Non-metastatic Triple-negative Breast Cancer Research Articles

All HER2-negative breast cancer patients need gBRCA testing: cost-effectiveness and clinical benefits

BackgroundThe OlympiA trial demonstrated the benefits of adjuvant usage of olaparib for high-risk patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC) and germline BRCA (gBRCA) mutation. This provoked thoughts on the clinical criteria of gBRCA testing. This study aims to estimate the costs and benefits of gBRCA testing and adjuvant olaparib therapy for patients with triple-negative breast cancer (TNBC) and hormone-receptor (HR)-positive and HER2-negative BC in China and the United States of America (USA).MethodsWe used a Markov chain decision tree analytic model to compare three gBRCA screening policies in China and the USA: (1) no gBRCA testing; (2) selected gBRCA testing and (3) universal gBRCA testing for nonmetastatic TNBC and HR-positive HER2-negative BC patients. We modelled the benefit of systemic therapy and risk-reducing surgeries among patients identified with pathogenic or likely pathogenic variants (PVs) in BRCA1 and BRCA2.ResultsChanging from the selected gBRCA testing to the universal gBRCA testing in TNBC patients is cost-effective, with the incremental cost-effectiveness ratios (ICERs) being 10991.1 and 56518.2 USD/QALY in China and the USA, respectively. Expanding universal gBRCA testing to HR-positive HER2-negative BC and TNBC patients has ICERs of 2023.3 and 16611.1 USD/QALY in China and the USA, respectively.DiscussionBy performing gBRCA testing on all HER2-negative BC patients, adjuvant olaparib can be offered to high-risk patients with a PV in BRCA1 or BRCA2. These patients are also candidates for risk-reducing surgeries, an important aspect of their survivorship care, and these interventions can improve survival outcomes. With the willingness-to-pay thresholds being 31,500.0 and 100,000.0 USD per QALY gained in China and the USA, respectively, universal gBRCA testing is likely cost-effective for all HER2-negative BC patients. This simplified criterion of gBRCA testing for BC is recommended for adoption by current guidelines in China and the USA.

SPARC in cancer-associated fibroblasts is an independent poor prognostic factor in non-metastatic triple-negative breast cancer and exhibits pro-tumor activity.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and lacks specific targeted therapeutic agents. The current mechanistic evidence from cell-based studies suggests that the matricellular protein SPARC has a tumor-promoting role in TNBC; however, data on the clinical relevance of SPARC expression/secretion by tumor and stromal cells in TNBC are limited. Here, we analyzed by immunohistochemistry the prognostic value of tumor and stromal cell SPARC expression in 148 patients with non-metastatic TNBC and long follow-up (median: 5.4 years). We also quantified PD-L1 and PD-1 expression. We detected SPARC expression in tumor cells (42.4%), cancer-associated fibroblasts (CAFs; 88.1%), tumor-associated macrophages (77.1%), endothelial cells (75.2%) and tumor-infiltrating lymphocytes (9.8%). Recurrence-free survival was significantly lower in patients with SPARC-expressing CAFs. Multivariate analysis showed that SPARC expression in CAFs was an independent prognostic factor. We also detected tumor and stromal cell SPARC expression in TNBC cytosols, and in patient-derived xenografts and cell lines. Furthermore, we analyzed publicly available single-cell mRNA sequencing data and found that in TNBC, SPARC is expressed by different CAF subpopulations, including myofibroblasts and inflammatory fibroblasts that are involved in tumor-related processes. We then showed that fibroblast-secreted SPARC had a tumor-promoting role by inhibiting TNBC cell adhesion and stimulating their motility and invasiveness. Overall, our study demonstrates that SPARC expression in CAFs is an independent prognostic marker of poor outcome in TNBC. Patients with SPARC-expressing CAFs could be eligible for anti-SPARC targeted therapy.

Pembrolizumab (Keytruda)


 CADTH recommends that Keytruda be reimbursed by public drug plans for the treatment of adult patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as monotherapy as adjuvant treatment after surgery only if certain conditions are met.
 Keytruda should only be covered for adult (18 years of age or older) patients with early-stage TNBC who are at high risk for breast cancer coming back.
 Keytruda should only be used with chemotherapy before surgery, then alone after surgery. Keytruda should only be reimbursed if: prescribed by a specialist, if the patient is in relatively good health (i.e., have a good performance status, as determined by a specialist), the patient has not received prior systemic therapy for non-metastatic TNBC; and the patient has no clinical contraindication to immunotherapy.

Programmed death-ligand 1 (PD-L1) expression predicts response to neoadjuvant chemotherapy in triple-negative breast cancer: a systematic review and meta-analysis

