First-Line (1L) Treatment Decision Patterns and Survival of Hormone Receptor (HR)-Positive/HER2-Negative Advanced Breast Cancer (ABC) Patients in a Latin American (LATAM) Public Institution

Advanced breast cancer is an incurable disease, with a median overall survival of 3 years, including in countries without access problems. Although chemotherapy is reserved in some cases, it is still used in many countries as a first-line therapy. The aim of our study is to evaluate the first-line treatment choices and the factors that influence therapeutic decisions. A retrospective analysis was conducted of hormone receptor (+)/HER2 (-) advanced breast cancer patients classified into three groups according to the first-line and second-line treatment received: endocrine therapy-chemotherapy, endocrine therapy-endocrine therapy and chemotherapy-endocrine therapy. Additionally, we explored the overall survival of sequencing therapy groups. First-line chemotherapy was chosen in 34% of patients. Also, around 60% of our patients met the "aggressive disease" criteria from the RIGHT Choice trial, justifying the use of chemotherapy in a population with poor prognosis. Furthermore, de novo and progressive disease were prognostic factors that influenced the use of chemotherapy as a first-line treatment. Regarding overall survival, the sequencing treatment groups in this trial saw an increase in survival compared with patients of the MONALEESA trials (endocrine therapy alone arms). No significant differences in progression-free survival or overall survival were found in the treatment sequencing groups. There was a higher use of chemotherapy as a first-line therapy, with de novo and "aggressive disease" criteria being the main factors to influence the decision.

Final Results of RIGHT Choice: Ribociclib Plus Endocrine Therapy Versus Combination Chemotherapy in Premenopausal Women With Clinically Aggressive Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer

PURPOSE

A head-to-head comparison of efficacy between a cyclin-dependent kinase 4/6 inhibitor plus endocrine therapy (ET) versus combination chemotherapy (CT) has never been reported in patients with clinically aggressive hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC).

METHODS

In this open-label, multicenter, randomized phase II trial, pre/perimenopausal women with clinically aggressive HR+/HER2- ABC were randomly assigned 1:1 to first-line ribociclib (600 mg once daily; 3 weeks on, 1 week off) plus letrozole/anastrozole and goserelin or investigator's choice of combination CT (docetaxel plus capecitabine, paclitaxel plus gemcitabine, or capecitabine plus vinorelbine). The primary end point was progression-free survival (PFS).

RESULTS

Among 222 patients randomly assigned to ribociclib plus ET (n = 112) or combination CT (n = 110), 150 (67.6%) had symptomatic visceral metastases, 41 (18.5%) had rapid disease progression per investigator's judgment, and 31 (14.0%) had symptomatic nonvisceral disease. Overall, 106 (47.7%) patients had investigator-assessed visceral crisis. The median follow-up time was 37.0 months. At data cutoff, 31.3% (ribociclib arm) and 15.5% (CT arm) of patients had completed study treatment and transitioned to post-trial access. The median PFS was 21.8 months (ribociclib plus ET; [95% CI, 17.4 to 26.7]) and 12.8 months (combination CT; [95% CI, 10.1 to 18.4); hazard ratio, 0.61 [95% CI, 0.43 to 0.87]; P = .003. The overall response rates and the median time to response in the ribociclib versus CT arms, respectively, were 66.1% and 61.8% and 4.9 months and 3.2 months (hazard ratio, 0.76 [95% CI, 0.55 to 1.06]). Lower rates of symptomatic adverse events were observed in the ribociclib versus CT arm.

CONCLUSION

First-line ribociclib plus ET showed a significant PFS benefit, similar response rates, and better tolerability over combination CT in patients with clinically aggressive HR+/HER2- ABC.

Visceral crisis in metastatic breast cancer: an old concept with new perspectives

Visceral Crisis (VC) in breast cancer is a critical scenario when the burden of metastatic disease results in rapid deterioration of organ functions. There are no widely accepted objective clinical criteria for the definition of VC, and different studies have reported diverse clinical conditions such as visceral crises. Diagnosis of VC is associated with a dismal prognosis and the management of this condition is currently based on limited retrospective evidence and expert opinions. International guidelines have recommended cytotoxic polychemotherapy in the management of VC, to achieve rapid symptomatic control and preserve organ function. Nevertheless, in the case of hormone receptor-positive breast cancer, the role of chemotherapy as the treatment of choice for VC has been recently questioned, since endocrine therapy plus CDK4/6 inhibitors yielded similar response rates, with better quality of life. For HER2-positive and triple-negative breast cancer, combined chemotherapy (plus HER2-directed therapy for HER2-positive) remains a standard option for VC, but novel effective drugs such as antibody-drug conjugates are emerging and their role in the VC context shall soon be elucidated. This review aims to critically discuss the definition, prognosis, management, and future directions regarding the visceral crisis in metastatic breast cancer.

Oestrogen receptor low positive breast cancer: associations with prognosis

PURPOSE

In this study of oestrogen receptor (ER) Low Positive breast cancers (BC) in three large cohorts of BC patients, we assess associations between levels of ER expression and tumour characteristics and prognosis.

METHODS

Cases were stratified into patients unlikely to have received adjuvant therapy according to treatment guidelines at time of diagnosis (before 1995), and those who could have received adjuvant therapy (diagnosed in 1995 or later). ER status was divided into < 1%; ≥ 1 < 10%; ≥ 10%. Results were correlated with time of diagnosis, histopathological grade, proliferation status, and molecular subtypes, using Pearson's Chi-square test. For prognosis, hazard ratios and cumulative incidence of death from BC were used.

