US incidence of breast cancer subtypes defined by joint hormone receptor and HER2 status

A phase III trial of adjuvant ribociclib plus endocrine therapy versus endocrine therapy alone in patients with HR-positive/HER2-negative early breast cancer: final invasive disease-free survival results from the NATALEE trial

BACKGROUND

NATALEE assessed efficacy and tolerability of 3 years of adjuvant ribociclib plus a nonsteroidal aromatase inhibitor (NSAI) compared with an NSAI alone in a broad population of patients with hormone receptor (HR)-positive/human epidermal growth factor 2 (HER2)-negative early breast cancer, including a select group without nodal involvement. This is the final preplanned analysis of invasive disease-free survival (iDFS).

PATIENTS AND METHODS

Premenopausal/postmenopausal women and men were randomized 1 : 1 to ribociclib (n = 2549; 400 mg/day, 3 weeks on/1 week off for 36 months) plus NSAI (letrozole 2.5 mg/day or anastrozole 1 mg/day for 60 months) or NSAI alone (n = 2552). Men and premenopausal women also received goserelin (3.6 mg once every 28 days). Patients had anatomical stage IIA (N0 with additional risk factors or N1), IIB, or III disease. The primary endpoint was iDFS. Secondary efficacy endpoints were recurrence-free survival (RFS), distant DFS, and overall survival. This final iDFS analysis was planned after ∼500 events.

RESULTS

At data cut-off (21 July 2023), ribociclib was stopped for 1996 patients (78.3%); 1091 (42.8%) completed 3 years of ribociclib, and ribociclib treatment was ongoing for 528 (20.7%). Median follow-up for iDFS was 33.3 months. Overall, 226 and 283 iDFS events occurred with ribociclib plus NSAI versus NSAI alone, respectively. Ribociclib plus NSAI demonstrated significant iDFS benefit over NSAI alone [hazard ratio 0.749, 95% confidence interval (CI) 0.628-0.892; P = 0.0012]. The 3-year iDFS rates were 90.7% (95% CI 89.3% to 91.8%) versus 87.6% (95% CI 86.1% to 88.9%). A consistent benefit was observed across prespecified subgroups, including stage (II/III) and nodal status (positive/negative). Distant DFS and RFS favored ribociclib plus NSAI. Overall survival data were immature. No new safety signals were observed.

CONCLUSIONS

With longer follow-up and most patients off ribociclib, NATALEE continues to demonstrate iDFS benefit with ribociclib plus NSAI over NSAI alone in the overall population and across key subgroups. Observed adverse events remained stable.

Real-World Analysis of Breast Cancer Patients Qualifying for Adjuvant CDK4/6 Inhibitors

BACKGROUND

Adjuvant CDK4/6 inhibitors abemaciclib and ribociclib improved disease-free survival (DFS) added to endocrine therapy in hormone receptor (HR)-positive HER2-negative early breast cancer (EBC), in monarchE (NCT03155997) and NATALEE (NCT03701334) trials respectively. We assessed the proportion and outcome of EBC patients qualifying for adjuvant CDK4/6 inhibitors in the real-world.

METHODS

Consecutive female patients with HR-positive HER2-negative EBC between 1997 and 2017 from the Australian Capital Territory and South-East New South Wales Breast Cancer Treatment Group registry were analyzed. Patients eligible for abemaciclib had ≥4 axillary nodes involved or 1-3 nodes plus primary >5 cm or grade 3. Ribociclib eligibility was defined as node-positive and node-negative with primary >5 cm or >2 cm grade 3.

RESULTS

Of 3840 patients, 671 (17.5%) were abemaciclib-eligible and 1587 (41.3%) ribociclib-eligible . The 5-year DFS was 77% and 94% in abemaciclib-eligible and noneligible registry patients respectively (HR 2.6, 95% CI 2.26-3.05, P < .001). The 5-year DFS was 86% and 97% in ribociclib-eligible and noneligible registry patients respectively (HR 1.92, 95% CI 1.67-2.19, P < .001). Compared with monarchE trial patients, abemaciclib-eligible registry patients were older (median 55 years in registry vs. 51 years in trial), with lower nodal burden (≥4 nodes in 44% in registry vs. 60% in trial). There were more stage III cancers in NATALEE trial patients (60%) than ribociclib-eligible registry patients (24%).

CONCLUSIONS

Many women with EBC will qualify for adjuvant CDK4/6 inhibitors (17.5% abemaciclib, 41.3% ribociclib) with resource and workforce implications. In the real-world setting, a greater proportion of adjuvant CDK4/6-eligible patients have lower stage disease, therefore the absolute benefit from treatment may be smaller than estimated by the trials.

Ongoing Symptoms and Concerns Experienced by Low-Risk Breast Cancer Survivors Following Active Treatment

INTRODUCTION

Little is known about the symptom burden of breast cancer survivors with early-stage disease. Many studies have focused on symptoms of patients who are undergoing or recently completed systemic therapy. However, with the increased use of Oncotype DX, the proportion of early-stage hormone receptor-positive patients who undergo chemotherapy has declined, making existing studies of the symptom experience less useful for these patients.

OBJECTIVE

The aim of this study was to assess symptom burden for early-stage breast cancer survivors.

