Evaluation of Sensitivity to Endocrine Therapy Index (SET2,3) for Response to Neoadjuvant Endocrine Therapy and Longer-Term Breast Cancer Patient Outcomes (Alliance Z1031)

Further Optimizing Care of Patients With Operable Hormone Receptor-Sensitive Breast Cancer

Harmonized global collaborations are crucial to improving outcomes in hormone sensitive operable breast cancer.

Adjuvant Dose-Dense Chemotherapy in Hormone Receptor-Positive Breast Cancer

PURPOSE

In light of evolving evidence that some patients with node-positive estrogen receptor-positive (ER+) disease may receive less benefit from chemotherapy, this study reports 12-year outcomes of the C9741 trial overall, and by the sensitivity to endocrine therapy (SET2,3) test index, a biomarker measuring endocrine transcriptional activity, to identify patients most likely to benefit from dose-dense chemotherapy.

METHODS

In all, 1,973 patients were randomly assigned to dose-dense versus conventional chemotherapy. Hazard ratios (HRs) for prognosis and for predictive interaction with chemotherapy schedule were estimated from Cox models of long-term disease-free survival (DFS) and overall survival (OS). SET2,3 was tested on the 682 banked RNA samples from ER+ cancers.

RESULTS

Dose-dense chemotherapy improved DFS in the overall study population by 23% (HR, 0.77 [95% CI, 0.66 to 0.90]) and OS by 20% (HR, 0.80 [95% CI, 0.67 to 0.95]); the benefits of dose-dense therapy were seen for ER+ and ER-negative subsets, without significant interaction between treatment arm and ER status. Low SET2,3 status was highly prognostic, but also predicted improved outcomes from dose-dense chemotherapy (interaction P = .0998 for DFS; 0.027 for OS), independent of menopausal status. Specifically, low endocrine transcriptional activity predicted benefit from dose-dense chemotherapy, whereas tumor burden and proliferation-driven signatures for molecular subtype classification did not.

CONCLUSION

At 12-year follow-up, C9741 confirmed the sustained long-term benefit of adjuvant dose-dense chemotherapy for node-positive breast cancer. SET2,3 identified patients with ER+ breast cancer who benefited from dose-dense chemotherapy, and specifically, this benefit was predicted by low endocrine activity in the cancer, rather than tumor burden, molecular subtype, or menopausal status.

Comparative analysis of Ficoll-Hypaque and CytoLyt techniques for blood removal in breast cancer malignant effusions: effects on RNA quality and sequencing outcomes

INTRODUCTION

To optimize RNA sequencing (RNA-seq) outcomes, we investigated preanalytical variables in malignant effusions containing metastatic breast cancer. We compared 2 processing methods-Ficoll-Hypaque density gradient enrichment and CytoLyt hemolysis-focusing on their effects on RNA quality, transcript abundance, and variant detection from cytospin slides, relative to fresh-frozen samples. Additionally, we compared read-based and Unique Molecular Identifier (UMI)-based library preparation methods.

MATERIALS AND METHODS

Thirteen malignant effusion specimens from metastatic breast cancer were processed using both the Ficoll-Hypaque and Cytolyt methods. RNA was extracted from fresh-frozen samples stored in RNA preservative and from cytospin slides fixed in Carnoy's solution. RNA quality was evaluated using RNA integrity number (RIN) and the percentage of fragments >200 bases (DV200). Sequencing was conducted with both read- and UMI-based methods.

RESULTS

Purified RNA was more fragmented by the Cytolyt method (mean RIN: 3.56, DV200: 78.97%), compared to the Ficoll-Hypaque method (mean RIN: 6.29, DV200: 88.08%). Sequencing data had high concordance correlation coefficient (CCC) for measurements of gene expression, whether from Cytolyt or Ficoll-Hypaque treated samples, and whether using the UMI- or read-based sequencing methods (read-based mean CCC: 0.967 from Cytolyt versus 0.974 from Ficoll-Hypaque, UMI-based mean CCC: 0.972 from Cytolyt versus 0.977 from Ficoll-Hypaque).

