Circulating tumor cells and palbociclib treatment in patients with ER-positive, HER2-negative advanced breast cancer: results from a translational sub-study of the TREnd trial.

BACKGROUND: Circulating tumor cells (CTCs) are prognostic in patients with advanced breast cancer (ABC). However, no data exist about their use in patients treated with palbociclib. We analyzed the prognostic role of CTC counts in patients enrolled in the cTREnd study, a pre-planned translational sub-study of TREnd (NCT02549430), that randomized patients with ABC to palbociclib alone or palbociclib plus the endocrine therapy received in the prior line of treatment. Moreover, we evaluated RB1 gene expression on CTCs and explored its prognostic role within the cTREnd subpopulation. METHODS: Forty-six patients with ER-positive, HER2-negative ABC were analyzed. Blood samples were collected before starting palbociclib treatment (timepoint T0), after the first cycle of treatment (timepoint T1), and at disease progression (timepoint T2). CTCs were isolated and counted by CellSearch® System using the CellSearch™Epithelial Cell kit. Progression-free survival (PFS), clinical benefit (CB) during study treatment, and time to treatment failure (TTF) after study treatment were correlated with CTC counts. Samples with ≥ 5 CTCs were sorted by DEPArray system® (DA). RB1 and GAPDH gene expression levels were measured by ddPCR. RESULTS: All 46 patients were suitable for CTCs analysis. CTC count at T0 did not show significant prognostic value in terms of PFS and CB. Patients with at least one detectable CTC at T1 (n = 26) had a worse PFS than those with 0 CTCs (n = 16) (p = 0.02). At T1, patients with an increase of at least three CTCs showed reduced PFS compared to those with no increase (mPFS = 3 versus 9 months, (p = 0.004). Finally, patients with ≥ 5 CTCs at T2 (n = 6/23) who received chemotherapy as post-study treatment had a shorter TTF (p = 0.02). Gene expression data for RB1 were obtained from 19 patients. CTCs showed heterogeneous RB1 expression. Patients with detectable expression of RB1 at any timepoint showed better, but not statistically significant, outcomes than those with undetectable levels. CONCLUSIONS: CTC count seems to be a promising modality in monitoring palbociclib response. Moreover, CTC count at the time of progression could predict clinical outcome post-palbociclib. RB1 expression analysis on CTCs is feasible and may provide additional prognostic information. Results should be interpreted with caution given the small studied sample size.

Comparative effectiveness of first-line palbociclib plus letrozole versus letrozole alone for HR+/HER2- metastatic breast cancer in US real-world clinical practice.

BACKGROUND: Findings from randomized clinical trials may have limited generalizability to patients treated in routine clinical practice. This study examined the effectiveness of first-line palbociclib plus letrozole versus letrozole alone on survival outcomes in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor-negative (HER2-) metastatic breast cancer (MBC) treated in routine clinical practice in the USA. PATIENTS AND METHODS: This was a retrospective observational analysis of electronic health records within the Flatiron Health Analytic Database. A total of 1430 patients with ≥ 3 months of follow-up received palbociclib plus letrozole or letrozole alone in the first-line setting between February 3, 2015, and February 28, 2019. Stabilized inverse probability treatment weighting (sIPTW) was used to balance baseline demographic and clinical characteristics. Real-world progression-free survival (rwPFS) and overall survival (OS) were analyzed. RESULTS: After sIPTW adjustment, median follow-up was 24.2 months (interquartile range [IQR], 14.2-34.9) in the palbociclib group and 23.3 months (IQR, 12.7-34.3) in those taking letrozole alone. Palbociclib combination treatment was associated with significantly longer median rwPFS compared to letrozole alone (20.0 vs 11.9 months; hazard ratio [HR], 0.58; 95% CI, 0.49-0.69; P < 0.0001). Median OS was not reached in the palbociclib group and was 43.1 months with letrozole alone (HR, 0.66; 95% CI, 0.53-0.82; P = 0.0002). The 2-year OS rate was 78.3% in the palbociclib group and 68.0% with letrozole alone. A propensity score matching analysis showed similar results. CONCLUSIONS: In this "real-world" population of patients with HR+/HER2- MBC, palbociclib in combination with endocrine therapy was associated with improved survival outcomes compared with patients treated with letrozole alone in the first-line setting. TRIAL REGISTRATION: Clinicaltrials.gov; NCT04176354.