METHODS

Eligible survivors had stage I-II, estrogen receptor (ER)- or progesterone receptor (PR)-positive and HER2neu-negative breast cancer, did not receive chemotherapy, were 6 months-5 years post-diagnosis, and were cancer-free. Survivors were enrolled at the University of Wisconsin Breast Center follow-up visits and were emailed a link to a patient-reported outcomes (PRO) survey. Survey domains were informed by American Cancer Society/American Society of Clinical Oncology (ACS/ASCO) survivorship guidelines and survivor/provider stakeholders. The prevalence of clinically significant symptoms are reported.

RESULTS

Overall, 98 patients participated. On average, participants were 61.3 years of age (standard deviation [SD] 11.5) and 2.5 years post-diagnosis (SD 1.2); 71.3% underwent breast-conserving surgery. The average item-level missingness rate was low (2.0%). Most survivors (86.2%) experienced symptoms (38.8% reporting one to two symptoms; 47.9% reporting more than three symptoms).

CONCLUSIONS

Early-stage breast cancer survivors report a high symptom burden. Given nearly 50% of survivors report more than three symptoms, many topics may not be discussed or addressed during time-limited follow-up visits. Some symptoms, such as sexual health, may be less feasible to address in-clinic given their complex/sensitive nature. Use of PROs allows for a comprehensive evaluation and identification of unrecognized needs, representing an opportunity to improve survivorship care.

CARDIAC-STAR: prevalence of cardiovascular comorbidities in patients with HR + /HER2 - metastatic breast cancer

BACKGROUND

Cardiovascular (CV) comorbidities and concurrent medications with risk of heart rate-corrected QT interval (QTc) prolongation can impact treatment decisions and safety discussions for patients with breast cancer. However, limited data are available regarding their prevalence in patients with HR + /HER2- metastatic breast cancer (mBC). We evaluated the prevalence of CV comorbidities, the use of concurrent medications with risk of QTc prolongation, and treatment patterns in patients with newly diagnosed HR + /HER2 - mBC.

METHODS

This retrospective analysis utilized claims data from Merative™ Marketscan® Commercial and Medicare databases. Claims-based algorithms identified patients with newly diagnosed HR + /HER2- mBC between January 2016 and December 2022. The index date was defined as the first date of an mBC claim during this period. For each patient, data on pre-existing CV comorbidities and first-line treatments were captured for 12 months before and 6 months after the index date, respectively.

RESULTS

A total of 6525 patients with newly diagnosed HR + /HER2 - mBC were identified. At mBC diagnosis, 61.7% of patients had ≥ 1 CV comorbidity. Of patients with CV comorbidities, 22.5% and 30.6% took 1 or ≥ 2 medications, respectively, with risk of QTc prolongation. First-line use of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors increased from 22.1% of patients with CV comorbidities diagnosed in 2016-2017 to 31.5% of those diagnosed in 2018-2022.

CONCLUSIONS

We found that CV comorbidities and use of medications with risk of QTc prolongation were common in patients with newly diagnosed HR + /HER2 - mBC. These factors should inform treatment decision-making (including CDK4/6 inhibitor selection), safety discussions with patients, and CV monitoring.

Phase I trial of hydroxychloroquine to enhance palbociclib and letrozole efficacy in ER+/HER2- breast cancer

Endocrine therapy with CDK4/6 inhibitors is standard for estrogen receptor-positive, HER2-negative metastatic breast cancer (ER+/HER2- MBC), yet clinical resistance develops. Previously, we demonstrated that low doses of palbociclib activate autophagy, reversing initial G1 cell cycle arrest, while high concentrations induce off-target senescence. The autophagy inhibitor hydroxychloroquine (HCQ) induced on-target senescence at lower palbociclib doses. We conducted a phase I trial (NCT03774472 registered in ClinicalTrials.gov on 8/20/2018) of HCQ (400, 600, 800 mg/day) with palbociclib (75 mg/day continuous) and letrozole, using a 3 + 3 design. Primary objectives included safety, tolerability, and determining the recommended phase 2 dose (RP2D) of HCQ. Secondary objectives included tumor response and biomarker analysis. Fourteen ER+/HER2- MBC patients were evaluable [400 mg (n = 4), 600 mg (n = 4), 800 mg (n = 6)]. Grade 3 adverse events (AEs) included hematological (3 at 800 mg), skin rash (2 at 600 mg), and anorexia (1 at 400 mg), with no serious AEs. The best responses were partial (2), stable (11), and progression (1). Tumor reductions ranged from 11% to 30%, with one 55% increase. The two partial responders sustained tumor size reductions of 30% to 55% over an extended treatment period, lasting nearly 300 days. Biomarker analysis in responders demonstrated significant decreases in Ki67, Rb, and nuclear cyclin E levels and increases in autophagy markers p62 and LAMP1, suggesting a correlation between these biomarkers and treatment response. This phase I study demonstrated that HCQ is safe and well-tolerated and the RP2D was established at 800 mg/day with continuous low-dose palbociclib (75 mg/day) and letrozole (2.5 mg/day). These findings suggest that adding HCQ could potentially enhance the efficacy of low-dose palbociclib and standard letrozole therapy, pending verification in larger randomized studies.

Non-Luminal Disease Score for Everolimus in Patients with Hormone Receptor‑positive and Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: A Multicenter and Retrospective Study

Purpose

This study aims to explore the role of the non-luminal disease score (NOLUS) for everolimus in patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC).

