-BOnon-BOnon-BON (%)median OS monthsmedian PFS1 months5-year OS rate %N (%)median OS monthsmedian PFS1 months5-year OS rate %(95% CI)(95% CI)(95% CI)(95% CI)(95% CI)(95% CI)Overall population5,041 (100%)52.1 (50.3-54.1) 13.1 (12.6-13.8) 43.41 (41.66-45.15)15,054 (100%)34.7 (34.0-35.6) 8.5 (8.3-8.7) 30.55 (29.62-31.48)HR+/HER-4,102 (81.4%)52.6 (50.5-54.8)13.6 (13.0-14.3)43.52 (41.56-45.46)9,127 (60.6%) 39.0 (37.8-40.1)9.6 (9.3-9.9)32.69 (31.47-33.93)HER2+644 (12.8%)66.4 (59.8-71.9) 14.9 (12.9-17.3) 54.49 (49.54-59.16)3,265 (21.7%) 46.5 (44.2-48.9)10.6 (10.1-11.3)39.88 (37.77-41.98)HR-/HER2-295 (5.9%)20.8 (18.3-27.4) 5.6 (4.9-7.5)16.21 (11.21-22.02)2,662 (17.7%) 14.3 (13.6-15.1)4.8 (4.6-5.0)10.89 (9.4-12.5)De novo MBC patients1,909 (37.9%)58.6 (55.4-62.1)17.9 (17.0-18.9)48.24 (45.28-51.14)4,399 (29.2%) ---Relapsed MBC patients3,132 (62.1%)48.3 (46.5-50.5)10.7 (10.2-11.2)40.51 (38.34-42.67)10,655 (70.8%)---

Citation Format: Marion Bertho, Julien Fraisse, Anne Patsouris, Paul Cottu, Suzette Delaloge, David Pérol, Anne Jaffré, Anthony Goncalves, Marie-Paule Lebitasy, Véronique D'Hondt, Florence Dalenc, Jean-Marc Ferrero, Christelle Levy, Patrick Arveux, Roman Rouzier, Frédérique Penault-Llorca, Lionel Uwer, Jean-Christophe Eymard, Mathias Breton, Michaël Chevrot, Marianne Leheurteur, Michel Velten, Gaëtane Simon, Jean-Sébastien Frenel. Impact of bone-only metastatic breast cancer on outcome in a real-life setting: A comprehensive analysis of 5,041 women from the ESME database [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-19-01.

Benefits versus risk profile of buparlisib for the treatment of breast cancer

Introduction: Activation of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways occurs in 70% of breast cancer, including PIK3CA activating mutations, PTEN loss and AKT mutation. It is associated with poor prognosis and resistance to anti-HER2 and endocrine therapy. PI3K inhibitors are promising anticancer targets that can reverse resistance to these therapies. Buparlisib (BKM-120) is an orally active pan-PI3K inhibitor evaluated in different solid tumors as monotherapy or in combination. Areas covered: This article reviews preclinical data, clinical studies that have evaluated the efficacy and safety profiles of buparlisib as a monotherapy or in combination with targeted therapy (including endocrine and anti-HER2 therapy) or cytotoxics. The authors cover completed and ongoing studies to evaluate the benefit vs risk profile of buparlisib. Expert opinion: Targeting PI3K showed efficacy in BC. Buparlisib, a pan PI3K inhibitor, presents manageable but not negligible toxicity with an activity/toxicity ratio in favor of the use of emerging second generation, α-selective PI3K inhibitors for ongoing and future trials.