Racial/ethnic differences in 21-gene recurrence score and survival among patients with estrogen receptor-positive breast cancer

BACKGROUND

Despite numerous studies on racial/ethnic disparities among patients with breast cancer, there is a paucity of literature evaluating racial/ethnic differences in 21-gene recurrence score (RS) and survival differences stratified by RS risk categories. We thus performed an observational cohort study to examine racial/ethnic disparities in the context of RS.

METHODS

The National Cancer Database (NCDB) was queried for female patients diagnosed between 2006 and 2018 with estrogen receptor (ER)-positive, pT1-3N0-1aM0 breast cancer who received surgery followed by adjuvant endocrine therapy and had RS data available. Logistic multivariable analysis (MVA) was built to evaluate variables associated with RS ≥ 26. Cox MVA was used to evaluate OS. Subgroup analyses were performed to compare the magnitude of racial/ethnic differences stratified by RS. P values less than 0.017 were considered statistically significant based on Bonferroni correction.

RESULTS

A total of 140,133 women were included for analysis. Of these, 115,651 (82.5%), 8,213 (5.9%), 10,814 (7.7%), and 5,455 (3.9%) were NHW, Hispanic, Black, and API women, respectively. Median (IQR) follow up was 66.2 months (48.0-89.8). Logistic MVA showed that, compared with NHW women, Black women were associated with higher RS (≥ 26 vs < 26: adjusted odds ratio [aOR] 1.19, 95% confidence interval [CI] 1.12-1.26, p < 0.001), while HW (aOR 0.93, 95% CI 0.86-1.00, p = 0.04) and API women (aOR 1.03, 95% CI 0.95-1.13, p = 0.45) were not. Cox MVA showed that, compared with NHW women, Black women had worse OS (adjusted hazards ratio [aHR] 1.10, 95% CI 1.02-1.19, p = 0.012), while HW (aHR 0.85, 95% CI 0.77-0.94, p = 0.001) and API (aHR 0.66, 95% CI 0.56-0.77, p < 0.001) women had better OS. In subgroup analysis, similar findings were noted among those with RS < 26, while only API women were associated with improved OS among others with RS ≥ 26.

CONCLUSION

To our knowledge, this is the largest study using nationwide oncology database to suggest that Black women were associated with higher RS, while HW and API women were not. It also suggested that Black women were associated with worse OS among those with RS < 26, while API women were associated with improved OS regardless of RS when compared to NHW women.

A plain language summary of the TROPiCS-02 study in patients with breast cancer (HR-positive/HER2-negative)

WHAT IS THIS SUMMARY ABOUT?

Sacituzumab govitecan (brand name: TRODELVY®) is a new treatment for certain types of advanced or metastatic breast cancer. One common type of breast cancer has at least 1 of 2 hormone receptors (HR positive) and does not have human epidermal growth factor 2 (HER2 negative). The HR and HER2 receptors are known to influence how severe a case of breast cancer is. Certain treatments will only work if a specific receptor is present on breast cancer cells. HR-positive/HER2-negative advanced or metastatic breast cancer can be treated with sacituzumab govitecan. This is a summary of the results of the TROPiCS-02 study. This study compared sacituzumab govitecan with standard chemotherapy in participants with HR-positive/HER2-negative advanced or metastatic breast cancer.

WHAT WERE THE RESULTS?

The study showed that participants treated with sacituzumab govitecan lived significantly longer without their cancer getting worse than participants treated with chemotherapy. Participants also survived significantly longer and their tumors became significantly smaller in more participants treated with sacituzumab govitecan than with chemotherapy. In general, participants treated with sacituzumab govitecan were more likely to have side effects and had more severe side effects. These side effects included low levels of a type of white blood cell known as neutrophils and diarrhea. Oncologists (doctors that treat cancer) know of these side effects as they are common among people being treated for cancer. Doctors can control these side effects by following standard treatment guidelines and the package insert for sacituzumab govitecan. Participants treated with sacituzumab govitecan maintained their sense of well-being and ability to do daily activities (quality of life) longer than participants treated with chemotherapy. It also took longer for fatigue and other symptoms of cancer to worsen in participants treated with sacituzumab govitecan compared with chemotherapy.

