Twenty-years experience with de novo metastatic breast cancer

Research progress of exosomes in drug resistance of breast cancer

Since breast cancer is a heterogeneous disease, there are currently a variety of treatment methods available, including chemotherapy, endocrine therapy, molecular targeted therapy, immunotherapy, radiation therapy, etc. Breast cancer recurrence and metastasis, despite many treatment modalities, constitute a considerable threat to patients' survival time and pose a clinical challenge that is difficult to tackle precisely. Exosomes have a very special and crucial role in the treatment of drug resistance in breast cancer as a carrier of intercellular communication in the tumor microenvironment. Exosomes and breast cancer treatment resistance have been linked in a growing number of clinical investigations in recent years. This paper covers the status of research on exosomes in the treatment of breast cancer drug resistance and offers theoretical guidance for investigating new strategies to treat breast cancer drug resistance.

Extracellular Vesicles in Breast Cancer: From Biology and Function to Clinical Diagnosis and Therapeutic Management

Breast cancer (BC) is the first worldwide most frequent cancer in both sexes and the most commonly diagnosed in females. Although BC mortality has been thoroughly declining over the past decades, there are still considerable differences between women diagnosed with early BC and when metastatic BC is diagnosed. BC treatment choice is widely dependent on precise histological and molecular characterization. However, recurrence or distant metastasis still occurs even with the most recent efficient therapies. Thus, a better understanding of the different factors underlying tumor escape is mainly mandatory. Among the leading candidates is the continuous interplay between tumor cells and their microenvironment, where extracellular vesicles play a significant role. Among extracellular vesicles, smaller ones, also called exosomes, can carry biomolecules, such as lipids, proteins, and nucleic acids, and generate signal transmission through an intercellular transfer of their content. This mechanism allows tumor cells to recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. By reciprocity, stromal cells can also use exosomes to profoundly modify tumor cell behavior. This review intends to cover the most recent literature on the role of extracellular vesicle production in normal and cancerous breast tissues. Specific attention is paid to the use of extracellular vesicles for early BC diagnosis, follow-up, and prognosis because exosomes are actually under the spotlight of researchers as a high-potential source of liquid biopsies. Extracellular vesicles in BC treatment as new targets for therapy or efficient nanovectors to drive drug delivery are also summarized.

HR+/HER2- de novo metastatic breast cancer: a true peculiar entity?

De novo metastatic breast cancer (dnMBC) accounts for ~6-10% of all breast cancers and for ~30% of MBC with increasing incidence over time. Hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR⁺/HER2^-) tumours are the most frequent subtype with a similar incidence to that observed amongst recurrent MBC (rMBC). Higher frequency of PI3KCA and ARID2 mutations and a lower frequency of ESR1 mutations and of genes involved in DNA damage, as compared with rMBC, have been reported in HR⁺/HER2^- dnMBC; however, these are not correlating with prognosis, whilst tumour mutational burden is inversely correlated with outcome. Bone represents the most frequent metastatic site, being the single site in up to 60% of patients with dnMBC. HR⁺/HER2^- dnMBC has been generally reported to have better outcomes than rMBC, with a median overall survival ranging from 26 months to nearly 5 years in patients with favourable features such as age <40 years and bone-only disease, but not when compared with patients with late recurring disease (≥2-5 years). Analyses of the de novo cohorts within randomized clinical trials and large real-world series report a better outcome after treatment with CDK4/6 inhibitors and endocrine agents as compared to rMBC. Despite the limitations of retrospective studies and controversial results of the randomized trials, locoregional treatment of the primary tumour after response to systemic therapy appears to confer a survival benefit, particularly in patients with favourable prognostic factors. Altogether genomic, biological and clinical findings highlight HR⁺/HER2^- dnMBC as a peculiar entity as compared with rMBC and deserve a dedicated treatment algorithm. This article is part of the Tackling clinical complexity in breast cancer Special Issue: https://www.drugsincontext.com/special_issues/tackling-clinical-complexity-in-breast-cancer/.

Clinical Characteristics and Survival Outcomes of Patients with De Novo Metastatic Breast Cancer

Purpose

Though less than 5% of patients with breast cancer present with De Novo Metastasis (dnMBC) in Western societies, this percentage may reach 30% in developing countries. In this study, we present survival outcomes of patients diagnosed with dnMBC treated at a tertiary center in a developing country.

Patients and Methods

Using hospital-based database, consecutive patients with dnMBC diagnosed between 2013 and 2017 were identified. Demographic data, tumor characteristics, types of treatment, and survival data were retrospectively collected.

