Circulating tumor DNA for predicting recurrence in patients with operable breast cancer: a systematic review and meta-analysis

BACKGROUND

The incorporation of circulating tumor DNA (ctDNA) into the management of operable breast cancer (BC) has been hampered by the heterogeneous results from different studies. We aimed to assess the prognostic value of ctDNA in patients with operable (non metastatic) BC.

MATERIALS AND METHODS

A systematic search of databases (PubMed/Medline, Embase, and CENTRAL) and conference proceedings was conducted to identify studies reporting the association of ctDNA detection with disease-free survival (DFS) and overall survival (OS) in patients with stage I-III BC. Log-hazard ratios (HRs) were pooled at each timepoint of ctDNA assessment (baseline, after neoadjuvant therapy, and follow-up). ctDNA assays were classified as primary tumor-informed and non tumor-informed.

RESULTS

Of the 3174 records identified, 57 studies including 5779 patients were eligible. In univariate analyses, ctDNA detection was associated with worse DFS at baseline [HR 2.98, 95% confidence interval (CI) 1.92-4.63], after neoadjuvant therapy (HR 7.69, 95% CI 4.83-12.24), and during follow-up (HR 14.04, 95% CI 7.55-26.11). Similarly, ctDNA detection at all timepoints was associated with worse OS (at baseline: HR 2.76, 95% CI 1.60-4.77; after neoadjuvant therapy: HR 2.72, 95% CI 1.44-5.14; and during follow-up: HR 9.19, 95% CI 3.26-25.90). Similar DFS and OS results were observed in multivariate analyses. Pooled HRs were numerically higher when ctDNA was detected at the end of neoadjuvant therapy or during follow-up and for primary tumor-informed assays. ctDNA detection sensitivity and specificity for BC recurrence ranged from 0.31 to 1.0 and 0.7 to 1.0, respectively. The mean lead time from ctDNA detection to overt recurrence was 10.81 months (range 0-58.9 months).

CONCLUSIONS

ctDNA detection was associated with worse DFS and OS in patients with operable BC, particularly when detected after treatment and using primary tumor-informed assays. ctDNA detection has a high specificity for anticipating BC relapse.

How I treat endocrine-dependent metastatic breast cancer

Estrogen receptor-positive (ER+)/HER2-negative (HER2-), the so-called luminal-type breast cancer, is the most frequent subset, accounting for around 70% of all breast cancer cases. Endocrine therapy (ET) combined with cyclin-dependent kinases (CDK) 4/6 inhibitors is the standard first option in the management of advanced luminal breast cancer independently of disease extension. Classically, patients undergo multiple lines of ET ± targeted treatments until endocrine resistance occurs and palliative chemotherapy is proposed. Understanding endocrine resistance mechanisms and development of novel ET options is one of the main challenges in current clinical research. Another area of utmost interest is the improvement of post-endocrine therapeutic approaches. Among others, the development of antibody-drug conjugates (ADCs) is very promising, and some of these drugs will probably soon become a part of the therapeutic arsenal against this incurable disease. This review paper provides an overview of currently available treatment options in ER+/HER2- metastatic breast cancer and extensively discusses new approaches in late clinical development.

Reproductive potential and performance of fertility preservation strategies in BRCA-mutated breast cancer patients

Background

Preclinical evidence suggests a possible negative impact of deleterious BRCA mutations on female fertility. However, limited and rather conflicting clinical data are available. This study assessed the reproductive potential and performance of fertility preservation strategies in BRCA-mutated breast cancer patients.

Patients and methods

This was a retrospective analysis of two prospective studies investigating oocyte cryopreservation and ovarian tissue cryopreservation in newly diagnosed early breast cancer patients. In the current analysis, baseline anti-Mullerian hormone (AMH) and performance of cryopreservation strategies were compared between patients with or without germline deleterious BRCA mutations.

