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Abstract Genomic analysis of structural variants(SVs) in breast cancer (BC) patients has been conducted, but the relationship between genomic alterations and BC prognosis remains unclear. We performed RNA sequencing of 297 early BC fresh-frozen tissues. We identified SVs using three tools (STAR.Arriba, STAR.fusion, and STAR.SEQR) with the COSMIC and Mitelman databases as guide references. We found a median of five to eight fusions per sample. In BC intrinsic subtypes, normal subtype had the fewest fusions (median: 1, interquartile range [IQR]: 0, 3) followed by luminal A (median: 5.5, IQR: 2.75, 10.25), luminal B (median: 9, IQR: 6, 16.5), HER2-enriched (median: 9, IQR: 6, 16.5) and basal (median 10, IQR: 6, 15.5) subtypes (p

Abstract Aim Patients with locoregionally uncontrolled breast tumors are frequently referred for breast palliative radiotherapy (PRT) to mitigate symptoms. We analyzed the outcomes following breast PRT to optimize PRT according to risk groups. Methods We reviewed 133 patients who underwent breast PRT. A median total dose of 45 Gy was prescribed with an equivalent dose in 2 Gy fractions (EQD2, α/β = 3.5) of 53 Gy. The Cox proportional hazards model was used to analyze the prognostic factors of local control (LC). Results Most (90.2%) had polymetastatic disease (> 5 lesions), and 48.9% had bone metastasis. With a median follow-up of 17.2 months, the 2-year LC and overall survival (OS) rates were 49.4%, and 48.3%, respectively. Multivariable analyses demonstrated progressive or mixed responses outside the breast and > 2 lines of previous therapy as adverse features for clinical outcomes. Group 1 (0 risk factors) showed favorable 2-year LC and OS of 63.9%, and 72.8%, respectively, whereas group 3 (2 risk factors) showed the worst outcomes of 0%, and 6.8%, respectively. Breast PRT with EQD2 ≥ 63 Gy showed a significant benefit in LC for group 1 and marginal benefit (p = 0.055) for group 2, but no improvement for group 3 (p = 0.300). Conclusion Breast PRT showed favorable LC outcomes in patients with stable disease outside the breast and treated with ≤ 2 lines of systemic treatment. Our findings warrant future clinical trials investigating the role of higher than palliative dose and early intervention of PRT in stage IV patients.

Taselisib is a potent β‐sparing phosphatidylinositol 3‐kinase (PI3K) inhibitor that, with endocrine therapy, improves outcomes in phosphatidylinositol‐4,5‐bisphosphate 3‐kinase catalytic subunit alpha (PIK3CA)‐mutated (PIK3CAmut) advanced breast cancer. To understand alterations associated with response to PI3K inhibition, we analysed circulating tumour DNA (ctDNA) from participants enrolled in the SANDPIPER trial. Participants were designated as either PIK3CAmut or PIK3CA no mutation was detected (NMD) per baseline ctDNA. The top mutated genes and tumour fraction estimates identified were analysed for their association with outcomes. In participants with PIK3CAmut ctDNA treated with taselisib + fulvestrant, tumour protein p53 (TP53; encoding p53) and fibroblast growth factor receptor 1 (FGFR1) alterations were associated with shorter progression‐free survival (PFS) compared to participants with NMD in these genes. Conversely, participants with PIK3CAmut ctDNA harbouring a neurofibromin 1 (NF1) alteration or high baseline tumour fraction estimate experienced improved PFS upon treatment with taselisib + fulvestrant compared to placebo + fulvestrant. Broadly, alterations in oestrogen receptor (ER), PI3K and p53 pathway genes were associated with resistance to taselisib + fulvestrant in participants with PIK3CAmut ctDNA. Altogether, we demonstrated the impact of genomic (co‐)alterations on outcomes with one of the largest clinico‐genomic datasets of ER+, HER2−, PIK3CAmut breast cancer patients treated with a PI3K inhibitor.

Abstract Apocrine carcinoma is a rare breast cancer subtype. As such, the genomic characteristics of apocrine carcinoma with triple negative immunohistochemical results (TNAC), which has been treated as triple negative breast cancer (TNBC), have not been revealed. In this study, we evaluated the genomic characteristics of TNAC compared to TNBC with low Ki-67 (LK-TNBC). In the genetic analysis of 73 TNACs and 32 LK-TNBCs, the most frequently mutated driver gene in TNAC was TP53 (16/56, 28.6%), followed by PIK3CA (9/56, 16.1%), ZNF717 (8/56, 14.3%), and PIK3R1 (6/56, 10.71%). Mutational signature analysis showed enrichment of defective DNA mismatch repair (MMR)-related signatures (SBS6 and SBS21) and the SBS5 signature in TNAC, whereas an APOBEC activity-associated mutational signature (SBS13) was more prominent in LK-TNBC (Student’s t test, p

Abstract Background TP53 is the most commonly mutated gene across all cancer types. R175H mutation was considered structural mutation where the mutation causes misfolding of the protein and leads to a significant conformational alterations within p53's DNA binding domain. The aim of this study was to explain the reason why R175H worse the response to immunotherapy by analyzing tumor immune microenvironment through the expression of immune cells and PD‐1. Materials and Methods Patients diagnosed with metastatic carcinoma, including colorectal cancer (CRC), breast cancer (BRCA), gastric cancer (GC), non‐small cell lung cancer (NSCLC), and 20 other cancer types, treated in a palliative setting at Samsung Medical Center between October 2019 and April 2021, were enrolled. Of these patients, those who underwent TDS analysis (TruSight™ Oncology 500 assay [TSO 500]) were finally analyzed. Results Of 1770 patients, 1012 (57.2%) harbored genetic alterations in TP53. All mutations were single nucleotide variants (SNVs), and the most frequent SNV was R175H (n = 84, 7.5%) which was known as one of the most common hotspot TP53 mutation. The overall survival of patients with TP53 R175H mutations was significantly worse following chemotherapy (606 vs. 456 days, p

