Tackling endocrine resistance in ER-positive HER2-negative advanced breast cancer: A tale of imprecision medicine

Efficacy and safety of cyclin-dependent kinase 4/6 inhibitor in patients with advanced breast cancer: A real-world experience

BACKGROUND

Cyclin-dependent kinases 4 and 6 inhibitors (CDK4/6i) have been shown to improve progression-free survival (PFS) in patients with metastatic breast cancer (MBC) in randomized control trials. This study aimed to evaluate the efficacy and safety of CDK4/6i in patients with advanced breast cancer (ABC) in a clinical setting.

METHODS

Consecutive patients with ABC were treated between October 2019 and March 2023 at Taipei Tzu Chi Hospital, Taiwan. Patients who had received at least one dose of CDK4/6i were included in this retrospective study. The main outcome of this study was efficacy based on the treating physicians' assessments in terms of PFS, and overall survival (OS), as well as the factors associated with patient outcome. The secondary outcome was safety.

RESULTS

A total of 85 patients were included in the analysis, with a mean age of 66.8 years. After a median follow-up of 16.1 months, the median PFS was 28.4 months (95% CI: 22.5-33.6) and the median OS could not yet be estimated. The most common adverse events (AE) were fatigue (50.8%), anorexia (45.9%), and leukopenia (44.7%). In multivariable analysis, treatment with CDK4/6i with any grade AE or response to treatment effect (CR/PR) was an independent predictor for longer PFS (hazard ratio [HR] = 0.27, 95% CI: 0.11-0.68; HR = 0.21, 95% CI: 0.06-0.67; p < 0.05).

CONCLUSION

CDK4/6i administered in a real-world setting exhibits a similar survival benefit with the clinical trials.

Ruxolitinib and exemestane for estrogen receptor positive, aromatase inhibitor resistant advanced breast cancer

Circulating IL-6, an activator of JAK/STAT signaling, is associated with poor prognosis and aromatase inhibitor (AI) resistance in hormone-receptor positive (HR+) breast cancer. Here we report the results of a phase 2 single-arm Simon 2-stage trial combining Ruxolitinib, an oral selective inhibitor of JAK1/2, with exemestane, a steroidal AI, in patients with HR+ metastatic breast cancer (MBC) after progression on non-steroidal AI (NSAI). Safety and efficacy were primary objectives, and analysis of inflammatory markers as predictors of response was a key secondary objective. Twenty-five subjects enrolled. The combination of ruxolitinib and exemestane was safe, though anemia requiring transfusion in 5/15 (33%) at the 25 mg dose in stage 1 led to a reduction to 15 mg twice daily in stage 2 (with no additional transfusions). Clinical benefit rate (CBR) in the overall study population was 24% (95% CI 9.4-45.1); 6/25 patients demonstrated stable disease for ≥6 months. Median progression-free survival was 2.8 months (95% CI 2.6-3.9). Exploratory biomarkers revealed high levels of systemic inflammation and 60% harbored a high-risk IL-6 genotype. Pharmacodynamics demonstrated modest on-target inhibition of phosphorylated-STAT3 by ruxolitinib at a tolerable dose. Thus, ruxolitinib combined with exemestane at a tolerable dose was safe but minimally active in AI-resistant tumors of patients with high levels of systemic inflammation. These findings highlight the need for more potent and specific therapies targeting inflammation in MBC.

Objective Response to First-Line Treatment as a Predictor of Overall Survival in Metastatic Breast Cancer: A Retrospective Analysis from Two Centers over a 25-Year Period