Methods

NOLUS has previously been established as an algorithm: NOLUS (0-100) = - 0.45 × ER(%) - 0.28 × PR(%) + 0.27 × Ki67(%) + 73. Information of cancer patients was retrospectively collected from three cancer centers in China.

Results

Totally, 198 HR+/HER2- ABC patients with complete records in expression rates (%) of ER, PR and Ki67 were enrolled in the study. The expression rates (%) of ER, PR, and Ki67 were 38.8 ± 27.9 versus 80.9 ± 14.2 (p < 0.001), 13.9 ± 14.3 versus 50.2 ± 30.4 (p < 0.001), and 37.8 ± 23.6 versus 28.7 ± 19.9 (p = 0.04), respectively, for NOLUS-positive patients and NOLUS-negative patients. For the overall population, the median PFS was 5.8 months versus 5.1 months in NOLUS-positive and NOLUS-negative patients (p = 0.16, HR = 0.75, 95% CI = 0.50, 1.12). The median 1L-, 2L, and 3L-PFS was 13.9 months versus 11.8 months (p = 0.22, HR = 1.63, 95% CI = 0.74, 3.62), 6.7 months versus 3.6 months (p = 0.08, HR = 0.34, 95% CI = 0.10, 1.18), and 4.6 months versus 4.0 months (p = 0.81, HR = 1.07, 95% CI = 0.63, 1.79) respectively, for NOLUS-positive patients and NOLUS-negative patients.

Conclusion

NOLUS-positive patients have a lower percentage of ER and PR, but a higher percentage of Ki67 index. The correlation between the benefits of everolimus and NOLUS failed to develop significance, suggesting that NOLUS may not be applicable in predicting everolimus efficacy in patients with HR+/HER2- ABC. Further research is expected.

Real-world clinical multi-omics analyses reveal bifurcation of ER-independent and ER-dependent drug resistance to CDK4/6 inhibitors

To better understand drug resistance mechanisms to CDK4/6 inhibitors and inform precision medicine, we analyze real-world multi-omics data from 400 HR+/HER2- metastatic breast cancer patients treated with CDK4/6 inhibitors plus endocrine therapies, including 200 pre-treatment and 227 post-progression samples. The prevalences of ESR1 and RB1 alterations significantly increase in post-progression samples. Integrative clustering analysis identifies three subgroups harboring different resistance mechanisms: ER driven, ER co-driven and ER independent. The ER independent subgroup, growing from 5% pre-treatment to 21% post-progression, is characterized by down-regulated estrogen signaling and enrichment of resistance markers including TP53 mutations, CCNE1 over-expression and Her2/Basal subtypes. Trajectory inference analyses identify a pseudotime variable strongly correlated with ER independence and disease progression; and revealed bifurcated evolutionary trajectories for ER-independent vs. ER-dependent drug resistance mechanisms. Machine learning models predict therapeutic dependency on ESR1 and CDK4 among ER-dependent tumors and CDK2 dependency among ER-independent tumors, confirmed by experimental validation.

Cost-effectiveness analysis of trastuzumab emtansine for second-line treatment of HER2+ advanced breast cancer in Singapore

OBJECTIVE

To evaluate the cost-effectiveness of trastuzumab emtansine (T-DM1) compared to both lapatinib plus capecitabine (lapcap) and trastuzumab plus capecitabine (trascap) for treating human epidermal growth factor 2-positive advanced breast cancer patients, who have received prior treatment with trastuzumab and a taxane, in Singapore.

RESEARCH DESIGN AND METHODS

A three-state partitioned survival model was used to evaluate the cost-effectiveness from the local healthcare system perspective. Key effectiveness data, including progression-free survival and overall survival from the pivotal EMILIA trial, were used alongside local clinician inputs. Health state utilities (in quality-adjusted life years [QALYs]) were obtained from the literature and direct medical costs obtained from the public health institutions in Singapore. Scenario, one-way, and probabilistic sensitivity analyses were conducted to explore the impact of uncertainties on cost-effectiveness.

RESULTS

The base-case incremental cost-effectiveness ratios (ICERs) for T-DM1, compared to lapcap and trascap, were S$472,600 and S$495,200 per QALY gained, respectively. Sensitivity and scenario analyses showed high ICERs, with a 50% price reduction for T-DM1 resulting in an ICER above S$200,000.

CONCLUSION

At current prices, T-DM1 is unlikely to be a cost-effective use of Singapore's limited healthcare budget. These findings can help inform policymakers, alongside other considerations, on funding decisions.

Efficacy, safety, and patient-reported outcomes across young to older age groups of patients with HR+/HER2- advanced breast cancer treated with ribociclib plus endocrine therapy in the randomized MONALEESA-2, -3, and -7 trials

BACKGROUND

Ribociclib + endocrine therapy (ET) showed significant progression-free survival (PFS) and overall survival (OS) benefits in the MONALEESA trials in patients with HR+ /HER2 - advanced breast cancer (ABC). We report efficacy, safety, and patient-reported outcomes (PROs) across age groups, including older patients, in these trials.

METHODS

Data from the MONALEESA-2, -3, and -7 trials for pre- and postmenopausal patients receiving first-line treatment for ABC were pooled and analyzed by age (<65y, 65-74y, and ≥75y). PFS, OS, time to first chemotherapy (TTC), and time to definitive deterioration (TTD) in PROs were evaluated using Kaplan-Meier methods; a Cox regression model stratified by study and liver/lung metastasis was used for hazard ratios.