RESULTS

Of the 1955 tumours, 65 (3.3%) were ER Low Positive (ER ≥ 1 < 10%). Overall, the highest proportion of ER Low Positive tumours was observed among Luminal B (HER2 +) subtype (9.4%) and grade 3 tumours (4.3%). The risk of death from BC was lower in ER Low Positive and ER ≥ 10% compared to ER-negative cases. Compared to patients diagnosed before 1995, women diagnosed in 1995 or later showed a higher proportion of ER Low Positive BCs, and their tumours were of smaller size, lower grade, and lower proliferative status. There was no significant difference in prognosis compared to those with ER ≥ 10% tumours.

CONCLUSION

Women with ER Low Positive tumours diagnosed in a time period when adjuvant therapy was available had tumours of smaller size, lower grade, and lower proliferative status, and similar prognosis to those with ER ≥ 10% compared to women diagnosed earlier.

The Present and Future of Clinical Management in Metastatic Breast Cancer

Regardless of the advances in our ability to detect early and treat breast cancer, it is still one of the common types of malignancy worldwide, with the majority of patients decease upon metastatic disease. Nevertheless, due to these advances, we have extensively characterized the drivers and molecular profiling of breast cancer and further dividing it into subtypes. These subgroups are based on immunohistological markers (Estrogen Receptor-ER; Progesterone Receptor-PR and Human Epidermal Growth Factor Receptor 2-HER-2) and transcriptomic signatures with distinct therapeutic approaches and regiments. These therapeutic approaches include targeted therapy (HER-2+), endocrine therapy (HR+) or chemotherapy (TNBC) with optional combination radiotherapy, depending on clinical stage. Technological and scientific advances in the identification of molecular pathways that contribute to therapy-resistance and establishment of metastatic disease, have provided the rationale for revolutionary targeted approaches against Cyclin-Dependent Kinases 4/6 (CDK4/6), PI3 Kinase (PI3K), Poly ADP Ribose Polymerase (PARP) and Programmed Death-Ligand 1 (PD-L1), among others. In this review, we focus on the comprehensive overview of epidemiology and current standard of care treatment of metastatic breast cancer, along with ongoing clinical trials. Towards this goal, we utilized available literature from PubMed and ongoing clinical trial information from clinicaltrials.gov to reflect the up to date and future treatment options for metastatic breast cancer.

Experimental models of endocrine responsive breast cancer: strengths, limitations, and use

Breast cancers characterized by expression of estrogen receptor-alpha (ER; ESR1) represent approximately 70% of all new cases and comprise the largest molecular subtype of this disease. Despite this high prevalence, the number of adequate experimental models of ER+ breast cancer is relatively limited. Nonetheless, these models have proved very useful in advancing understanding of how cells respond to and resist endocrine therapies, and how the ER acts as a transcription factor to regulate cell fate signaling. We discuss the primary experimental models of ER+ breast cancer including 2D and 3D cultures of established cell lines, cell line- and patient-derived xenografts, and chemically induced rodent models, with a consideration of their respective general strengths and limitations. What can and cannot be learned easily from these models is also discussed, and some observations on how these models may be used more effectively are provided. Overall, despite their limitations, the panel of models currently available has enabled major advances in the field, and these models remain central to the ability to study mechanisms of therapy action and resistance and for hypothesis testing that would otherwise be intractable or unethical in human subjects.

Locoregional therapy in de novo metastatic breast cancer: Systemic review and meta-analysis

BACKGROUND

Locoregional therapy (LRT) in de novo metastatic disease is controversial with inconsistent results from randomized control trials (RCTs).

METHODS

RCTs comparing LRT and systemic therapy to standard therapy alone in de novo metastatic breast cancer were identified. Hazard ratios (HRs) and their associated 95% confidence intervals (CIs) were computed and pooled in a meta-analysis using generic inverse variance. Overall survival (OS) and time to locoregional progression data were extracted for the intention to treat (ITT) population. Data on OS for pre-specified subgroups defined by tumor subtype and by site of metastases were also extracted.

RESULTS

Analyses included 4 trials comprising 970 patients. LRT included standard surgery to the primary breast tumor in all studies, and adjuvant radiation per standard of care was required in 3 studies. Compared to standard treatment, LRT was not associated with improved OS in the ITT population (HR 0.97, 95% CI 0.72-1.29, p = 0.81). However, LRT was associated with improved time to locoregional progression (HR 0.36, 95% CI 0.14-0.95, p = 0.04). LRT was not associated with improved OS in any tumor subtypes, including hormone receptor positive (HR 0.96, 95% CI 0.65-1.43), triple negative (HR 1.4, 95% CI 0.50-3.91) and human epidermal growth factor receptor 2 positive disease (HR 0.93, 95% CI 0.68-1.28). Additionally, LRT did not improve OS in bone only disease (HR 0.97, 95% CI 0.58-1.62) and in visceral disease (HR = 1.02, 95% CI 0.77-1.35). Our critical appraisal has identified some methodological problems in the design and conduct of the studies included that could affect the meta-analysis result.

CONCLUSIONS

LRT in de novo metastatic breast cancer is not associated with improved OS. Results are consistent among different breast cancer subgroups. However, this conclusion should be interpreted with caution in view of the limitations identified in meta-analysis.

The Signal Transducer IL6ST (gp130) as a Predictive and Prognostic Biomarker in Breast Cancer

Novel biomarkers are needed to continue to improve breast cancer clinical management and outcome. IL6-like cytokines, whose pleiotropic functions include roles in many hallmarks of malignancy, rely on the signal transducer IL6ST (gp130) for all their signalling. To date, 10 separate independent studies based on the analysis of clinical breast cancer samples have identified IL6ST as a predictor. Consistent findings suggest that IL6ST is a positive prognostic factor and is associated with ER status. Interestingly, these studies include 4 multigene signatures (EndoPredict, EER4, IRSN-23 and 42GC) that incorporate IL6ST to predict risk of recurrence or outcome from endocrine or chemotherapy. Here we review the existing evidence on the promising predictive and prognostic value of IL6ST. We also discuss how this potential could be further translated into clinical practice beyond the EndoPredict tool, which is already available in the clinic. The most promising route to further exploit IL6ST's promising predicting power will likely be through additional hybrid multifactor signatures that allow for more robust stratification of ER+ breast tumours into discrete groups with distinct outcomes, thus enabling greater refinement of the treatment-selection process.