CONCLUSIONS

Despite the increased RNA fragmentation with the Cytolyt, RNA-seq data quality was comparable across Cytolyt and Ficoll-Hypaque methods. Both clearing methods are viable for short-read RNA-seq analysis, with read and UMI-based approaches performing similarly.

Adjuvant and neoadjuvant therapy with or without CDK4/6 inhibitors in HR+/HER2- early breast cancer: a systematic review and meta-analysis

Background

The combination of cyclin-dependent kinases 4/6 (CDK4/6) inhibitors and endocrine therapy is the standard treatment for patients with hormone receptor-positive (HR+)/HER2-negative (HER2-) advanced breast cancer. However, the role of CDK4/6 inhibitors in early breast cancer remains controversial.

Methods

This study aimed to evaluate the efficacy and safety of CDK4/6 inhibitors combined with endocrine therapy versus endocrine therapy alone in patients with HR+, HER2- early breast cancer. A systematic review of Cochrane, PubMed and EMBASE databases was conducted. The efficacy endpoints of adjuvant therapy were invasive disease-free survival (IDFS), overall survival (OS) and distant relapse-free survival (DRFS). The efficacy endpoint included complete cell cycle arrest (CCCA) and complete pathologic response (PCR) with neoadjuvant therapy. Grade 3/4 adverse events (AEs) were assessed as safety outcomes.

Results

Eight randomized controlled trials (RCTs) were included in the study. CDK4/6 inhibitors combined with endocrine therapy showed a significant improvement in IDFS (hazard ratio (HR) = 0.81, 95% confidence interval (CI) = 0.68-0.97, P = 0.024), but not DRFS (HR = 0.84, 95% CI = 0.56-1.29, P = 0.106) or OS (HR = 0.96, 95% CI = 0.77-1.19, P = 0.692) in adjuvant therapy. In the neoadjuvant therapy setting, CDK4/6 inhibitors improved CCCA compared with the control group (RR = 2.08, 95% CI = 1.33-3.26, P = 0.001). The risk of 3/4 grade AEs increased significantly with the addition of CDK4/6 inhibitors to endocrine therapy.

Conclusion

The addition of CDK4/6 inhibitors in HR+/HER2- early breast cancer patients significantly improved IDFS in adjuvant therapy and CCCA in neoadjuvant. However, CDK4/6 inhibitors also showed significant toxicities during therapy.

Systematic Review Registration

Identifier CRD42024530704.

Favorable outcome of neoadjuvant endocrine treatment than surgery-first in female HR-positive/HER2-negative breast cancer patients-A NCDB analysis (2010-2016)

PURPOSE

To assess the efficacy of neoadjuvant endocrine therapy in female HR-positive/HER2-negative breast cancer patients.

DATA AND METHODS

We identified female patients aged ≥18 years with cT1-4N0-XM0, HR(+), and HER2(-) breast cancer from the National Cancer Database. The patients who underwent surgery first were categorized as "surgery-first," while those who received NET before surgery were classified as "NET." Propensity score-matching, Cox proportional-hazard model, variance inflation factors, and interaction analysis were employed to estimate the correlation between NET and survival outcomes.

RESULTS

Among 432,387 cases, 2914 NET patients and 2914 surgery-first patients were matched. Compared with the surgery-first group, the NET group received less adjuvant chemotherapy (p < 0.001). Furthermore, the NET group exhibited higher survival probabilities compared with the surgery-first group (3 years: 91.4% vs. 82.1%; 5 years: 82.1% vs. 66.8%). Multivariate Cox analysis indicated that NET was associated with improved OS (surgery-first vs. NET: HR 2.17, 95% CI: 1.93-2.44). Age over 55 years old, having public insurance, higher CDCC score, higher NSBR grade, ER(+)PR(-), and advanced clinical stage were related to worse OS (all p < 0.05). There was an interaction between age, race, income, and home and treatment regimen (all p < 0.05).

CONCLUSION

NET may be a more effective treatment procedure than surgery-first in female HR-positive/HER2-negative, non-metastatic breast cancer patients. Future clinical studies with more detailed data will provide higher-level evidence-based data.