Correlation between modified Magee equation-2 and Oncotype-Dx recurrence scores using both traditional and TAILORx cutoffs and the clinical application of the Magee Decision Algorithm: a single institutional review.

BACKGROUND: Oncotype Dx (ODX) is used to predict recurrence risk for estrogen-positive (ER +), HER2-negative and lymph node negative breast cancer, however, due to the cost its use may be limited in low-resource areas. The aim of this study is to assess the concordance between the modified Magee Equation-2 (MME-2) and ODX recurrence scores (RS). The secondary aim is to apply the Magee Decision Algorithm (MDA) using the MME-2 to determine which patients are unlikely to benefit from ODX testing. METHODS: All newly diagnosed ER + , HER2 negative, lymph node negative breast cancer patients with available ODX-RS from 2008-2018 were included. The original pathology reports were reviewed and chart review was performed. The MME-2 scores were calculated and correlated with the ODX-RS. The MDA was applied to our cohort to assess which patients would not benefit from ODX testing. RESULTS: A total of 579 patients were included. There was an overall moderate correlation between ODX-RS and MME-2 score (Pearson correlation coefficient = 0.635). The overall concordance between ODX and MME-2 scores was similar when using both the traditional and TAILORx cutoffs (63.3% vs. 63.7%, respectively). Applying the MDA, for patients with MME-2 scores < 18, 96.8% of patients had the expected ODX-RS of < 25. For patients with MME-2 RS > 30, 90% had the expected ODX-RS of > 25. Concordance was highest in the high-risk category using both cutoffs. For patients with MME-2 18-25 and a mitotic score of 1, 88.8% had the expected ODX-RS of > 25. CONCLUSION: There is a moderate correlation between MME-2 score and ODX-RS. The overall concordance was similar for both traditional and TAILORx cutoffs. The strongest concordance was found in the high-risk category for both cutoffs. The MME-2 can be used to identify patients unlikely to benefit from ODX testing using the MDA.

Analysis of subsequent therapy in Japanese patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative advanced breast cancer who received palbociclib plus endocrine therapy in PALOMA-2 and -3.

BACKGROUND: In the double-blind, phase 3 PALOMA-2 and PALOMA-3 studies, palbociclib plus endocrine therapy (ET) demonstrated significant improvement in progression-free survival versus placebo plus ET in patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative advanced breast cancer. This analysis assessed subsequent treatment patterns after palbociclib therapy in Japanese patients enrolled in the PALOMA-2 and PALOMA-3 studies. METHODS: PALOMA-2 included postmenopausal women who had not received prior systemic therapy for advanced disease. PALOMA-3 included pre- or postmenopausal women who had progressed on previous ET. Types of subsequent therapy were assessed, and treatment durations of subsequent therapy were estimated using the Kaplan-Meier method. RESULTS: Japanese patients were enrolled in PALOMA-2 (n = 46) and PALOMA-3 (n = 35). In both studies, the most common first subsequent therapy was ET (PALOMA-2, 77% in the palbociclib group and 75% in the placebo group; PALOMA-3, 55% and 43%, respectively), followed by chemotherapy (PALOMA-2, 18% and 8%; PALOMA-3, 32% and 57%). The median (95% CI) duration of first subsequent therapy was 6.4 (2.3‒13.9) months with palbociclib plus letrozole and 6.7 (2.8‒13.0) months with placebo plus letrozole in PALOMA-2 and 3.8 (2.4‒5.7) months with palbociclib plus fulvestrant and 9.7 (1.0‒not estimable) months with placebo plus fulvestrant in PALOMA-3. CONCLUSIONS: The types of first subsequent therapy received by Japanese patients in the palbociclib plus ET and placebo plus ET groups were similar. Further evaluation of subsequent therapy data in the real-world setting is warranted considering the small sample size of this analysis.

Relationships of physical and breast cancer phenotypes with three single-nucleotide polymorphisms (rs2046210, rs3757318, and rs3803662) associated with breast cancer risk in Japanese women.