Aim: The role of regional nodal irradiation (RNI) after preoperative systemic treatment (PST) with targeted therapy for HER2-positive breast cancer remains uncertain. This study aimed to investigate the impact of RNI on locoregional recurrence (LRR) and disease-free survival (DFS) outcomes after docetaxel/carboplatin/trastuzumab/pertuzumab (TCHP) for PST. Methods: We retrospectively analyzed 255 patients who were treated with six cycles of TCHP between 2016 and 2019. The patients were divided into four groups based on clinical nodal involvement: group A, with no nodal disease; group B, with axillary lymph node (AXL) level I; group C, with AXL level I with II/III; and group D, with supraclavicular or internal mammary nodes. Results: The RNI group had more advanced nodal disease (C/D) than the no RNI group (56.9 % vs. 6.8 %). With a median follow-up of 51.3 months, there were two (0.8 %), three (1.2 %), and 15 (5.9 %) local, regional, and distant metastases, respectively. LRR did not differ significantly according to the RNI (2.6 % vs. 1.0 %, p = 0.651). Group D had the most frequent distant metastases (17.5 %; p = 0.005). The 4-year DFS rate was 92.7 %, and DFS did not improve significantly after RNI (p = 0.074). When stratified by clinical nodal groups and pathological axillary response, RNI had no effect on LRR/DFS outcomes. Conclusion: With a rare incidence of LRR, RNI did not significantly affect LRR or DFS in patients with HER2-positive breast cancer after with PST-TCHP. However, intensive systemic treatment is required for advanced diseases (C/D). Selective de-intensified RNI and intensified systemic treatment should be investigated in future studies.

As most erb‐b2 receptor tyrosine kinase 2 (HER2)‐positive breast cancer (BC) patients currently receive dual HER2‐targeting added to neoadjuvant chemotherapy, improved methods for identifying individual response, and assisting postsurgical salvage therapy, are needed. Herein, we evaluated the 41‐gene classifier trastuzumab advantage risk model (TRAR) as a predictive marker for patients enrolled in the NeoSphere trial. TRAR scores were computed from RNA of 350 pre‐ and 166 post‐treatment tumor specimens. Overall, TRAR score was significantly associated with pathological complete response (pCR) rate independently of other predictive clinico‐pathological variables. Separate analyses according to estrogen receptor (ER) status showed a significant association between TRAR score and pCR in ER‐positive specimens but not in ER‐negative counterparts. Among ER‐positive BC patients not achieving a pCR, those with TRAR‐low scores in surgical specimens showed a trend for lower distant event‐free survival. In conclusion, in HER2‐positive/ER‐positive BC, TRAR is an independent predictor of pCR and represents a promising tool to select patients responsive to anti‐HER2‐based neoadjuvant therapy and to assist treatment escalation and de‐escalation strategies in this setting.

IntroductionImmune checkpoint inhibitor (ICI) is one of the standard treatment strategies in triple negative breast cancer (TNBC). However, the benefit of ICI with chemotherapy is limited in metastatic TNBC. In this study, we evaluated the effect of PD-L1 and LAG-3 expression on tissue microenvironment of mTNBC treated with ICI.MethodsWe reviewed representative formalin-fixed paraffin embedded specimens from metastatic or archival tumor tissues of TNBCs who treated with PD-1/PD-L1 inhibitors in metastatic setting. We used the Opal multiplex Detection kit with six antibodies (anti-PD-L1, anti-LAG-3, anti-CD68, anti-panCK, anti-CD8, anti-CD107a/LAMP antibody).ResultsWe evaluated the association between LAG-3+cells and survival outcome regarding CK expression. Stromal LAG-3+/CK+ and LAG-3+/CK- cells were not associated with ICI-progression free survival(PFS) (P=0.16). However, LAG-3+ cell distributions in the tumor area impacted on ICI-PFS. A high density of LAG-3+CK+ cells was associated with shorter ICI-PFS compared with low densities of both LAG-3+CK+ and LAG-3+CK- cells (1.9 vs. 3.5 months). In addition, a high density of LAG-3+CK- cells had a relatively longer ICI-PFS compared with other groups (P=0.01). In terms of total area, the pattern of densities of LAG-3+CK+ cells and LAG-3+CK- cells were similar to those in the tumor area In addition, ICI-PFS of LAG-3+CK- and LAG-3+CK+ cell densities in the total area was equal to that in the tumor area.DiscussionIn conclusion, our findings revealed tumor-intrinsic LAG-3 expression was the resistance mechanism toward PD-1/PD-L1 inhibitors in mTNBCs. Multivariate analysis also suggested that LAG-3 expression in tumor cells was an independent predictive biomarker.

Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). Materials and Methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45-65 Gy in 15--30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan--Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis- free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00-3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57-14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. Conclusion: In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients. [ABSTRACT FROM AUTHOR]

Abstract The achievement of the pathologic complete response (pCR) has been considered a metric for the success of neoadjuvant chemotherapy (NAC) and a powerful surrogate indicator of the risk of recurrence and long-term survival. This study aimed to develop a multimodal deep learning model that combined clinical information and pretreatment MR images for predicting pCR to NAC in patients with breast cancer. The retrospective study cohort consisted of 536 patients with invasive breast cancer who underwent pre-operative NAC. We developed a deep learning model to fuse high-dimensional MR image features and the clinical information for the pretreatment prediction of pCR to NAC in breast cancer. The proposed deep learning model trained on all datasets as clinical information, T1-weighted subtraction images, and T2-weighted images shows better performance with area under the curve (AUC) of 0.888 as compared to the model using only clinical information (AUC = 0.827, P

We developed a model for improving the prediction of survival outcome using postoperative Ki-67 value in combination with residual cancer burden (RCB) in patients with breast cancer (BC) who underwent neoadjuvant chemotherapy (NAC). We analyzed the data from BC patients who underwent NAC between 2010 and 2019 at Samsung Medical Center and developed our residual proliferative cancer burden (RPCB) model using semi-quantitative Ki-67 value and RCB class. The Cox proportional hazard model was used to develop our RPCB model according to disease free survival (DFS) and overall survival (OS). In total, 1,959 patients were included in this analysis. Of 1,959 patients, 905 patients were excluded due to RCB class 0, and 32 were due to a lack of Ki-67 data. Finally, an RPCB model was developed using data from 1,022 patients. The RPCB score was calculated for DFS and OS outcomes, respectively (RPCB-DFS and RPCB-OS). For further survival analysis, we divided the population into 3 classes according to the RPCB score. In the prediction of DFS, C-indices were 0.751 vs 0.670 and time-dependent areas under the receiver operating characteristic curves (AUCs) at 3-year were 0.740 vs 0.669 for RPCB-DFS and RCB models, respectively. In the prediction of OS, C-indices were 0.819 vs 0.720 and time-dependent AUCs at 3-year were 0.875 vs 0.747 for RPCB-OS and RCB models, respectively. The RPCB model developed using RCB class and semi-quantitative Ki-67 had superior predictive value for DFS and OS compared with that of RCB class. This prediction model could provide the basis to decide risk-stratified treatment plan for BC patients who had residual disease after NAC.