Results

A total of 435 patients were included; median age (range) at time of diagnosis was 51 (24-85) years. Most of the tumors expressed hormone receptors (81% Estrogen Receptor positive, 77% Progesterone Receptor positive). Human epidermal growth factor receptor-2 (HER2) overexpression was reported in 134 (30.9%) patients, while only 24 (5.5%) had Triple Negative (TN) disease. Bone, lung and liver were the most common sites of metastasis involved in 70.6%, 36.1%, and 32.0%, respectively. The median Overall Survival (OS) for all patients was 38 months, and 5-year OS was 32.6%. On univariate analysis, high tumor grade, advanced T-stage, TN-disease and metastasis to multiple sites, but not HER2 status, were associated with poor OS. On multivariate analysis, high tumor grade (Hazard Ratio =1.6, p=0.002), advanced T-stage (Hazard Ratio=1.6, p=0.003), and triple negative status (Hazard Ratio= 2.1, p=0.008) predicted poor OS.

Conclusion

The overall survival of patients with dnMBC remains poor. Better understanding of the disease behavior and factors affecting survival is required for optimal utilization of available regimens and new drugs to hopefully improve patients' outcomes.

Evaluation of Information Theoretic Network Meta-analysis to Rank First-Line Anticancer Regimens for Hormone Receptor-Positive, ERBB2-Negative Metastatic Breast Cancer

IMPORTANCE

Hormone receptor-positive, ERBB2 (formerly HER2/neu)-negative metastatic breast cancer (HR-positive, ERBB2-negative MBC) is treated with targeted therapy, endocrine therapy, chemotherapy, or combinations of these modalities; however, evaluating the increasing number of treatment options is challenging because few regimens have been directly compared in randomized clinical trials (RCTs), and evidence has evolved over decades. Information theoretic network meta-analysis (IT-NMA) is a graph theory-based approach for regimen ranking that takes effect sizes and temporality of evidence into account.

OBJECTIVE

To examine the performance of an IT-NMA approach to rank HR-positive, ERBB2-negative MBC treatment regimens.

DATA SOURCES

HemOnc.org, a freely available medical online resource of interventions, regimens, and general information relevant to the fields of hematology and oncology, was used to identify relevant RCTs.

STUDY SELECTION

All primary and subsequent reports of RCTs of first-line systemic treatments for HR-positive, ERBB2-negative MBC that were referenced on HemOnc.org and published between 1974 and 2019 were included. Additional RCTs that were evaluated by a prior traditional network meta-analysis on HR-positive, ERBB2-negative MBC were also included.

DATA EXTRACTION AND SYNTHESIS

RCTs were independently extracted from HemOnc.org and a traditional NMA by separate observers. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline for NMA with several exceptions: the risk of bias within individual studies and inconsistency in the treatment network were not assessed.

MAIN OUTCOMES AND MEASURES

Regimen rankings generated by IT-NMA based on clinical trial variables, including primary end point, enrollment number per trial arm, P value, effect size, years of enrollment, and year of publication.

RESULTS

A total of 203 RCTs with 63 629 patients encompassing 252 distinct regimens were compared by IT-NMA, which resulted in 151 rankings as of 2019. Combinations of targeted and endocrine therapy were highly ranked, especially the combination of endocrine therapy with cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors. For example, letrozole plus palbociclib was ranked first and letrozole plus ribociclib, third. Older monotherapies that continue to be used in RCTs in comparator groups, such as anastrozole (251 of 252) and letrozole (252), fell to the bottom of the rankings. Many regimens gravitated toward indeterminacy by 2019.

CONCLUSIONS AND RELEVANCE

In this network meta-analysis study, combination therapies appeared to be associated with better outcomes than monotherapies in the treatment of HR-positive, ERBB2-negative MBC. These findings suggest that IT-NMA is a promising method for longitudinal ranking of anticancer regimens from RCTs with different end points, sparse interconnectivity, and decades-long timeframes.

The Impact of Breast Cancer Treatment Delays on Survival Among South African Women

BACKGROUND

In high-income settings, delays from breast cancer (BC) diagnosis to initial treatment worsen overall survival (OS). We examined how time to BC treatment initiation (TTI) impacts OS in South Africa (SA).

METHODS

We evaluated women enrolled in the South African BC and HIV Outcomes study between July 1, 2015 and June 30, 2019, selecting women with stages I-III BC who received surgery and chemotherapy. We constructed a linear regression model estimating the impact of sociodemographic and clinical factors on TTI and separate multivariable Cox proportional hazard models by first treatment (surgery and neoadjuvant chemotherapy (NAC)) assessing the effect of TTI (in 30-day increments) on OS.

