Efficacy of Oral SERDs in the treatment of ER+, HER2 - metastatic breast cancer, a stratified analysis of the ESR1 wild type and mutant subgroups

BACKGROUND

Oral SERDs are a novel drug class that have been developed to counteract resistance due to ESR1 mutations. Several SERDs have emerged from phase 2 and 3 trials, with the FDA limiting approval for Elacestrant to patients with ESR1mt tumours despite PFS benefit in the overall population. However, questions remain on whether patients with ESR1wt tumours stand to benefit from oral SERDs.

PATIENTS AND METHODS

Manuscripts and conference presentations of Randomised Controlled Trials were extracted after a systematic search of Embase, PubMed and Cochrane from inception until January 21,2023. RCTs investigating the efficacy of oral SERDs versus endocrine therapy for ER positive, HER2 negative advanced breast cancer, and which reported the Kaplan Meier (KM) curves of PFS in the overall and ESR1 mutant (ESR1mt) population were selected. A graphical reconstructive algorithm was applied to estimate time-to-event outcomes from reported KM curves in all overall and ESR1mt cohorts. A bipartite matching algorithm, KMSubtraction, was used to derive survival data for unreported (ESR1wt) subgroups. An individual patient data (IPD) meta-analysis was then pursued, pooling data by ESR1 mutation status in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane Guidelines for IPD.

RESULTS

The randomized clinical trials ACELERA, AMEERA-3, EMERALD and SERENA-2 were included, totalling 1290 patients. In the pooled analysis of the overall cohort, PFS benefit was observed with oral SERDs when compared with treatment of physicians choice (TPC) (HR 0.783, 95%CI 0.681-0.900, p<0.001). In the ESR1mt subgroup, oral SERDs demonstrated improved PFS (HR 0.557, 95%CI 0.440-0.705, p<0.001) compared to TPC. In the ESR1wt subgroup, oral SERDs demonstrated no significant PFS benefit (HR 0.944, 95%CI 0.783-1.138, p=0.543) when compared to TPC.

CONCLUSIONS

The results of this IPD meta-analysis suggests that PFS benefit in the overall population is mainly driven by the ESR1mt subgroup.

Acute urine retention following medullary compression of metastatic breast cancer in the spinal cord: Rare symptomatlogic presentation and management

The management of locally advanced and metastatic breast cancer has evolved since 2021, with confirmation of the role of cell cycle inhibitors. The discovery of breast cancer is often the result of self-examination through the discovery of a nodule, but may also be due to symptoms at the metastatic site. The spinal cord is one of the rare sites of metastatic breast cancer involvement. We report the management of a rare case of metastatic breast cancer in the spinal cord, discovered following acute urinary retention.

18F-FDG PET/CT for the Evaluation of Therapy Response in Hormone Receptor-Positive Bone-Dominant Metastatic Breast Cancer

Fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/CT has shown promise for use in assessing treatment response in patients with bone-only or bone-dominant (BD) metastatic breast cancer (mBC). In this single-institution, prospective single-arm study of 23 women (median age, 59 years [range, 38-81 years]) with biopsy-proven estrogen receptor-positive bone-only or BD mBC about to begin new endocrine therapy between October 3, 2013, and August 3, 2018, the value of early 4-week 18F-FDG PET/CT in predicting progression-free survival (PFS) was evaluated. 18F-FDG PET/CT was performed at baseline, 4 weeks, and 12 weeks. Maximum standardized uptake value (SUVmax) and peak SUV (SUVpeak) were measured for up to five index lesions. The primary end point was PFS. Secondary end points were overall survival (OS) and time to skeletal-related events (tSREs). All end points were compared between responders (reduction of 30% or more in the sum of SUVmax for target lesions) and nonresponders at 4 weeks and 12 weeks. Percentage change from baseline in SUVmax at 4- and 12-week 18F-FDG PET/CT were highly correlated (r = 0.81). At the 4-week time point PET responders had numerically longer PFS (14.2 months vs 6.3 months; P = .53), OS (44.0 months vs 29.7 months; P = .47), and tSRE (27.4 months vs 25.2 months; P = .66) compared with nonresponders, suggesting the clinical utility of 4-week 18F-FDG PET/CT as an early predictor of treatment failure. Keywords: Breast Cancer, Metastatic Breast Cancer, Bone-Dominant Metastatic Breast Cancer, FDG PET/CT, Estrogen-Receptor Positive Metastatic Breast Cancer Supplemental material is available for this article. Clinical trial registration no. NCT04316117 © RSNA, 2022.

Patient-reported pain severity, pain interference and health status in HR+/HER2- advanced/metastatic breast cancer

Introduction

Patient-reported pain severity and related impact in advanced/metastatic breast cancer (ABC/MBC) are not well documented. The objective of this study was to assess pain and general health status in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) ABC/MBC.

Methods

Data were collected in the USA and Europe in a real-world, cross-sectional study. Patients were recruited at oncology practices and completed validated questionnaires; pain severity and interference were assessed using the Brief Pain Inventory (BPI) and general health status using the EuroQoL-5D (EQ-5D-3L). Descriptive statistics were generated for the overall cohort, and stratified by type of therapy and sites of metastases. Differences between patient groups were assessed via the Mann-Whitney Wilcoxon test. The relationship between pain scores and general health status was assessed using Kruskal-Wallis tests.

Results

Overall, 173 oncologists and 739 patients participated. The majority of patients rated their worst pain, average pain and pain interference as mild (59%, 77% and 70%, respectively). Most patients (>90%) reported no problems or moderate problems for all items of the EQ-5D-3L. Current treatment had no significant associations with pain severity or interference. Patients on chemotherapy reported significantly higher proportions of moderate/extreme levels of anxiety/depression (66.7%) and significantly lower general health status (60.7) compared with those on endocrine therapy (53.1% and 64.4, respectively). Pain severity and interference, all EQ-5D-3L items except self-care and the EQ-5D-3L health utility index were also significantly associated with sites of metastases, with greater impact in patients with visceral and bone metastases than those with bone only or visceral only metastases. Significant associations were observed between pain and health status, with increased pain severity and pain interference associated with worse health utility and general health status.

Conclusion

There is a clear unmet need for treatments that can reduce pain and preserve health status in patients with HR+/HER2− ABC/MBC.

Recent developments and translational aspects in targeted therapy for metastatic breast cancer

Biologically distinct subtypes of metastatic breast cancer (MBC) have been defined by multiple efforts in recent years, showing broad heterogeneity at the molecular level of disease. Throughout this endeavour, oncogenic drivers within MBC were identified as potential therapeutic targets. With recent results from clinical trials targeting these well-known cancer-promoting pathways, this review is trying to elucidate as well as summarise current new therapeutic aspects in MBC and shed light on translational aspects within this entity.