BACKGROUND: Recent genome-wide association studies have shown that many single-nucleotide polymorphisms (SNPs) are associated with breast cancer risk. However, it is often unclear how these SNPs are related to breast cancer. Analysis of associations between SNPs and phenotypes may be important for determining mechanisms of action, including carcinogenesis. METHODS: In previous case-control studies, we found three SNPs (rs2046210, rs3757318, and rs3573318) associated with breast cancer risk in Japanese women. Among these SNPs, two (rs2046210 and rs3757318) are located at 6q25.1, in proximity to the estrogen receptor 1 gene (ESR1). Using data from these studies, we examined associations between factors related to breast cancer risk, such as height, weight, and breast density, and the three SNPs in cases and controls. We also investigated whether the SNPs correlated with breast cancer features, such as estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor type-2 (HER2) status, and clinical stage. RESULTS: There was a significant difference in mean height between risk and non-risk allele carriers for rs2046210 (156.0 ± 5.8 vs. 154.3 ± 5.5 cm, p = 0.002), and rs3757318 (155.8 ± 5.7 vs. 154.7 ± 5.6 cm, p = 0.035) in cases, but no significant associations between height and these SNPs in controls. There was also a significant difference in breast density between risk and non-risk allele carriers for rs2046210 (p = 0.040) and rs3757318 (p = 0.044) in cases. rs2046210 and rs3757318 risk allele carriers tended to have higher breast density in all subjects and in controls. In cases, rs3757318 risk allele carriers were also significantly more likely to be ER-negative compared to non-risk allele carriers (ER-positive rate: 77% vs. 84%, p = 0.036). CONCLUSIONS: SNPs rs2046210 and rs3757318, which are associated with breast cancer risk in Japanese women, were significantly associated with height and high breast density, and this association was particularly strong in those with breast cancer. These findings suggest that SNPs in the ESR1 gene region affect phenotypes such as height and breast density.

Loss of HER2 and decreased T-DM1 efficacy in HER2 positive advanced breast cancer treated with dual HER2 blockade: the SePHER Study.

BACKGROUND: HER2-targeting agents have dramatically changed the therapeutic landscape of HER2+ advanced breast cancer (ABC). Within a short time frame, the rapid introduction of new therapeutics has led to the approval of pertuzumab combined with trastuzumab and a taxane in first-line, and trastuzumab emtansine (T-DM1) in second-line. Thereby, evidence of T-DM1 efficacy following trastuzumab/pertuzumab combination is limited, with data from some retrospective reports suggesting lower activity. The purpose of the present study is to investigate T-DM1 efficacy in pertuzumab-pretreated and pertuzumab naïve HER2 positive ABC patients. We also aimed to provide evidence on the exposure to different drugs sequences including pertuzumab and T-DM1 in HER2 positive cell lines. METHODS: The biology of HER2 was investigated in vitro through sequential exposure of resistant HER2 + breast cancer cell lines to trastuzumab, pertuzumab, and their combination. In vitro experiments were paralleled by the analysis of data from 555 HER2 + ABC patients treated with T-DM1 and evaluation of T-DM1 efficacy in the 371 patients who received it in second line. Survival estimates were graphically displayed in Kaplan Meier curves, compared by log rank test and, when possibile, confirmed in multivariate models. RESULTS: We herein show evidence of lower activity of T-DM1 in two HER2+ breast cancer cell lines resistant to trastuzumab+pertuzumab, as compared to trastuzumab-resistant cells. Lower T-DM1 efficacy was associated with a marked reduction of HER2 expression on the cell membrane and its nuclear translocation. HER2 downregulation at the membrane level was confirmed in biopsies of four trastuzumab/pertuzumab-pretreated patients. Among the 371 patients treated with second-line T-DM1, median overall survival (mOS) from diagnosis of advanced disease and median progression-free survival to second-line treatment (mPFS2) were 52 and 6 months in 177 patients who received trastuzumab/pertuzumab in first-line, and 74 and 10 months in 194 pertuzumab-naïve patients (p = 0.0006 and 0.03 for OS and PFS2, respectively). CONCLUSIONS: Our data support the hypothesis that the addition of pertuzumab to trastuzumab reduces the amount of available plasma membrane HER2 receptor, limiting the binding of T-DM1 in cancer cells. This may help interpret the less favorable outcomes of second-line T-DM1 in trastuzumab/pertuzumab pre-treated patients compared to their pertuzumab-naïve counterpart.

Nutritional combinatorial impact on the gut microbiota and plasma short-chain fatty acids levels in the prevention of mammary cancer in Her2/neu estrogen receptor-negative transgenic mice.