Background In patients with metastatic triple-negative breast cancer (TNBC), programmed death-ligand 1 (PD-L1) expression has been demonstrated to predict response to immunotherapy. It is unclear whether PD-L1 expression measured with currently available validated assays can predict chemotherapy response in patients with non-metastatic TNBC. Methods We conducted a systematic review and meta-analysis of clinical studies to assess the PD-L1 expression as a predictor of response to chemotherapy in non-metastatic TNBC using validated assays. The primary endpoint was pathological complete response (pCR) rate to neoadjuvant chemotherapy. Secondary endpoints included the prevalence of PD-L1 expression in non-metastatic TNBC and its impact on disease-free survival (DFS) and overall survival (OS). Moreover, RNA sequence data from the TCGA breast cancer cohort was used to define the relationship between PDCD1 expression and response to chemotherapy and prognosis. Results Nineteen studies were eligible for the meta-analysis with a total of 2403 patients with non-metastatic TNBC disease. The PD-L1-positive cohort had a significantly higher likelihood of achieving pCR with neoadjuvant chemotherapy (pooled odds ratio = 1.95; 95% CI = 1.39–2.73, p < 0.0001). In studies which reported long-term outcomes, PD-L1 positivity was associated with significantly better DFS and OS compared to PD-L1 negative patients (pooled hazard ratio = 0.51; 95% CI = 0.35–0.74, p < 0.0001 and 0.51; 95% CI = 0.27–0.94, p = 0.031, respectively). Transcriptomic data suggested that PD-L1 expression is a surrogate marker for the upregulation of key immune-related genes that mediate response to chemotherapy in TNBC. Conclusion This analysis clearly shows that patients with PD-L1 positive TNBC respond better to neoadjuvant chemotherapy and are associated with better survival outcomes compared to patients with PD-L1 negative tumours. The newly distinct quadruple negative breast cancer (QNBC) subtype should be defined as the BC subtype with the poorest outcome in the non-metastatic setting, highlighting the need for more aggressive therapy approaches.

Abstract 1599: Genes subject to changes in heterogeneity can function as regulators of metastasis

Abstract Tumor cell heterogeneity has been strongly implicated in metastatic progression of solid tumors such as triple-negative breast cancer (TNBC), leading to resistance and recurrence. Raf Kinase Inhibitory Protein (RKIP or PEBP1) effectively suppresses metastasis in TNBC but is lost in many patients. We hypothesize that RKIP works in part by reducing the variability of gene expression in TNBC cells. To test whether RKIP reduces overall transcriptional heterogeneity, we compared the variation in gene expression between individual cells in metastatic (low RKIP) versus non-metastatic (high RKIP) TNBC tumors. Single-cell RNA-sequencing revealed transcriptional heterogeneity was decreased with RKIP overexpression. Many cancer regulatory genes were more homogeneous and up-regulated in the RKIP-expressing cells. Among these enriched and homogenously expressed genes is KMT5C, a histone methyltransferase that facilitates epigenetic transcriptional repression. Cell, mouse, and clinical studies suggest KMT5C expression blocks invasion, extravasation, and colonization of tumor cells, consistent with a role as a novel suppressor of metastasis. These studies reveal the importance of genes involved in heterogeneity as potential regulators of metastatic progression in cancer. Citation Format: Dongbo Yang, Christopher Dann, Andrea Valdespino, Lydia Robinson-Mailman, Mengjie Chen, Sebastian Pott, Marsha Rosner. Genes subject to changes in heterogeneity can function as regulators of metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1599.

Abstract 969: Epithelial and mesenchymal CTC detection in triple negative breast cancer patients using ANGLE’s Parsortix®system

Abstract Introduction: Isolation of circulating tumor cells (CTCs) is widely recognised as a prognostic biomarker in metastatic breast cancer. Recently, it was shown that CTC clearance following specific therapies may predict chemosensitivity in triple negative breast cancer (TNBC) patients. However, a limited amount of CTC research is available in TNBC due to the inability of epitope-dependent CTC platforms to capture CTCs in a sufficient proportion of patients, especially when evaluating non-metastatic patients (Stage I-III). ANGLE has developed a Research Use Only (RUO) workflow including the Parsortix® system, an epitope-independent microfluidic device that isolates and harvests rare cells from blood based on their size and deformability, followed by an immunofluorescent (IF) assay for the identification and characterization of CTCs. This five-color multiplex IF assay enables the identification of both epithelial and mesenchymal CTCs as well as the investigation of other targets of interest on the CTCs. Methods: 7.5mL of peripheral blood drawn into a Streck CellFree DNA Blood Collection Tube from 11 TNBC patients (four Stage IV and seven Stage IIIa) was processed on Parsortix® system between 96 and 144 hours post collection. Harvested CTCs were cytospun onto a charged slide and immunofluorescently stained using an optimised antibody panel allowing for detection of epithelial and mesenchymal CTCs. Stained slides were imaged using a BioView Allegro Plus automated imaging system. Results: CTCs were identified in 9 (82%) of the 11 TNBC patients, with a median of 6 and mean of 30 CTCs identified per patient. CTC clusters were harvested by the Parsortix® system and were observed in the majority (8/9) of the CTC-positive patients. Cluster size ranged from 2-68 CTCs per cluster, and the number of clusters per patient ranged from 1-50. Phenotypically, a large proportion of the CTCs identified expressed only mesenchymal markers (80%), with the remainder expressing both epithelial and mesenchymal markers (20%). In 6 of the 7 non-metastatic (Stage IIIa) patients, high numbers of CTC clusters were detected. Lower numbers of CTC clusters were detected in 3 (75%) of the 4 metastatic (Stage IV) patients. Conclusions: This study demonstrated the ability of ANGLE’s multiplex IF assay to detect and phenotype CTCs. The proportion of non-metastatic TNBC patients found to have CTCs was much higher compared to previous reports using epitope-dependent systems (82% vs 25%). This highlights the advantages of epitope-independent CTC capture in TNBC. ANGLE’s RUO Parsortix® system and multiplex IF assay provide an efficient solution for the harvesting and characterization of multiple CTC phenotypes, with the added advantage of being able to process the blood between 96 and 144 hours post collection, allowing for the shipment of samples at room temperature for centralised analysis in support of global clinical trials. Citation Format: Amina Mezni, Matthew Hardy, Mariacristina Ciccioli, Anne-Sophie Pailhes-Jimenez. Epithelial and mesenchymal CTC detection in triple negative breast cancer patients using ANGLE’s Parsortix®system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 969.