Lineage-specific mechanisms and drivers of breast cancer chemoresistance revealed by 3D biomimetic culture

To improve the success rate of current preclinical drug trials, there is a growing need for more complex and relevant models that can help predict clinical resistance to anticancer agents. Here, we present a three‐dimensional (3D) technology, based on biomimetic collagen scaffolds, that enables the modeling of the tumor hypoxic state and the prediction of in vivo chemotherapy responses in terms of efficacy, molecular alterations, and emergence of resistance mechanisms. The human breast cancer cell lines MDA‐MB‐231 (triple negative) and MCF‐7 (luminal A) were treated with scaling doses of doxorubicin in monolayer cultures, 3D collagen scaffolds, or orthotopically transplanted murine models. Lineage‐specific resistance mechanisms were revealed by the 3D tumor model. Reduced drug uptake, increased drug efflux, and drug lysosomal confinement were observed in triple‐negative MDA‐MB‐231 cells. In luminal A MCF‐7 cells, the selection of a drug‐resistant subline from parental cells with deregulation of p53 pathways occurred. These cells were demonstrated to be insensitive to DNA damage. Transcriptome analysis was carried out to identify differentially expressed genes (DEGs) in treated cells. DEG evaluation in breast cancer patients demonstrated their potential role as predictive biomarkers. High expression of the transporter associated with antigen processing 1 (TAP1) and the tumor protein p53‐inducible protein 3 (TP53I3) was associated with shorter relapse in patients affected by ER⁺ breast tumor. Likewise, the same clinical outcome was associated with high expression of the lysosomal‐associated membrane protein 1 LAMP1 in triple‐negative breast cancer. Hypoxia inhibition by resveratrol treatment was found to partially re‐sensitize cells to doxorubicin treatment. Our model might improve preclinical in vitro analysis for the translation of anticancer compounds as it provides: (a) more accurate data on drug efficacy and (b) enhanced understanding of resistance mechanisms and molecular drivers.

In-Vitro Application of Magnetic Hybrid Niosomes: Targeted siRNA-Delivery for Enhanced Breast Cancer Therapy

Even though the administration of chemotherapeutic agents such as erlotinib is clinically established for the treatment of breast cancer, its efficiency and the therapy outcome can be greatly improved using RNA interference (RNAi) mechanisms for a combinational therapy. However, the cellular uptake of bare small interfering RNA (siRNA) is insufficient and its fast degradation in the bloodstream leads to a lacking delivery and no suitable accumulation of siRNA inside the target tissues. To address these problems, non-ionic surfactant vesicles (niosomes) were used as a nanocarrier platform to encapsulate Lifeguard (LFG)-specific siRNA inside the hydrophilic core. A preceding entrapment of superparamagnetic iron-oxide nanoparticles (FexOy-NPs) inside the niosomal bilayer structure was achieved in order to enhance the cellular uptake via an external magnetic manipulation. After verifying a highly effective entrapment of the siRNA, the resulting hybrid niosomes were administered to BT-474 cells in a combinational therapy with either erlotinib or trastuzumab and monitored regarding the induced apoptosis. The obtained results demonstrated that the nanocarrier successfully caused a downregulation of the LFG gene in BT-474 cells, which led to an increased efficacy of the chemotherapeutics compared to plainly added siRNA. Especially the application of an external magnetic field enhanced the internalization of siRNA, therefore increasing the activation of apoptotic signaling pathways. Considering the improved therapy outcome as well as the high encapsulation efficiency, the formulated hybrid niosomes meet the requirements for a cost-effective commercialization and can be considered as a promising candidate for future siRNA delivery agents.

Association of Sperm-Associated Antigen 5 and Treatment Response in Patients With Estrogen Receptor-Positive Breast Cancer

Importance

There is no proven test that can guide the optimal treatment, either endocrine therapy or chemotherapy, for estrogen receptor-positive breast cancer.

Objective

To investigate the associations of sperm-associated antigen 5 (SPAG5) transcript and SPAG5 protein expressions with treatment response in systemic therapy for estrogen receptor-positive breast cancer.

Design, Settings, and Participants

This retrospective cohort study included patients with estrogen receptor-positive breast cancer who received 5 years of adjuvant endocrine therapy with or without neoadjuvant anthracycline-based combination chemotherapy (NACT) derived from 11 cohorts from December 1, 1986, to November 28, 2019. The associations of SPAG5 transcript and SPAG5 protein expression with pathological complete response to NACT were evaluated, as was the association of SPAG5 mRNA expression with response to neoadjuvant endocrine therapy. The associations of distal relapse-free survival with SPAG5 transcript or SPAG5 protein expressions were analyzed. Data were analyzed from September 9, 2015, to November 28, 2019.

Main Outcomes and Measures

The primary outcomes were breast cancer-specific survival, distal relapse-free survival, pathological complete response, and clinical response. Outcomes were examined using Kaplan-Meier, multivariable logistic, and Cox regression models.