WHAT DO THE RESULTS MEAN?

Sacituzumab govitecan is more effective than standard chemotherapies for people who have already received multiple treatments for HR-positive/ HER2-negative advanced breast cancer. The side effects from sacituzumab govitecan could generally be managed well by doctors. Although there were more side effects with sacituzumab govitecan than with chemotherapy, they were generally mild to moderate.

Efficacy and Safety of Anti-HER2 Targeted Therapy for Metastatic HR-Positive and HER2-Positive Breast Cancer: A Bayesian Network Meta-Analysis

Despite the development of HER2-targeted drugs, achieving favorable outcomes for patients with HR+/HER2+MBC remains challenging. This study utilized Bayesian Network Meta-analysis to compare the efficacy and safety of anti-HER2 combination regimens. The primary analysis focused on progression-free survival (PFS), while secondary analyses included objective response rate, overall survival (OS) and the incidence rate of grade 3/4 adverse events (AEs). A comprehensive search across seven databases identified 25 randomized controlled trials for inclusion in this meta-analysis. For patients eligible for endocrinotherapy, our findings revealed that dual-target combined endocrine therapy, such as Her2-mAb+Her2-mAb+Endo (HR = 0.38; 95%CrI: 0.16-0.88) and Her2-mAb+Her2-tki+Endo (HR = 0.45; 95%CrI: 0.23-0.89), significantly improved PFS compared to endocrine therapy alone. According to the surface under the cumulative ranking curves (SUCRAs), Her2-mAb+Her2-mAb+Endo and Her2-mAb+Her2-tki+Endo ranked highest in terms of PFS and OS, respectively. For patients unsuitable for endocrine therapy, anti-HER2 dual-target combined chemotherapy, such as Her2-mAb+Her2-mAb+Chem (HR = 0.76; 95%CrI: 0.6-0.96) and Her2-mAb+Her2-tki+Chem (HR = 0.48; 95%CrI: 0.29-0.81), demonstrated significant improvements in PFS compared to Her2-mAb+Chem. The results were the same when compared with Her2-tki+Chem. According to the SUCRAs, Her2-mAb+Her2-tki+Chem and Her2-mAb+Her2-mAb+Chem ranked highest for PFS and OS, respectively. Subgroup analyses consistently supported these overall findings, indicating that dual-target therapy was the optimal approach irrespective of treatment line.

Treatment efficacy of ribociclib or palbociclib plus letrozole in hormone receptor-positive/HER2-negative metastatic breast cancer

Background: Ribociclib, palbociclib and abemaciclib are currently approved CDK4/6 inhibitors along with aromatase inhibitors as the first-line standard-of-care for patients with hormone receptor-positive, HER2-negative metastatic breast cancer. Methods: The authors report retrospective real-life data for 600 patients with estrogen receptor- and/or progesterone receptor-positive and HER2-negative metastatic breast cancer who were treated with ribociclib and palbociclib in combination with letrozole. Results & conclusion: The results demonstrated that the combination of palbociclib or ribociclib with letrozole has similar progression-free survival and overall survival benefit in real life for the patient group with similar clinical features. Specifically, endocrine sensitivity may be a factor to be considered in the treatment preference.

Neoadjuvant treatment and survival outcomes by pathologic complete response in HER2-negative early breast cancers

Background: The benefit of pathologic complete response (pCR) in early breast cancer (eBC) is not well described in the real-world setting. This study used the nationwide Flatiron Health electronic health record-derived deidentified database to describe treatment patterns and survival outcomes by pCR status after neoadjuvant therapy (NAT) in women with triple-negative or HR⁺/HER2^- eBC. Materials & methods: Observational cohort study analyzing women with eBC who started NAT between 2011 and 2018. Results: 496 women were included in the study; of those, 16.1% achieved pCR, of which 35.7% were triple-negative and 6.1% were HR⁺/HER2^- eBC. More women with triple-negative eBC (95.2%) were exclusively treated with chemotherapy-based NAT versus HR⁺/HER2^- eBC (56.1%). In multivariate analyses from NAT start, not achieving pCR was associated with increased risk of death and progression. Conclusion: pCR status may be a reliable prognostic indicator for survival in these eBC subtypes in the real-world setting.