Results

Out of 156 patients included, 101 had known BRCA status of whom 29 (18.6%) were BRCA-mutated and 72 (46.1%) had no mutation. Median age in the entire cohort was 31 years [interquartile range (IQR) 28-33). Median AMH levels were 1.8 μg/l (IQR 1.0-2.7) and 2.6 µg/l (IQR 1.5-4.1) in the BRCA-positive and BRCA-negative cohorts, respectively (P = 0.109). Among patients who underwent oocyte cryopreservation (N = 29), women in the BRCA-positive cohort tended to retrieve (6.5 versus 9; P = 0.145) and to cryopreserve (3.5 versus 6; P = 0.121) less oocytes than those in the BRCA-negative cohort. Poor response rate (i.e. retrieval of ≤4 oocytes) was 40.0% and 11.1% in the BRCA-positive and BRCA-negative cohorts, respectively (P = 0.147). Among patients who underwent ovarian tissue cryopreservation (N = 72), women in the BRCA-positive cohort tended to have a numerically lower number of oocytes per fragment (0.08 versus 0.14; P = 0.193) and per square millimeter (0.33 versus 0.78; P = 0.153) than those in the BRCA-negative cohort. Two BRCA-mutated patients were transplanted after chemotherapy and one delivered at term a healthy baby. No difference between BRCA1- and BRCA2-mutated patients was observed in any of the above-mentioned outcomes.

Conclusion

A consistent trend for reduced reproductive potential and performance of cryopreservation strategies was observed in BRCA-mutated breast cancer patients. Independent validation of these results is needed.

Abstract OT3-05-02: ALEXANDRA/IMpassion030: A phase III study of standard adjuvant chemotherapy with or without atezolizumab in early triple negative breast cancer

Background: Triple negative breast cancer (TNBC) is a subtype with a high risk of relapse in the early disease setting. Because TNBC does not currently have specific targeted agents approved for use in the early setting it is treated primarily with chemotherapy. A growing body of evidence indicates that TNBC is more immunogenic than other subtypes of breast cancer and promising clinical activity has been reported with atezolizumab (an anti–PD-L1 antibody) in Phase 1/1b metastatic TNBC trials. Furthermore, the anti-tumor activity of PD-1/PD-L1 targeting drugs is hypothesized to be enhanced when co-administered with chemotherapy. ALEXANDRA/IMpassion030 will evaluate the efficacy and safety of atezolizumab in combination with standard adjuvant chemotherapy in early TNBC.

Methods: ALEXANDRA/IMpassion030 is a global, prospective, randomised, open-label Phase 3 trial investigating the efficacy, safety and pharmacokinetic (PK) profile of adjuvant atezolizumab plus standard chemotherapy versus chemotherapy alone in early TNBC. In total, 2300 patients diagnosed with non-metastatic operable stage II or III TNBC confirmed by central pathology review will be randomised. TumorPD-L1evaluationwill be performed centrally. Patients will be stratified by type of surgery, nodal status, and PD-L1 status. The adjuvant treatment will consist of weekly paclitaxel 80 mg/m2 for 12 weeks followed by dose dense anthracycline (epirubicin 90 mg/m2 or doxorubicin 60 mg/m2) and cyclophosphamide 600 mg/m2 for 4 doses every 2 weeks or the same chemotherapy regimen (T-EC/AC) given concomitantly with atezolizumab 840 mg every 2 weeks followed by maintenance atezolizumab 1200 mg every 3 weeks until completion of 1 year of atezolizumab. Primary end-point is invasive disease-free survival (iDFS) and secondary end-points include iDFS by PD-L1 and lymph node status, overall survival, safety, patient functioning and health related quality of life (HRQoL). Tumour tissue and blood samples will be collected for biomarker research. The first site was activated in May 4th, and approximately 430 sites are expected to be open globally in 30 countries. This trial is sponsored by Roche and conducted in partnership with the Breast International Group, Frontier Science and Technology Research Foundation, Institute Jules Bordet and Alliance Foundation Trials. Clinicaltrials.gov NCT03498716.

Citation Format: Ignatiadis M, McArthur H, Bailey A, Martinez J-L, De Azambuja E, Metzger O, Lai C, Ponde N, Goulioti T, Daly F, Bouhlel A, Balta V, Van Dooren V, Viale G, Maetens M, Dufrane C, Nguyen Duc A, Winer E, Gelber R, Piccart M. ALEXANDRA/IMpassion030: A phase III study of standard adjuvant chemotherapy with or without atezolizumab in early triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-05-02.

