Patterns of treatment and outcome with 500-mg fulvestrant in postmenopausal women with hormone receptor-positive/HER2-negative metastatic breast cancer: a real-life multicenter Italian experience

Retrospective Evaluation of Fulvestrant Efficacy and Clinical Results in Patients Using Fulvestrant

AIM

Fulvestrant is a drug used in the treatment of metastatic hormone receptor-positive breast cancer (mHRPBC). Although clinical trials have shown the efficacy of fulvestrant, real-life data are limited and data from clinical trials and real-life settings sometimes may be seen differently. Therefore, we retrospectively reviewed mHRPBC patients followed in our center and taking fulvestrant to evaluate the efficacy and clinical outcomes of the drug and also to identify factors affecting the efficacy and clinical outcomes of fulvestrant.

MATERIALS AND METHODS

Patients who were followed up with the diagnosis of metastatic breast cancer between 2010 and 2022 and using fulvestrant were retrospectively analyzed.

RESULTS

The median progression-free survival (PFS) time was 9 [95% confidence interval (CI): 7.13-10.18] months and the median overall survival time was 28 (95% CI: 22.53-34.93) months. According to multivariate analyses, PFS was associated with age (p=0.041), body mass index (BMI) (p=0.043), brain metastasis (p=0.033), fulvestrant line (p=0.002), and use of pre-fulvestrant chemotherapy (p=0.032).

CONCLUSION

Fulvestrant is an effective drug in mHRPBC. Fulvestrant is more effective in patients whose BMI index is under 30, without brain metastases, without prior chemotherapy, under 65 years of age, and used fulvestrant in the early treatment line. The efficacy of fulvestrant may vary according to age and BMI.

Predictors of fulvestrant long-term benefit in hormone receptor-positive/HER2 negative advanced breast cancer

We retrospectively investigated in women treated with fulvestrant for HR+/HER2 negative advanced breast cancer clinical, pathological and molecular features associated with long-term benefit from treatment defined as being progression-free at 18 months. Specifically, we analyzed on formalin-fixed paraffin-embedded tumor samples ESR1 and PI3KCA mutations and miRNAs profiles. 59 patients were evaluable (median age of 67 years, range 32-92). 18-month PFS rate was 27%; the lack of visceral metastases significantly predicted the likelihood of being progression-free at 18 months, while PI3KCA mutations, found in 36% of patients, were not associated with 18-month PFS. As of miRNAs, miR-549a, miR-644a, miR-16-5p were negatively while let-7c-5p was positively associated with 18-month PFS. In addition, miR-520d-3p and miR-548g-3p values were significantly lower while miR-603, miR-181a-5p and miR-199a-miR-199b-3p values were significantly higher in patients achieving 18-month PFS. In silico analysis of targets modulated by these two latter groups of miRNAs show that in patients achieving 18-month PFS the Hippo and Wnt signaling pathways were predicted to be upregulated while endocrine resistance was potentially repressed by miR-603, miR-181a-5p and miR-199a-miR-199b-3p. Our results provide additional clues on the molecular mechanisms involved in fulvestrant activity and resistance. Underlying pathways should be further elucidated and confirmed in larger cohorts.

Comparison of endocrine therapy and chemotherapy as different systemic treatment modes for metastatic luminal HER2-negative breast cancer patients —A retrospective study

Purpose

The purpose of this study was to evaluate endocrine therapy and chemotherapy for first-line, maintenance, and second-line treatment of hormone receptor-positive HER-2-negative metastatic breast cancer (HR+HER-2-MBC) and the relationship between different treatment options and survival.

Patients and methods

The patients included in this study were all diagnosed with metastatic breast cancer (MBC) at Shandong Cancer Hospital from January 2013 to June 2017. Of the 951 patients with MBC, 307 patients with HR+HER-2-MBC were included in the analysis. The progression-free survival (PFS) and overall survival (OS) of the various treatment modes were evaluated using Kaplan–Meier analysis and the log-rank test. Because of the imbalance in data, we used the synthetic minority oversampling technique (SMOTE) algorithm to oversample the data to increase the balanced amount of data.