Breast cancer is the second leading cause of cancer-related mortality in women. Various nutritional compounds possess anti-carcinogenic properties which may be mediated through their effects on the gut microbiota and its production of short-chain fatty acids (SCFAs) for the prevention of breast cancer. We evaluated the impact of broccoli sprouts (BSp), green tea polyphenols (GTPs) and their combination on the gut microbiota and SCFAs metabolism from the microbiota in Her2/neu transgenic mice that spontaneously develop estrogen receptor-negative [ER(-)] mammary tumors. The mice were grouped based on the dietary treatment: control, BSp, GTPs or their combination from beginning in early life (BE) or life-long from conception (LC). We found that the combination group showed the strongest inhibiting effect on tumor growth volume and a significant increase in tumor latency. BSp treatment was integrally more efficacious than the GTPs group when compared to the control group. There was similar clustering of microbiota of BSp-fed mice with combination-fed mice, and GTPs-fed mice with control-fed mice at pre-tumor in the BE group and at pre-tumor and post-tumor in the LC group. The mice on all dietary treatment groups incurred a significant increase of Adlercreutzia, Lactobacillus genus and Lachnospiraceae, S24-7 family in the both BE and LC groups. We found no change in SCFAs levels in the plasma of BSp-fed, GTPs-fed and combination-fed mice of the BE group. Marked changes were observed in the mice of the LC group consisting of significant increases in propionate and isobutyrate in GTPs-fed and combination-fed mice. These studies indicate that nutrients such as BSp and GTPs differentially affect the gut microbial composition in both the BE and LC groups and the key metabolites (SCFAs) levels in the LC group. The findings also suggest that temporal factors related to different time windows of consumption during the life-span can have a promising influence on the gut microbial composition, SCFAs profiles and ER(-) breast cancer prevention.

Downregulated METTL14 Expression Correlates with Breast Cancer Tumor Grade and Molecular Classification.

It is unclear whether the methyltransferase-like 14 (METTL14) protein promotes or suppresses cancer growth. We examined the association between METTL14 expression, cancer progression, and patient prognosis in a total of 398 breast cancer tissue specimens. Significantly fewer cancer tissue specimens compared with normal breast tissue expressed high levels of METTL14 (52.8% vs. 75.0%). METTL14 expression was negatively associated with tumor grade and positively associated with patient age, estrogen, and progesterone receptor status. High METTL14 expression was more common in luminal A and luminal B tissue (75.9% and 60.8%, respectively), compared with human epidermal growth factor receptor 2- (HER2-) enriched and triple-negative breast cancer (TNBC) samples (38.2% and 18.6%, respectively). In multiple logistic regression analysis, independent predictors of METTL14 expression in breast cancer included higher tumor grade (odds ratio (OR) = 0.494, 95% confidence interval (CI): 0.289-0.844; P = 0.010), TNBC subtype (OR = 0.109, 95% CI: 0.054-0.222; P < 0.001), and HER2-enriched subtype (OR = 0.298, 95% CI: 0.156-0.567; P < 0.001). No clear relationship was observed between patient prognosis and METTL14 expression. It appears that downregulated METTL14 expression in breast cancer is associated with tumor grade and molecular classification.

Human leucocyte antigen class I in hormone receptor-positive, HER2-negative breast cancer: association with response and survival after neoadjuvant chemotherapy.

BACKGROUND: Clinical application of cancer immunotherapy requires a better understanding of tumor immunogenicity and the tumor microenvironment. HLA class I molecules present antigens to CD8+ cytotoxic cells. Their loss or downregulation is frequently found in tumors resulting in reduced T cell responses and worse prognosis. METHODS: We evaluated HLA class I heavy chain expression by immunohistochemistry in 863 biopsies (GeparTrio trial). Patients received neoadjuvant chemotherapy and adjuvant endocrine treatment if tumors were hormone receptor-positive (HR+). In parallel, the expression of HLA-A was analyzed using a microarray cohort of 320 breast cancer patients from the MD Anderson Cancer Center. We evaluated its association with clinical outcome, tumor-infiltrating lymphocytes (TILs), and immune cell metagenes. RESULTS: In HR+/HER2- breast cancer, HLA class I heavy chain expression was associated with increased TILs and better response to chemotherapy (7% vs. 14% pCR rate, P = 0.029), but worse disease-free survival (hazard ratio (HR) 1.6 (1.1-2.4); P = 0.024). The effect was significant in a multivariate model adjusted for clinical and pathological variables (HR 1.7 (1.1-2.6); P = 0.016) and was confirmed by analysis of HLA-A in a microarray cohort. HLA-A was correlated to most immune cell metagenes. There was no association with response or survival in triple-negative or HER2+ disease. CONCLUSIONS: The study confirms the negative prognostic role of lymphocytes in HR+ breast cancer and points at a complex interaction between chemotherapy, endocrine treatment, and tumor immunogenicity. The results point at a subtype-specific and potentially treatment-specific role of tumor-immunological processes in breast cancer with different implications in triple-negative and hormone receptor-positive disease.