<b><i>Introduction:</i></b> The purpose of this study was to study the efficacy of subsequent treatment lines for metastatic breast cancer (MBC), as well as the association between radiologic objective response rate (ORR) and overall survival (OS). <b><i>Methods:</i></b> In this retrospective study, consecutive patients treated for MBC in two centers in Greece from January 1, 1992, to December 31, 2016, were identified and clinicopathologic data regarding tumor characteristics and administered treatments were collected. The efficacy per treatment line in terms of ORR, progression-free survival (PFS) and OS, as well as the prognostic value of ORR at first line were investigated. <b><i>Results:</i></b> A total of 977 patients with MBC were identified; 950 received any treatment. At first line, ORR was 43.5%, PFS 11.4 months (95% CI 10.4–12.4), and median OS 52.4 months (95% CI 47.7–57.1). Lower ORR and shorter PFS were observed with each subsequent line. Median OS was significantly longer for patients that had an objective response at first line, 61.9 months (95% CI 51.1–69.7) for responders versus 41.3 months (95% CI 44.1–63.3) for nonresponders (<i>p</i> &#x3c; 0.001). In multivariable analysis, failure to achieve an objective response was an independent predictor of poor survival (hazard ratio 1.70, 95% CI 1.34–2.15, <i>p</i> &#x3c; 0.001). <b><i>Conclusion:</i></b> Late treatment lines for MBC seem to have limited efficacy, while response to first-line therapy is associated with long-term survival. The latter should be considered in the treatment strategy of patients with MBC.

Ki67 and progesterone receptor status predicts sensitivity to palbociclib: a real-world study

Background

Palbociclib combined with endocrine therapy has been approved as a front-line treatment for hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer (ABC). A key challenge remains to uncover biomarkers to identify those patients who may benefit from palbociclib treatment.

Methods

We retrospectively analyzed the values of Ki67 and progesterone receptor (PR) as detected by immunohistochemistry in 81 ABC patients with palbociclib and hormone therapy treatment, and evaluated the impact on progression-free survival (PFS).

Results

In the total population, women with Ki67 ≥14% had marginally significantly shorter PFS than those with Ki67 <14% (P=0.062). Patients with Ki67 ≥30% had significantly shorter PFS than those with Ki67 <30% (P=0.048). Meanwhile, PR ≥20% was associated with longer PFS. Moreover, the change of Ki67 or PR from primary tissue to metastatic lesions was related to PFS. As for the hormone therapy subgroup, there were significant associations between Ki67 and PR levels and PFS in the aromatase inhibitors (AIs) subgroup. Patients with Ki67 ≥14% or Ki67 ≥30% had shorter PFS than those with Ki67 <14% or Ki67 <30%, respectively (P=0.024, P<0.001). Additionally, the change of Ki67 or PR from primary tissue to metastatic lesions was related to PFS. When both Ki67 and PR were considered, there were significant differences between the different cohorts. Compared with patients with Ki67 ≥14% and PR <20%, those with Ki67 <14% and PR ≥20% had significantly longer PFS. In addition, patients with Ki67 <30% and PR ≥20% had significantly longer PFS than those with Ki67 ≥30% and PR <20%. Furthermore, in the AI cohort, patients with Ki67 <14% and PR ≥20% had significantly longer PFS than those with Ki67 ≥14% and PR <20%. Women with Ki67 <30% and PR ≥20% had significantly longer PFS than those with Ki67 ≥30% and PR <20%.

Conclusions

The present study indicates that both Ki67 and PR have great impacts on palbociclib and hormone therapy and may contribute to selecting more effective partners for palbociclib.

Deciphering of Key Pharmacological Pathways of Poria Cocos Intervention in Breast Cancer Based on Integrated Pharmacological Method

OBJECTIVE

Poria cocos (Fuling), a natural plant, has recently emerged as a promising strategy for cancer treatment. However, the molecular mechanisms of Poria cocos action in breast cancer remain poorly understood.

METHODS

TCMSP database was used to screen the potential active ingredients in Poria cocos. GEO database was used to identify differentially expressed genes. Network pharmacology was used to identify the specific pathways and key target proteins related to breast cancer. Finally, molecular docking was used to validate the results.

RESULTS

In our study, 237 targets were predicted for 15 potential active ingredients found in Poria cocos. An interaction network of predicted targets and genes differentially regulated in breast cancers was constructed. Based on the constructed network and further analysis including network topology, KEGG, survival analysis, and gene set enrichment analysis, 3 primary nodes were identified as key potential targets that were significantly enriched in the PPAR signaling pathway.

CONCLUSION

The results showed that potential active ingredients of Poria cocos might interfere with breast cancer through synergistic regulation of PTGS2, ESR1, and FOS.