Radiomic features quantifying pixel-level characteristics of breast tumors from magnetic resonance imaging predict risk factors in triple-negative breast cancer.

e12612 Background: Computationally derived quantitative imaging (radiomic) features that describe tumor phenotypes at the pixel level have demonstrated associations with clinical characteristics in early investigations of other cancers. This implies that molecular differences among tumors may be reflected in their structure on the scales probed by 3D magnetic resonance imaging (MRI). We investigated whether radiomic features computed over tumor volumes from pre-treatment breast MRI could predict risk factors in triple-negative breast cancer (TNBC). Methods: We evaluated breast tumors on pre-treatment, post-contrast T1-weighted MRI from 156 patients with non-metastatic TNBC who underwent neoadjuvant chemotherapy. Tumor regions of interest were segmented by a convolutional neural network algorithm, with validation by breast radiologists. Features quantifying tumor shape and texture were extracted for the largest tumor present in each patient. We identified 23 principal components (PCs) describing these data within the original 364-dimensional feature space for further analysis. Tumor volume was also extracted for comparison with the shape and texture PCs, clinical variables and outcomes, but was kept separate from other radiomic features, since it directly correlates with clinical stage. We compiled for the cohort clinical variables including demographics, stage, grade, and, where available, absolute lymphocyte count (ALC) and Ki-67, a cellular proliferation index routinely used in clinical practice. We then performed a series of univariate and multivariate regression analyses to identify radiomic PCs and clinical variables that significantly predict patient outcomes, and radiomic PCs that predict established risk factors. Our multivariate analyses utilized 5-fold cross-validation and Monte-Carlo determination of p-values (based on 3000 random samplings from the null hypothesis), to ensure statistical rigor in identifying predictive relationships while correcting for multiple hypothesis testing. Results: Our univariate analyses confirmed expected correlations between: overall survival and pre-treatment tumor volume (p = 0.010); survival and ALC (p = 0.002); and clinical stage and tumor volume (p = 1.2⨉10-7). From our multivariate analysis, shape and texture radiomic features were predictive of: tumor volume (p &lt; 0.001); clinical stage (p &lt; 0.001); and Ki-67 (p = 0.02). We confirmed that Ki-67 was predictive of post-treatment residual cancer (p = 0.014), as has been previously reported. Conclusions: Radiomic features predict breast cancer risk factors that are significant for determining outcomes for TNBC patients. Combinations of radiomic shape and texture features track closely with tumor volumes, stage, and proliferative activity, potentially reflecting underlying molecular evolution.

Translational relevance of HER2-low expression in triple-negative breast cancer: A retrospective single-center study.

e13061 Background: In current clinical practice, the decision of using anti-HER2 targeted agents for breast cancer is based primarily on HER2 protein overexpression, assessed using immunohistochemistry and/or HER2 gene amplification on FISH assay(2018 ASCO/CAP guidelines). It is increasingly being recognized that HER2-negative breast cancer is characterized by a wide spectrum of HER2 expression, particularly important for the triple-negative breast cancer (TNBC) group, the treatment options for which are far less compared to hormone receptor-positive tumors. HER2-low breast cancer (HER1+ or 2+, without gene amplification) is an emerging subtype with differing clinicopathologic and prognostic implications. There is accumulating evidence that HER2-negative tumors may switch to HER2-low status and vice versa at tumor recurrence. The development of newer drug classes like antibody-drug conjugates and immunotherapy have created a window of opportunity for this sub-category of breast cancer. Methods: We aimed to evaluate HER2 0/normal and HER2-low expression in TNBCs, their clinicopathological characteristics, and prognostic significance. Clinical and laboratory data for 207 TNBC cases (184 non-metastatic and 23 metastatic) diagnosed between February 2010 and December 2019 was available for analysis and cases were followed up until December 2021. Androgen receptor (AR) immunohistochemistry was performed on available FFPE blocks. Results: Non-metastatic TNBCs: Median age was 50 (SD 11.77; range 23 to 82) years. 91.9% of HER2-low cases were more than 40years old compared to 70.1% of HER2 0 cases, p = 0.006. 79.9% were HER2 0, 14.1% were HER2 1+, and 6% were HER2 2+. 30.7% (39/127) of cases were AR+. Compared with HER2 0, HER2-low cases exhibited a lower histological grade (Her2 0 - Grade 3: 72.7%, Grade 2: 27.3%; Her2-low- Grade 3: 57.1%, Grade 2: 40%, Grade 1: 2.9% p=0.048). Compared with HER2 0, more of HER2-low cases were AR+ (For Her2 0 26.5% were AR+; For Her2-low 48% were AR+, p=0.036). There was no significant difference in disease-free survival between the two groups. There was no significant difference in overall survival (OS) between the two groups (Her2 0- Mean: 102.0 months, Median: Not achieved; Her2-low - Mean: 69.60 months, Median: 77.4 months p=0.73). Within the Her2-low group, patients ≤40 years had a median OS of 44.3 months. Metastatic TNBCs: Median age was 47 (SD 10.38; range 30 to 74) years. There was no significant correlation between the clinicopathological characteristics. No significant difference in OS was seen (Her2 0- Median: 44.9 months; Her2-low- Median: 24.3 months, p=0.20). Conclusions: The non-significant trend towards a lower survival for Her2-low TNBCs, coupled with a surprisingly lower histologic grade and a higher AR positivity needs to be further evaluated in larger studies. Further translational research to optimize treatment for this subgroup is needed.