RESULTS

Of 1260 women, 45.6% had upfront surgery, 54.4% had NAC, and 19.5% initiated treatment >90 days after BC diagnosis. Compared to the surgery group, more women in the NAC group had stage III BC (34.8% vs 81.5%). Living further away from a hospital and having hormone receptor positive (vs negative) BC was associated with longer TTI (8 additional days per 100 km, P = .003 and 8 additional days, P = .01, respectively), while Ki67 proliferation index >20 and upfront surgery (vs NAC) was associated with shorter TTI (12 and 9 days earlier; P = .0001 and.007, respectively). Treatment initiation also differed among treating hospitals (P < .0001). Additional 30-day treatment delays were associated with worse survival in the surgery group (HR 1.11 [95%CI 1.003-1.22]), but not in the NAC group.

CONCLUSIONS

Delays in BC treatment initiation are common in SA public hospitals and are associated with worse survival among women treated with upfront surgery.

Genomic Characterization of De Novo Metastatic Breast Cancer

De novo metastatic breast cancer (dnMBC) represents a minority of MBC cases, and as such, its genomics are poorly understood. Characterizing the genomics of dnMBC represents an opportunity to delineate metastatic drivers in the absence of treatment selection. In this review, we first summarize the literature of the genomics of MBC which showed that MBCs have greater mutational burden than early stage, treatment naïve breast cancers. We then turn to recent studies that have sought to focus on dnMBC. We propose that understanding genomic differences between dnMBC and relapsed MBC can inform treatment choices. Finally, we discuss translational strategies to better dissect the genomics of dnMBC.

De novo and recurrent metastatic breast cancer - A systematic review of population-level changes in survival since 1995

BACKGROUND

Advances in breast cancer (BC) care have reduced mortality, but their impact on survival once diagnosed with metastasis is less well described. This systematic review aimed to describe population-level survival since 1995 for de novo metastatic BC (dnMBC) and recurrent MBC (rMBC).

METHODS

We searched MEDLINE 01/01/1995-12/04/2021 to identify population-based cohort studies of MBC reporting overall (OS) or BC-specific survival (BCSS) over time. We appraised risk-of-bias and summarised survival descriptively for MBC diagnoses in 5-year periods from 1995 until 2014; and for age, hormone receptor and HER2 subgroups.

FINDINGS

We identified 20 eligible studies (14 dnMBC, 1 rMBC, 5 combined). Potential sources of bias in these studies were confounding and shorter follow-up for the latest diagnosis period.For dnMBC, 13 of 14 studies reported improved OS or BCSS since 1995. In 2005-2009, the median OS was 26 months (range 24-30), a median gain of 6 months since 1995-1999 (range 0-9, 4 studies). Median 5-year OS was 23% in 2005-2009, a median gain of 7% since 1995-1999 (range -2 to 14%, 4 studies). For women ≥70 years, the median and 5-year OS was unchanged (1 study) with no to modest difference in relative survival (range: -1·9% (p = 0.71) to +2·1% (p = 0.045), 3 studies). For rMBC, one study reported no change in survival between 1998 and 2006 and 2007-2013 (median OS 23 months). For combined MBC, 76-89% had rMBC. Three of four studies observed no change in median OS after 2000. Of these, one study reported median OS improved for women ≤60 years (1995-1999 19·1; 2000-2004 22·3 months) but not >60 years (12·7, 11·6 months).

INTERPRETATION

Population-level improvements in OS for dnMBC have not been consistently observed in rMBC cohorts nor older women. These findings have implications for counselling patients about prognosis, planning cancer services and trial stratification.

FUNDING

SL was funded in part by a National Health and Medical Research Council (NHMRC) Project Grant ID: 1125433. NH was funded by the NBCF Chair in Breast Cancer Prevention grant (EC-21-001) and a NHMRC Investigator (Leader) grant (194410). BD and SAP were funded in part by the NHMRC Centre of Research Excellence in Medicines Intelligence (1196900).

Progression-free survival on endocrine therapy, before or after chemotherapy, in hormone receptor-positive HER2-negative metastatic breast cancer

PURPOSE

A major question when treating HR+/HER2- metastatic breast cancer (MBC) is whether early introduction of chemotherapy (CT) increases endocrine resistance. We aimed to describe progression-free survival (PFS) under first endocrine therapy (ET) depending on whether given before or after CT in a large nationwide cohort, in the pre-CDK era.

METHODS

The real-life retrospective ESME database includes all patients with MBC whose first-line treatment was initiated between 2008 and 2014 in one of the 18 French Comprehensive Cancer Centres. Our primary objective was to compare PFS from start of first ET in patients with HR+/HER2- MBC who received ET or CT first.