Results

This retrospective study included 307 patients with HR+HER-2-MBC; 246 patients (80.13%) and 61 patients (19.87%) were treated with first-line chemotherapy and first-line endocrine therapy, respectively. First-line endocrine therapy was better than first-line chemotherapy in terms of PFS and OS. After adjusting for known prognostic factors, patients receiving first-line chemotherapy had poorer PFS and OS outcomes than patients receiving first-line endocrine therapy. In terms of maintenance treatment, the endocrine therapy-endocrine therapy maintenance mode achieved the best prognosis, followed by the chemotherapy-endocrine therapy maintenance mode and chemotherapy-chemotherapy maintenance mode, and the no-maintenance mode has resulted in the worst prognosis. In terms of first-line/second-line treatment, the endocrine therapy/endocrine therapy mode achieved the best prognosis, while the chemotherapy/chemotherapy mode resulted in the worst prognosis. The chemotherapy/endocrine therapy mode achieved a better prognosis than the endocrine therapy/chemotherapy mode. There were no significant differences in the KI-67 index (<15%/15-30%/≥30%) among the patients receiving first-line treatment modes, maintenance treatment modes, and first-line/second-line treatment modes. There was no statistical evidence in this study to support that the KI-67 index affected survival. However, in the first-line/second-line model, after SMOTE, we could see that KI-67 ≥ 30% had a poor prognosis.

Conclusions

Different treatment modes for HR+HER-2-MBC were analyzed. Endocrine therapy achieved better PFS and OS outcomes than chemotherapy. Endocrine therapy should be the first choice for first-line, maintenance, and second-line treatment of HR+HER-2-MBC.

Real-World First-Line Treatment Patterns and Outcomes in Hormone Receptor-Positive Advanced Breast Cancer Patients: A Multicenter, Retrospective Study in China

Background

Recent data on first-line treatment patterns administered to hormone receptor-positive (HR+) advanced breast cancer (ABC) patients in the real-world setting are limited. This study aimed to report the first-line treatment patterns and outcomes of HR+ ABC patients in China.

Methods

This was a multicenter, noninterventional study. Eligible patients were cytologically or histologically confirmed to have HR+ ABC with ≥2 complete medical records and received first-line therapies between January 2015 and June 2019. Treatment patterns and outcomes were extracted from structured or unstructured electronic medical records. Progression-free survival (PFS) was analyzed with the Kaplan-Meier method.

Results

In total, 1072 patients with HR+ ABC were enrolled at 6 treatment sites: 327 human epidermal growth factor receptor 2-positive (HER2+) patients, 696 HER2-negative (HER2-) patients and 49 HER2-unknown patients. Overall, 62.41% of patients received first-line chemotherapy (CT), 21.08% received targeted therapy (TT) and 15.49% received endocrine therapy (ET). For HR+/HER2+ patients, 65.14% received TT, 28.44% received CT, and 5.81% received ET. Compared with patients who received TT, patients who received CT alone, had a significantly worse median PFS (adjusted hazard ratio [HR] =2.59, 95% confidence interval [CI], 1.64-4.10, p<0.001). For HR+/HER2- patients, 77.01% received CT, 20.69% received ET and 1.15% received TT. Compared with patients who received ET, patients who received CT with maintenance therapy had a significantly prolonged median PFS (adjusted HR =0.57, 95% CI, 0.44-0.76, p<0.001). Among HR+/HER2- patients who received CT with maintenance treatment, those with maintenance ET had a longer median PFS than those with maintenance CT, but the difference was not significant (adjusted HR=0.92, 95% CI, 0.64-1.33, p=0.66).

Conclusions

This real-world study demonstrates that CT remains the mainstream first-line treatment option for HR+ patients in China. Among patients with HR+/HER2+ ABC, the majority received first-line TT and experienced a PFS benefit. A high percentage of HR+/HER2- patients received CT as first-line therapy in clinical practice. PFS benefit was significantly longer in patients who received CT with maintenance therapy. Moreover, there was no obvious difference in PFS between maintenance ET and CT. Maintenance ET may be a better choice considering its lower toxicity and better quality of life.