The 5-Year Disease-Free Survival of Third Generation Aromatase Inhibitor for Postmenopausal Women with HR-Positive HER2-Negative Non-Metastatic Breast Cancer

Background: Several studies showed the superiority of aromatase inhibitor (AI) as first-line therapy for patients with hormone-receptor (HR)-positive breast cancer (BC). For the clinician, studies in the real world are warranted to determine treatment based on the efficacy of each drug. We compared a 5-y disease-free survival (DFS) of each AI in terms of survival benefit. Materials and Methods: We evaluated 450 medical records of postmenopausal women who were diagnosed with HR-positive HER2-negative BC (stage I - III) at Dr. Sardjito General Hospital from January to December 2019. All patients had undergone surgery and chemotherapy or radiation therapy. Moreover, study participants received anastrozole, letrozole, or exemestane for at least one year. Kaplan Meier estimation survival curve was used to analyze the survival rate. Result: Of 79 patients meeting inclusion criteria, there were 21.52% distant metastases documented. Time to disease progression of anastrozole, letrozole, and exemestane was 49 months, 58 months, and 53 months, respectively. Letrozole was found better than anastrozole (hazard ratio (HR)=4.342, 95% CI 0.95-19.95; p=0.038). Letrozole versus exemestane (HR=2.757, 95% CI 0.53-14.33; p=0,206) and anastrozole versus exemestane (HR=1.652, 95% CI 0.56-4.84; p=0.351) were found not significantly different. 5-y DFS rate of letrozole was better found (87.5%) than exemestane (73.7%) and anastrozole (61.4%). Conclusion: 5-year letrozole administration could be proposed as first-line therapy for postmenopausal women with HR-positive HER2-negative BC. A considerable subject and long-term follow-up are needed for validation.

Preclinical Platform Using a Triple-negative Breast Cancer Syngeneic Murine Model to Evaluate Immune Checkpoint Inhibitors

BACKGROUND/AIM

To evaluate the feasibility of syngeneic mouse models of breast cancer by analyzing the efficacy of immune checkpoint inhibitors (ICIs) and potential predictive biomarkers.

MATERIALS AND METHODS

To establish the murine triple-negative breast cancer (TNBC) models, JC, 4T1, EMT6, and E0771 cells were subcutaneously implanted into female syngeneic mice. When the tumor reached 50-100 mm³, each mouse model was divided into a treatment (using a murine PD-1 antibody) and a no-treatment control group. The treatment group was further divided into the responder and non-responder groups. Potential predictive biomarkers were evaluated by analyzing serum cytokines, peripheral blood T cells and tumor infiltrating immune cells.

RESULTS

The EMT6 model showed the highest tumor response rate (54%, 6/11) of the syngeneic models: 4T1 (45%, 5/11), JC (40%, 4/10), or E0771 (23%, 3/13). Early changes in tumor size at 7 days post-PD-1 inhibitor treatment predicted the final efficacy of the PD-1 inhibitor. Peripheral blood CD8+ and CD4+ T cells with or without Ki67 expression at 7 days post-PD-1 inhibitor treatment were higher in the finally designated responder group than in the non-responder group. At the time of sacrifice, analyses of tumor infiltrating lymphocytes consistently supported these results. We also demonstrated that retro-orbital blood sampling procedures (baseline, 7 days post-treatment, time of sacrifice) were safe for serum cytokine analyses, suggesting that our preclinical platform may be used for biomarker research using serum cytokines.

CONCLUSION

Our syngeneic mouse model of TNBC is a feasible preclinical platform to evaluate ICI efficacy combined with other drugs and predictive biomarkers in the screening process of immune-oncology drug development.

Adjuvant Abemaciclib Combined with Endocrine Therapy for High Risk Early Breast Cancer: Safety and Patient-Reported Outcomes From the monarchE Study

BACKGROUND

In monarchE, abemaciclib plus endocrine therapy (ET) as adjuvant treatment of hormone receptor-positive, human epidermal growth factor 2-negative, high risk, early breast cancer demonstrated a clinically meaningful improvement in invasive disease-free survival versus ET alone. Detailed safety analyses conducted at a median follow-up of 27 months and key patient-reported outcomes (PRO) are presented.