Results

This study included 12 720 women aged 24 to 78 years (mean [SD] age, 58.46 [12.45] years) with estrogen receptor-positive breast cancer, including 1073 women with SPAG5 transcript expression and 361 women with SPAG5 protein expression of locally advanced disease stage IIA through IIIC. Women with SPAG5 transcript and SPAG5 protein expressions achieved higher pathological complete response compared with those without SPAG5 transcript or SPAG5 protein expressions (transcript: odds ratio, 2.45 [95% CI, 1.71-3.51]; P < .001; protein: odds ratio, 7.32 [95% CI, 3.33-16.22]; P < .001). Adding adjuvant anthracycline chemotherapy to adjuvant endocrine therapy for SPAG5 mRNA expression in estrogen receptor-positive breast cancer was associated with prolonged 5-year distal relapse-free survival in patients without lymph node involvement (hazard ratio, 0.34 [95% CI, 0.14-0.87]; P = .03) and patients with lymph node involvement (hazard ratio, 0.35 [95% CI, 0.18-0.68]; P = .002) compared with receiving 5-year endocrine therapy alone. Mean (SD) SPAG5 transcript was found to be downregulated after 2 weeks of neoadjuvant endocrine therapy compared with pretreatment levels in 68 of 92 patients (74%) (0.23 [0.18] vs 0.34 [0.24]; P < .001).

Conclusions and Relevance

These findings suggest that SPAG5 transcript and SPAG5 protein expressions could be used to guide the optimal therapies for estrogen receptor-positive breast cancer. Retrospective and prospective clinical trials are warranted.

Third Line Eribulin for Triple-negative Metastatic Breast Ductal Carcinoma Resulting in Extended Progression-free Survival of 57 Months

Eribulin is a non-taxane microtubule inhibitor approved for the treatment of metastatic breast carcinoma after two prior chemotherapeutic regimens. We report a patient with extended progression-free survival (PFS) of more than 57 months with metastatic breast carcinoma treated with eribulin in the third-line setting. A 48-year-old lady was diagnosed with stage IIA (pT2N0M0), high grade, triple-negative, invasive ductal carcinoma (IDC) of the left breast on core needle biopsy. She underwent neoadjuvant chemotherapy with adriamycin, and cyclophosphamide followed by a negative sentinel lymph node (SLN) biopsy. Subsequent mastectomy and axillary lymph node dissection revealed a 2.5 cm, high grade, triple-negative IDC with three additional lymph nodes negative for metastatic carcinoma, consistent with the initial diagnosis. Eight months into the surveillance program, the patient developed a 2.8 cm right lower lobe (RLL) lung mass with standard uptake value (SUV) of 27 on positron emission tomography-computed tomography (PET/CT). Core needle biopsy of the lung lesion revealed sheets of poorly differentiated carcinoma, immunophenotypically compatible with the initial diagnosis of breast pathology. She then commenced single-agent paclitaxel in the 1st line metastatic setting with a significant decrease in RLL lung mass to less than 1 cm with an SUV of 1.7 noted. The patient developed progression after seven months and started 2nd line gemcitabine noting initial improvement and subsequent stable disease for a period of 12 months. Eventual progression of RLL lung nodule measuring 2.1 cm with SUV of 10 noted. Initiated 3rd line eribulin with a notable response on imaging studies within three months and with no evidence of disease (NED) on scans over the subsequent 57 months. Eribulin related mild neuropathy superimposed on previous paclitaxel associated grade 2 neuropathy required a 20% eribulin dose reduction. The patient is currently clinically and radiographically stable with plateaued serum tumor markers. Our patient has shown excellent response and tolerance to eribulin with PFS of over 57 months (nineteen times the norm) which is rare.

Baseline circulating stem-like cells predict survival in patients with metastatic breast Cancer

Background

Circulating tumor cells (CTCs) are associated with breast cancer prognosis. Research is limited regarding the role of circulating cancer stem-like cells (cCSCs) considering the treatment response and survival among patients with metastatic breast cancer. Accordingly, we performed this prospective study to clarify the prognostic significance of baseline cCSCs for metastatic breast cancer in terms of first-line chemotherapy.

Methods

Between April 2014 and January 2016, we prospectively enrolled 48 patients with stage IV breast invasive ductal carcinoma who underwent first-line chemotherapy. We identified and analyzed CTCs and cCSCs by using a protocol based on negative selection and flow cytometry before chemotherapy. CTCs were identified as EpCAM⁺Hoechst⁺CD45^– cells and cCSCs as CD133⁺EpCAM⁺Hoechst⁺CD45^– cells. cCSCs were expressed as a percentage of CTCs. The associations between CTCs, cCSCs, and the clinicopathological variables that were predictive of the treatment response and survival outcome were analyzed using univariate and multivariate analyses.

Results

We identified CTCs in all the enrolled patients, with a median number of 33.9/mL CTCs. CSCs were isolated in 97.9% of the patients; the median percentage of cCSCs was 14.7%. A high baseline level of cCSCs was correlated with an inferior tumor response rate (54.2% vs. 95.8%, p < 0.001), overall survival (OS; median: 27.7 months vs. not reached, p < 0.001), and progression-free survival (PFS; median: 5.7 vs. 18.0 months, p < 0.001). Multivariate analysis revealed that along with other clinical variables, baseline cCSCs remained an independent prognostic factor for OS and PFS.

Conclusions

Baseline cCSCs predict the treatment response as well as survival in patients with metastatic breast cancer undergoing first-line chemotherapy. Therefore, the measurement of cCSCs may assist in identifying early cancer treatment response and prognosis.

Differential Expression of HSP90β in MDA-MB-231 and MCF-7 Cell Lines after Treatment with Doxorubicin

Background

Breast cancer is a complex, heterogeneous disease and one of the most common malignancies in women worldwide. The efficacy of chemotherapy as an important breast cancer treatment option has been severely limited because of the inherent or acquired resistance of cancer cells. The molecular chaperone heat shock protein 90 (HSP90) upregulated in response to cellular stress is required for functions such as conformational maturation, activation and stability in more than 200 client proteins, mostly of the signaling type. In this study, the expression of HSP90 isoforms including HSP90α and HSP90β in breast cancer cell lines before and after treatment with doxorubicin (DOX) was assessed.