34P Quadruple-negative breast cancer (PD-L1-negative triple-negative breast cancer, TNBC): Poorer response to chemotherapy and poorer survival compared to other TNBCs: A systematic review and meta-analysis

PD-L1 expression has shown to be predictive of response to immunotherapy in patients with metastatic triple-negative breast cancer (TNBC). It is unclear if PD-L1 expression by currently available validated assays has predictive capacity for response to chemotherapy in patients with non-metastatic TNBC.

Anemia requiring transfusion in breast cancer patients on dose-dense chemotherapy: Prevalence, risk factors, cost and effect on disease outcome.

PurposeDose-dense chemotherapy improves survival but with increased toxicity and treatment-related cost. We report the prevalence of anemia and the possible risk factors associated with chemotherapy-related anemia and determine the cost and time-delay associated with transfusion requirement in Indian patients with non-metastatic breast cancer on dose-dense preoperative chemotherapy.MethodsIn this study, triple-negative breast cancer (TNBC) patients were treated preoperatively with docetaxel and cyclophosphamide alternating with epirubicin and cisplatin every 2 weeks. Patients were evaluated for anemia pre- and post-chemotherapy. We examined trends in the red cell indices, transfusion requirement, time to transfusion, as well as risk factors associated with transfusion during treatment, along with delay in treatment due to anemia and the additional cost incurred.ResultsA total of 116 consecutive women with nonmetastatic TNBC were treated with preoperative chemotherapy. The median age was 44.5 years. 56.1% of patients had stage III disease. Anemia was detected at baseline in 54 (46.5%) patients with mild anemia (10–12 g/dl) in 42 (36.2%) patients and moderate anemia (8–10 g/dl) in 12 (10.3%) patients. During the course of treatment, all patients developed anemia. A total of 44 patients (37.9%) required transfusion during chemotherapy, with 55(47.4%) patients developing grade 1–2 anemia and 40 (34.5%) patients developing grade 3 anemia. The factors associated with anemia requiring transfusion were a steeper decline in hemoglobin after two cycles (OR 1.65, p = 0.02), low-grade tumor (OR 2.48, p = 0.03), and thrombocytopenia grade 3 or 4 (OR 4.35, p = 0.034), of which tumor grade and thrombocytopenia remained significant in multivariate analysis. Nearly one-fourth of the study population had a delay between two cycles of chemotherapy due to anemia. A median additional cost of INR 7000 was incurred among those requiring blood transfusion.ConclusionAnemia is a common toxicity associated with dose-dense chemotherapy during curative breast cancer treatment leading to delay in treatment and increased cost. Low-grade tumor, grade 3 or 4 thrombocytopenia, and grade 2 or higher anemia after two cycles of chemotherapy are risk factors for blood transfusions during treatment.

Abstract P1-05-05: Prognostic value of HER2 expression levels in non-metastatic triple-negative breast cancer and correlation with other biomarkers