Background: The phase III MONALEESA-7 trial (NCT02278120) assessed ribociclib + endocrine therapy (ET) versus ET in premenopausal women with HR+/HER2− advanced breast cancer (ABC). The relationship between work productivity loss (WPL) and domains of European Organisation for Research and Treatment of Cancer Quality of Life (EORTC QLQ-C30) and the breast cancer (BC)-specific module (QLQ-BR23) has not been explored in ABC. In this post hoc analysis (data cutoff, November 30, 2018), we assessed the correlation between the WPL component of the Work Productivity and Activity Impairment: General Health (WPAI:GH) questionnaire and EORTC QLQ-C30/BR23 domains. Methods: We analyzed EORTC and WPAI:GH data from 329 patients in both treatment arms of MONALEESA-7 who were employed during the trial. Separate univariable mixed-model repeated measures (MMRM) regression models were fitted for each domain, with WPL as dependent variable and each EORTC domain score as a single fixed-effect covariate. Linear and quadratic relationships were considered based on the Akaike information criterion. Next, two separate multivariable MMRM regression models were fitted with WPL a dependent variable and all QLQ-C30/BR23 domain scores as fixed-effect covariates. The strength of correlation between WPL and EORTC domains was assessed in terms of minimally important differences for the QLQ-C30/BR23 modules. Results: Our univariable analysis showed that greater WPL was statistically significantly associated with lower levels of overall quality of life (QoL) and other functional domains and with higher levels of all symptomatic domains of the QLQ-C30/BR23 modules. Our multivariable analysis determined that this correlation was primarily driven by changes in QoL; physical, role, social, and future perspective domains; and BC-specific symptomatic domains. Conclusion: This analysis determined the QoL domains that correlate with WPL in premenopausal patients with HR+/HER2− ABC. These results may inform prognostic tools to identify and characterize patients with greater risk for WPL and help design interventional strategies to minimize WPL.

In this study, we evaluated clinical parameters to predict the primary resistance of palbociclib in combination with endocrine therapy as the first-line treatment in patients with hormone receptor (HR)+, human epidermal growth factor receptor 2 (HER2)- metastatic breast cancer (MBC). We performed a data analysis of patients diagnosed with HR+, HER2-MBC who received palbociclib plus letrozole as the first-line treatment in the metastatic setting from the clinical data warehouse in Samsung Medical Center. In this study, 305 patients were included in the final data analysis. The median follow-up duration was 31 months, and we observed 123 cases of disease progression. The median progression-free survival (PFS) was 28.7 months, and 38 patients (12.5%) had less than a 6-month PFS. The multivariate analysis suggested that primary resistance to adjuvant endocrine therapy (ET) (hazard ratio: 1.91), presence of liver metastasis (hazard ratio: 2.17), initial elevation of serum CA-15-3 (hazard ratio: 1.99), weak positivity of estrogen receptor (ER) (hazard ratio: 2.28), Ki-67 3+ or 4+ (hazard ratios: 2.58 and 10.28), and presence of mutation (hazard ratio: 9.59) were associated with a short PFS duration. A further prediction model was developed with data from 256 patients and 33 cases of disease progression in 6 months. This model included five factors—primary resistance to adjuvant ET (odds ratio, OR: 1.14), liver metastasis (OR: 1.56), initial CA-15-3 elevation (OR: 1.51), weak ER expression (OR: 2.22), and BRCA2 mutation (OR: 2.85)—and the area under the receiver operating characteristic curve was 0.842 (95% CI: 0.775, 0.909; p < 0.001). Finally, we divided them into four risk groups according to the prediction model with the five risk factors. These four groups had different PFS (p < 0.001) and primary resistance of palbociclib with letrozole [OR of group 2 vs. group 1 (ref): 2.18 (p = 0.002), OR of group 3: 3.91 (p < 0.001), and OR of group 4: 4.25 (p < 0.001)]. We developed a prediction model of primary resistance to palbociclib with letrozole as the first-line treatment for HR+, HER2-MBC. Our prediction model might be helpful for considering the first-line treatment strategies. Further well-designed clinical trials would be warranted to validate our prediction model.

Background/Aims We conducted a retrospective analysis of the clinical activity of fulvestrant in postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) previously treated with endocrine therapy and/or chemotherapy. Methods We reviewed the medical records of all patients with MBC treated at Samsung Medical Center between January 2009 and August 2016. Patients received fulvestrant 250 mg intramuscularly every 28 days (from January 2009 to November 2010) or 500 mg intramuscularly every 28 days (from December 2010 to August 2016). Tumor responses were assessed every 8 weeks and at the end of treatment, as well as when disease progression was suspected. Results A total of 84 patients were included in this study. A median of two previous endocrine treatments had been performed; 79% of the patients had received two or more endocrine treatments. Forty-five patients (54%) had been treated with chemotherapy for MBC before the fulvestrant treatment course. Visceral metastasis was found in 49 patients (58%). The estimated median progression-free survival and overall survival were 4.4 months (95% confidence interval [CI], 3.4 to 5.5) and 32.5 months (95% CI, 17.6 to 47.4), respectively. The disease control rate was 40.5% (95% CI, 30.5 to 51.5); partial response was observed in 16% of the patients and stable disease was observed in 25% of the patients. The most frequently reported adverse reactions were mild-to-moderate grade myalgia (10.5% of the patients), injection site pain (7%), and fatigue (7%). Fulvestrant was generally well tolerated. Conclusions Fulvestrant showed encouraging clinical activity and favorable feasibility in postmenopausal women with MBC who had been treated with multiple endocrine therapies and/or cytotoxic chemotherapies.