RESULTS

We identified 6293 patients who received at least one ET line during their first two therapeutic lines for MBC. As first-line therapy, 3832 (60.9%) received ET alone (ET1 1st group), whilst 2461 (39.1%) received CT, including 2024 patients (32.2%) with maintenance ET after CT (ET1 after CT group). Median PFS under first ET was 12.4 months (95% CI 11.9-13.1) in ET 1st group vs. 12.6 months in ET1 after CT group (95% CI 12.1-13.4), HR 0.96 (95% CI 0.90-1.01, P = 0.1277).

CONCLUSIONS

PFS under first ET appears identical whether prescribed before or after chemotherapy. These data suggest chemotherapy does not promote endocrine resistance.

De novo Metastatic Breast Cancer Arising in Young Women: Review of the Current Evidence

Women with metastatic breast cancer remains a heterogeneous group of patients with different prognostic outcomes and therapeutic needs. Young women with de novo metastatic breast cancer (dnMBC) represent a peculiar population with respect to tumor biology, prognosis, clinical management and survivorship issues. Overall, these patients are able to attain long-term survival with a proper management of both primary tumor and distant metastases. On the other hand, they are also at higher risk of experiencing a deterioration in their quality of life (QoL) due to primary cancer-related side effects. Young women are also likely to harbor germline pathogenic variants in cancer predisposition genes which could affect treatment decisions and have a direct impact on the lives of patients' relatives. The loco-regional management of the primary tumor represents another thorny subject, as the surgical approach has shown controversial effects on the survival and the QoL of these patients. This review aims to provide an update on these issues to better inform the clinical management of dnMBC in young women.

The association between molecular type and prognosis of patients with stage IV breast cancer: an observational study based on SEER database

Background

Molecular subtype, the basis for personalized treatment of breast cancer, is of great value in evaluating prognosis and guiding treatment of early-stage breast cancer. However, its value in stage IV patients remains unclear. In this study, we investigated the association between molecular subtype and prognosis of de novo stage IV breast cancer using Surveillance, Epidemiology, and End Results (SEER) database with the purpose to provide evidence for optimal therapeutic options for breast cancer patients.

Methods

We retrospectively analyzed de novo stage IV breast cancer patients with the SEER Program data from 2010 to 2015. Characteristics of patients with different molecular subtypes were compared by chi-square test and survival curves for breast cancer specific survival (BCSS) according to subtypes were plotted by Kaplan-Meier method. The Cox proportional hazards model was performed to search for independent prognostic factors in stage IV breast cancer patients.

Results

A total of 11,974 patients were included in this study, among which 7,100 (59.30%) patients were of HR⁺/HER2^-, 2,093 (17.48%) of HR⁺/HER2⁺, 1,139 (9.51%) of HR^-/HER2⁺ and 1,642 (13.71%) of HR^-/HER2^-. Multivariate Cox analysis revealed that molecular subtype, age, race, marital status, grade, surgery and chemotherapy were independent prognostic factors for BCSS in de novo stage IV patients. Taking HR⁺/HER2^- patients as reference, HR⁺/HER2⁺ patients had better BCSS (HR =0.81, 95% CI: 0.75-0.88, P<0.001), HR^-/ HER2^- patients had worse BCSS (HR =1.42, 95% CI: 1.29-1.46, P<0.001) and HR^-/HER2⁺ patients had no significant difference (HR =1.03, 95% CI: 0.98-1.08, P=0.188). In patients with different single organ metastases, the prognosis of HR⁺/HER2⁺ subtype was the best (except brain metastasis), while that of HR^-/HER2^- subtype was the worst.

Conclusions

Molecular subtypes were closely associated with the prognosis of de novo stage IV breast cancer. Among the four subtypes, HR⁺/HER2⁺ patients had the best prognosis while HR^-/HER2^- patients had the worst. The prognosis of patients with different single organ metastases was the same, but in patients with brain metastases, HR⁺/HER2⁺ ones did not have a significantly better prognosis than other subtypes except triple-negative type.