Dynamics of breast-cancer relapse reveal late-recurring ER-positive genomic subgroups.

The rates and routes of lethal systemic spread in breast cancer are poorly understood owing to a lack of molecularly characterized patient cohorts with long-term, detailed follow-up data. Long-term follow-up is especially important for those with oestrogen-receptor (ER)-positive breast cancers, which can recur up to two decades after initial diagnosis1-6. It is therefore essential to identify patients who have a high risk of late relapse7-9. Here we present a statistical framework that models distinct disease stages (locoregional recurrence, distant recurrence, breast-cancer-related death and death from other causes) and competing risks of mortality from breast cancer, while yielding individual risk-of-recurrence predictions. We apply this model to 3,240 patients with breast cancer, including 1,980 for whom molecular data are available, and delineate spatiotemporal patterns of relapse across different categories of molecular information (namely immunohistochemical subtypes; PAM50 subtypes, which are based on gene-expression patterns10,11; and integrative or IntClust subtypes, which are based on patterns of genomic copy-number alterations and gene expression12,13). We identify four late-recurring integrative subtypes, comprising about one quarter (26%) of tumours that are both positive for ER and negative for human epidermal growth factor receptor 2, each with characteristic tumour-driving alterations in genomic copy number and a high risk of recurrence (mean 47-62%) up to 20 years after diagnosis. We also define a subgroup of triple-negative breast cancers in which cancer rarely recurs after five years, and a separate subgroup in which patients remain at risk. Use of the integrative subtypes improves the prediction of late, distant relapse beyond what is possible with clinical covariates (nodal status, tumour size, tumour grade and immunohistochemical subtype). These findings highlight opportunities for improved patient stratification and biomarker-driven clinical trials.

Cost-effectiveness of bevacizumab plus paclitaxel versus paclitaxel for the first-line treatment of HER2-negative metastatic breast cancer in specialist oncology centers in France.

BACKGROUND: Evidence from clinical trials suggests that the addition of bevacizumab to chemotherapy in the first-line treatment of patients with HER2-negative metastatic breast cancer improves progression-free survival (PFS) but not overall survival (OS). However, a retrospective analysis of real-world data from the French Comprehensive Cancer Centers (FCCC) through the Epidemiological Strategy and Medical Economics (ESME) Research Program, suggested that in this setting, the addition of bevacizumab may confer a significant benefit in terms of both PFS and OS. A cost-effectiveness analysis was performed to determine the cost-effectiveness of bevacizumab plus paclitaxel versus paclitaxel alone in the first-line treatment of HER2-negative metastatic breast cancer at specialist oncology centers in France. METHODS: The analysis was performed using a three-state Markov model and clinical input data from N = 3426 HER2-negative metastatic breast cancer patients treated with bevacizumab plus paclitaxel or paclitaxel alone. The analysis was performed from a third party payer perspective over a 10-year time horizon; future costs and clinical outcomes were discounted at 4% per annum. RESULTS: In the overall population, the addition of bevacizumab to paclitaxel led to incremental gain of 0.72 life years and 0.48 quality-adjusted life years (QALYs) relative to paclitaxel alone. The incremental lifetime cost of the addition of bevacizumab was EUR 27,390, resulting in an incremental cost-effectiveness ratio (ICER) of EUR 56,721 per QALY gained for bevacizumab plus paclitaxel versus paclitaxel alone. In a subgroup of triple negative patients the ICER was EUR 66,874 per QALY gained. CONCLUSIONS: The analysis indicated that the combination of bevacizumab plus paclitaxel is likely to be cost-effective compared with paclitaxel alone for the first-line treatment of HER2-negative metastatic breast cancer in specialized oncology centers in France.