Total choline quantification measured by 1H MR spectroscopy as early predictor of response after neoadjuvant treatment for locally advanced breast cancer: The impact of immunohistochemical status

BACKGROUND

Validation of new biomarkers is essential for the early evaluation of neoadjuvant treatments.

PURPOSE

To determine whether measurements of total choline (tCho) by 1H spectroscopy could predict morphological or pathological complete response (pCR) of neoadjuvant treatment and whether breast cancer subgroups are related to prediction accuracy.

STUDY TYPE

Prospective, nonrandomized, monocentric, diagnostic study.

POPULATION

Sixty patients were initially included with 39 women participating in the final cohort.

FIELD STRENGTH/SEQUENCE

A 1.5T scanner was used for acquisition and MRS was performed using the syngo GRACE sequence.

ASSESSMENT

MRS and MRI examinations were performed at baseline (TP1), 24-72 hours after first chemotherapy (TP2), after the end of anthracycline treatment (TP3), and MRI only after the end of taxane treatment (TP4). Early (EMR) and late (LMR) morphological response were defined as %ΔDmax13 or %ΔDmax14, respectively. Responders were patients with %ΔDmax >30. Pathological complete response (pCR) patients achieved a residual cancer burden score of 0.

STATISTICAL TESTS

T-test, receiver operating characteristic (ROC) curves, multiple regression, logistic regression, one-way analysis of variance (ANOVA) analysis were used for the analysis.

RESULTS

At TP1 there was a significant difference between response groups for tCho1 concerning EMR prediction (P = 0.05) and pCR (P < 0.05) and for K_ep 1 (P = 0.03) concerning LMR prediction. At TP2, no modification of tCho and other parameters could predict response. At TP3, ΔtCho, ΔDmax, and ΔVol could predict LMR (P < 0.05 for all parameters), pCR (P < 0.05 for all parameters), and ΔK^trans could predict only pCR (P = 0.04). Logistic regression at baseline showed the highest area under the curve (AUC) of 0.9 for prediction of pCR. The triple negative (TN) subgroup showed significantly higher tCho at baseline (P = 0.02) and higher ΔtCho levels at TP3 (P < 0.05).

DATA CONCLUSION

Baseline measurements of tCho in combination with clinicopathological criteria could predict non-pCR with a high AUC. Furthermore, tCho quantification for prediction of pCR was more sensitive for TN tumors.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018;48:982-993.

Unravelling triple-negative breast cancer molecular heterogeneity using an integrative multiomic analysis

Background

Recent efforts of genome-wide gene expression profiling analyses have improved our understanding of the biological complexity and diversity of triple-negative breast cancers (TNBCs) reporting, at least six different molecular subtypes of TNBC namely Basal-like 1 (BL1), basal-like 2 (BL2), immunomodulatory (IM), mesenchymal (M), mesenchymal stem-like (MSL) and luminal androgen receptor (LAR). However, little is known regarding the potential driving molecular events within each subtype, their difference in survival and response to therapy. Further insight into the underlying genomic alterations is therefore needed.

Patients and methods

This study was carried out using copy-number aberrations, somatic mutations and gene expression data derived from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and The Cancer Genome Atlas. TNBC samples (n = 550) were classified according to Lehmann's molecular subtypes using the TNBCtype online subtyping tool (http://cbc.mc.vanderbilt.edu/tnbc/).

Results

Each subtype showed significant clinic-pathological characteristic differences. Using a multivariate model, IM subtype showed to be associated with a better prognosis (HR = 0.68; CI = 0.46-0.99; P = 0.043) whereas LAR subtype was associated with a worst prognosis (HR = 1.47; CI = 1.0-2.14; P = 0.046). BL1 subtype was found to be most genomically instable subtype with high TP53 mutation (92%) and copy-number deletion in genes involved in DNA repair mechanism (BRCA2, MDM2, PTEN, RB1 and TP53). LAR tumours were associated with higher mutational burden with significantly enriched mutations in PI3KCA (55%), AKT1 (13%) and CDH1 (13%) genes. M and MSL subtypes were associated with higher signature score for angiogenesis. Finally, IM showed high expression levels of immune signatures and check-point inhibitor genes such as PD1, PDL1 and CTLA4.