RESULTS

Among 1229 patients included, 63 % were < 65y, 27 % were 65-74y, and 10 % were ≥ 75y. Baseline characteristics were generally well balanced. Regardless of patient age, ribociclib+ET showed a consistent PFS and OS benefit and delayed TTC. With ribociclib+ET, the most common first subsequent treatment was ET. Safety results were consistent with those in the overall trial population; no new signals were identified. Rates of discontinuation due to AEs with ribociclib+ET were numerically higher in patients ≥ 75y. Among patients who discontinued treatment due to AEs, the percentage without prior dose reduction was higher in those ≥ 75y. A PRO benefit with ribociclib+ET was observed across all age groups for pain and fatigue scores.

CONCLUSIONS

This analysis demonstrated that ribociclib+ET is an effective and well-tolerated treatment for patients of all age groups with HR+ /HER2 - ABC, including older patients. (MONALEESA-2, NCT01958021; MONALEESA-3, NCT02422615; MONALEESA-7, NCT02278120).

Adjuvant endocrine therapy with cyclin-dependent kinase 4/6 inhibitor, ribociclib, for localized hormone receptor-positive/HER2- breast cancer (LEADER)

Optimal timing and dosing of adjuvant cyclin-dependent kinase (CDK) 4/6 inhibitor in early breast cancer is controversial. This prospective phase II clinical trial investigated tolerability and safety of two ribociclib dosing schedules. Patients with stage I-III hormone receptor-positive (HR+)/HER2- breast cancer on adjuvant endocrine therapy (ET) were randomized to two ribociclib dosing schedules: 400 mg continuous vs 600 mg intermittent, with initiation in early (prior ET < 2 years) vs delayed (prior ET ≥ 2 years) setting. Primary objective was to evaluate safety and tolerability of continuous vs intermittent schedule. Primary endpoint was proportion of patients who discontinued ribociclib before completion of all 12 cycles (measured at 12 months). Recurrence free survival (RFS) and circulating tumor DNA (ctDNA) detection were also evaluated. 81 patients were enrolled. Only six serious adverse events occurred, with no significant difference between treatment arms and no subject deaths. Twenty-five patients (31%) discontinued ribociclib before completion of 12 months, with no significant difference between treatment arms. Ribociclib discontinuation was higher in early vs delayed initiation (36% vs 21%). At median follow-up of 20 months, two patients in the intermittent arm (600 mg; Arm 2) experienced disease recurrence (2-year RFS 97%, 95%CI 88-99%), vs none in the continuous arm (400 mg; Arm 1) (2-year RFS 100%). ctDNA was only identified in the two subjects with recurrent disease at median of 7.5 months prior to radiological recurrence. Ribociclib is a safe and well-tolerated adjunct to adjuvant ET in early-stage breast cancer. Delayed initiation of ribociclib at 400 mg continuous dosing was feasible, better tolerated and associated with promising outcomes. ctDNA detection preceded clinical evidence of recurrence and may be considered as a surveillance tool in breast cancer.

Radiolabeled HER2-targeted molecular probes in breast cancer imaging: current knowledge and future prospective

Breast cancer is the most frequent non-dermatologic malignancy in women. Breast cancer is characterized by the expression of the human epidermal growth factor receptor type 2 (HER2), and the presence or lack of estrogen receptor (ER) and progesterone receptor (PR) expression. HER2 overexpression is reported in about 20 to 25% of breast cancer patients, which is usually linked to cancer progression, metastases, and poor survival. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are the gold standards for determining HER2 status, even though IHC has largely focused on quantifying HER2+ status versus "other" HER2 status (including variants with low or no expression). Recent findings regarding the beneficial therapeutic effects of anti-HER2 monoclonal antibodies (mAb) in HER2low metastatic patients lead to changes in the classic definition of advanced breast cancer, and methods for precise assessment of HER2 status are being developed. As a result, various radiolabeled HER-targeted mAbs and antibody fragments have been designed to avoid repeated biopsies with potential bias due to tumor heterogeneity, including single-chain variable fragment (scFv), F(ab')2, affibody, and nanobody. These small targeting radiotracers displayed favorable biodistributions, clearance, and stability, allowing for higher image quality, shorter circulation half-life, and lower immunogenicity. This study aimed to comprehensively review the application of radiolabeled anti-HER2 antibody fragments in breast cancer in vivo imaging and provide a better understanding of targeted HER2 quantification.

Incidence Rate Trends of Breast Cancer Overall and by Molecular Subtype by Race and Ethnicity and Age

Importance

Black and Hispanic women in the US experience higher incidence rates of aggressive molecular subtypes of breast cancer, including triple-negative disease. However, how these rates are changing, particularly across different age groups, has not been well documented.

Objective

To assess changes in overall and subtype-specific breast cancer incidence rates in the US by age and race and ethnicity.

Design, Setting, and Participants

This cohort study used Surveillance, Epidemiology, and End Results program cancer registry data from 22 US cancer registries on 1 123 658 females who received a diagnosis of invasive breast cancer from 2010 to 2019. Statistical analysis was conducted from August 2023 to October 2024.

Exposures

Age and race and ethnicity.