Metformin plus chemotherapy versus chemotherapy alone in the first-line treatment of HER2-negative metastatic breast cancer. The MYME randomized, phase 2 clinical trial.

PURPOSE: To investigate the efficacy of metformin (M) plus chemotherapy versus chemotherapy alone in metastatic breast cancer (MBC). METHODS: Non-diabetic women with HER2-negative MBC were randomized to receive non-pegylated liposomal doxorubicin (NPLD) 60 mg/m2 + cyclophosphamide (C) 600 mg/m2 × 8 cycles Q21 days plus M 2000 mg/day (arm A) versus NPLD/C (arm B). The primary endpoint was progression-free survival (PFS). RESULTS: One-hundred-twenty-two patients were evaluable for PFS. At a median follow-up of 39.6 months (interquartile range [IQR] 24.6-50.7 months), 112 PFS events and 71 deaths have been registered. Median PFS was 9.4 months (95% CI 7.8-10.4) in arm A and 9.9 (95% CI 7.4-11.5) in arm B (P = 0.651). In patients with HOMA index < 2.5, median PFS was 10.4 months (95% CI 9.6-11.7) versus 8.5 (95% CI 5.8-9.7) in those with HOMA index ≥ 2.5 (P = 0.034). Grade 3/4 neutropenia was the most common toxicity, occurring in 54.4% of arm A patients and 72.3% of the arm B group (P = 0.019). M induced diarrhea (G2) was observed in 8.8% of patients in Arm A. The effect of M was similar in patients with HOMA index < 2.5 and ≥ 2.5, for PFS and OS. CONCLUSIONS: The MYME trial failed to provide evidence in support of an anticancer activity of M in combination with first line CT in MBC. A significantly shorter PFS was observed in insulin-resistant patients (HOMA ≥ 2.5). Noteworthy, M had a significant effect on CT induced severe neutropenia. Further development of M in combination with CT in the setting of MBC is not warranted.

Abemaciclib: a CDK4/6 inhibitor for the treatment of HR+/HER2- advanced breast cancer.

Although early breast cancer (BC) is highly curable, advanced or metastatic disease poses numerous challenges in terms of medical management and treatment decisions and is associated with significantly worse prognosis. Among the new targeted agents, anticancer drugs exploiting the cell-cycle machinery have shown great potential in preclinical studies. CDK4/6 inhibitors target the cyclin D/CDK/retinoblastoma signaling pathway, inducing cell-cycle arrest, reduced cell viability and tumor shrinking. As the cyclin D/CDK complex is activated downstream of estrogen signaling, the combination of CDK4/6 inhibitors with standard endocrine therapies represents a rational approach to elicit synergic antitumor activity in hormone receptor-positive BC. The results of clinical trials have indeed confirmed the superiority of the combination of CDK4/6 inhibitors plus endocrine therapies over endocrine therapy alone. Currently approved are three compounds that exhibit similar structural characteristics as well as biological and clinical activities. Abemaciclib is the latest CDK4/6 inhibitor approved by the US Food and Drug Administration (FDA) in view of the results of the MONARCH 1 and 2 trials. Further trials are ongoing as other important questions await response. In this review, we focus on abemaciclib to examine preclinical and clinical results, describing current therapeutic indications, open questions and ongoing clinical trials.

The Application of Non-Invasive Apoptosis Detection Sensor (NIADS) on Histone Deacetylation Inhibitor (HDACi)-Induced Breast Cancer Cell Death.

Breast cancer is the most common malignancy in women and the second leading cause of cancer death in women. Triple negative breast cancer (TNBC) subtype is a breast cancer subset without ER (estrogen receptor), PR (progesterone receptor) and HER2 (human epidermal growth factor receptor 2) expression, limiting treatment options and presenting a poorer survival rate. Thus, we investigated whether histone deacetylation inhibitor (HDACi) could be used as potential anti-cancer therapy on breast cancer cells. In this study, we found TNBC and HER2-enriched breast cancers are extremely sensitive to Panobinostat, Belinostat of HDACi via experiments of cell viability assay, apoptotic marker identification and flow cytometry measurement. On the other hand, we developed a bioluminescence-based live cell non-invasive apoptosis detection sensor (NIADS) detection system to evaluate the quantitative and kinetic analyses of apoptotic cell death by HDAC treatment on breast cancer cells. In addition, the use of HDACi may also contribute a synergic anti-cancer effect with co-treatment of chemotherapeutic agent such as doxorubicin on TNBC cells (MDA-MB-231), but not in breast normal epithelia cells (MCF-10A), providing therapeutic benefits against breast tumor in the clinic.