PURPOSE: We evaluated the clinical features and outcomes of invasive breast cancer (BC) among different age groups by analyzing a modern BC registry including subtypes and treatment information. METHODS: This was a retrospective cohort study of 6,405 women aged 18 years or older with pathologically confirmed stage I, II, or III BC who underwent curative surgery followed by adjuvant therapy at a university-based hospital in Seoul, South Korea, between January 2003 and December 2011. The study end point was all-cause mortality. We used Cox proportional hazards models and hazard ratios (HRs) with 95% CIs calculated after adjusting for age, body mass index, stage, subtype, and treatment, including type of surgery and use of chemotherapy, radiation therapy, hormone therapy, and targeted therapy. RESULTS: During 36,360 person-years of follow-up (median follow-up: 5.45 years; interquartile range, 4.3-7.1), 256 deaths were reported (mortality rate, 7.0/1,000 person-years). The adjusted HR for all-cause mortality was higher in patients older than 40 years (HR, 2.03; 95% CI, 1.44 to 2.87) and older than 60 years (HR, 2.35; 95% CI, 1.63 to 3.39) than in patients aged 40 to 49 years. Across age groups, advanced stage at diagnosis, luminal type as well as triple-negative BC, and not receiving adjuvant treatment were associated with increased risk of mortality. CONCLUSION: A strong J-shaped relationship was observed between age and mortality, indicating worse clinical outcomes in young and old patients. This study suggested a possible benefit of personalized BC screening examination and precise and active treatment strategies to reduce BC-related mortality.

Abstract Background The phase III EMILIA and TH3RESA trials demonstrated clinical benefits of trastuzumab emtansine (T-DM1) therapy in patients with previously treated HER2-positive metastatic breast cancer (MBC). Data from these and other trials showed that T-DM1–associated survival benefits were observed across biomarker subgroups tested in these trials. Prespecified, exploratory analyses of the phase III MARIANNE study examined the effects of HER2-related biomarkers on PFS in patients administered T-DM1 in the first-line MBC setting. Methods In MARIANNE, patients with previously untreated HER2-positive MBC were randomized (1:1:1) to trastuzumab plus taxane, T-DM1 plus placebo, or T-DM1 plus pertuzumab. Biomarker subgroups included HER2 and HER3 mRNA expression levels (≤median vs. >median), HER2 staining intensity (IHC 3+ vs. 2+ vs. 0/1+), PIK3CA status (mutated vs. non-mutated), PTEN H-score (≤median vs. >median), and PTEN protein expression level (0 vs. 1+ vs. 2+ vs. 3+ vs. 4+). PFS was analyzed descriptively for each subgroup using Kaplan–Meier methodology. Additional exploratory post-hoc analyses evaluated the effects of HER2 heterogeneity. Multivariate analyses were also performed. Results Median PFS was numerically longer for patients with HER2 mRNA levels >median versus ≤median across treatment arms. In general, there were no predictive biomarkers of benefit for either T-DM1 treatment arm; most hazard ratios were close to 1 with wide confidence intervals that included the value 1. Focal HER2 expression (IHC 3+ or IHC 2+) was present in 3.8% of patients and was associated with numerically shorter PFS in the T-DM1–containing treatment arms versus trastuzumab plus taxane. Compared with non-mutated PIK3CA, mutated PIK3CA was associated with numerically shorter median PFS across treatment groups. Post-hoc multivariate analysis showed HER2 mRNA expression and mutated PIK3CA were prognostic for PFS (P ≤ 0.001 for both biomarkers). Conclusions In MARIANNE, biomarkers related to the HER2 pathway did not have predictive value for PFS when comparing T-DM1 (with or without pertuzumab) with trastuzumab plus taxane. However, HER2 mRNA level and PIK3CA mutation status showed prognostic value. Evaluation of other potential biomarkers, including immune markers, is ongoing. Trial registration Registration number: NCT01120184. Date of registration: April 28, 2010 (registered prospectively).

PURPOSE: In PALOMA-2, palbociclib plus letrozole significantly improved progression-free survival (PFS) as initial treatment of estrogen receptor–positive/human epidermal growth factor receptor 2–negative advanced breast cancer. We assessed the benefit of palbociclib plus letrozole in Asians. PATIENTS AND METHODS: Of 666 enrolled postmenopausal women with estrogen receptor–positive/human epidermal growth factor receptor 2–negative advanced breast cancer (no prior treatment of advanced disease), 95 were Asian. Patients were randomly assigned 2:1 to receive palbociclib plus letrozole or placebo plus letrozole. The primary end point was investigator-assessed PFS. Secondary end points were overall survival, objective response, patient-reported outcomes, pharmacokinetics, and safety. RESULTS: Median PFS was significantly longer in Asian patients who received palbociclib plus letrozole versus placebo plus letrozole (25.7 months [95% CI, 19.2 months to not estimable] v 13.9 months [95% CI, 7.4 to 22.0 months]; hazard ratio, 0.48; 95% CI, 0.27 to 0.87; P = .007). The most common toxicities with palbociclib were hematologic and more frequent among Asians versus non-Asians: neutropenia (any grade, 95.4% v 76.8%; grade 3/4, 89.2% v 62.5%), leukopenia (43.1% v 38.3%; 32.3% v 23.5%), and thrombocytopenia (27.7% v 13.5%; 4.6% v 1.1%). No Asians had febrile neutropenia. Discontinuation rates as a result of adverse events were similar among Asian and non-Asian patients who received palbociclib plus letrozole (10.8% and 9.5%). In Asians, quality of life (QOL) was maintained with no significant differences observed between treatments from baseline in breast cancer–specific QOL and general health status scores. Change from baseline in EuroQol five dimensions index scores was significantly higher with palbociclib plus letrozole (0.013 v –0.069; P = .0132). Geometric mean palbociclib trough concentration values were higher in Asians versus non-Asians (93.8 v 61.7 ng/mL). CONCLUSION: Consistent with the overall study population, the addition of palbociclib to letrozole significantly improved PFS in Asians. Hematologic toxicities were more frequent in Asians versus non-Asians but manageable with early dose modifications while maintaining QOL.