Main Outcomes and Measures

Age-adjusted incidence rates of invasive breast cancer overall and across the 4 major molecular subtypes by age and by race and ethnicity, as well as their associated annual percentage changes using Joinpoint Trend Analysis software.

Results

Of the 1 123 658 participants in the study, 219 112 (19.5%) were younger than 50 years, 409 257 (36.4%) were aged 50 to 64 years, and 495 289 (44.1%) were 65 years or older. A total of 141 703 participants (12.6%) were Hispanic, 3253 (0.3%) were non-Hispanic American Indian or Alaska Native, 78 306 (7.0%) were non-Hispanic Asian or Pacific Islander, 124 560 (11.1%) were non-Hispanic Black, 769 043 (68.4%) were non-Hispanic White, and 6793 participants (0.6%) had an unknown race and/or ethnicity. Overall, breast cancer incidence rates increased 0.5% per year from 2010 to 2019. Variation by race and ethnicity was observed, with increases of 1.4% per year among Hispanic females, 1.9% per year among non-Hispanic American Indian or Alaska Native females, and 2.1% per year among non-Hispanic Asian or Pacific Islander females, while rates increased only 0.8% per year among non-Hispanic Black females and 0.5% per year among non-Hispanic White females. In subtype analyses, increases of the greatest magnitude in recent years were observed in the incidence rates of triple-negative breast cancer per year among participants aged 65 years or older (Hispanic females, 2.3%; non-Hispanic Asian or Pacific Islander females, 5.5%; and non-Hispanic Black females, 4.3%), while remaining unchanged among non-Hispanic White females.

Conclusions and Relevance

In this cohort study of 1 123 658 females with breast cancer over the 10-year period from 2010 to 2019, there were substantial differences in trends in the incidence rates of breast cancer overall and by subtype across different racial and ethnic groups. Further research is needed to understand the factors associated with these trends.

Real-world outcomes of everolimus-based treatment in a Taiwanese cohort with metastatic HR+/HER2- breast cancer

BACKGROUND

Everolimus was the first orally targeted therapy for certain cancers. It was introduced before CDK4/6 inhibitors and is widely used to treat advanced hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. This study presents comprehensive findings including updated data and long-term survival analyses focusing on patients with HR+/HER2- metastatic breast cancer who received everolimus-based treatment. The objectives were to assess the impact of everolimus on overall survival (OS) and progression-free survival (PFS) by treatment line, and to evaluate its role in therapeutic strategies in a real-world setting.

METHODS

We included 299 women aged over 20 years with histologically confirmed HR+/HER2- breast cancer who received everolimus-based treatment from multiple medical centers in Taiwan. Survival curves were generated using the Kaplan-Meier method, with the log-rank test for comparisons. Univariate and multivariate analyses were performed using a Cox proportional hazards regression model. Adverse effects were graded according to the Common Terminology Criteria for Adverse Events version 5.0.

RESULTS

The median PFS was 5.6 months, and the median OS was 60.1 months. Patients receiving everolimus treatment in three or more lines and those who underwent chemotherapy before everolimus-based treatment had a significantly shorter PFS but longer OS. Patients with liver and central nervous system metastases had significantly shorter PFS and OS. The disease control rate was 51.5%, and the overall response rate was 8.0%.

CONCLUSION

These findings support current guidelines and advocate for the inclusion of everolimus in treatment plans for patients with metastatic HR+/HER2- breast cancer, particularly in late-line treatment, with careful consideration of the benefit-risk profile for each patient.

Combined pyrotinib and fulvestrant for hormone receptor-positive and HER2-positive metastatic breast cancer: A multicenter, single-arm, phase II trial

This multicenter, single-arm, phase II clinical trial (NCT04034589) evaluated the efficacy and safety of pyrotinib combined with fulvestrant in patients with HR-positive/HER2-positive metastatic breast cancer who had experienced trastuzumab treatment failure. A total of 46 patients were enrolled, receiving pyrotinib orally once daily and fulvestrant intramuscularly on days 1 and 15 of cycle 1, followed by monthly doses on day 1. The primary endpoint was progression-free survival (PFS), while secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. The median PFS was 18.2 months (95% CI, 11.9-31.1) overall, 19.5 months (95% CI, 10.6-NA) for those receiving the combination as first-line therapy, and 18.4 months (95% CI, 16.7-NA) for patients with brain metastases. Median OS was not reached, with a 3-year OS rate of 75.2% (95% CI, 62.8-90.2%). The ORR was 32.5%, and the DCR was 97.5%. Responses were observed in patients with low tumor mutation burden and ZNF217 mutation. Importantly, no grade 4 or higher treatment-related adverse events or deaths were reported, indicating a favorable safety profile. In conclusion, the combination of pyrotinib and fulvestrant demonstrated promising antitumor activity and acceptable safety in HR-positive/HER2-positive metastatic breast cancer patients.