PATIENTS AND METHODS

The safety population included all patients who received at least one dose of study treatment (n=5591). Safety analyses included incidence, management, and outcomes of common and clinically relevant adverse events (AEs). Patient-reported health-related quality-of-life, ET symptoms, fatigue, and side effect burden were assessed.

RESULTS

The addition of abemaciclib to ET resulted in higher incidence of Grade≥3 AEs (49.7% vs 16.3% with ET alone), predominantly laboratory cytopenias (e.g., neutropenia [19.6%]) without clinical complications. Abemaciclib-treated patients experienced more serious adverse events (SAEs; 13.3% vs 7.8%). Discontinuation of abemaciclib and/or ET due to AEs occurred in 18.5% of patients, mainly due to Grade1/2 AEs (66.8%). AEs were managed with comedications (e.g., antidiarrheals), abemaciclib dose holds (61.7%), and/or dose reductions (43.4%). Diarrhea was generally low grade (Grade1/2: 77%); Grade2/3 events were highest in the first month (20.5%), most short-lived (≤7 days) and did not recur. Venous thromboembolic events (VTE) were higher with abemaciclib+ET (2.5%) vs ET (0.6%); in the abemaciclib arm, increased VTE risk was observed with tamoxifen vs AIs (4.3% vs 1.8%). PROs were similar between arms, including being 'bothered by side effects of treatment', except for diarrhea. At ≥3 months, most patients reporting diarrhea reported "a little bit" or "somewhat".

CONCLUSION

In patients with high risk EBC, adjuvant abemaciclib+ET has an acceptable safety profile and tolerability is supported by PRO findings. Most AEs were reversible and manageable with comedications and/or dose modifications, consistent with the known abemaciclib toxicity profile.

How we treat HR-positive, HER2-negative early breast cancer

The present goal of therapy for early hormone receptor-positive (HR+)/human EGF receptor 2-negative (HER2-) BC is to optimize disease-free survival (DFS) and overall survival (OS) rates with the currently available therapies while avoiding any relevant long-term sequalae. Local therapies have evolved toward less aggressive techniques (i.e. breast-preserving surgery, sentinel lymph node biopsy and intraoperative radiotherapy), which significantly reduce the long-term sequalae observed with more radical treatments. Endocrine therapy (ET) is still the cornerstone of adjuvant treatment because it significantly reduces BC relapse and mortality. Adjuvant chemotherapy is today recommended only for a particular subset of patients with a high risk of recurrence with ET alone, identified through genomic assays, age and/or disease stage. Bisphosphonates reduce the risk of bone metastasis and produce a slight although statistically significant improvement in survival in postmenopausal women. The CDK 4/6 inhibitor abemaciclib has been recently approved by the US FDA for patients at high risk of relapse.

CDK4/6 inhibitors as adjuvant treatment for hormone receptor-positive, HER2-negative early breast cancer: a systematic review and meta-analysis

Background

The combination of cyclin-dependent kinases 4/6 inhibitors (CDK4/6is) and endocrine therapy (ET) is standard of care for patients with hormone receptor-positive (HR+), HER2-negative (HER2−) advanced breast cancer (BC). However, studies evaluating adjuvant CDK4/6is provided contradictory results thus far.

Materials and methods

We conducted a systematic review and meta-analysis to assess if the addition of CDK4/6is to adjuvant ET impacts on survival's outcomes and safety of patients with HR+/HER2− early BC (EBC). This study was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and was registered in the PROSPERO database (ID: CRD42020218597). A systematic review of PubMed, Cochrane and EMBASE databases and major conference proceedings was performed up to 15 December 2020. All randomized controlled trials including patients with HR+/HER2− EBC treated with CDK4/6is plus ET versus ET alone in the adjuvant setting were included. Pooled hazard ratios (HRs) and odds ratios (ORs) for survival and safety outcomes, respectively, were calculated with 95% confidence intervals (95% CIs) using random effect models.