Abstract Background: HER2 low breast cancer (BC), presenting 1+ or 2+ (without gene amplification) IHC staining, is an emerging subtype due to dedicated treatments that are now tested. Very few data have been reported on this specific subtype, especially in the triple-negative breast cancer (TNBC) group. Our aim was to evaluate HER2 expression and its prognostic value in a large retrospective series of patients with non-metastatic TNBC and a long follow-up, characterized for Basal-like (BL) or molecular apocrine-like (MA) IHC profiles as well as TILs infiltrate, PDL1 expression and PIK3CA/PTEN mutations. Patients and methods: HER2 expression (0, 1+, 2+) was evaluated on the clinical sample with the HercepTestTM immunohistochemical (IHC) assay, using the 2018 ASCO-CAP guidelines for HER2 scoring, in a series of 296 patients with non-metastatic TNBC treated in our center between 2002 and 2012. HER2 2+ IHC cases were evaluated by FISH and amplified cases were excluded. BL and MA profiles were defined as IHC CK5/6 and/or EGFR expression, and Androgen-receptor and FOXA1 IHC expression, respectively, in a previously used Tissue MicroArray. HER2 expression levels were tested for their association with baseline clinicopathological variables, and for Relapse-Free Survival (RFS) and Overall survival (OS). Results: A total of 296 TNBC tumors was selected for this analysis (248 HER2=0 (83.8%), 40 HER2=1+ (13.5%), 8 HER2=2+ (2.7%)). Considering these percentages, HER2 1+ and 2+ cases were grouped for statistical analysis. Median age was 57.7 years (range 28.5-98.6). 45.8% of tumors were classified pT1 and 63.5% pN0. We found 81.9% of patients had ductal carcinomas, 5.5% lobular carcinomas and 12.6% other histological types. Histological grade 1-2 represented 21% of all tumors. A BL phenotype was observed in 63.8% of cases, and an MA profile in 40.2% of the cases. Adjuvant chemotherapy (ACT) was delivered in 75.3% of patients. Compared to HER2 0 tumors, HER2 1+/2+ tumors exhibited a lower nuclear grade (1/2) (35.4% vs. 18.2%, p=0.007) and MA profile (57.5% vs. 36.7%, p=0.008). With a median follow-up of 9.7 years, HER2 2+ tumors (compared to HER2 0/1+ tumors) were associated, in univariate analysis, with a worse RFS (HR=3.16, 95%CI [1.27; 7.85], p=0.034). No statistically significant OS or RFS difference was found when using the HER2 0 vs. 1+/2+ grouping. Multivariate analyses results are summarized in Table 1. Conclusions: HER2 1+/2+ expression is associated with lower histological grade and MA profile, a specific subgroup of TNBC with a worse prognosis. Considering the current development of anti-androgens for MA tumors and anti-HER2 antibody-drug conjugates in this HER2 1+/2+ population, this clinicopathological association could have therapeutic implications. While rare (2.7% of cases in our series), HER2 2+ TNBC seems to be affected with a worse RFS, advocating for a dedicated evaluation of this subgroup. VariablesOS (N=263)RFS (N=285)HR95% CIP-valueHR95% CIP-valueTumor size &amp;lt;0.001 T11 T2/T3/T42.551.49 – 4.37 Nodal status 0.004 &amp;lt;0.001N-11 N+2.011.26 - 3.224.472.71 - 7.37HistologyDuctal10.001Other0.340.16 – 0.72Adjuvant chemotherapy &amp;lt;0.001 0.001No11 Yes0.330.21 - 0.530.400.24 - 0.66Molecular Apocrine profileNo10.041Yes1.611.02 – 2.54TILs (%) 0.024 0.002≤ 51 1 &amp;gt; 5 0.570.34 – 0.95 0.440.25 - 0.77HER2 (0 vs 1+/2+)010.46610.3001+/2+0.810.45 – 1.451.370.77 - 2.42 Citation Format: William Jacot, Aurélie Maran-Gonzales, Oceane Massol, Charlotte Sorbs, Caroline Mollevi, Séverine Guiu, Florence Boissière-Michot, Jeanne Ramos. Prognostic value of HER2 expression levels in non-metastatic triple-negative breast cancer and correlation with other biomarkers [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-05-05.

Abstract P2-10-01: Estimating risk of breast cancer-specific mortality (BCSM) and non-BCSM in patients with triple-negative breast cancer

Abstract Background: Triple-negative breast cancer (TNBC) is associated with high risk of distant recurrence and death. At present, our ability to estimate risk of death from causes other than breast cancer is limited. Particularly among elderly patients (pts), who have been historically underrepresented in clinical trials. In pts with TNBC, assessing both risks is important for our treatment recommendations. The aim of this study was to evaluate risk of BCSM and non-BCSM in TNBC by patient (pt) and tumor characteristics. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER) program, we identified women diagnosed with non-metastatic invasive TNBC between 2010-2016. Fine and Gray regression was used to evaluate the association of BCSM with pre-specified variables including pt age, tumor size (T), nodal status (N), and tumor grade, while considering deaths from other causes as competing events. We then estimated cumulative risk of BCSM, non-BCSM and all-cause mortality within subgroups defined by baseline clinical and pathologic variables. We conducted a subset analysis of N0 pts older than 50 years, given that we anticipated this subgroup would have the most clinically useful balance between BCSM and non-BCSM. Results: We included 37,293 pts. Age distribution was: 27.1% &amp;lt;50 years, 51.3% 50-69 years, 15.0% 70-79 years, and 6.6% ≥80 years. Among all pts, 42.4% presented with T2 tumors and 69.5% had N0 disease. In adjusted Fine and Gray regression, risks of BCSM were higher for pts aged &amp;gt;80 years vs 50-69 years (Hazard ratio [HR] 1.62; 95% CI, [1.45 - 1.80]), T4 vs T1a (HR 8.51; 95% CI, [6.20 - 11.68]), N3 vs N0 (HR 6.31; 95% CI, [5.70 - 7.00]) and grade III/IV vs grade I (HR 2.10; 95% CI, [1.44 - 3.07]). The cumulative risk of BCSM in year 0-7 was 10.7% for N0, 27.9% for N1, 46.4% for N2 and 64.0% for N3. In contrast, the cumulative risk of non-BCSM over the same period ranged from 7.5% in N1 to 8.7% in N2. The table shows risks of BCSM, non-BCSM and all-cause mortality among pts with N0 disease by age at diagnosis and tumor size. Pts 50-69 years had an increasing cumulative risk of BCSM by tumor size up to 13.0% in those with T2 tumors, while the risk of non-BCSM ranged from 4.8% to 5.9%. Pts aged 70-79 years with T1a/b, N0 tumors had risks of BCSM that were approximately 60% lower than the risks of non-BCSM. In pts aged ≥80 years, the risk of non-BCSM increased and is significantly higher than BCSM in patients with T1b-T2 disease. Conclusions: The risk of BCSM in TNBC depends on traditional clinicopathologic factors and is in general, much higher than the risk of non-BCSM. However, the high risk of non-BCSM among older pts is substantial which needs to be taken into consideration when making treatment recommendations. An interactive tool to estimate risks of BCSM, non-BCSM and all-cause mortality for TNBC will be presented at the meeting. BCSMnon-BCSMAll-cause mortalityCumulative risk (%) and 95% CICumulative risk (%) and 95% CICumulative risk (%) and 95% CIyears 0-7years 0-7years 0-7Tumor size among age 50-69, N0 onlyT1a2.6 (1.0 - 4.3)5.9 (3.2 - 8.6)8.5 (5.3 - 11.6)T1b3.9 (2.8 - 5.0)4.8 (3.3 - 6.3)8.7 (6.9 - 10.5)T1c8.1 (6.9 - 9.4)4.8 (3.9 - 5.8)13.0 (11.4 - 14.5)T213.0 (11.6 - 14.4)5.5 (4.4 - 6.5)18.5 (16.8 - 20.2)Tumor size among age 70-79, N0 onlyT1a6.1 (0 - 12.7)13.9 (7.0 - 20.9)20.0 (10.2 - 28.7)T1b5.3 (3.0 - 7.7)13.3 (9.0 - 17.7)18.6 (13.7 - 23.3)T1c11.0 (8.7 - 13.4)14.3 (11.4 - 17.2)25.3 (21.7 - 28.8)T221.0 (17.4 - 24.6)17.4 (13.4 - 21.5)38.5 (33.3 - 43.2)Tumor size among age ≥80, N0 onlyT1a6.6 (0 - 19.7)27.0 (11.0 - 43.1)33.7 (11.8 - 50.1)T1b7.1 (2.1 - 12.2)33.2 (23.2 - 43.2)40.3 (28.9 - 49.9)T1c8.4 (5.2 - 11.6)32.7 (26.4 - 39.0)41.1 (34.1 - 47.3)T222.7 (18.1 - 27.3)41.6 (34.2 - 49.1)64.3 (56.0 - 71.1) Citation Format: Jose P Leone, Noah Graham, Julieta Leone, Sara M Tolaney, Bernardo A Leone, Rachel A Freedman, Michael J Hassett, Carlos T Vallejo, Eric P Winer, Nancy U Lin, Nabihah Tayob. Estimating risk of breast cancer-specific mortality (BCSM) and non-BCSM in patients with triple-negative breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-10-01.