Carboplatin-Paclitaxel in triple-negative metastatic breast cancer during pregnancy with neoplastic thrombosis

The treatment of breast cancer diagnosed during pregnancy is a challenging situation for the patient, family and healthcare providers. Here we describe the case of a 35-year-old woman diagnosed with a triple-negative breast cancer relapse during pregnancy. She previously underwent neoadjuvant chemotherapy without any response, subsequent left skin sparing mastectomy plus axillary node dissection and radiation therapy to the chest wall and supraclavicular lymph nodes. Two years later, during her first single pregnancy, the patient presented a subclavian vein thrombosis and a BC relapse to locoregional lymph nodes. At 24 weeks of gestation, a first line treatment with weekly paclitaxel and carboplatin was started. Considering the disease progression after two complete cycles of chemotherapy, the patient had an elective caesarean section at 32+6 weeks. A full-body CT-scan and a PET-scan after the delivery showed a massive neoplastic thrombosis involving the left jugular, brachiocephalic and internal mammary vein, as well the superior vena cava and the right atrium. Few data are available on platinum-based chemotherapy during pregnancy in breast cancer patients. Nevertheless, the choice of therapy was conditioned by the previous absence of response to anthracycline and taxane. In case of breast cancer diagnosis during pregnancy, a multidisciplinary management as in the case described is recommended to increase the chance of survival both for the patients and their babies.

Epidemiology of De Novo Metastatic Breast Cancer

Most cases of metastatic breast cancer (MBC) arise as a recurrence of a previously treated early breast cancer. Distinct from recurrent MBC is de novo MBC (dnMBC), which describes patients who present with distant sites of disease at initial diagnosis and is reviewed here. dnMBC represents approximately 3% to 6% of new breast cancer diagnoses in high-income countries. This incidence has not declined despite decades of widespread use of population-based mammography screening. Overrepresentation of both biologically aggressive tumors and patients negatively impacted by social determinants of health are characteristics of dnMBC. Survival has generally been superior for patients with dnMBC compared with those with recurrent MBC, although it is similar to that for patients with recurrent MBC with long disease-free intervals. Subgroups of patients with dnMBC who experience prolonged survival include those with human epidermal growth factor receptor-2-positive disease or hormone receptor-positive bone-only disease. Opportunities to decrease dnMBC presentation may include novel screening modalities suited for biologically aggressive breast tumors and improved access to health care. Recognizing that there will remain some women diagnosed with dnMBC, refining our ability to identify those likely to be long-term survivors could allow for appropriate escalation or de-escalation of care. Finally, evaluation of tumor genomics in robust sample sizes has the potential to advance our knowledge of the biology of dnMBC as an entity distinct from recurrent MBC.

A population-based comparison of treatment, resource utilization, and costs by cancer stage for Ontario patients with HER2-positive breast cancer

PURPOSE

We sought to expand the currently limited, Canadian, population-based data on the characteristics, treatment pathways, and health care costs according to stage in patients with human epidermal growth factor receptor-2 positive (HER2+) breast cancer (BC).

METHODS

We extracted data from the publicly funded health care system in Ontario. Baseline characteristics, treatment patterns, and health care costs were descriptively compared by cancer stage (I-III vs. IV) for adult women diagnosed with invasive HER2+ BC between 2012 and 2016. Resource use was multiplied by unit costs for publicly funded health care services to calculate costs.

RESULTS

Overall, 4535 patients with stage I-III and 354 with stage IV HER2+ BC were identified. Most patients with stage I-III disease were treated with surgery (4372, 96.4%), with the majority having a lumpectomy, and 3521 (77.6%) received radiation. Neoadjuvant (NAT) and adjuvant (AT) systemic treatment rates were 20.1% (n = 920) and 88.8% (n = 3065), respectively. Systemic treatment was received by 311 patients (87.9%) with metastatic HER2+ BC, 264 of whom (84.9%) received trastuzumab. Annual health care costs per patient were nearly 3 times higher for stage IV vs. stage I-III HER2+ BC.

CONCLUSION

Per-patient annual costs were substantially higher for women with metastatic HER2+ BC, despite less frequent exposure to surgery and radiation compared to those with early stage disease. Increasing NAT rates in early stage disease represent a critical opportunity to prevent recurrence and reduce the costs associated with treating metastatic HER2+ BC.

Predicting the Incidence and Prognosis of Bone Metastatic Breast Cancer: A SEER-Based Observational Study

Background

To determinate the association relationship of breast cancer bone metastasis and cancer characteristics and molecular subtype. Furthermore, to evaluate the impact of molecular subtype on prevalence and prognosis of bone metastasis from the breast cancer base on a large population real-word program, the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

We collected and analyzed the data obtained from SEER, which showed molecular subtype information for each patient. The prevalence and outcome of bone metastasis in breast cancer were estimated as per the different molecular subtypes.

Results

Occurrence of bone metastasis in conformity with four different molecular subtypes in all 42684 breast cancer patients was 6.2, 9.4, 7.9, and 6.4%, respectively. The most unfavorable subtype was the triple-negative breast cancer (TNBC), followed by the luminal A, luminal B, and HER2 subtypes (hazard ratio [HR] of luminal A compared with TNBC, 0.533, 95% confidence interval, 0.444–0.641; HR of luminal B, 0.482, 95% CI 0.419–0.555; HR of HER2 subtype, 0.542, 95% CI 0.484–0.608). Brain metastasis impacts overall survival (OS) (p < 0.001) fundamentally, and visceral metastases also significantly decreased OS (p < 0.001).