Abstract Background A phase II clinical trial of the comparison between eribulin plus gemcitabine (EG) and paclitaxel plus gemcitabine (PG) as first-line chemotherapy for patients with metastatic breast cancer (MBC) found that the EG regimen was less neurotoxic, but was similar in efficacy to the PG regimen. In the present study, we analyzed functional assessment of cancer therapy-taxane (FACT-Taxane) questionnaires from patients in this clinical trial to determine their quality of life (QoL). Methods QoL was assessed using the Korean version of the FACT-Taxane questionnaires. After baseline assessment, QoL was assessed every 2 cycles for 12 cycles and every 3 cycles thereafter. The linear mixed model was used to evaluate the difference in QoL between the EG and PG arms. Results Of the 118 enrolled patients, 117 responded to the FACT-Taxane questionnaires at baseline, 1 in the PG arm did not. Baseline QoL scores were not different between the EG and PG arms. During treatment, taxane subscale scores were significantly higher in the PG arm than in the EG arm after 2–13 cycles of chemotherapy (all P

Abstract Background As a large-scale study of Koreans, we evaluated the association between BRCA mutation and the prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients. Methods We organized familial pedigrees of 2555 patients with breast cancer who underwent genetic screening for BRCA1/2 in Samsung Medical Center between January 2002 and May 2018. Families with a member that had a history of cancer other than of the breast or ovary were regarded positive for other primary cancer. Results The median age of the population was 40 years (range, 19 to 82 years). BRCA mutation was detected in 377 (14.8%) of the patients. The BRCA-positive group had a higher frequency of family history of breast or ovarian cancer (p

Abstract Background In this study, we observe the patterns initial palliative treatment for premenopausal patients with HR-positive/HER2-negative MBC and determine if nonadherence to clinical guidelines are associated with worse clinical outcomes in terms of progression-free survival (PFS) and overall survival (OS) in the South Korean population. Methods A retrospective review was performed for premenopausal patients diagnosed with HR-positive/HER2-negative MBC between October 1997 and May 2016 who received palliative systemic treatments at a large tertiary medical center. Survival outcomes were analyzed according to the palliative treatment received prior to disease progression. Results The review identified a total of 272 premenopausal patients meeting study criteria, whose median age was 39 years. Endocrine therapy was the initial treatment in 137 patients (Group 1) with chemotherapy as initial treatment in 135 patients. In the latter group, chemotherapy was continued in 78 patients (Group 2), whereas chemotherapy was switched to endocrine treatment in 57 patients prior to any disease progression (Group 3). Both PFS and OS were significantly longer for chemotherapy-endocrine therapy (median PFS 18.2 months and OS 85.2 months) than for chemotherapy-alone (median PFS 12.6 months and OS 45.5 months) or endocrine therapy-alone (median PFS 7.0 months and OS 57.3 months) (all p values

Several prognosis prediction models have been developed for breast cancer (BC) patients with curative surgery, but there is still an unmet need to precisely determine BC prognosis for individual BC patients in real time. This is a retrospectively collected data analysis from adjuvant BC registry at Samsung Medical Center between January 2000 and December 2016. The initial data set contained 325 clinical data elements: baseline characteristics with demographics, clinical and pathologic information, and follow-up clinical information including laboratory and imaging data during surveillance. Weibull Time To Event Recurrent Neural Network (WTTE-RNN) by Martinsson was implemented for machine learning. We searched for the optimal window size as time-stamped inputs. To develop the prediction model, data from 13,117 patients were split into training (60%), validation (20%), and test (20%) sets. The median follow-up duration was 4.7 years and the median number of visits was 8.4. We identified 32 features related to BC recurrence and considered them in further analyses. Performance at a point of statistics was calculated using Harrell's C-index and area under the curve (AUC) at each 2-, 5-, and 7-year points. After 200 training epochs with a batch size of 100, the C-index reached 0.92 for the training data set and 0.89 for the validation and test data sets. The AUC values were 0.90 at 2-year point, 0.91 at 5-year point, and 0.91 at 7-year point. The deep learning-based final model outperformed three other machine learning-based models. In terms of pathologic characteristics, the median absolute error (MAE) and weighted mean absolute error (wMAE) showed great results of as little as 3.5%. This BC prognosis model to determine the probability of BC recurrence in real time was developed using information from the time of BC diagnosis and the follow-up period in RNN machine learning model.

Background: The role of chemotherapy for isolated locoregional recurrence (iLRR) of breast cancer has not been firmly established after local therapies.Methods: We performed a multicenter, retrospective analysis to evaluate the clinical implications of chemotherapy in breast cancer patients with HER2-negative iLRR.Results: Of a total of 277 patients, 146 (52.7%) received chemotherapy for iLRR. Median follow-up duration was 56.1 months. Eighty-six (31.0%) patients had luminal B-like and 100 (36.1%) had TNBC iLRR. There was a trend of longer disease free survival (DFS) in the chemotherapy group (4-year DFS: 70.4 vs. 59.5%, HR = 0.68, 95% CI 0.45–1.02, log-rank p = 0.059). When adjusted with clinically relevant factors, DFS was significantly prolonged with chemotherapy (adjusted HR = 0.61, 95% CI 0.40–0.94, p = 0.023). Subgroup analyses for DFS showed patients with disease free interval (DFI)