Abstract P4-01-05: Multi-omics data shows downregulation of mismatch repair, purin and tublin pathways in AR-negative triple-negative chemotherapy-resistant tumors

Abstract Introduction. The standard treatment for non-metastatic triple-negative breast cancer (TNBC) is neoadjuvant chemotherapy (NAC) and nearly 50% exhibit pathological complete response (pCR). However, patients with residual disease after NAC are at increased risk for recurrence and death. Prior studies examining the transcriptome of TNBC pre/post-NAC have examined a limited number of genes (&amp;lt;500) in heterogeneous subgroups of TNBC (e.g. LAR and non-LAR). We explored the transcriptome of androgen-receptor (AR) negative (non-LAR) TNBC subtype both pre/post NAC to identify pathways associated with NAC response. Methods. Tumors obtained pre/post NAC from TNBC patients enrolled in the Breast Cancer Genome Guided therapy study (BEAUTY) underwent RNA sequencing and reverse-phase protein array (RPPA). EdgeR was applied for differentially expressed (DE) analysis and regression methods for RPPA. Digital deconvolution method (CIBERSORTx) and TNBC single-cell data were used to obtain cell types. Pathway analysis was carried out using 2972 gene sets and gene set variation analysis (GSVA). Functional enrichment analysis was conducted with significant genes. Results. Of the 44 TNBC patients, 32 patients were excluded from the analysis cohort due to: LAR tumor (6 pts.), non-LAR tumor with pCR (23 pts.), and cell type issues with RNA-seq data (3 pt.). Paired RNA-Seq data were available for 12 TNBC patients (4 with progression &amp;lt;2 years [EP]) and 8 who were progression-free &amp;gt; 4 years [NP]) and paired RPPA data were available for 9 of these 12 patients. Differentially expressed genes, proteins and cell types between EP and NP in post-NAC. We identified 489 genes differentially expressed (DE) between EP and NP (logFC=|2|, FDR &amp;lt; 0.05). Analysis of cytobands from these 489 genes showed an enrichment of genes on chromosome 6p22.1-2 and 17q25.3 regions (enrichment ratio &amp;gt;5; p-value &amp;lt;10E-4). Critical genes identified in the AR- network (p-value &amp;lt; 10E-3) were IL1RN, SLAMF9, KRT81, BHLHE22, B3GALT5, PCP4, TREM1, AQP9, NRTN, and COL2A1.In addition, preliminary results from RPPA data of post-NAC tumors showed astrocytic phosphoprotein (PEA-15), involved in apoptosis, proliferation, glucose metabolism, as well as cell proliferation and Y box binding (YB1) proteins (involved in metastases), were more DE in EP than NP (p &amp;lt; 0.05). CIBERSORTx was applied to estimate the proportions of different cell types in post-NAC tumors. Cancer-associated fibroblasts iCAFs were low and myCAFs are high in EP vs NP. It is known that the cross-talk between CAFs and tumor cells may induce tumor resistance to chemotherapy. Differentially expressed pathways in post and pre-NAC EP tumors. Using genome-wide expression data from the paired 12 tumors and the GSVA method, we obtained individual pathway scores for 2972 pathways. One hundred ninety pathways were downregulated and 61 pathways were upregulated (p-value &amp;lt;= 0.05) in the post-NAC residual disease of EP relative to NP. We further examined these 190 pathways in the paired EPs and found 71% of those pathways were upregulated in the pre-NAC. These 190 downregulated pathways were enriched with FOXO, TGF-beta, PI3k, FGFR1, insulin and others. The 61 upregulated pathways in post-NAC EP tumors were enriched with mismatch repair, purine, tubulin, telomere, polymerase and gap-junction related pathways; 77% of those 61 pathways were downregulated in pre-NAC. Conclusions. Using a comprehensive “omics” approach, we have identified novel cancer and drug response pathways associated with recurrence in AR-TNBC disease. Further work to evaluate these as markers of outcome and potential drug targets is warranted. Citation Format: Krishna R Kalari, Vera J Suman, Xiaojia Tang, Jason P Sinnwell, Kevin J Thompson, Peter T Vedell, Jodi M Carter, Sarah A McLaughlin, Alvaro Moreno Aspitia, Donald W Northfelt, Richard J Gray, Richard Weinshilboum, Liewei Wang, Judy C Boughey, Matthew Goetz. Multi-omics data shows downregulation of mismatch repair, purin and tublin pathways in AR-negative triple-negative chemotherapy-resistant tumors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-01-05.