Results

With data available from three studies (N = 12 647), the addition of CDK4/6is to adjuvant ET showed a trend for a benefit in terms of invasive disease-free survival (IDFS; HR 0.85, 95% CI 0.71-1.01; P = 0.071). No significant improvement in distant relapse-free survival was observed (HR 0.83, 95% CI 0.58-1.19; P = 0.311). The risk of all-grade toxicities and early treatment discontinuation increased significantly with the addition of CDK4/6is to ET (OR 9.36, 95% CI 3.46-25.33, P < 0.001, and OR 22.11, 95% CI 9.45-51.69, P < 0.001, respectively).

Conclusion

The administration of adjuvant CDK4/6is to patients with HR+/HER2− EBC showed a trend for an IDFS benefit and an increase in the risk of toxicities and treatment discontinuation. The role of adjuvant CDK4/6is remains controversial and a longer follow-up of these randomized controlled trials is needed before supporting a straightforward change in clinical practice.

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Studies evaluating CDK4/6is in the adjuvant setting provided contradictory results thus far.

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In our meta-analysis, adjuvant CDK4/6is showed a trend for IDFS benefit.

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No significant improvement in DRFS was observed.

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Adjuvant CDK4/6is were associated with an increased risk of toxicities and treatment discontinuation.

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The role of adjuvant CDK4/6is remains controversial, and a longer follow-up is needed.

Efficacy and Safety of Cyclin-Dependent Kinases 4 and 6 Inhibitors in HR+/HER2- Advanced Breast Cancer

Purpose

To assess the efficacy and safety of cyclin-dependent kinases 4 and 6 inhibitors (CDKi) combined with endocrine therapy (ET) in women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) and compare the efficacy of different CDKi (palbociclib, ribociclib, or abemaciclib).

Materials and Methods

This study based on randomized Phase 2 or 3 trials of CDKi plus ET compared with placebo plus ET for women with HR+/HER2−ABC and identify relevant randomized clinical trials (RCTs) published prior to February 2020. The primary endpoint was progression-free survival (PFS), the secondary endpoints included overall survival (OS), objective response rate (ORR), clinical benefit response (CBR) and safety. The PROSPERO registry number is 42018081105.

Results

The results from eight trials including 4580 participants were pooled. Evidence indicated that the PFS of CDKi group was significantly prolonged (hazard ratio [HR] 0.55, 95% confidence interval [CI] 0.50–0.60, P < 0.01) compared with placebo group. The ORR and CBR were better (risk ratio [RR] 1.47, 95% CI 1.30–1.67, P < 0.01; 1.24, 95% CI 1.15–1.35, P < 0.01) in the CDKi group. The OS of CDKi group (HR 0.75, 95% CI 0.67–0.85, P < 0.01) was significantly longer than ET alone. Subgroup analyses confirmed that the benefit was consistent across most subgroups. Subgroup analyses showed no statistically significant difference of PFS among three CDKi: palbociclib vs ribociclib (HR 0.55, 95% CI 0.49–0.60, P = 0.34), palbociclib vs abemaciclib (HR 0.53, 95% CI, 0.47–0.59, P = 0.61), and ribociclib vs abemaciclib (HR 0.56, 95% CI, 0.51–0.62, P = 0.72). Treatment-related grade 3 or 4 hematologic adverse events (AEs) were more frequently in CDKi group.

Conclusion

CDKi combined with ET can significantly prolong PFS and improve the ORR, CBR and OS in patients with HR+/HER2− ABC. However, the advantage of different CDKi has not been established.

TROPiCS-02: A Phase III study investigating sacituzumab govitecan in the treatment of HR+/HER2- metastatic breast cancer

Patients with HR+/HER2- metastatic breast cancer (MBC) whose cancers have progressed despite conventional therapies represent an unmet clinical need. Trop-2, a transmembrane calcium signal transducer, is highly expressed in MBC and plays a role in tumor growth and progression. Sacituzumab govitecan (SG) is a novel antibody-drug conjugate comprising an Trop-2 antibody coupled to SN-38, the active metabolite of irinotecan, via a unique hydrolyzable linker. SG has demonstrated promising activity in a Phase I/II IMMU-132-01 basket study in heavily pretreated solid tumors, including HR+/HER2- MBC. We describe the registrational Phase III TROPiCS-02 study (NCT03901339), evaluating SG versus treatment of physician's choice in HR+/HER2- MBC. Trial registration number: NCT03901339.