Background: This analysis evaluated patient-reported outcomes (PROs) to assess health-related quality of life (HRQoL) in the phase III MONALEESA-7 trial, which previously demonstrated improvements in progression-free survival (PFS) and overall survival (OS) with ribociclib (cyclin-dependent kinase 4/6 inhibitor) + endocrine therapy (ET) compared with placebo + ET in pre- and perimenopausal patients with hormone-receptor-positive, HER2-negative (HR+/HER2−) advanced breast cancer (ABC). Methods: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life questionnaire C30 (QLQ-C30) and the EQ-5D-5L were used to evaluate HRQoL. Results: EORTC QLQ-C30 assessments were evaluable for 335 patients in the ribociclib arm and 337 patients in the placebo arm. Adherence rates at baseline and ⩾1 postbaseline time point were 90% and 83%, respectively. Patients treated with ribociclib + ET had a longer time to deterioration (TTD) ⩾ 10% in global HRQoL {hazard ratio (HR), 0.67 [95% confidence interval (CI), 0.52–0.86]}. TTD ⩾ 10% in global HRQoL was delayed in ribociclib-treated patients without versus with disease progression [HR, 0.31 (95% CI, 0.21–0.48)]. TTD ⩾ 10% in pain was longer with ribociclib + ET than with placebo + ET [HR, 0.65 (95% CI, 0.45–0.92)]. Patients who received a nonsteroidal aromatase inhibitor experienced similar benefits with ribociclib versus placebo in global HRQoL and pain. Conclusion: HRQoL was maintained longer in patients who received ribociclib + ET versus placebo + ET. These data, combined with previously reported improvements in PFS and OS, support a strong clinical benefit-to-risk ratio with ribociclib-based treatment in pre- and perimenopausal patients with HR+/HER2− ABC.

While breast cancer incidence in the Asia Pacific region is rising, the molecular basis remains poorly characterized. Here the authors perform genomic screening of 187 Korean breast cancer patients and find differences in molecular subtype distribution, mutation pattern and prevalence, and gene expression signature when compared to TCGA.

High-throughput sequencing is used to identify somatic variants in cancer patients. Here, the authors perform panel-based profiling of 5095 clinical samples and demonstrate that many clinically-actionable variants have low variant allele fractions, requiring assays with high detection sensitivity.

Purpose: To assess efficacy and safety of palbociclib plus fulvestrant in Asians with endocrine therapy–resistant metastatic breast cancer. Patients and Methods: The Palbociclib Ongoing Trials in the Management of Breast Cancer 3 (PALOMA-3) trial, a double-blind phase III study, included 521 patients with hormone receptor–positive/human epidermal growth factor receptor 2–negative metastatic breast cancer with disease progression on endocrine therapy. Patient-reported outcomes (PROs) were assessed on study treatment and at the end of treatment. Results: This preplanned subgroup analysis of the PALOMA-3 study included premenopausal and postmenopausal Asians taking palbociclib plus fulvestrant (n = 71) or placebo plus fulvestrant (n = 31). Palbociclib plus fulvestrant improved progression-free survival (PFS) compared with fulvestrant alone. Median PFS was not reached with palbociclib plus fulvestrant (95% CI, 9.2 months to not reached) but was 5.8 months with placebo plus fulvestrant (95% CI, 3.5 to 9.2 months; hazard ratio, 0.485; 95% CI, 0.270 to 0.869; P = .0065). The most common all-cause grade 3 or 4 adverse events in the palbociclib arm were neutropenia (92%) and leukopenia (29%); febrile neutropenia occurred in 4.1% of patients. Within-patient mean trough concentration comparisons across subgroups indicated similar palbociclib exposure between Asians and non-Asians. Global quality of life was maintained; no statistically significant changes from baseline were observed for patient-reported outcome scores with palbociclib plus fulvestrant. Conclusion: This is the first report, to our knowledge, showing that palbociclib plus fulvestrant improves PFS in asian patients. Palbociclib plus fulvestrant was well tolerated in this study.

Background Pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) has been associated with favorable clinical outcome in breast cancer patients. However, the possibility that the prognostic significance of pCR differs among various definitions has not been established. Methods We retrospectively evaluated the pathologic response after NAC in 353 breast cancer patients and compared the prognoses after applying the following different definitions of pCR: ypT0/is, ypT0, ypT0/is ypN0, and ypT0 ypN0. Results pCR was significantly associated with improved distant disease-free survival (DDFS) regardless of the definition (ypT0/is, p = .002; ypT0, p = .008; ypT0/is ypN0, p < .001; ypT0 ypN0, p = .003). Presence of tumor deposits of any size in the lymph nodes (LNs; ypN ≥ 0(i+)) was associated with worse DDFS (ypT0 ypN0 vs ypT0 ypN ≥ 0(i+), p = .036 and ypT0/is ypN0 vs ypT0/is ypN ≥ 0(i+), p = .015), and presence of isolated tumor cells was associated with decreased overall survival (OS; ypT0/is ypN0 vs ypT0/is ypN0(i+), p = .013). Residual ductal carcinoma in situ regardless of LN status showed no significant difference in DDFS or OS (DDFS: ypT0 vs ypTis, p = .373 and ypT0 ypN0 vs ypTis ypN0, p = .462; OS: ypT0 vs ypTis, p = .441 and ypT0 ypN0 vs ypTis ypN0, p = .758). In subsequent analysis using ypT0/is ypN0, pCR was associated with improved DDFS and OS in triple-negative tumors (p < .001 and p = .003, respectively). Conclusions Based on our study results, the prognosis and rate of pCR differ according to the definition of pCR and ypT0/is ypN0 might be considered a more preferable definition of pCR.

Genetic diagnosis for human epidermal growth factor receptor 2-negative metastatic breast cancer patients with the germline BRCA (gBRCA) mutation has been emphasized since the development of polyadenosine diphosphate-ribose polymerase inhibitors. Myriad Genetics, Inc.’s (Salt Lake City, UT, USA) companion diagnostics service is almost exclusively used for genetic testing. The aim of this study was to compare the results of germline BRCA mutation tests returned by a local laboratory and those performed by Myriad. Between April 2014 and February 2018, 31 patients with gBRCA 1/2 mutation test results from both Samsung Medical Center (Seoul, Korea) and Myriad were enrolled. “Discordant: Opposite classification” was observed for only one among 27 (3.7%). This discrepancy was due to the detection of a deleterious large genomic rearrangement of BRCA 1 by Myriad. Samsung Medical Center performed multiple ligation-dependent probe amplifications (MLPA) to detect large genomic rearrangements only in high-risk patients. This one case was not suspected as high risk and MLPA was not performed. The concordant rate was 74.1% for all 27 patients. “Discordant: Laboratory’s uncertain classification” was found in 22.2% of the sample (six patients). All discrepancies were generated during interpretation of BRCA 2 gene sequencing. Further studies and standardization of genetic testing for BRCA 1/2 genes are required.