Targeting metabolic adaptations in the breast cancer-liver metastatic niche using dietary approaches to improve endocrine therapy efficacy

Estrogen receptor-positive (ER+) metastatic tumors contribute to nearly 70% of breast cancer-related deaths. Most patients with ER+ metastatic breast cancer (MBC) undergo treatment with the estrogen receptor antagonist fulvestrant (Fulv) as standard-of-care. Yet, among such patients, metastasis in the liver is associated with reduced overall survival compared to other metastasis sites. The factors underlying the reduced responsiveness of liver metastases to ER-targeting agents remain unknown, impeding the development of more effective treatment approaches to improve outcomes for patients with ER+ liver metastases. We therefore evaluated site-specific changes in MBC cells and determined the mechanisms through which the liver metastatic niche specifically influences ER+ tumor metabolism and drug resistance. We characterized ER activity of MBC cells both in vitro, using a novel system of tissue-specific extracellular matrix hydrogels representing the stroma of ER+ tumor metastatic sites (liver, lung and bone), and in vivo, in liver and lung metastasis mouse models. ER+ metastatic liver tumors and MBC cells grown in liver hydrogels displayed upregulated expression of glucose metabolism enzymes in response to Fulv. Furthermore, differential ERα activity, but not expression, was detected in liver hydrogels. In vivo, increased glucose metabolism led to increased glycogen deposition in liver metastatic tumors, while a fasting-mimicking diet increased efficacy of Fulv treatment to reduce the metastatic burden. Our findings identify a novel mechanism of endocrine resistance driven by the liver tumor microenvironment. Implications: These results may guide the development of dietary strategies to circumvent drug resistance in liver metastasis, with potential applicability in other metastatic diseases.

Treatment Strategy for Patients with HR-Positive HER2-Negative Metastatic Breast Cancer That Progressed on CDK4/6 Inhibitors

Background/Aims

The study aim was to evaluate if mTOR inhibitors can be considered as a treatment option for HR+ HER2- metastatic breast cancer (MBC) after progression on CDK4/6 inhibitors in clinical practice.

Methods

We retrospectively collected the clinicopathological data of patients with HR+ HER2- MBC treated with CDK4/6 inhibitors and subsequent therapies at our institution between 2014 and 2020. The patients were divided into 3 groups according to the type of subsequent treatment: (A) exemestane plus everolimus, (B) endocrine monotherapy, and (C) chemotherapy. Overall survival (OS) was estimated by using the Kaplan-Meier method and compared by using the log-rank test. The efficacy and adverse events (AEs) of each subsequent treatment were assessed by using Fisher's exact tests.

Results

Eighty-six patients (34 in group A, 20 in group B, 32 in group C) were included. The most common endocrine therapy in group B was fulvestrant (40%). The major chemotherapy regimen in group C was eribulin (25%). The median OS times after stopping CDK4/6 inhibitors were 34.5 months (95% confidence interval, 17.2 to NA), 13.6 months (3.9 to NA), and 19.5 months (18.8 to NA) in group A, group B, and group C, respectively. The only significant difference in OS was observed between group A and group B (20.9 months; p = 0.003). There was no difference in the incidence of grade 3 AEs between groups A and C or in the frequency of treatment discontinuation because of AEs among the 3 groups.

Conclusion

Our study shows that mTOR inhibitors might be an effective treatment option for patients with HR+ HER2- MBC previously treated with CDK4/6 inhibitors.

Real-World Efficacy of Fulvestrant Monotherapy as the First Treatment or Maintenance Treatment in Patients with Metastatic Breast Cancer

Background

Fulvestrant 500 mg monotherapy is recommended as the first-line endocrine treatment in postmenopausal women with hormone receptor-positive metastatic breast cancer (MBC). It is also used in MBC maintenance treatment. However, few studies have compared the efficacy of fulvestrant during the initial treatment with that during maintenance treatment.

Patients and Methods

MBC patients who were treated with fulvestrant either as initial therapy for metastatic disease or after progression following one line of chemotherapy between January 2016 and December 2017 were identified from the database of the Affiliated Hospital of Qingdao University. The primary end point was progression-free survival (PFS).

Results

The study included 135 MBC patients who were treated with fulvestrant; 116 patients who received fulvestrant as first-line treatment were divided into 2 groups: the no-chemotherapy treatment (NCT) group received fulvestrant as initial therapy during disease progression, and the chemotherapy treatment (CT) group received fulvestrant as maintenance following disease stabilization or response to previous chemotherapy. The median PFS was 16 months in NCT patients and 8 months in the CT group. Patients who had a longer disease-free survival, no visceral metastasis and one metastasis site, benefited from fulvestrant as first-line treatment during disease progression. Patients with 2 or more metastasis sites benefited from chemotherapy as first-line treatment and fulvestrant as maintenance treatment.