Conclusion

Bone metastasis patients present a more favorable oncological survival consequence than other metastases, and the TNBC subtype with bone metastasis showed the poorest tumor outcome compared with the other three molecular subtypes.

Exosomes and breast cancer drug resistance

Drug resistance is a daunting challenge in the treatment of breast cancer (BC). Exosomes, as intercellular communicative vectors in the tumor microenvironment, play an important role in BC progression. With the in-depth understanding of tumor heterogeneity, an emerging role of exosomes in drug resistance has attracted extensive attention. The functional proteins or non-coding RNAs contained in exosomes secreted from tumor and stromal cells mediate drug resistance by regulating drug efflux and metabolism, pro-survival signaling, epithelial–mesenchymal transition, stem-like property, and tumor microenvironmental remodeling. In this review, we summarize the underlying associations between exosomes and drug resistance of BC and discuss the unique biogenesis of exosomes, the change of exosome cargo, and the pattern of release by BC cells in response to drug treatment. Moreover, we propose exosome as a candidate biomarker in predicting and monitoring the therapeutic drug response of BC and as a potential target or carrier to reverse the drug resistance of BC.

Survival and disease characteristics of de novo versus recurrent metastatic breast cancer in a cohort of young patients

BACKGROUND

It is not clear how the pathology, presentation and outcome for patients who present with de novo metastatic breast cancer (dnMBC) compare with those who later develop distant metastases. DnMBC is uncommon in younger patients. We describe these differences within a cohort of young patients in the United Kingdom.

METHODS

Women aged 40 years or younger with a first invasive breast cancer were recruited to the prospective POSH national cohort study. Baseline clinicopathological data were collected, with annual follow-up. Overall survival (OS) and post-distant relapse-free survival (PDRS) were assessed using Kaplan-Meier curves.

RESULTS

In total, 862 patients were diagnosed with metastatic disease. DnMBC prevalence was 2.6% (76/2977). Of those with initially localised disease, 27.1% (786/2901) subsequently developed a distant recurrence. Median follow-up was 11.00 years (95% CI 10.79-11.59). Patients who developed metastatic disease within 12 months had worse OS than dnMBC patients (HR 2.64; 1.84-3.77). For PDRS, dnMBC was better than all groups, including those who relapsed after 5 years. Of dnMBC patients, 1.3% had a gBRCA1, and 11.8% a gBRCA2 mutation.

CONCLUSIONS

Young women with dnMBC have better PDRS than those who develop relapsed metastatic breast cancer. A gBRCA2 mutation was overrepresented in dnMBC.

De novo metastatic breast cancer: Subgroup analysis of molecular subtypes and prognosis

The purpose of the present study was to analyze the clinical and pathological characteristics, treatment, and prognosis of de novo metastatic breast cancer (DnMBC). Information regarding 1,890 patients treated for advanced breast cancer at the Tianjin Medical University Cancer Hospital between January 2008 to December 2017 was collected. Clinicopathological characteristics, treatments and outcomes of these patients were compared using the chi-square test, log-rank test, and Cox regression analysis. A total of 171 patients were diagnosed with DnMBC. The median age at diagnosis was 53 years (range, 23–77). The percentage of T4 staging was higher (37.4%), 69.6% of patients were estrogen receptor (ER) positive, 59.1% were progesterone receptor positive, 29.8% had positive human epidermal growth factor receptor 2 (HER2) status, 68.4% had Ki-67 ≥20%, 55% had oligometastasis at the initial diagnosis, ~87.7% were treated with chemotherapy initially and 24% received palliative surgery for the primary tumor. After a median follow-up time of 26 months, the median progression-free survival (PFS) and overall survival (OS) among patients with DnMBC were 11 (8.7–13.3) months and 34 (27.9–40.1) months, respectively. In the multivariable model, ER status and sites of first metastasis (oligometastasis or polymetastasis) were identified to be independent predictors of PFS (P<0.05); ER status, primary tumor stage, and surgical treatment of primary tumors were identified to be independent predictors of OS (P<0.05). In conclusion, the clinicopathological characteristics of DnMBC are greater invasiveness and a higher risk of progression. Palliative surgical treatment may improve the prognosis of HR+/HER2-patients with oligometastasis. Therefore, individualized treatment as required is particularly important.