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers: from chemotherapy to hormonal therapy, CDK inhibitors, and beyond

INTRODUCTION

Chemotherapy has been traditionally used as neo-adjuvant therapy in breast cancer for down-staging of locally advanced disease in all sub-types. In the adjuvant setting, genomic assays have shown that a significant proportion of ER positive/HER2 negative patients do not derive benefit from the addition of chemotherapy to adjuvant endocrine therapy. An interest in hormonal treatments as neo-adjuvant therapies in ER positive/HER2 negative cancers has been borne by their documented success in the adjuvant setting. Moreover, cytotoxic chemotherapy is less effective in ER positive/HER2 negative disease compared with other breast cancer subtypes in obtaining pathologic complete responses.

AREAS COVERED

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers and associated biomarkers are reviewed, using a Medline survey. A focus of discussion is the prediction of patients that are unlikely to derive extra benefit from chemotherapy and have the highest probabilities of benefiting from hormonal and other targeted therapies.

EXPERT OPINION

Predictive biomarkers of response to neo-adjuvant chemotherapy and hormonal therapies are instrumental for selecting ER positive/HER2 negative breast cancer patients for each treatment. Chemotherapy remains the standard of care for many of those patients requiring neo-adjuvant treatment, but other neo-adjuvant therapies are increasingly used.

Neoadjuvant therapy in hormone Receptor-Positive/HER2-Negative breast cancer

Neoadjuvant therapy is commonly used in patients with locally advanced or inoperable breast cancer (BC). Neoadjuvant chemotherapy (NACT) represents an established treatment modality able to downstage tumours, facilitate breast-conserving surgery, yet also achieve considerable pathologic complete response (pCR) rates in HER2-positive and triple-negative BC. For patients with HR+/HER2- BC, the choice between NACT and neoadjuvant endocrine therapy (NET) is still based on clinical and pathological features and not guided by biomarkers of defined clinical utility, differently from the adjuvant setting where gene-expression signatures have been widely adopted to drive decision-making. In this review, we summarize the evidence supporting the choice of NACT vs NET in HR+/HER2- BC, discussing the issues surrounding clinical trial design and proper selection of patients for every treatment. It is time to question the binary paradigm of responder vs non-responders as well as the "one size fits all" approach in luminal BC, supporting the utilization of continuous endpoints and the adoption of tissue and plasma-based biomarkers at multiple timepoints. This will eventually unleash the full potential of neoadjuvant therapy which is to modulate patient treatment based on treatment sensitivity and surgical outcomes. We also reviewed the current landscape of neoadjuvant studies for HR+/HER2- BC, focusing on antibody-drug conjugates (ADCs) and immunotherapy combinations. Finally, we proposed a roadmap for future neoadjuvant approaches in HR+/HER2- BC, which should be based on a staggered biomarker-driven treatment selection aiming at impacting long-term relevant endpoints.

Pre-analytical effects on whole transcriptome and targeted RNA sequencing analysis in cytology: The effects of prolonged time in storage of effusion specimens prior to preservation

OBJECTIVES

To investigate the pre-analytics of the molecular testing of cytology specimens, we studied the effects of time in refrigerator storage (4°C) of malignant effusions on RNA sequencing (RNAseq) results.

METHODS

Ten effusion specimens were stored in a refrigerator (4°C) for different durations (day 0, 1, 4, and 7). All specimens were prepared as cytospins fixed in either Carnoy's solution or 95% ethanol (EtOH) and in an RNA preservative for a fresh frozen (FF) high-quality reference. Whole transcriptome (wt) and targeted (t)RNAseq of two multigene expression signatures were performed. We then compared transcript expression levels (including mutant allele fraction) according to pre-analytical variables using a concordance correlation coefficient (CCC) and a mixed effect model.

RESULTS

Sequencing results were mostly stable over increasing time in storage. Cytospins fixed in Carnoy's solution were more concordant with FF samples than cytospins fixed in 95% EtOH at all timepoints. This finding was consistent for both wtRNAseq (averages: day 0 CCC = 0.98 vs 0.91; day 7 CCC = 0.88 vs 0.78) and tRNAseq methods (averages: day 0 CCC = 0.98 vs 0.81; day 7 CCC = 0.98 vs 0.90). Cytospins fixed in Carnoy's solution did not show significant changes in expression over timepoints or between expression signatures, whereas 95% EtOH did.