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

Simple SummaryThe 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. (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 (SUVmax, SUVmean, SUVpeak, 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.

Pattern of Recurrence and Survival Outcomes in Non-Metastatic Triple-Negative Breast Cancer; A Retrospective Analysis

Pattern of Recurrence and Survival Outcomes in Non-Metastatic Triple-Negative Breast Cancer; A Retrospective Analysis

Modified neoadjuvant clinicopathological risk stratification as a prognostic score in early and locally advanced triple-negative breast cancer.

Triple-negative subtype is an aggressive breast cancer with inferior survival. Pathological complete remission (pCR) is a good surrogate endpoint for survival among patients receiving neoadjuvant chemotherapy (NACT). We attempted to validate the clinical pathological score (CPS) with a modified risk grouping among Triple-negative breast cancer (TNBC) patients receiving NACT at our center. Data of patients with TNBC who underwent NACT between January 2014 to July 2017 were retrospectively analyzed. The composite CPS score included cTN stage and y pTN stage and ranged from 0 to 4. This was calculated using an available online software developed by MD Anderson Center. The score obtained from the calculator was used to develop a risk grouping into low risk (0, 1) and high risk (2, 3, 4). Invasive disease-free survival (iDFS) and locoregional recurrence-free survival (LRFS) were calculated using the Kaplan-Meier method. Seventy-eight patients with TNBC (median age: 45 [24-75]) had received NACT (anthracyclines and taxanes). Early and locally advanced breast cancer constituted 17 (21.8%) and 61 (78.2%), respectively, and 22 (28.2%) achieved pCR. After a median follow-up of 25 months (5-62), 3-year iDFS and OS were 59% and 81%, respectively, for the entire population. The 3-year iDFS in low-risk (n = 18) and high-risk (n = 60) patients was 85% and 51%, respectively (P = 0.03). The 3-year LRFS in low risk and high risk was 93% versus 58% (P = 0.03). The 3-year OS in the low and high risk was 93% and 77%, respectively (P = 0.24, NS). Our study supports the use of the modified neoadjuvant clinicopathological score as a prognostic marker in patients with nonmetastatic triple-negative breast cancer. This needs to be validated in a larger subset of patients.

Current State of Knowledge on the Immune Checkpoint Inhibitors in Triple-Negative Breast Cancer Treatment: Approaches, Efficacy, and Challenges.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with limited treatment options. Recently, there has been a growing interest in immunotherapy with immune checkpoint inhibitors (ICIs) in TNBC, leading to extensive preclinical and clinical research. This review summarizes the current state of knowledge on ICIs efficacy and their predictive markers in TNBC and highlights the areas where the data are still limited. Currently, the only approved ICI-based regimen for TNBC is pembrolizumab with chemotherapy. Its advantage over chemotherapy alone was confirmed for non-metastatic TNBC regardless of programmed death-ligand 1 (PD-L1) expression (KEYNOTE-522) and for metastatic, PD-L1-positive TNBC (KEYNOTE-355). Pembrolizumab’s efficacy was also evaluated in monotherapy, or in combination with niraparib and radiation therapy, showing potential efficacy and acceptable safety profile in phase 2 clinical trials. Atezolizumab + nab-paclitaxel increased the overall survival (OS) over placebo + nab-paclitaxel in early TNBC, regardless of PD-L1 status (IMpassion031). In IMpassion130 (untreated, advanced TNBC), the OS improvement was not statistically significant in the intention-to-treat population but clinically meaningful in the PD-L1 positive cohort. The durvalumab–anthracycline combination showed an increased response durability over placebo anthracycline in early TNBC (GeparNuevo). Several phase 1 clinical trials also showed a potential efficacy of atezolizumab and avelumab monotherapy in metastatic TNBC. ICIs appear to be applicable in both neoadjuvant and adjuvant settings, and are both pretreated and previously untreated patients. Further research is necessary to determine the most beneficial drug combinations and optimize patient selection. It is essential to identify the predictive markers for ICIs and factors affecting their expression.

Chemotherapy regimen choice and patient outcomes in early-stage triple-negative breast cancer: a retrospective analysis.