Adipocytes are active sources of numerous adipokines that work in both a paracrine and endocrine manner. It is not known that the direct contact between tumor and neighboring fat measured by pretreatment breast magnetic resonance imaging (MRI) affects treatment outcomes to neoadjuvant chemotherapy (NAC) in breast cancer patients. A biomarker quantifying the tumor–fat interface volume from pretreatment MRI was proposed and used to predict pathologic complete response (pCR) in breast cancer patients treated with NAC. The tumor–fat interface volume was computed with data-driven clustering using multiphasic MRI. Our approach was developed and validated in two cohorts consisting of 1140 patients. A high tumor–fat interface volume was significantly associated with a non-pCR in both the development and validation cohorts (p = 0.030 and p = 0.037, respectively). Quantitative measurement of the tumor–fat interface volume based on pretreatment MRI may be useful for precision medicine and subsequently influence the treatment strategy of patients.

This study explored the clinical implications of tumor mutational burden (TMB) in a well-defined HER2-positive metastatic breast cancer (MBC) patient population who had been previously treated but had subsequent disease progression. Whole exome sequencing was performed on formalin-fixed paraffin-embedded tumor samples and matched normal tissue. Among the 46 patients, 13 (28.3%) were estrogen receptor-positive and nine (19.6%) were progesterone receptor-positive by immunohistochemistry analysis. Twenty patients (43.5%) had recurrent MBC compared with de novo MBC (n = 26, 56.5%). Sixteen patients (34.6%) demonstrated more than 100 somatic non-synonymous SNV mutations, which was predefined as a high TMB. The median follow-up duration was 57.5 months. The median overall survival (mOS) differed significantly between low and high TMB status (44.9 months vs. 85.8 months, respectively, p = 0.016). In a multivariate Cox regression analysis, TMB was the only independent prognostic factor for good metastatic overall survival after adjusting for age and recurrence (Hazard ratio [HR] = 0.32, 95% confidence interval [CI], 0.103–0.998, p = 0.049). These data suggest that high TMB may be a prognostic marker for predicting good overall survival for patients undergoing conventional HER2-directed treatments and chemotherapy. Further, future clinical trials harnessing TMB may benefit by identifying an appropriate population who may have a favorable response to immunotherapy after recurrence following HER2-directed treatments.

Following publication of the original article [1], the authors reported the following errors in the article.

Purpose This single-arm phase II trial investigate the efficacy and safety of S-1 plus oxaliplatin (SOX) in patients with metastatic breast cancer. Materials and Methods Patients with metastatic breast cancer previously treated with anthracyclines and taxanes were enrolled. Patients received S-1 (40-60 mg depending on patient's body surface area, twice a day, day 1-14) and oxaliplatin (130 mg/m², day 1) in 3 weeks cycle until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumor 1.1. Secondary endpoints included time-to-progression (TTP), duration-of-response (DoR), overall survival (OS), and adverse events. Results A total of 87 patients were enrolled from 11 institutions in Korea. Hormone receptor was positive in 54 (62.1%) patients and six (6.9%) had human epidermal growth factor receptor 2-positive disease. Forty-eight patients (85.1%) had visceral metastasis and 74 (55.2%) had more than three sites of metastases. The ORR of SOX regimen was 38.5% (95% confidence interval [CI], 26.9 to 50.0) with a median TTP of 6.0 months (95% CI, 5.1 to 6.9). Median DoR and OS were 10.3 months (95% CI, 5.5 to 15.1) and 19.4 (95% CI, not estimated) months, respectively. Grade 3 or 4 neutropenia was reported in 28 patients (32.1%) and thrombocytopenia was observed in 23 patients (26.6%). Conclusion This phase II study showed that SOX regimen is a reasonable option in metastatic breast cancer previously treated with anthracyclines and taxanes. [ABSTRACT FROM AUTHOR]

BACKGROUND:Metastatic breast cancer (MBC) remains a devastating and incurable disease. Over the past decade, the implementation of clinical trials both with and without molecular targeted therapeutics has impacted the daily clinical treatment of patients with MBC. In this study, we determine whether including MBC patients in clinical trials affects clinical outcomes. METHODS:We retrospectively reviewed data for a total of 863 patients diagnosed with initial or recurrent (after receiving adjuvant systemic treatments following surgery) metastatic disease between January 2000 and December 2013. Data were obtained from the breast cancer database of Samsung Medical Center. RESULTS:Among the 806 patients selected for inclusion, 188 (23%) had participated in clinical trials. A total of 185 clinical trials were conducted from 2000 to 2014. When compared with earlier periods (n = 10 for 2000-2004), clinical trial enrollment significantly increased over time (n = 103 for 2005-2009, P = 0.024; n = 110 for 2010-2014, P = 0.046). Multivariate analyses revealed that biologic subtype, distant recurrence free interval (DRFI), and clinical trial enrollment were independent predictors of overall survival. Patients who participated in clinical trials showed improved survival, with a hazard ratio of 0.75 (95% CI, 0.59-0.95), which was associated with a 25% reduction in the risk of death. However, subgroup analysis showed that this improved survival benefit was not maintained in patients with triple negative breast cancer (TNBC). CONCLUSIONS:Although not conclusive, we could speculate that there were differences in the use of newer agents or regimens over time, and these differences appear to be associated with improved survival.

The purpose of this study was to investigate the clinicopathologic features and prognostic factors affecting outcome in patients with isolated locoregional recurrence of breast cancer (ILRR).We retrospectively analyzed the medical records of 104 patients who were diagnosed with ILRR and underwent curative surgery from January 2000 to December 2010 at Samsung Medical Center.Among 104 patients, 43 (41%) underwent total mastectomy and 61 (59%) underwent breast-conserving surgery for primary breast cancer. The median time from initial operation to ILRR was 35.7 months (4.5-132.3 months). After diagnosis of ILRR, 45 (43%) patients were treated with mastectomy, 41 (39%) with excision of recurred lesion, and 18 (17%) with node dissection. During a median follow-up of 8.9 years, the 5-year overall survival was 77% and 5-year distant metastasis-free survival (DMFS) was 54%. On multivariate analysis, younger age (< 35 years), higher stage, early onset of elapse (≤ 24 months), lymph node recurrences, and subtype of triple negative breast cancer (TNBC) were found to be independently associated with DMFS. Patients in the no chemotherapy group showed a longer DMFS after surgery for ILRR than those treated with chemotherapy (median 101.5 vs. 48.0 months, p = 0.072) but without statistical significance.Our analysis showed that younger age (< 35 years), higher stage, early onset of relapse (≤ 24 months), lymph node recurrence, and subtype of TNBC are the worst prognostic factors for ILRR.