Efficacy and safety of cyclin dependent kinases 4/6 inhibitors in the treatment of metastatic breast cancer: a real-world experience

BACKGROUND

Randomized trials have shown survival gains for patients with metastatic breast cancer (BC) treated with CDK4/6 inhibitors (CDK4/6i) in combination with endocrine agents. It is not unlikely that there may be discrepancies between the generally fit clinical study population and the real-world setting that could affect adherence to treatment guidelines, tolerance to treatment and outcome.

MATERIAL AND METHODS

Consecutive patients with metastatic or locally advanced and unresectable BC that were treated between July 2017 and January 2020 at Karolinska University Hospital, Stockholm, Sweden and that had received at least one dose of CDK4/6i were included in this retrospective study. The primary endpoint was safety, including toxicity according to CTCAE 5 and rates of treatment interruptions, dose reductions and discontinuations. The secondary endpoint was efficacy based on the treating physicians' assessments in terms of progression free (PFS) and overall survival (OS), as well as the factors associated with patient outcome.

RESULTS

Eighty-eight patients were included in the analysis, with a median age of 67.2 years. Grade 4 neutropenia occurred in 9.1% of patients and one episode of neutropenic infection was observed. Dose reductions were made in 38.6% of patients, while 11.4% discontinued treatment due to toxicity, most commonly non-hematologic. After a median follow-up of 18.33 months, median PFS was 13.30 months (95% CI, 11.39-15.21) and median OS could yet not be estimated. In multivariable analysis, number of prior chemotherapy lines was an independent predictor for shorter PFS (HR = 3.28, 95% CI 1.50-7.16, p = .003).

CONCLUSIONS

CDK4/6i administered in a real-world setting exhibits a similar toxicity profile but higher incidence of treatment discontinuation compared to randomized trials. Efficacy of CDK4/6i among patients pretreated with multiple therapy lines is markedly reduced.

Targeting Cell Cycle in Breast Cancer: CDK4/6 Inhibitors

Deregulation of cell cycle, via cyclin D/CDK/pRb pathway, is frequently observed in breast cancer lending support to the development of drugs targeting the cell cycle control machinery, like the inhibitors of the cycline-dependent kinases (CDK) 4 and 6. Up to now, three CDK4/6 inhibitors have been approved by FDA for the treatment of hormone receptor-positive (HR+), HER2-negative metastatic breast cancer. These agents have been effective in improving the clinical outcomes, but the development of intrinsic or acquired resistance can limit the efficacy of these treatments. Clinical and translational research is now focused on investigation of the mechanism of sensitivity/resistance to CDK4/6 inhibition and novel therapeutic strategies aimed to improve clinical outcomes. This review summarizes the available knowledge regarding CDK4/6 inhibitor, the discovery of new biomarkers of response, and the biological rationale for new combination strategies of treatment.

Chemotherapy use near the end-of-life in patients with metastatic breast cancer

Introduction

Very few data are available regarding the use of chemotherapy in patients with metastatic breast cancer (MBC) near the end-of-life, i.e., the final month. The aim of this study was to provide a descriptive analysis of its use in two different European geographic areas (Sweden and Greece).

Materials and methods

We retrospectively collected data regarding clinicopathologic characteristics, survival, and use of chemotherapy during the final 30 days of life using two sources: for the Swedish cohort, patients who were diagnosed with MBC in 2010–2015 were identified from the Stockholm-Gotland population-based Breast Cancer Registry and treatment data were collected using hospital charts. For the Greek cohort, patients with MBC were identified from hospital charts at two hospitals in Athens and Crete.

Results

In the Swedish cohort, 1571 patients were identified; median overall survival was 16.96 months (95% CI 15.4–18.4). 23.2% of patients were treated with chemotherapy during the final month of life, with higher rates among patients ≤ 60 years (p < 0.001). Per OS monotherapy such as capecitabine or vinorelbine was most commonly used. In contrast, median OS in the Greek cohort (n = 966) was 49.8 months (95% CI 45.6–54.1) and 46.5% of patients received chemotherapy at the end-of-life, most commonly intravenous drug combinations. In multivariable analysis, age and albumin levels were statistically significantly associated with chemotherapy use in the Swedish cohort.

Conclusion

Chemotherapy use near the end-of-life was common, which might negatively impact patient quality of life.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05663-w) contains supplementary material, which is available to authorized users.