Background:Triple-negative breast cancer (TNBC) is associated with a poor prognosis when compared to hormone receptor–positive breast cancers. Anthracycline-based regimens (ABRs) are mainstay for treatment of non-metastatic TNBC. However, anthracyclines are associated with an increased risk of potentially life-threatening adverse effects. We sought to evaluate outcomes in patients with early TNBC treated with ABRs versus those treated with anthracycline-sparing regimens (ASRs).Methods:All patients treated for stage I–III TNBC who had undergone curative-intent surgery at a large academic medical center between January 2013 and May 2018 were included in this retrospective study. Event-free survival (EFS) and disease-free survival (DFS) were the primary endpoints, with overall survival (OS) as a secondary endpoint and were defined as per standardized STEEP criteria. Kaplan–Meier, multivariable Cox regression, and log-rank tests were used to define key survival and treatment-related differences between subjects treated with ABRs versus ASRs.Results:One hundred thirty-two patients met inclusion criteria with a median follow-up of 55.9 months. Twenty-seven patients (20%) had disease recurrence and 20 (15%) died. Patients in the ABR group were more likely to have nodal involvement (chi-square p = 0.011). Patients treated with ABRs (n = 26, 20%) compared with ASRs (n = 106, 80%) had significantly shorter median EFS (32.4 months vs not reached (NR), p < 0.001), DFS (26.2 months vs NR, p < 0.001), and OS (49.2 months vs NR, p < 0.001). The shorter survival observed in the ABR group persisted after adjusting for nodal status and on multivariate analysis. Of the 26 ABR-treated patients, 9 (35%) had an anthracycline added after suboptimal response to an ASR. Regardless of reason for anthracycline inclusion, the survival outcomes were similar. No cardiac or secondary leukemic events were observed in either group.Conclusion:ABRs were associated with shorter EFS, DFS, and OS, even after adjusting for certain high-risk clinical features.

Prognostic Value of HER2-Low Expression in Non-Metastatic Triple-Negative Breast Cancer and Correlation with Other Biomarkers.

Simple SummaryHER2-low breast cancer is an emerging subtype for which very few data are available, especially within the triple-negative breast cancer (TNBC) group. Our aim was to evaluate HER2 expression using the 2018 ASCO/CAP guidelines for HER2 scoring and its prognostic value in a large retrospective series of 296 patients with non-metastatic TNBC. In this large, homogeneous series of patients with early TNBC, HER2 1+/2+ expression was associated with a lower histological grade and molecular apocrine profile, and a specific subgroup of androgen receptor-expressing TNBC with worse long-term prognosis. Considering the current development of anti-androgens for molecular apocrine-like tumors and anti-HER2 antibody–drug conjugates for this HER2 1+/2+ population, this clinicopathological association could have therapeutic implications. Although rare (2.7% of patients in our series), HER2 2+ TNBC seems to have worse relapse-free survival, advocating a dedicated clinical, biological and therapeutic evaluation of this subgroup.HER2-low breast cancer (i.e., HER 1+ or 2+, without gene amplification) is an emerging subtype for which very few data are available, especially within the triple-negative breast cancer (TNBC) group. Our aim was to evaluate HER2 expression and its prognostic value in a large retrospective series of patients with non-metastatic TNBC (median age: 57.7 years; range: 28.5–98.6). Among the 296 TNBC samples, 83.8% were HER2 0, 13.5% were HER2 1+, and 2.7% were HER2 2+ (HercepTestTM and 2018 ASCO/CAP guidelines for HER2 scoring). CK5/6 and/or EGFR-expressing androgen receptors and FOXA1-expressing tumors were classified as basal-like (63.8%) and molecular apocrine-like (MA, 40.2%), respectively. Compared with HER2 0 tumors, HER2 1+/2+ tumors exhibited a lower histological grade (1/2) (35.4% vs. 18.2%, p = 0.007) and MA profile (57.5% vs. 36.7%, p = 0.008). Moreover, patients with HER2 1+/2+ tumors were older (p = 0.047). After a median follow-up of 9.7 years, HER2 2+ tumors (compared with HER2 0/1+ tumors) were associated with worse relapse-free survival (RFS) (HR = 3.16, 95% CI [1.27; 7.85], p = 0.034) in a univariate analysis. Overall survival (OS) and RFS were not different in the HER2 0 and 1+/2+ groups. HER2 levels were not significantly associated with OS or RFS in a multivariate analysis.

Molecular characterization of triple negative breast cancer formaldehyde-fixed paraffin-embedded samples by data-independent acquisition proteomics.

Triple negative breast cancer accounts for 15%-20% of all breast carcinomas and is clinically characterized by an aggressive phenotype and poor prognosis. Triple negative tumors do not benefit from targeted therapies, so further characterization is needed to define subgroups with potential therapeutic value. In this work, the proteomes of 125 formalin-fixed paraffin-embedded samples from patients diagnosed with non-metastatic triple negative breast cancer were analyzed using data-independent acquisition + in a LTQ-Orbitrap Fusion Lumos mass spectrometer coupled to an EASY-nLC 1000. 1206 proteins were identified in at least 66% of the samples. Hierarchical clustering, probabilistic graphical models and Significance Analysis of Microarrays were combined to characterize proteomics-based molecular groups. Two molecular groups were defined with differences in biological processes such as glycolysis, translation and immune response. These two molecular groups showed also several differentially expressed proteins. This clinically homogenous dataset may serve to design new therapeutic strategies in the future.