Cardiovascular Health Considerations for Primary Care Physicians Treating Breast Cancer Survivors

Breast cancer (BC) survivors are at increased risk for cardiovascular disease (CVD) and require their primary care physicians to manage their long-term general medical care, including cardiovascular (CV) health. Yet, evidence exists that some primary care physicians possess insufficient knowledge about survivorship care. With the goal of bridging these knowledge gaps, a PubMed review was conducted from July 7, 2020, through October 2, 2020, with an updated PubMed review from January 3, 2024, through April 28, 2024, focusing on CV health considerations in the primary care of BC survivors. Search terms included variations of "breast cancer survivors" and "cardiovascular." In total, 152 publications were included. Breasts cancer survivors may have increased CVD risk because some anticancer therapies are cardiotoxic and risk factors for BC often also increase the risk for CVD. Multiple risk factors overlap for BC and CVD such as older age, Western diet, early menarche, physical inactivity, high body mass index, and smoking. In this review, results are summarized from studies that report the presence of CV risk factors and CVD in BC survivors. Also described are the CV effects of BC therapies (chemotherapy, hormonal agents, targeted therapies, and radiotherapy) and the type of CV evaluation (cardiac imaging and measurement of biomarkers) that these patients may need. Primary care physicians have an important role in managing the CV health of BC survivors from preventing, assessing, and managing CV risk factors to referring patients to appropriate specialists when needed.

Clinicopathogenomic analysis of PI3K/AKT/PTEN-altered luminal metastatic breast cancer in Japan

This rapid communication highlights the correlation between protein kinase B alpha (AKT1)-phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)- phosphatase and tensin homolog (PTEN) alterations and clinicopathological factors in Japanese patients with metastatic recurrent breast cancer (mBC). This study analyzed 1967 patients with luminal-type breast cancer who underwent cancer gene panel testing. The results demonstrated that AKT pathway alterations, including PI3K/AKT/PTEN, occurred in 1038 (52.8%) cases. Patients with AKT pathway mutations were older (p = 0.002) and had a higher rate of invasive lobular carcinoma (ILC) histology (p = 0.001), progesterone receptor (PgR) positivity (p = 0.006), and bone metastases (p = 0.001), and a lower rate of germline BRCA2 (p < 0.001). Comprehensive genomic profile results demonstrated a higher tumor mutational burden (TMB) (< 0.001) and lower tumor BRCA1/2 expression (< 0.001) in patients with mutations in the AKT pathway. These results are crucial for characterizing candidates for AKT pathway-targeted molecular therapies and conceptualizing optimal treatment strategies. Clinical trial registration: This study is an observational study and is therefore not registered with the clinical trials registration.

Fasting-mimicking diet potentiates anti-tumor effects of CDK4/6 inhibitors against breast cancer by suppressing NRAS- and IGF1-mediated mTORC1 signaling

AIMS

Acquired resistance to cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) frequently emerges, and CDK4/6i-containing therapies in triple-negative breast cancer (TNBC) remain to be determined.

METHODS

RNA-sequencing, cell viability analysis, immunoblotting, siRNA transfection et al. were used to investigate and verify the resistance mechanism. BALB/c nude mice xenograft models and spontaneous MMTV-PyMT models were used to explore in vivo efficacy.

RESULTS

The mTOR pathway was activated in acquired CDK4/6i-resistant cells and inhibition of mTORC1 restored the sensitivity. While fasting-mimicking diet (FMD) enhances the activity of anticancer agents by inhibiting the mTORC1 signaling, we assessed FMD and found that FMD restored the sensitivity of CDK4/6i-resistant cells to abemaciclib and potentiated the anti-tumor activity of CDK4/6i in TNBC. The anti-tumor effects of FMD and/or CDK4/6i were accompanied by the downregulation of S6 phosphorylation. FMD cooperated with CDK4/6i to suppress the levels of IGF1 and RAS. The combination of FMD and abemaciclib also led to a potent inhibition of tumor growth in spontaneous transgenic MMTV-PyMT mouse models.

CONCLUSIONS

Our data demonstrate that FMD overcomes resistance and potentiates the anti-tumor effect of CDK4/6i by inhibiting mTORC1 signaling via lowering the levels of IGF1 and RAS, providing the rationale for clinical investigation of a potential FMD-CDK4/6i strategy in breast cancer.

Identification and Management of Medical Comorbidities in Patients With HR+/HER2- Metastatic Breast Cancer Treated With CDK4/6 Inhibitors: Literature Review and Recommendations From Experts in Spain Opinion

Approximately one-third of patients with breast cancer have comorbidities at the time of their diagnosis. Recommendations for managing metastatic breast cancer are usually based on the results of clinical trials, which often limit patients with comorbidities. However, comorbidities greatly influence the quality of life, patient survival rate and treatment choice, particularly in older patients. The objective of this review was to identify clinically relevant comorbidities in patients with metastatic breast cancer, analyze the clinical approach to the treatment of these comorbidities, and propose recommendations from experts. An expert panel of eight medical oncologists identified seven therapeutic areas associated with the most relevant comorbidities in metastatic breast cancer: cardiovascular, gastrointestinal, endocrine/metabolic, renal, geriatric, psychological, and pain related. A clinical specialist from each therapeutic area specific to the relevant comorbidities (n = 8) joined the panel of experts (n = 8) to provide guidance on the appropriate management of these comorbidities. The specific comorbidities analyzed were hypertension, atrial fibrillation, venous thromboembolism, obesity, diabetes mellitus, cancer cachexia, chronic kidney disease, age-related disorders, arthritis, and fibromyalgia. In most cases, patients with metastatic breast cancer and medical comorbidities are polymedicated and/or vulnerable to toxicity. The oncologists provided recommendations on initial assessment and monitoring, follow-up recommendations, and warning signs and symptoms for referral to corresponding specialists based on their experience. The panel of experts also explored clinical scenarios related to each comorbidity and recommended a preferred CDK4/6 inhibitor based on available evidence regarding drug-drug interactions and potential for toxicity.