The Clinical and Molecular Characteristics of Sex-Determining Region Y-Box 2 and its Prognostic Value in Breast Cancer: A Systematic Meta-Analysis

Objective

Transcription factor SOX2 (sex-determining region Y-box 2) has a crucial role in the maintenance of the stem cell state. However, current evidence regarding the role of SOX2 in breast cancer is conflicting. We conducted this meta-analysis to clarify the association of SOX2 expression with clinical and molecular features and its prognostic effect on breast cancer.

Methods

All relevant articles were searched using electronic databases. The pooled odds ratios (ORs) or hazard ratios (HRs: multivariate Cox survival analysis) with their 95% confidence intervals (CIs) were calculated.

Results

A final total of 18 studies containing 3,080 patients with breast cancer were included. SOX2 protein expression was not related to age, menopausal status, lymph node metastasis, lymphovascular invasion, molecular estrogen receptor status, progesterone receptor status, triple-negative status, and the overall survival in breast cancer, but was closely associated with advanced tumor grade (grade 3 vs. grade 1-2: OR = 2.74, 95% CI = 1.85-4.06, p < 0.001), clinical stage (stage 3-4 vs. stage 0-2: OR = 2.46, 95% CI = 1.37-4.40, p = 0.002), pT stage (T stage 2-4 vs. T stage 1: OR = 1.52, 95% CI = 1.07-2.17, p = 0.019), molecular human epidermal growth factor receptor 2 (HER2) status (positive vs. negative: OR = 1.61, 95% CI = 1.21-2.14, p = 0.001), epidermal growth factor receptor (EGFR) status (positive vs. negative: OR = 2.21, 95% CI = 1.13-4.33, p = 0.021), and worse disease-free survival (DFS) (HR = 2.66, 95% CI = 1.20-5.91, p = 0.016) of breast cancer.

Conclusions

SOX2 expression is correlated with breast cancer progression, HER2 status, and EGFR status, and may be an independent prognostic marker for predicting poor DFS.

Novel Strategies on Personalized Medicine for Breast Cancer Treatment: An Update

Breast cancer is the most common cancer type among women worldwide. With breast cancer patients and survivors being reported to experience a repertoire of symptoms that are detrimental to their quality of life, the development of breast cancer treatment strategies that are effective with minimal side effects is therefore required. Personalized medicine, the treatment process that is tailored to the individual needs of each patient, is recently gaining increasing attention for its prospect in the development of effective cancer treatment regimens. Indeed, recent studies have identified a number of genes and molecules that may be used as biomarkers for predicting drug response and severity of common cancer-associated symptoms. These would provide useful clues not only for the determination of the optimal drug choice/dosage to be used in personalized treatment, but also for the identification of gene or molecular targets for the development of novel symptom management strategies, which ultimately would lead to the development of more personalized therapies for effective cancer treatment. In this article, recent studies that would provide potential new options for personalized therapies for breast cancer patients and survivors are reviewed. We suggest novel strategies, including the optimization of drug choice/dosage and the identification of genetic changes that are associated with cancer symptom occurrence and severity, which may help in enhancing the effectiveness and acceptability of the currently available cancer therapies.

The next era of treatment for hormone receptor-positive, HER2-negative advanced breast cancer: Triplet combination-based endocrine therapies

Until recently, the standard of care for hormone receptor-positive (HR+) breast cancer was single-agent endocrine therapy, which aims to prevent estrogen receptor signaling. This therapeutic strategy has extended survival without the toxicity associated with chemotherapy, but primary endocrine therapy resistance is common, and secondary resistance develops over time. Adjunct downstream inhibition of the cyclin-dependent kinase (CDK)4/6 pathway, intended to delay and prevent endocrine therapy resistance, has further extended progression-free survival in patients receiving endocrine therapy; however, resistance still eventually develops in these patients. Addition of phosphatidylinositol-3 kinase (PI3K) or mammalian target of rapamycin (mTOR) inhibitors to combined CDK4/6 and endocrine inhibitor regimens may help prolong CDK4/6 inhibitor sensitivity. Early trials combining CDK4/6 inhibitors, PI3K or mTOR inhibitors, and endocrine therapy have shown encouraging signs of clinical activity. However, further research is needed to help understand the extent of treatment benefit from triplet therapy and where this strategy will fit in the treatment sequence for patients with HR+ breast cancer.