CYP2D6*3 (A2549del), *4 (G1846A), *10 (C100T) and *17 (C1023T) genetic polymorphisms in Iranian breast cancer patients treated with adjuvant tamoxifen

There is controversy regarding the efficacy of tamoxifen in breast cancer patients who are carriers of cytochrome P450 2D6 (CYP2D6) gene polymorphisms. Poor metabolizer genotypes may not fully convert tamoxifen to its active metabolite endoxifen and thus have less exposure to anti-estrogen therapy. The present study was conducted to identify the prevalence of CYP2D6 genotypes among Iranian breast cancer patients. A total of 84 estrogen receptor-positive breast cancer patients treated at a referral center in the north of Iran were examined. A peripheral blood sample was obtained from each patient to determine the presence of *3, *4, *10 and *17 single nucleotide polymorphisms of the CYP2D6 gene by polymerase chain reaction-based restriction fragment-length polymorphism analysis. Of the four genotypes assessed, CYP2D6*4 was the most common variant and was identified in 41 (48.8%) patients as heterozygous (G/A) and 3 (3.6%) as homozygous (A/A) alleles. CYP2D6*10 heterozygous mutated alleles (C/T) were also a common genotype that presented in 22 (26.2%) of the study subjects. Variant *17 was less common and was detected only as heterozygous (C/T) in 3 patients (3.6%). No CYP2D6*3 heterozygous or homozygous mutated alleles were observed. In conclusion, the frequency of the CYP2D6 nonfunctional alleles *4 and *10 appeared relatively high in Iranian patients with hormone-sensitive breast cancer. This finding may affect the selection of an optimal hormone therapy, as patients with low CYP2D6 pathway activity may not sufficiently convert tamoxifen to its active metabolite endoxifen.

The Difference in Prognostic Outcomes Between De Novo Stage IV and Recurrent Metastatic Patients with Hormone Receptor-positive, HER2-negative Breast Cancer

BACKGROUND/AIM

Patients with de novo stage IV and recurrent metastatic breast cancer are often treated with the same strategies, although the difference in prognostic outcomes remains unclear. The objective of this retrospective chart review study was to compare the prognostic outcomes between two types of patients with hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer.

PATIENTS AND METHODS

We estimated overall survival of the two groups and evaluated the progressive course of the disease using disease-free interval (DFI) and interval from the end of adjuvant treatment to the first recurrence (AFI).

RESULTS

We studied 172 patients with HR+/HER2- breast cancer, of which 65 were de novo and 107 were recurrent. Median OS between de novo and recurrent BC was 4.85 and 3.45 years, respectively (p=0.046). Recurrent patients with a DFI<2 years were found to have a significantly poorer prognosis than recurrent patients with a DFI≥2 years (p=0.016) and de novo patients (p=0.002). Similarly, recurrent patients with an AFI<1 year had a significantly poorer prognosis compared to de novo patients (p=0.026).

CONCLUSION

De novo patients had better prognoses than recurrent patients with DFI<2 years or AFI<1 year, likely due to their therapy-naïve status or lower resistance to systemic treatment.

Delaying Chemotherapy in the Treatment of Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer

Global guidelines for the management of locally advanced or metastatic hormone receptor-positive (HR-positive), human epidermal growth factor 2-negative (HER2-negative) breast cancer recommend endocrine therapy as first-line treatment for all patients, regardless of age or postmenopausal status. However, current practice patterns in the United States and Europe suggest that these modes of therapy are not being used as recommended, and many patients with advanced HR-positive, HER2-negative disease are being treated first-line with chemotherapy or switched to chemotherapy after a single endocrine therapy. Given that chemotherapy is associated with increased toxicity and reduced quality of life (QOL) compared with endocrine therapy, prolonging the duration of response obtained with endocrine therapy may help delay chemotherapy and its attendant toxicities. Several strategies to delay or overcome endocrine resistance and thereby postpone chemotherapy have been explored, including the use of second-line endocrine agents with different mechanisms of action, adding targeted agents that inhibit specific resistance pathways, and adding agents that act in complementary or synergistic ways to inhibit tumor cell proliferation. This review analyzes the different therapy options available to HR-positive, HER2-negative patients with advanced breast cancer that can be used to delay chemotherapy and enhance QOL.