To investigate the combined prognostic impact of body mass index (BMI) and tumor standardized uptake value (SUV) measured on pretreatment 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in patients with breast cancer.We evaluated a cohort of 332 patients with newly diagnosed breast cancer (stage I-III) who underwent pretreatment FDG PET/CT followed by curative resection. Patients were categorized as overweight (BMI ≥ 23 kg/m2) or normal weight (BMI < 23 kg/m2). Primary tumor maximum SUV was measured by FDG PET/CT. Associations between BMI and tumor SUV with disease recurrence were assessed using Cox regression models.Median follow-up was 39 months. There were 76 recurrences and 15 cancer-related deaths. Multivariable Cox regression analysis demonstrated that high tumor SUV (hazard ratio [HR] = 1.75; 95% CI, 1.02-3.02; P = 0.044) and overweight (HR = 1.84; 95% CI, 1.17-2.89; P = 0.008) were independent poor prognostic factors. Positive hormone receptor status was an independent predictor of favorable outcome (HR = 0.42; 95% CI, 0.26-0.68; P < 0.001). Overweight patients with high tumor SUV had a two-fold risk of recurrence compared to patients with normal weight or low tumor SUV after adjusting for clinical stage and tumor subtype (HR = 2.06; 95% CI, 1.30-3.27; P = 0.002).In patients with breast cancer, higher tumor SUV was associated with a more adverse outcome particularly in overweight women. BMI status combined with tumor SUV data allows better risk-stratification of breast cancer, independent of clinical stage and tumor subtype.

Purpose Trastuzumab has markedly improved the survival outcomes of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer, and dual blockade of HER2 using trastuzumab and pertuzumab in combination with taxanes (THP) has become a standard of care for HER2-positive metastatic breast cancer (MBC) worldwide since the CLEOPATRA trial. We assessed the outcomes of THP as a first-line treatment for Korean HER2-positive MBC patients in the real-world setting. Materials and Methods Between August 2008 and October 2020, we identified 228 HER2-positive MBC patients who received THP as a first-line palliative chemotherapy. We analyzed survival outcomes, efficacy, and adverse events of THP retrospectively. Results After a median follow-up duration of 28.7 months, median overall survival and progression-free survival were 58.3 months (95% confidence interval [CI], 36.6 to 80.0) and 19.1 months (95% CI, 16.2 to 21.9), respectively. Better survival outcomes were observed in patient who received docetaxel for more than six cycles. Patients exposed to anti-HER2 directed therapies in a perioperative setting had poor survival outcomes. The overall response rate was 86.8% with a complete response (CR) rate of 17.7%. Among responders, 16.7% of patients sustained THP over 35 months and showed better survivals and higher CR rates. Adverse events were comparable to those reported in previous studies. Conclusion In a real-world context, clinical outcomes of Korean HER2-positive MBC patients treated with THP were similar to those of patients in the CLEOPATRA trial. Much longer follow-up results would be warranted. [ABSTRACT FROM AUTHOR]

Purpose Docetaxel/carboplatin/trastuzumab/pertuzumab (TCHP) regimen is frequently used to treat early and locally advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) in neoadjuvant setting. However, large-scaled real-world evidence did not exist. Materials and Methods We retrospectively reviewed medical records of patients with early or locally advanced HER2-positive BC who underwent neoadjuvant TCHP followed by curative surgery at Samsung Medical Center between January 2016 and August 2020. Results Of 447 patients, 316 (70.7%) received breast-conserving surgery and 131 (29.3%) received total mastectomy. In terms of neoadjuvant chemotherapy response, pathologic complete response (pCR) and residual cancer burden (RCB) score were analyzed. The rate of pCR was 64% a class of RCB 0 was observed in 65% of cases, RCB class I in 12%, RCB class II in 14%, and RCB class III in 2%. The 3-year event-free survival rate was 90.6%, BC with pCR occurred in 92.8%, and BC with non-pCR in 86.3% (p=0.016). In terms of distant metastasis, the 3-year distant recurrence-free survival rate was 93.5%; BC with pCR occurred in 95.9% and BC with non-pCR in 89.2% (p=0.013). Mucositis (85.2%), pain (83.2%), and diarrhea (70.5%) were the most common non-hematologic adverse events. In terms of hematologic adverse events, anemia (89.9%) was the most commonly observed adverse events followed by thrombocytopenia (29.8%). Conclusion Neoadjuvant TCHP therapy had a pCR rate of 64% and a 3-year event-free survival of 90% in real world experience. In terms of toxicity profile, anemia was frequently observed and adequate management including occasional transfusion was required. [ABSTRACT FROM AUTHOR]

As most erb-b2 receptor tyrosine kinase 2 (HER2)-positive breast cancer (BC) patients currently receive dual HER2-targeting added to neoadjuvant chemotherapy, improved methods for identifying individual response, and assisting postsurgical salvage therapy, are needed. Herein, we evaluated the 41-gene classifier trastuzumab advantage risk model (TRAR) as a predictive marker for patients enrolled in the NeoSphere trial. TRAR scores were computed from RNA of 350 pre- and 166 post-treatment tumor specimens. Overall, TRAR score was significantly associated with pathological complete response (pCR) rate independently of other predictive clinicopathological variables. Separate analyses according to estrogen receptor (ER) status showed a significant association between TRAR score and pCR in ER-positive specimens but not in ER-negative counterparts. Among ER-positive BC patients not achieving a pCR, those with TRARlow scores in surgical specimens showed a trend for lower distant eventfree survival. In conclusion, in HER2-positive/ER-positive BC, TRAR is an independent predictor of pCR and represents a promising tool to select patients responsive to anti-HER2-based neoadjuvant therapy and to assist treatment escalation and de-escalation strategies in this setting. [ABSTRACT FROM AUTHOR]