Material and Methods

The cell cytotoxicity of DOX in MDA-MB-231 and MCF-7 cell lines was determined using the MTT assay. Immunofluorescence and western blotting techniques were used to determine the expression of HSP90β in the cell lines before and after DOX treatment. Immunofluorescence was also conducted to ascertain the expression of HSP90α.

Results

The MTT assay results showed that the MDA-MB- 231 cells (IC₅₀=14.521 μM) were more sensitive than the MCF-7 cells (IC₅₀=16.3315 μM) to DOX. The immunofluorescence results indicated that the expression of HSP90α in both cell lines decreased after exposure to DOX. The western blot and immunofluorescence analyses showed that HSP90β expression decreased in the MCF-7 cells but increased in the MDA-MB- 231 cells after DOX treatment. Conclusion: The obtained results suggested that HSP90α and HSP90β expression levels were reduced in the MCF-7 cells after exposure to DOX. In the MDA-MB-231 cells, HSP90α expression was reduced while HSP90β was found to be overexpressed following DOX treatment.

Palbociclib and endocrine therapy in heavily pretreated hormone receptor-positive HER2-negative advanced breast cancer: the UK Compassionate Access Programme experience

PURPOSE

Palbociclib is approved in 1st line for hormone receptor (HR)-positive HER2-negative advanced breast cancer (ABC). A Compassionate Access Programme previously allowed patients to receive it in 4th line. However, Palbociclib has not been specifically tested in this population. We aimed to determine the safety and efficacy profile of Palbociclib within the Programme across ten institutions in the United Kingdom.

METHODS

We retrospectively identified HR-positive HER2-negative ABC patients on the Programme between December 2015 and September 2017. Demographics, disease characteristics, prior treatments, blood tests, toxicities, treatment delays and responses were recorded. Simple statistics, Fisher's exact test, χ² method and Cox regression were used.

RESULTS

118 patients identified had a median age of 59. 82.2% were postmenopausal and 92.4% performance status 0-1. 81.4% had visceral involvement and 6.8% bone-only disease after a median of 5 prior treatments and 3 prior chemotherapies. Clinical benefit rate was 47.5%, overall response rate 15.8%, median PFS 4.5 months and median OS 15.8 months. Longer progression-free survival on prior endocrine therapy was a predictor of longer PFS and OS. 89.7% developed neutropenia (grade ≥ 3 in 56.8%). 5.1% experienced febrile neutropenia. 48.3% had dose reductions and 3.4% discontinued Palbociclib following toxicity. No statistically significant difference in grade ≥ 3 neutropenia was observed according to metastatic sites nor previous treatments.

CONCLUSIONS

This is the most extensive analysis of palbociclib in ≥ 4th-line setting. Clinical benefit was confirmed particularly for endocrine-sensitive, predominantly bony disease and in earlier lines of treatment. Safety was similar to PALOMA trials with higher febrile neutropenia rate.

The Difference in Prognostic Outcomes Between De Novo Stage IV and Recurrent Metastatic Patients with Hormone Receptor-positive, HER2-negative Breast Cancer

BACKGROUND/AIM

Patients with de novo stage IV and recurrent metastatic breast cancer are often treated with the same strategies, although the difference in prognostic outcomes remains unclear. The objective of this retrospective chart review study was to compare the prognostic outcomes between two types of patients with hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer.

PATIENTS AND METHODS

We estimated overall survival of the two groups and evaluated the progressive course of the disease using disease-free interval (DFI) and interval from the end of adjuvant treatment to the first recurrence (AFI).

RESULTS

We studied 172 patients with HR+/HER2- breast cancer, of which 65 were de novo and 107 were recurrent. Median OS between de novo and recurrent BC was 4.85 and 3.45 years, respectively (p=0.046). Recurrent patients with a DFI<2 years were found to have a significantly poorer prognosis than recurrent patients with a DFI≥2 years (p=0.016) and de novo patients (p=0.002). Similarly, recurrent patients with an AFI<1 year had a significantly poorer prognosis compared to de novo patients (p=0.026).

CONCLUSION

De novo patients had better prognoses than recurrent patients with DFI<2 years or AFI<1 year, likely due to their therapy-naïve status or lower resistance to systemic treatment.

Long-term exposure to estrogen enhances chemotherapeutic efficacy potentially through epigenetic mechanism in human breast cancer cells

Chemotherapy is the most common clinical option for treatment of breast cancer. However, the efficacy of chemotherapy depends on the age of breast cancer patients. Breast tissues are estrogen responsive and the levels of ovarian estrogen vary among the breast cancer patients primarily between pre- and post-menopausal age. Whether this age-dependent variation in estrogen levels influences the chemotherapeutic efficacy in breast cancer patients is not known. Therefore, the objective of this study was to evaluate the effects of natural estrogen 17 beta-estradiol (E2) on the efficacy of chemotherapeutic drugs in breast cancer cells. Estrogen responsive MCF-7 and T47D breast cancer cells were long-term exposed to 100 pg/ml estrogen, and using these cells the efficacy of chemotherapeutic drugs doxorubicin and cisplatin were determined. The result of cell viability and cell cycle analysis revealed increased sensitivities of doxorubicin and cisplatin in estrogen-exposed MCF-7 and T47D cells as compared to their respective control cells. Gene expression analysis of cell cycle, anti-apoptosis, DNA repair, and drug transporter genes further confirmed the increased efficacy of chemotherapeutic drugs in estrogen-exposed cells at molecular level. To further understand the role of epigenetic mechanism in enhanced chemotherapeutic efficacy by estrogen, cells were pre-treated with epigenetic drugs, 5-aza-2-deoxycytidine and Trichostatin A prior to doxorubicin and cisplatin treatments. The 5-aza-2 deoxycytidine pre-treatment significantly decreased the estrogen-induced efficacy of doxorubicin and cisplatin, suggesting the role of estrogen-induced hypermethylation in enhanced sensitivity of these drugs in estrogen-exposed cells. In summary, the results of this study revealed that sensitivity to chemotherapy depends on the levels of estrogen in breast cancer cells. Findings of this study will have clinical implications in selecting the chemotherapy strategies for treatment of breast cancer patients depending on the serum estrogen levels that varies among pre- and post-menopausal age of the patients.