CONCLUSION

RNAseq can be accurately performed on effusion specimens after prolonged refrigerator storage. RNA extracted from scraped cytospin slides fixed in Carnoy's solution was marginally superior to 95% EtOH fixation, but either method had comparable analytic performance to high-quality FF RNA samples.

Evaluation of the Sensitivity to Endocrine Therapy Index and 21-Gene Breast Recurrence Score in the SWOG S8814 Trial

PURPOSE

Chemotherapy has not demonstrated benefit over adjuvant endocrine therapy alone for postmenopausal patients with node-positive breast cancer with a 21-gene breast recurrence score (RS) of 25 or below (RS ≤ 25). We tested whether combined results from RS and the sensitivity to endocrine therapy (SET2,3) index of endocrine-related transcription (SETER/PR) adjusted for baseline prognostic index (BPI) improve prognostic assessment, and whether SET2,3 predicted benefit from anthracycline-based chemotherapy.

METHODS

A blinded retrospective clinical validation of SET2,3 in two randomized treatment arms from the SWOG S8814 trial comparing adjuvant anthracycline-based chemotherapy followed by tamoxifen endocrine therapy for 5 years, versus tamoxifen alone. SET2,3 assay was calibrated and measured using whole-transcriptome RNA sequence of tumor samples already tested for RS. The primary end point was disease-free survival (DFS).

RESULTS

There were 106 events in 283 patients over a median follow-up of 8.99 years. Proportional hazards assumptions were met during the first 5 years only. SET2,3 index and RS were not correlated (r = -0.04) and were independently prognostic (SET2,3: hazard ratio [HR], 0.48 per unit; 95% CI, 0.34 to 0.68; P < .001; RS: HR, 1.28 per 10 units; 95% CI, 1.14 to 1.44; P < .001). SET2,3 index did not predict chemotherapy benefit (interaction P = .77). SET2,3 was high in 93/175 (53%) patients with RS ≤ 25 (concordant low-risk), with 5-year DFS 97%. SET2,3 was low in 55/108 (51%) patients with RS > 25 (concordant high-risk), with 5-year DFS 53%. Both components of SET2,3 index were prognostic after adjustment for RS: SETER/PR (HR, 0.65; 95% CI, 0.46 to 0.92) and BPI (HR, 0.45; 95% CI, 0.31 to 0.64).

CONCLUSION

SET2,3 index was not correlated with RS, demonstrated additive prognostic performance, and was not chemopredictive in this subset of patients from S8814. The SETER/PR and BPI components of SET2,3 each added prognostic information to RS.

Neoadjuvant endocrine therapy in postmenopausal women with HR+/HER2- breast cancer

INTRODUCTION

While endocrine therapy is the standard-of-care adjuvant treatment for hormone receptor-positive (HR+) breast cancers, there is also extensive evidence for the role of pre-operative (or neoadjuvant) endocrine therapy (NET) in HR+ postmenopausal women.

AREAS COVERED

We conducted a thorough review of the published literature, to summarize the evidence to date, including studies of how NET compares to neoadjuvant chemotherapy, which NET agents are preferable, and the optimal duration of NET. We describe the importance of on-treatment assessment of response, the different predictors available (including Ki67, PEPI score, and molecular signatures) and the research opportunities the pre-operative setting offers. We also summarize recent combination trials and discuss how the COVID-19 pandemic led to increases in NET use for safe management of cases with deferred surgery and adjuvant treatments.

EXPERT OPINION

NET represents a safe and effective tool for the management of postmenopausal women with HR+/HER2- breast cancer, enabling disease downstaging and a wider range of surgical options. Aromatase inhibitors are the preferred NET, with evidence suggesting that longer regimens might yield optimal results. However, NET remains currently underutilised in many territories and institutions. Further validation of predictors for treatment response and benefit is needed to help standardise and fully exploit the potential of NET in the clinic.