Conclusion

Our findings highlight for the first time the substantial genomic heterogeneity that characterize TNBC molecular subtypes, allowing for a better understanding of the disease biology as well as the identification of several candidate targets paving novel approaches for the development of anticancer therapeutics for TNBC.

Abstract P1-13-09: Withdrawn

This abstract was withdrawn by the authors.

Abstract P2-05-04: Deregulation of A-to-I RNA editing is associated with poor prognosis in HER2+ breast cancers in the neoALTTO trial

Background

A-to-I RNA editing, a post-transcriptional modification of the RNA catalyzed by the ADAR family of enzymes, is emerging as a widespread phenomenon in breast cancer (BC). A-to-I RNA editing is more frequent in the highly repetitive Alu regions but can affect both coding and non-coding regions. It has been shown to greatly impact cell functionality. In a recent report, we have shown that A-to-I RNA editing is regulated both by ADAR copy number and type I interferon response (Fumagalli et al. Cell Rep 2015). The main aim of the current study was to investigate the extent and profile of A-to-I RNA editing in HER2+ BC patients (pts) treated in the NeoALTTO trial, and to explore its impact on pathologic complete response (pCR) and survival.

Methods

Aligned RNAseq reads of sufficient quality and quantity were obtained for 252 of the 455 pts enrolled in the study, as described previously (Fumagalli et al. JAMA Oncol 2016). Editing sites from the rediPortal database were assessed. The editing level at a given site was computed by counting the number of Gs and As. Sites with coverage more than 10 were considered for further analyses. Editing in normal tissues was obtained from the GTEx project of the rediPortal database. Tumor infiltrating lymphocytes (TILs) and copy number aberrations were previously reported. Correlations between different parameters were assessed using Spearman correlations (ρ). The Mann-Whitney test was used to relate binary and numerical features. Event-free survival (EFS) analysis was performed using the Cox proportional hazard model.

Results

There was a median of 71470 edited sites per sample. As expected, mean editing per sample correlated with ADAR expression (ρ=59%, p&lt;10-16) and ADAR copy number (ρ=54%, p&lt;10-16). It was also correlated with the IFN-gamma driven signature (ρ=22%, p=0.0005), as well as with ESR1 gene expression (ρ=24%, p=0.0002). Neither ADAR expression nor mean editing was correlated with TILs (ρ=-0.5% and ρ=3%). No relationship between mean editing and pCR or EFS was found. The correlations between editing in NeoALTTO tumor samples and GTEx normal tissues were computed, and the median editing per sample was taken. These median correlations, ranging from 32% to 56%, were not associated with ADAR expression (ρ=-25%, p=6x10-5) nor mean editing (ρ=8%, p=0.19). Of interest, patients whose tumors showed low correlation with editing in normal tissues were associated with poor EFS (p=0.028, HR=0.56 to 0.96) suggesting that deregulation of RNA editing may impact disease progression and outcome. Similar results were obtained when the correlations were assessed between tumor samples instead of between tumor and normal samples (ρ between the two median editing: 76%; p-value survival: 0.013). The median correlations were not predictive for pCR (p=0.44). There was no interaction between editing and treatment arm.

Conclusions

Our study shows for the first time that deregulated RNA editing, as compared to editing in normal tissues, is a widespread phenomenon in HER2+ BC patients treated in the NeoALTTO trial and is associated with poor outcome. These results may provide new perspectives for the treatment of HER2+ disease by developing therapies targeting RNA editing.

Citation Format: Venet D, Rothé F, Dupont F, Maetens M, Fumagalli D, Salgado R, Bradbury I, Pusztai L, Harbeck N, Izquierdo M, de la Pena L, Ignatiadis M, de Azambuja E, Huober J, Nuciforo P, Baselga J, Piccart M, Loi S, Sotiriou C. Deregulation of A-to-I RNA editing is associated with poor prognosis in HER2+ breast cancers in the neoALTTO trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-05-04.