Conclusions

Fulvestrant monotherapy showed good clinical activity and safety in patients with MBC who were treated upon disease progression and in those receiving maintenance therapy.

Efficacy of Fulvestrant in Women with Hormone-Resistant Metastatic Breast Cancer (mBC): A Canadian Province Experience

Simple Summary

Fulvestrant is a medication that is approved as first and second-line treatment in patients with hormone receptor positive advanced breast cancer. In clinical practice, fulvestrant is still used beyond the second line of treatment. This study investigated the use of fulvestrant in a Saskatchewan population of women with advanced breast cancer. We found that fulvestrant is effective when used in both the early and later lines of treatment, although the benefit is more pronounced in the earlier line of therapy. Women with disease affecting their visceral organs such as lung, liver or peritoneum had decreased disease control and survival on fulvestrant. Women who had received chemotherapy after fulvestrant and had a clinical response to fulvestrant had better survival.

Abstract

Introduction: Fulvestrant has demonstrated efficacy in hormone receptor positive (HR+) metastatic breast cancer (mBC), both in first-and second-line settings. In clinical practice, however, fulvestrant has been used as a later-line therapy. This study assessed the efficacy of fulvestrant in women with mBC in early-versus later-line therapy. Methods: This retrospective cohort study assessed Saskatchewan women with HR+ mBC who received fulvestrant between 2003–2019. A multivariate Cox proportional survival analysis was performed. Results: One hundred and eighty-six women with a median age of 63.5 years were identified—178 (95.6%) had hormone-resistant mBC, 57.5% had visceral disease, and 43.0% had received chemotherapy before fulvestrant. 102 (54.8%) women received ≤2-line-therapy, and 84 (45.2%) received ≥3 line-therapy before fulvestrant. The median time to progression (TTP) was 12 months in the early-treatment vs. 6 months in the later-treatment group, p = 0.015. Overall survival (OS) from the start of fulvestrant was 26 months in the early-treatment group vs. 16 months in the later-treatment group, p = 0.067. On multivariate analysis, absence of visceral metastasis, HR: 0.70 (0.50–0.99), was significantly correlated with better TTP, whereas post-fulvestrant chemotherapy, HR: 0.32 (0.23–0.47), clinical benefit from fulvestrant, HR: 0.44 (0.30–0.65), and absence of visceral metastasis, HR: 0.70 (0.50–0.97), were correlated with better OS. Conclusions: Fulvestrant has demonstrated efficacy as both early-and later-line therapy in hormone-resistant mBC. Our results show that women with clinical benefit from fulvestrant, who received post-fulvestrant chemotherapy, or had non-visceral disease, had better survival.

Impact of Adjuvant Treatment on Heparanase Concentration in Invasive, Unilateral Breast Cancer Patients: Results of a Prospective Single-Centre Cohort Study

Background: In recent years, great progress has been made in the treatment of breast cancer, but it is still one of the ten leading causes of death in women. The aim of the study was to evaluate the heparanase concentration of invasive breast cancer (IBrC) patients, before and after cancer adjuvant treatment. Methods: Eighty patients with stage IA to IIB IBrC receiving adjuvant treatment were included prospectively in this study. The heparanase concentrations were determined by an enzyme-linked immunosorbent assay. A univariate analysis was used to estimate the factors influencing the low or high pre-treatment concentration of heparanase and the low or high numerical decrease in heparanase concentration after completion of adjuvant treatment. Results: Treatment reduced the concentration of heparanase by almost four times in the general IBrC cohort. Higher levels of pre- and post-treatment heparanase were noted in oestrogen receptor-negative cancers than in positive ones. A higher post-treatment concentration of heparanase was found in patients with a triple-negative tumour compared to patients with a luminal B HER2 negative type of IBrC. Overweight IBrC subjects and those with a tumour diameter of ≥2 cm demonstrated a lower chance of a lower pre-treatment heparanase concentration. Interestingly, a pre-treatment heparanase concentration is the main predictor of the changes in heparanase concentration after adjuvant treatment. Follow-up revealed significantly lower progression-free survival (PFS) rates in IBrC patients with a pre-treatment concentration of heparanase higher than 181.46 pg/mL (PFS = 80%). Conclusions: Our findings provide supporting evidence that IBrC therapy reduced the heparanase levels, regardless of treatment patterns and a pre-treatment concentration of heparanase may serve as a prognostic indicator for future outcomes.