Inhibition of Nicotinamide Phosphoribosyltransferase Induces Apoptosis in Estrogen Receptor-Positive MCF-7 Breast Cancer Cells

PURPOSE

Tumor cells have increased turnover of nicotinamide adenine dinucleotide (NAD+), the main coenzyme in processes including adenosine diphosphate-ribosylation, deacetylation, and calcium mobilization. NAD+ is predominantly synthesized in human cells via the salvage pathway, with the first component being nicotinamide. Nicotinamide phosphoribosyltransferase (NAMPT) is the key enzyme in this pathway, and its chemical inhibition by FK866 has elicited antitumor effects in several preclinical models of solid and hematologic cancers. However, its efficacy in estrogen receptor (ER)-positive and human epidermal growth factor receptor 2-positive breast cancer cells has not been previously investigated. In this study, we aimed to deplete the NAD+ content of MCF-7 cells, a model cell line for ER-positive breast cancer, by inhibiting NAMPT in order to evaluate downstream effects on p53 and its acetylation, p21 and Bcl-2-associated X protein (BAX) expression, and finally, apoptosis in MCF-7 breast cancer cells.

METHODS

MCF-7 cells were cultured and treated with FK866. NAD+ levels in cells were determined colorimetrically. Levels of p53 and its acetylated form were determined by Western blotting. Expression of p21 and BAX was determined by real-time polymerase chain reaction. Finally, levels of apoptosis were assessed by flow cytometry using markers for annexin V and propidium iodide.

RESULTS

FK866 treatment was able to increase p53 levels and acetylation, upregulate BAX and p21 expression, and induce apoptosis in MCF-7 cells. Addition of exogenous NAD+ to cells reversed these effects, suggesting that FK866 exerted its effects by depleting NAD+ levels.

CONCLUSION

Results showed that FK866 could effectively inhibit NAD+ biosynthesis and induce programmed cell death in MCF-7 cells, suggesting that NAMPT inhibitors may be useful for the treatment of ER-positive breast cancers.

Use of maintenance endocrine therapy after chemotherapy in metastatic breast cancer

BACKGROUND

For women with oestrogen receptor+ metastatic breast cancer (MBC), the options for systemic treatment include endocrine therapy (ET) and chemotherapy. For women whose disease is also HER2+, anti-HER2 therapies are also routinely used either with chemotherapy or less commonly with ET. Where chemotherapy is used as initial therapy, treatment is often discontinued due to cumulative toxicity in the absence of disease progression. In this setting, there is the option of introducing ET with the aim of prolonging response and delaying relapse.

METHODS

Literature review revealed four trials addressing the question of whether there is a benefit from introducing ET following chemotherapy for MBC. We also sought evidence for alternative approaches, including concurrent chemotherapy and ET and continuing chemotherapy until disease progression.

RESULTS

The evidence for the use of ET after chemotherapy in MBC is limited, and the trials done were small. Furthermore, they were performed at a time when both the chemotherapy regimens and ET were different from those used currently. Despite these limitations, there is probably a modest improvement in time to progression for the sequential use of ET after chemotherapy but with no overall survival benefit. An alternative approach, particularly considering agents with relatively low toxicity, such as orally bioavailable fluoropyrimidines, is to continue chemotherapy until disease progression.

CONCLUSION

Where chemotherapy for MBC is discontinued due to toxicity, in the absence of progression, the use of ET, with its relatively low toxicity, is a reasonable approach with the aim of delaying relapse.

Predictive Value of IHC4 Score for Pathological Response to Neoadjuvant Chemotherapy in Hormone Receptor-Positive Breast Cancer

PURPOSE

This study aimed to explore the value of IHC4 in predicting pathological response after neoadjuvant chemotherapy in patients with hormonal receptor (HR)-positive breast cancer (BC).

MATERIALS AND METHODS

In this retrospective exploratory study, data for 68 HR-positive BC patients who received neoadjuvant chemotherapy were recorded. IHC4 scores were calculated based on estrogen receptors/progesterone receptors, Ki-67 and HER2 status. Logistic and ordinal regression analyses in addition to likelihood ratio test were used to explore associations of IHC4 scores and other clinico-pathological parameters with pathological complete response (pCR) and pathological stage.

RESULTS

Taking the 25th percentile as the cut-off, a lower IHC4 score was associated with an increased probability of pCR (low; 52.9% vs. High; 21.6%, OR=4.1, 95% CI= 1.28-13.16, p=0.018) and a lower pathological stage (OR =3.9, 95% CI=1.34-11.33, p=0.012). When the IHC4 score was treated as a continuous variable, a lower score was again associated with an increased probability of pCR (OR=1.010, 95% CI=1.001-1.018, p=0.025) and lower pathological stage (OR=1.009, 95% CI= 1.002-1.017, P=0.008). Lower clinical stage was associated with a better pCR rate that was of borderline significance (P=0.056). When clinical stage and IHC4 score were incorporated together in a logistic model, the likelihood ratio test gave a P-value of 0.004 after removal of the IHC4 score and 0.011 after removal of the stage, indicating a more significant predictive value of the IHC4 score for pCR.

CONCLUSIONS

This study suggests that the IHC4 score can predict pathological response to neoadjuvant chemotherapy in HR-positive BC patients. This finding now needs to be validated in a larger cohort of patients.

Clinical Outcomes with First-line Endocrine Therapy or Chemotherapy in Postmenopausal HR+/HER2- Metastatic Breast Cancer

OBJECTIVE

To describe patient profiles and clinical outcomes associated with first-line endocrine monotherapy (ET) and chemotherapy (CT) for postmenopausal HR+/HER2- metastatic breast cancer (mBC) patients.