The clinicomolecular landscape of de novo versus relapsed stage IV metastatic breast cancer

BACKGROUND

de novo metastatic breast cancer (dnMBC) is responsible for 6-10% of breast cancer presentations with increasing incidence and has remained resistant to detection by mammography screening. Recent publications hypothesized that in addition to poor screening uptake, the presentation of dnMBC may be due to its unfavourable biology which remains unknown at the molecular level. Here we investigated the tumour biology of dnMBC in the form of clinicopathology, genomic alterations and differential gene expression to create a comparative landscape of de novo versus relapsed metastatic breast cancer (rMBC). Additionally, to address the current screening limitations, we conducted a preliminary biomarker investigation for early dnMBC detection.

METHODS

In this retrospective case-control study, gene expression and clinical data were accessed from the Cancer Genome Atlas (TCGA) for primary tumours of treatment-naïve patients with dnMBC (n = 17), rMBC (n = 49), and normal tissue (n = 113). The clinical and histological data were assessed categorically using Fisher's Exact-Test for significance (p < .05), or continuously using the Mann-Whitney Test (p < .05) where appropriate. The differential gene expression analysis was performed using EdgeR's negative binomial distribution model with a false discovery rate (FDR) <0.05. The resulting gene list was analysed manually for roles in metastasis as well as ontologically using STRING-DB with FDR <0.05.

RESULTS

dnMBCs showed improved median survival vs rMBC (36 vs. 12 months). dnMBCs were more likely to be hormone receptor positive, less likely to be triple negative with lower histological lymphocytic infiltrate. In terms of genome alterations, dnMBCs had 4-fold increased PTEN mutations and poor survival with ABL2 and GATA3 alterations. Expression-wise, dnMBCs down-regulated TNFa, IL-17 signalling, and chemotaxis, while up-regulating steroid biosynthesis, cell migration, and cell adhesion. Biomarker analysis detected pre-existing and novel breast cancer biomarkers.

CONCLUSION

The comparative tumour landscape revealed significant clinical, pathological and molecular differences between dnMBC and rMBC, indicating that dnMBC may be a separate biological entity to rMBC at the primary level with differing paths to metastasis. Additionally, we provided a list of potential serum biomarkers that may be useful in detecting dnMBC in its pre-metastatic window if such a window exists.

Invasive breast cancer over four decades reveals persisting poor metastatic outcomes in treatment resistant subgroup - the "ATRESS" phenomenon

BACKGROUND

Major advances in breast cancer treatment have led to a reducuction in mortality. However, there are still women who are not cured. We hypothesize there is a sub-group of women with treatment-resistant cancers causing early death.

METHODS

Between 1975 and 2006, 5392 women with invasive breast cancer underwent surgery at Guy's Hospital, London. Data on patient demographics, tumour characteristics, treatment regimens, local recurrence, secondary metastasis, and death were prospectively recorded. We considered four time periods (1975-1982, 1983-1990, 1991-1998, 1999-2006). Risks and time to event analysis were performed with Cox proportional hazards model and Kaplan-Meier estimation.

RESULTS

Unadjusted hazard ratios for developing metastasis and overall mortality relative to the 1975-1982 cohort decreased steadily to 0.23 and 0.63, respectively in 1999-2006. However, metastasis-free interval shortened, with the proportion of women developing metastasis ≤5 years increasing from 73.9% to 83.0%. Furthermore, median post-metastatic survival decreased from 1.49 years to 0.94 years. Applying our risk criteria identified the presence of ±200 patients in each cohort who developed metastasis early and died within a much shorter time frame.

CONCLUSIONS

Advances in treatment have decreased the risk of metastasis and improved survival in women with invasive breast cancer over the last 40 years. Despite this, a subpopulation with shorter metastasis-free and post-metastatic survival who are unresponsive to available treatment remains. This may be due to the ATRESS phenomenon (adjuvant therapy-related shortening of survival) secondary to preselection inherent in adjuvant therapy, successful treatment of less malignant tumour cells and treatment-induced resistance in the remaining tumour clones.

Breast cancer subtypes and the risk of distant metastasis at initial diagnosis: a population-based study

Background

It was unclear whether breast cancer subtypes are associated with the risk of site-specific metastases. This study aimed to evaluate the relationship between molecular subtypes and distant metastatic sites and their prognostic significance.

Methods

We identified 295,213 patients with invasive breast cancer from 2010 to 2014 using the Surveillance, Epidemiology and End Results database. Subtypes were classified into four categories: hormone receptor (HR⁺)/human epidermal growth factor receptor 2 (HER2⁻), HR⁺/HER2⁺, HR⁻/HER2⁺, and triple-negative (HR⁻/HER2⁻). Logistic regression was used to assess the association between metastasis location and subtypes. Multivariate Cox models were used to estimate the overall survival (OS) of related factors.