Chemosensitivity to doxorubicin of ER-positive/HER2-negative breast cancers with high 21-gene recurrence score: A study based on in vitro chemoresponse assay.

AIM: The 21-gene recurrence score (RS) predicts a clinical benefit of chemotherapy for individuals with ER-positive/HER2-negative breast cancer. Using in vitro chemoresponse assay, we compared the chemosensitivity according to RS in these patients. METHOD: Among the patients with Oncotype Dx assay, we identified 63 patients who had chemotherapy response assays to doxorubicin based on adenosine triphosphate. The degree of chemosensitivity to doxorubicin was translated into the cell death rate (CDR). The RS was also dichotomized with a cutoff of 26. RESULTS: Of 63 patients, 34 (54%), 17 (27%), and 12 patients (19%) had a low, intermediate, and high RS, respectively. The mean CDR differed significantly according to categorized RS, with 17.3±10.8 in the low RS group vs. 23.6±16.3 in the intermediate RS group vs. 28.8±12.6 in the high RS group (P = 0.024, One-way ANOVA test). The mean CDR was significantly higher in the higher RS (26≥) group compared with the lower RS (<26) group (P = 0.025, the Student's t-test), as well as in the high RS (>30) group compared with the low RS (<18) group (P = 0.012, the Student's t-test). Also, continuous RS and CDR correlated positively (Pearson's R = 0.337; P = 0.007). High RS demonstrated the odds ratio (OR = 26.33; 95% CI = 1.69-410.0) for predicting tumors with chemosensitivity on the multivariate analysis. CONCLUSIONS: The chemosensitivity measured by in vitro chemoresponse assay was different according to the RS. Our findings support that tumors with high RS has the chemosensitivity even though they are luminal/HER2-negative tumors.

CRISPR-assisted receptor deletion reveals distinct roles for ERBB2 and ERBB3 in skin keratinocytes.

While the epidermal growth factor receptor (EGFR) is an established regulator of skin development and homeostasis, the functions of the related tyrosine kinase receptors ERBB2 and ERBB3 in this tissue have only recently been examined. Previously reported, skin-specific deletion of each of these receptors in mice resulted in similar defects in keratinocyte proliferation and migration, resulting in impaired wound healing and tumorigenesis. Because both ERBB2 and ERBB3 are targets for treating an array of cancer types, it is important to examine the consequences of receptor inhibition in human keratinocytes. Here, we employed the CRISPR/Cas9 technology to generate HaCaT cells (an established human keratinocyte cell line) lacking ERBB2 or ERBB3. HaCaT clones lacking ERBB2 or ERBB3 showed comparable reductions in cell proliferation as assessed by BrdU staining. Apoptosis, in contrast, was reduced in ERBB3-deficient HaCaT cells only. Assessment of cell migration using a wound healing (scratch) assay showed that the closure of the wound gaps was completed by 48 h in mock and in ERBB3 knockout clones. In contrast, this process was considerably delayed in ERBB2 knockout clones, and a complete closure of the gap in the latter cells did not occur before 72 h. In conclusion, both ERBB2 and ERBB3 are essential for normal proliferation of skin keratinocytes, but in contrast to ERBB3, ERBB2 is essential for migration of human keratinocytes. These observations might bear significance to patient adverse effects of therapeutic agents targeting ERBB2 and ERBB3.

Capecitabine and cisplatin (XP) combination systemic chemotherapy in heavily pre-treated HER2 negative metastatic breast cancer.