Current and future immunotherapy for breast cancer

Substantial therapeutic advancement has been made in the field of immunotherapy in breast cancer. The immune checkpoint inhibitor pembrolizumab in combination with chemotherapy received FDA approval for both PD-L1 positive metastatic and early-stage triple-negative breast cancer, while ongoing clinical trials seek to expand the current treatment landscape for immune checkpoint inhibitors in hormone receptor positive and HER2 positive breast cancer. Antibody drug conjugates are FDA approved for triple negative and HER2+ disease, and are being studied in combination with immune checkpoint inhibitors. Vaccines and bispecific antibodies are areas of active research. Studies of cellular therapies such as tumor infiltrating lymphocytes, chimeric antigen receptor-T cells and T cell receptor engineered cells are promising and ongoing. This review provides an update of recent major clinical trials of immunotherapy in breast cancer and discusses future directions in the treatment of breast cancer.

Addressing Breast Cancer Disparities: A Comprehensive Approach to Health Equity

This article addresses the persistent disparities in breast cancer outcomes across different racial, ethnic, and socioeconomic groups despite advancements in diagnosis and treatment. The disparities are rooted in various factors, including access to care, socioeconomic status, and cultural barriers. The article emphasizes the need for targeted interventions, such as expanding insurance coverage, mobile mammography units, and culturally tailored outreach programs to promote health equity. Achieving this requires comprehensive strategies addressing systemic and social determinants of health.

HER2-low prevalence among Hispanic/Latino women with breast cancer: A systematic review and meta-analysis

PURPOSE

HER2-low has garnered significant attention for the treatment of HER2-negative breast cancer. We aimed to determine the prevalence of HER2-low expression in Hispanic/Latino women with breast cancer (BC).

METHODS

We searched in Embase, LILACS, and Medline databases for articles reporting the expression of HER2 immunohistochemistry with scores reported as 0, 1+, 2+, or 3+, with equivocal cases (2+) confirmed through in situ hybridization (ISH).

RESULTS

A total of 12 articles were finally included, comprising 73,467 individuals. The prevalence of HER2-zero, HER2-low and HER2 positive cases among all BC (0, 1+, 2+/ISH-, 2+/ISH+ and 3+), was 45.0%, 32.0%, and 23.0%, respectively. The prevalence of HER2-zero and HER2-low expression among negative cases (0, 1+ and 2+/ISH-), was 53.0% and 47.0%, respectively.

CONCLUSION

There is an important percentage of Hispanic/Latino individuals who would benefit from HER2-targeted therapies, even in HER2 negative cases. Additional research on the prevalence of HER2-low tumors across a wider range of Latin American countries is required to better understand the molecular epidemiology of this biomarker within the Hispanic/Latino population.

Discovery of Thiochroman Derivatives as Potent, Oral Selective Estrogen Receptor Degraders and Antagonists for the Treatment of Endocrine-Resistant Breast Cancer

Selective estrogen receptor degraders (SERDs) deplete the ER signaling pathway via antagonism and degradation of ERα and represent a promising strategy to tackle endocrine resistance. Here, we report a new class of SERDs by pharmacological evolution of a selective estrogen receptor modulator, lasofoxifene. The structure-activity relationship study and efforts to circumvent the issue of human ether-a-go-go-related gene led to the identification of compounds 51. This bifunctional compound displayed broad activity across a vast array of cell backgrounds and was capable of effectively degrading and antagonizing wild-type ERα and clinically relevant ERα mutants. 51 exhibited favorable pharmacokinetic properties and good brain penetration, with a brain/plasma ratio of 3.05, and significantly suppressed the growth of tumor in a tamoxifen-resistant MCF-7 Tam1 xenograft model. Overall, the study demonstrates 51 as a highly potent, oral, and brain penetrant ER degrader and pure antagonist, showing a good potential in overcoming endocrine resistance.

Impact of Structural Racism and Social Determinants of Health on Disparities in Breast Cancer Mortality

The striking ethnic and racial disparities in breast cancer mortality are not explained fully by pathologic or clinical features. Structural racism contributes to adverse conditions that promote cancer inequities, but the pathways by which this occurs are not fully understood. Social determinants of health, such as economic status and access to care, account for a portion of this variability, yet interventions designed to mitigate these barriers have not consistently led to improved outcomes. Based on the current evidence from multiple disciplines, we describe a conceptual model in which structural racism and racial discrimination contribute to increased mortality risk in diverse groups of patients by promoting adverse social determinants of health that elevate exposure to environmental hazards and stress; these exposures in turn contribute to epigenetic and immune dysregulation, thereby altering breast cancer outcomes. Based on this model, opportunities and challenges arise for interventions to reduce racial and ethnic disparities in breast cancer mortality.

Alpelisib plus fulvestrant in PIK3CA-mutated, hormone receptor-positive advanced breast cancer after a CDK4/6 inhibitor (BYLieve): one cohort of a phase 2, multicentre, open-label, non-comparative study

BACKGROUND

Alpelisib, a PI3Kα-selective inhibitor and degrader, plus fulvestrant showed efficacy in hormone receptor-positive, HER2-negative, PIK3CA-mutated advanced breast cancer in SOLAR-1; limited data are available in the post-cyclin-dependent kinase 4/6 inhibitor setting. BYLieve aimed to assess alpelisib plus endocrine therapy in this setting in three cohorts defined by immediate previous treatment; here, we report results from cohort A.