METHODS

This is a retrospective chart review of 139 postmenopausal HR+/HER2- mBC patients initiating first-line ET monotherapy or CT. Overall survival (OS) was described using Kaplan-Meier curves. Exploratory comparative proportional hazards regression was conducted.

RESULTS

Patients on first-line CT had significantly more frequent liver metastases than patients on first-line ET monotherapy at baseline. The median OS was 35.5 months [95% confidence interval (CI), 22.7-41.2 months] for patients on first-line ET monotherapy and 22.2 months (95% CI, 13.6-25.9 months) for those on first-line CT (P = 0.021). Adjusting for baseline characteristics, the OS between first-line ET monotherapy and CT was not significantly different.

CONCLUSIONS

Patients who were prescribed CT as first-line treatment had evidence of more advanced disease at baseline and shorter OS than those who received ET monotherapy as first-line treatment, suggesting a need for additional safe and effective treatment options for these patients.

Everolimus use and associated factors among post-menopausal women with hormonal receptor positive/human epidermal growth factor receptor 2 negative metastatic breast cancer

BACKGROUND

Everolimus has been shown to be an effective HR+/HER2- mBC treatment in both clinical trials and real-world practice. The current study aims at understanding factors associated with everolimus use and how it is used in the real world.

METHODS

A retrospective chart review was conducted among postmenopausal HR+/HER2- mBC women who received everolimus, endocrine therapy (ET), or chemotherapy (CT) for mBC between 1 July 2012 and 15 April 2013 after an NSAI failure. Factors associated with everolimus use versus ET or CT were identified using multivariable logistic regressions. Reasons for prescribing everolimus and everolimus treatment patterns were described.

RESULTS

Liver metastasis and high tumor volume were associated with a higher likelihood of everolimus use versus ET (OR = 1.67, OR = 1.62) but a lower likelihood of everolimus use versus CT (OR = 0.43, OR = 0.30). Medicare-only insurance (OR = 0.30) as well as ECOG ≥2 (OR = 3.72) and prior CT in mBC (OR = 2.76) were associated with a lower and higher likelihood of everolimus use versus CT, respectively. The top reason for prescribing everolimus was efficacy (69-85%). About 15% and 29% of everolimus users in second line and third line or above received prior CT for mBC. Exemestane was the most common concomitant therapy with everolimus (56-87%). The majority of patients initiated everolimus at the labeled dose of 10 mg daily (>80%) and maintained this dose (>80%).

CONCLUSIONS

In the real world, everolimus was used in more severe patients than ET but less severe patients than CT based on visceral metastasis, tumor volume, and performance status. The top reason for prescribing everolimus was efficacy. A large proportion of patients received first or second line CT before everolimus initiation. The majority of patients used everolimus according to the labeled combination and dose. Future studies are needed to determine optimal sequencing of everolimus, ET, and CT for HR+/HER2- mBC.

Management of patients with hormone receptor-positive breast cancer with visceral disease: challenges and treatment options

Endocrine therapy is an important treatment option for women with hormone receptor-positive (HR+) advanced breast cancer (ABC), yet many tumors are either intrinsically resistant or develop resistance to these therapies. Treatment of patients with ABC presenting with visceral metastases, which is associated with a poor prognosis, is also problematic. There is an unmet need for effective treatments for this patient population. Although chemotherapy is commonly perceived to be more effective than endocrine therapy in managing visceral metastases, patients who are not in visceral crisis might benefit from endocrine therapy, avoiding chemotherapy-associated toxicities that might affect quality of life. To improve outcomes, several targeted therapies are being investigated in combination with endocrine therapy for patients with endocrine-resistant, HR+ ABC. Although available data have considered patients with HR+ ABC as a whole, there are promising data from a prespecified analysis of a Phase III study of everolimus (Afinitor(®)), a mammalian target of rapamycin (mTOR) inhibitor, in combination with exemestane (Aromasin(®)) in patients with visceral disease progressing after nonsteroidal aromatase inhibitor therapy. In this review, challenges and treatment options for management of HR+ ABC with visceral disease, including consideration of therapeutic approaches undergoing clinical investigation, will be assessed.

Treatment pattern by hormone receptors and HER2 status in patients with metastatic breast cancer in the UK, Germany, France, Spain and Italy (EU-5): results from a physician survey

BACKGROUND

The differences in country-specific treatment patterns across Europe for metastatic breast cancer (mBC) patients have not been extensively studied. This study compared the treatment choices in aggregate, as well as by biomarker status, between various lines of therapy in clinical practice in the EU-5 countries among newly diagnosed mBC patients.

MATERIALS & METHODS

The IMS LifeLink™ Oncology Analyzer database, based on surveys of practicing oncologists, was used to identify mBC patients aged ≥21 years. In this database, sample-level data are projected to national-level estimates for each country using a sample projection technique.

RESULTS

The prevalence of hormone receptors (71-74%) is quite similar across different countries, while HER2 overexpression varies from 22 (France) to 34% (Italy); chemotherapy combined with HER2-targeted medicine was the mainstay of treatment for HER2(+) patients. The use of HER2-targeted medicine and bevacizumab greatly varied: while they were most frequently used in France, they were least frequently used in the UK. Fewer treatment options existed for triple-negative patients and patients with HER2(+) disease following trastuzumab treatment. Chemotherapy was the treatment choice for triple-negative patients, as these patients do not respond to hormonal therapy and HER2-targeted medicine.

CONCLUSION

This study found that, while a trastuzumab-based regimen is the preferred option for treating HER2(+) mBC patients in the EU-5, variations in this personalized medicine approach exist between different EU-5 countries. However, fewer treatment options exist for triple-negative and HER2(+) patients after trastuzumab treatment, highlighting the unmet need for these patient subgroups.