Results

According to our study, 3.28%, 1.52%, 1.20%, and 0.35% of newly diagnosed breast cancers presented bone, lung, liver, and brain metastases at diagnosis, respectively. Both metastatic sites and subtypes significantly affected the OS after metastasis. In multivariate analysis, HR⁺/HER2⁺ subtype (OR as compared with HR⁺/HER2⁻ subtype, 1.30 [95% CI, 1.22–1.39]) significantly correlated with elevated bone metastasis risk, whereas HR⁻/HER2⁺ did not. Both HER2⁺ subtypes (HR⁺/HER2⁺ and HR⁻/HER2⁺) were significantly associated with higher rates of liver, brain, and lung metastases, while the highest OR was observed in liver metastases. Triple-negative tumors had a higher rate of brain (OR, 1.95 [95% CI, 1.61–2.35]), liver (OR, 1.35 [95% CI, 1.20–1.51]), and lung metastases (OR, 1.34 [95% CI, 1.21–1.47]), but a significantly lower rate of bone metastases (OR, 0.64 [95% CI, 0.59–0.69]) than HR⁺/HER2−tumors.

Conclusions

Breast cancer subtypes are associated with different metastatic patterns and confer different prognostic impacts. Molecular subtypes can identify patients at increased risk of site-specific metastases.

Trastuzumab and survival of patients with metastatic breast cancer

INTRODUCTION

Prognosis of Her2-positive breast cancer has changed since the introduction of trastuzumab for treatment in metastatic and early breast cancer. It was described to be even better compared to prognosis of Her2-negative metastatic breast cancer. The purpose of this study was to evaluate the effect of trastuzumab in our cohort. Besides the effect of adjuvant pretreatment with trastuzumab on survival of patients with metastatic Her2-positive breast cancer was analyzed.

METHODS

All patients with primary breast cancer of the Regional Breast Cancer Center Dresden diagnosed during the years 2001-2013 were analyzed for treatment with or without trastuzumab in the adjuvant and in the metastatic treatment setting using Kaplan-Meier survival estimation and Cox regression. Age and tumor stage at time of first diagnosis of breast cancer as well as hormone receptor status, grading, time, and site of metastasis at first diagnosis of distant metastatic disease were analyzed.

RESULTS

Of 4.481 female patients with primary breast cancer, 643 presented with metastatic disease. Her2-positive status was documented in 465 patients, including 116 patients with primary or secondary metastases. Median survival of patients with Her2-positive primary metastatic disease was 3.0 years (95% CI 2.3-4.0). After adjustment for other factors, survival was better in patients with Her2-positive breast cancer with trastuzumab therapy compared to Her2-negative metastatic disease (HR 2.10; 95% CI 1.58-2.79). Analysis of influence of adjuvant therapy with and without trastuzumab by Kaplan-Meier showed a trend for better survival in not pretreated patients. Median survival was highest in hormone receptor-positive Her2-positive (triple-positive) primary metastatic breast cancer patients with 3.3 years (95% CI 2.3-4.6).

CONCLUSION

Prognosis of patients with Her2-positive metastatic breast cancer after trastuzumab treatment is more favorable than for Her2-negative breast cancer. The role of adjuvant chemotherapy with or without trastuzumab warrants further research. Survival is best in triple-positive metastatic breast cancer. This will effect counseling at the time of first diagnosis of metastatic breast cancer.

Molecular Biomarkers for Prediction of Targeted Therapy Response in Metastatic Breast Cancer: Trick or Treat?

In recent years, the study of genomic alterations and protein expression involved in the pathways of breast cancer carcinogenesis has provided an increasing number of targets for drugs development in the setting of metastatic breast cancer (i.e., trastuzumab, everolimus, palbociclib, etc.) significantly improving the prognosis of this disease. These drugs target specific molecular abnormalities that confer a survival advantage to cancer cells. On these bases, emerging evidence from clinical trials provided increasing proof that the genetic landscape of any tumor may dictate its sensitivity or resistance profile to specific agents and some studies have already showed that tumors treated with therapies matched with their molecular alterations obtain higher objective response rates and longer survival. Predictive molecular biomarkers may optimize the selection of effective therapies, thus reducing treatment costs and side effects. This review offers an overview of the main molecular pathways involved in breast carcinogenesis, the targeted therapies developed to inhibit these pathways, the principal mechanisms of resistance and, finally, the molecular biomarkers that, to date, are demonstrated in clinical trials to predict response/resistance to targeted treatments in metastatic breast cancer.