PURPOSE/OBJECTIVE(S): After taxane and anthracycline failure, no standard chemotherapy regimen is established in metastatic breast cancer (MBC). Capecitabine and cisplatin (XP) combination shows promising results in gastrointestinal cancer, but there are relatively scarce data in MBC. We reviewed the clinical outcome of XP regimen in anthracycline and taxane resistant, heavily pretreated MBC patients. MATERIALS/METHODS: Between Jan. 2010 to Feb. 2016, 48 HER2 negative MBC patients who failed anthracycline and taxane based chemotherapy were enrolled. In 43.8% of patients, more than 4 regimens were administrated before XP. Thirty-four patients (70.8%) were hormone receptor (HR) positive MBC. Patients were treated with XP (capecitabine [2000mg/m2 per oral; day 1-14] plus cisplatin [60mg/m2 IV; day 1], every 3 weeks) regimen. RESULTS: Median progression-free survival (PFS) in total population was 4.33 months (range 1.1~33.57 months). HR positive patients showed trends for superior PFS compared to triple negative breast cancer (TNBC), without statistical significance (6.53 vs. 3.83 months, P = 0.168). In HR positive group, patients receiving 3 or less lines of chemotherapy showed superior PFS compared to others (10.1 vs. 3.0 months, P = 0.039). In multivariate analysis, HR positive patients receiving 3 or less lines of regimens still showed superior PFS (HR = 2.624, 95% CI; 1.071~6.43, P = 0.032). Most common toxicity was grade 3-4 neutropenia, without treatment-related deaths. CONCLUSIONS: XP combination regimen showed clinical benefit with tolerable toxicity in heavily pretreated patients, including HR positive patients. After anthracycline and taxane failure, early administration of XP regimen in selected patients may have improve clinical outcome in breast cancer.

Annexin A2 and its downstream IL-6 and HB-EGF as secretory biomarkers in the differential diagnosis of Her-2 negative breast cancer.

Background AnnexinA2 (AnxA2) membrane deposition has a critical role in HB-EGF shedding as well as IL-6 secretion in breast cancer cells. This autocrine cycle has a major role in cancer cell proliferation, migration and metastasis. The objective of the study is to demonstrate annexinA2-mediated autocrine regulation via HB-EGF and IL-6 in Her-2 negative breast cancer progression. Methods Secretory annexinA2, HB-EGF and IL-6 were analysed in the peripheral blood sample of Her-2 negative ( n = 20) and positive breast cancer patients ( n = 16). Simultaneously, tissue expression was analysed by immunohistochemistry. The membrane deposition of these secretory ligands and their autocrine regulation was demonstrated using triple-negative breast cancer cell line model. Results Annexina2 and HB-EGF expression are inversely correlated with Her-2, whereas IL-6 expression is seen in both Her-2 negative and positive breast cancer cells. RNA interference studies and upregulation of annexinA2 proved that annexinA2 is the upstream of this autocrine pathway. Abundant soluble serum annexinA2 is secreted in Her-2 negative breast cancer (359.28 ± 63.73 ng/mL) compared with normal (286.10 ± 70.04 ng/mL, P < 0.01) and Her-2 positive cases (217.75 ± 60.59 ng/mL, P < 0.0001). In Her-2 negative cases, the HB-EGF concentrations (179.16 ± 118.81 pg/mL) were highly significant compared with normal (14.92 ± 17.33 pg/mL, P < 0.001). IL-6 concentrations were increased significantly in both the breast cancer phenotypes as compared with normal ( P < 0.001). Conclusion The specific expression pattern of annexinA2 and HB-EGF in triple-negative breast cancer tissues, increased secretion compared with normal cells, and their major role in the regulation of EGFR downstream signalling makes these molecules as a potential tissue and serum biomarker and an excellent therapeutic target in Her-2 negative breast cancer.

Both bulk and cancer stem cell subpopulations in triple-negative breast cancer are susceptible to Wnt, HDAC, and ERα coinhibition.

Development of targeted therapies for triple-negative breast cancer (TNBC, a more aggressive subtype) is an unmet medical need. We analyzed data from 887 patients with invasive breast cancer and observed that increased Wnt and histone deacetylase (HDAC) activities are associated with estrogen receptor 1 (ESR1) and progesterone receptor (PGR) repression, poor survival, and increased relapse. The inverse correlation between Wnt signaling and repression of ESR1 and PGR expression was found to be magnified in cancer stem cell (CSC) subpopulations in TNBC cell lines. Cosuppression of Wnt, HDAC, and ESR1 using clinically relevant low-dose inhibitors effectively repressed both bulk and CSC subpopulations and converted CSCs to non-CSCs in TNBC cells without affecting MCF-10A mammary epithelial cells.