Epirubicin and docetaxel as first-line treatment for hormonal receptor positive metastatic breast cancer: the predictive value of luminal subtype: a retrospective cohort analysis

BACKGROUND

We retrospectively evaluated the efficacy of first-line epirubicin and docetaxel in patients with metastatic, hormonal receptor (HR)-positive, and human epidermal growth factor receptor-2-negative breast cancer. A subgroup analysis evaluated the predictive value of immunohistochemistry-defined luminal subtype.

METHODS

We included patients with at least one visceral and measurable site of metastatic disease. Patients were grouped as luminal A (HR(+) and Ki67<13%) or luminal B (HR(+) and Ki67>13%).

RESULTS

Forty-four patients were entered and prognostic variables were similar between the subgroups. Luminal B patients achieved higher objective response rate than luminal A (69% versus 19%; P = 0.001), longer time to progression (12.2 months versus 8.6 months; P = 0.039), and longer overall survival (24.6 months versus 19.5 months; P = 0.041). The multivariate analysis confirmed the predictive value of luminal B subtype for longer time to progression.

CONCLUSIONS

Identification by Ki67 labelling index of human epidermal growth factor receptor-2-negative luminal A could predict a substantial benefit from systemic chemotherapy. Endocrine therapy would be the most appropriate therapy for luminal A tumours.

ERα positively regulated DNMT1 expression by binding to the gene promoter region in human breast cancer MCF-7 cells

Estrogen receptors (ER) are expressed in approximately 65% of human breast cancer. Clinical trials and retrospective analyses showed that ER-positive (ER+) tumors were more vulnerable to development of chemotherapy resistance than ER-negative (ER-) tumors. The underlying mechanism is still to be elucidated. Aberrant DNA methylation has been recognized to be associated with cancer chemotherapy resistance. Recently, steroid hormone and their receptors have been found to be involved in the regulation of methyltransferases (DNMTs) and thereby contribute to chemotherapy resistance. The purpose of this study is to explore whether ERα could directly regulate the DNMTs expression. We first analyzed the methylation alterations and its correlation with the expression levels of three types of DNMTs in our established paclitaxel-resistant breast cancer lines, MCF-7(ER+)/PTX and MDA-MB-231(ER-)/PTX cell lines, using qMSP, real-time PCR and Western blot. Then we determined the function of ERα in regulation of DNMT1 using luciferase report gene systems. Our data demonstrated for the first time that ERα could upregulate DNMT1 expression by directly binding to the DNMT1 promoter region in MFC-7(ER+)/PTX cells.

A phase II multicenter study of two different dosages of pemetrexed given in combination with cyclophosphamide as first-line treatment in patients with locally advanced or metastatic breast cancer

Pemetrexed/cyclophosphamide was evaluated as first-line treatment for patients with locally advanced/metastatic breast cancer. In this randomized phase II study (NCT00190671), therapy consisted of either 600 mg/m(2) (P600) or 1,800 mg/m(2) (P1800) pemetrexed, followed by 600 mg/m(2) cyclophosphamide, every 21 days; 103 females (42 P600; 61 P1800) were enrolled. P600 was discontinued, as response rate (19.1%) was lower than targeted. In the P1800 arm, 20 patients had partial response (32.8%; 95% CI: 21.0-44.6) and 26 (42.6%) had stable disease. Median progression-free survival was 6.3 months (range: 0.3-31.1). P1800 plus cyclophosphamide 600 represents a regimen of reasonable efficacy and acceptable tolerability.

Combining emerging agents in advanced breast cancer

Newer treatments have improved survival for patients with metastatic breast cancer over the last two decades, and a battery of new cytotoxic and targeted therapies is continuing to enhance this trend. This review outlines recent data and ongoing research in this area, by highlighting new developments (regarding approved but relatively new classes of cytotoxic and targeted agents) and also new classes of targeted therapy that are undergoing clinical evaluation. Mechanisms for synergy between agents are discussed where data are available, as is information on the rationale behind the development of agents that inhibit angiogenesis, DNA repair, histone deacetylases, heat shock proteins, or various signaling pathways in tumor proliferation. The abundance of clinical research surrounding anticancer agents, together with ongoing cancer biology research, is expected to further increase the available pool of therapeutic options for metastatic breast cancer. Concomitantly, in the absence of an effective targeted monotherapy, a better understanding of the interplay between biologic and cytotoxic anticancer agents will improve our ability to rationally design combination regimens with better efficacy and tolerability.

ER-/ER+ breast cancer cell lines exhibited different resistance to paclitaxel through pulse selection

In this study, we established two PTX-resistant breast cancer cell lines, 231 TIM10 and MCF-7 TIM10, from ER-negative MDA-MB-231 cells and ER-positive MCF-7 cells by pulse selection, respectively. We found that 231 TIM10 variants acquired higher drug resistance than MCF-7 TIM10 variants by the pulse selection, although ER-positive MCF-7 cells were not as sensitive as ER-negative MDA-MB-231 to the initial pulses with PTX. 231 TIM10 had 11.9-fold greater resistance (RI = 11.9) than the parental MDA-MB-231 cells, while MCF-7 TIM10 got 5.5-fold resistance (RI = 5.5) when compared with the parental MCF-7 cells. In the presence of 5nM PTX, 231 TIM10 cells formed colonies, but no colony formed when MCF-7 TIM10 cells were cultured in the same condition. These data have two implications. First, the ER expression state might be an important determinant for the response of breast cancer cells to paclitaxel treatment. Second, ER-negative and ER-positive breast cancer cells develop drug-resistance phenotype with distinctive mechanisms. Our work not only established useful models for studying the paclitaxel resistance but also provides interesting clues to understand the mechanisms underlying the drug resistance of ER-negative and ER-positive breast cancer cells.