Utilizing Data Visualization to Identify Survival and Treatment Differences Between Women With De Novo and Recurrent Metastatic Breast Cancer

INTRODUCTION

De novo stage IV metastatic breast cancer (MBC) and recurrent MBC are considered the same when determining guideline-based care, but differences in treatment patterns exist. Data visualization can be used to understand these differences and optimize treatment delivery.

PATIENTS AND METHODS

This retrospective study evaluated treatment patterns for de novo and recurrent MBC using the American Society of Clinical Oncology's CancerLinQ Discovery database. Spatiotemporal graphics depicting treatment data were generated for MBC subtype and stratified by de novo and recurrent MBC. Descriptive statistics for categorical and continuous variables were calculated.

RESULTS

We identified 1668 patients diagnosed and treated for MBC: 391 patients with HER2⁺ MBC, 767 patients with HR⁺/HER2- MBC, and 510 patients with triple-negative MBC. Median survival from MBC diagnosis for patients with de novo MBC and recurrent MBC was 1.4 years (interquartile range, 0.6-3.0) and 1.8 years (interquartile range, 0.7-4.5), respectively. Both patients with de novo and recurrent HER2⁺ MBC were often treated with continuous HER2-targeted therapy. Patients with de novo HR⁺/HER2- MBC often received chemotherapy followed by hormone therapy. This contrasted with treatment trends observed among patients with recurrent HR⁺/HER2- MBC who, after receiving chemotherapy, seldom went on to receive hormone therapy. Patients diagnosed with triple-negative MBC displayed less heterogeneous treatment trends.

CONCLUSION

There are observable differences in survival and practice patterns between de novo and recurrent MBC. Visualization techniques are effective in assessing large databases and could give researchers and clinicians a clearer understanding of how survival differs by disease subtype, diagnosis status, and practice patterns.

Efficacy and Safety of Fulvestrant 500mg in Hormone-receptor Positive Human Epidermal Receptor 2 Negative Advanced Breast Cancer: A Real-world Study in China

Background: Fulvestrant 500mg has proved its clinical effectiveness in previous trials as primary or second line treatment of hormone receptor positive, human epidermal receptor 2 negative (HR+/HER2-) post-menopausal advanced breast cancer. This real-world study aimed to investigate the efficacy and safety of Fulvestrant in HR+/HER2- Chinese advanced breast cancer patients. Method: HR+/HER2- advanced breast cancer patients who received Fulvestrant 500mg from January 2015 to December 2018 in Beijing Cancer Hospital were enrolled in this retrospective study. Progression free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR), overall survival (OS) and adverse events (AEs) of Fulvestrant were investigated. Result: In total 303 enrolled patients [median age was 51 years (range: 21-82)], 255 (84.2%) patients were at postmenopausal status at the start of Fulvestrant treatment and 264 patients (87.1%) had advanced breast cancer. The median PFS (95% confidence interval) was 14.1 months (10.1-18.0) for the first-line, 11.2 months (2.2-20.3) for the second-line and 6.7 months (4.8-8.5) for ≥third-line of Fulvestrant. The ORR and CBR were 3.8% and 86.8% for the first-line, 5.5% and 75.4% for the second-line, 1.1% and 61.1% for ≥third-line of Fulvestrant. The multivariate subgroup analyses showed, PFS was significantly longer for the patients with light tumor burden, less palliative chemotherapy before Fulvestrant and long disease-free interval. For patients receiving Fulvestrant after palliative chemotherapy, the median PFS was numerically greater in maintenance treatment group than those who progressed after chemotherapy. Only 5.0% of patients (15/303) experienced adverse events and majority were grade 1-2. The most common adverse event was headache and palpitation, with merely one patient had severe adverse event (pulmonary embolism). Conclusion: Fulvestrant is an effective, safe and well-tolerated treatment regimen in endocrine therapy for HR+/HER2- metastatic breast cancer. Light tumor burden, less palliative chemotherapy before Fulvestrant and long disease-free survival (DFS) might be the ideal condition of Fulvestrant treatment. Fulvestrant can be effective for premenopausal patients with drug-induced menopause. Patients of different luminal subtypes can benefit from Fulvestrant. For patients with visceral metastases, presence of liver metastases rather than lung metastases was poor prognostic factor. Fulvestrant may also be considered as a maintenance treatment after first-line palliative chemotherapy.