METHODS

This ongoing, phase 2, multicentre, open-label, non-comparative study enrolled patients with hormone receptor-positive, HER2-negative, advanced breast cancer with tumour PIK3CA mutation, following progression on or after previous therapy, including CDK4/6 inhibitors, from 114 study locations (cancer centres, medical centres, university hospitals, and hospitals) in 18 countries worldwide. Participants aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 2 or less, with no more than two previous anticancer treatments and no more than one previous chemotherapy regimen, were enrolled in three cohorts. In cohort A, patients must have had progression on or after a CDK4/6 inhibitor plus an aromatase inhibitor as the immediate previous treatment. Patients received oral alpelisib 300 mg/day (continuously) plus fulvestrant 500 mg intramuscularly on day 1 of each 28-day cycle and on day 15 of cycle 1. The primary endpoint was the proportion of patients alive without disease progression at 6 months per local assessment using Response Evaluation Criteria in Solid Tumors, version 1.1, in patients with a centrally confirmed PIK3CA mutation. This trial is registered with ClinicalTrials.gov, NCT03056755.

FINDINGS

Between Aug 14, 2017, and Jul 29, 2022 (data cutoff), 127 patients with at least 18 months' follow-up were enrolled into cohort A. 119 patients had a centrally confirmed PIK3CA mutation. At data cutoff, median follow-up was 21·8 months (IQR 10·8-37·6). 64 (53·8%; 95% CI 44·4-63·0) of 119 patients were alive without disease progression at 6 months. The most frequent grade 3 or worse adverse events were hyperglycaemia (37 [29%] of 127 patients), rash (13 [10%]), and rash maculopapular (11 [9%]). Serious adverse events occurred in 37 (29%) of 127 patients. No treatment-related deaths were reported.

INTERPRETATION

BYLieve showed activity of alpelisib plus fulvestrant with manageable toxicity in patients with PIK3CA-mutated, hormone receptor-positive, HER2-negative advanced breast cancer, after progression on a CDK4/6 inhibitor plus an aromatase inhibitor.

FUNDING

Novartis Pharmaceuticals.

Navigating Treatment Pathways in Metastatic Hormone Receptor-Positive, HER2-Negative Breast Cancer: Optimizing Second-Line Endocrine and Targeted Therapies

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Effects of Adjuvant Endocrine Therapy-Specific Perceptions on Response to a Behavioral Intervention for Adjuvant Endocrine Therapy Adherence in Patients With Breast Cancer

PURPOSE

Adjuvant endocrine therapy (AET) is a life-saving medication for patients with hormone-sensitive breast cancer, yet many struggle with adherence, warranting behavioral intervention. In our recent trial, participation in a group cognitive behavioral intervention (STRIDE) for symptom management and adherence was associated with improvements in symptom distress, coping, quality of life, and mood. We now explore whether baseline patient- and medication-specific factors-which may be modifiable by clinician-led discussions-moderated the effect of STRIDE on adherence rates.

METHODS

From October 2019 to June 2021, 100 patients with early-stage breast cancer reporting AET-related distress were enrolled and randomly assigned to STRIDE or a medication monitoring (MM) control group. All patients stored their AET in electronic pill bottles to track objective adherence. Patients also self-reported their adherence on the Medication Adherence Report Scale-5 and their perceptions of AET on the Cancer Therapy Satisfaction Questionnaire at baseline. We conducted hierarchical linear modeling to test moderators of intervention effects on objective adherence rates. We report the time × group × moderator effects.

RESULTS

Among patients reporting greater perceived difficulties with AET adherence at baseline, STRIDE participants had higher adherence rates over time compared with MM (b = -13.80; SE = 4.56; P < .01). Patients with greater expectations of therapeutic benefit from AET also had improved adherence rates if they were assigned to STRIDE, versus MM (b = 0.25; SE = 0.10; P = .01). Patients who perceived taking AET as convenient and had been taking their AET for less time had higher adherence rates in STRIDE, versus MM.

CONCLUSION

The current study identified patient- and medication-specific factors that may augment AET adherence interventions and may be modifiable through clinician-led discussions, such as perceptions of adherence problems, therapeutic efficacy, and convenience of AET.

Evaluation of CDK4/6 inhibitors in first-line in symptomatic and asymptomatic patients with metastatic breast cancer

BACKGROUND

This study aimed to compare the efficacy of CDK4/6 inhibitors plus endocrine therapy in two groups of patients with HR-positive/HER2-negative metastatic breast cancer: those with symptomatic, high tumor burden disease and those with asymptomatic disease.

DESIGN AND METHODS

This retrospective study included 193 patients who received either ribociclib or palbociclib in combination with first-line ET. Patients were divided into symptomatic and asymptomatic groups and compared regarding baseline characteristics and progression-free survivals (PFS).

RESULTS

Symptomatic patients had a significantly shorter mPFS than asymptomatic patients (22.7 months vs. 35.0 months, p = 0.009). Among symptomatic patients, those treated with ribociclib had a longer mPFS than those treated with palbociclib (28.26 months vs. 17.18 months, p = 0.021). Multivariate analysis identified the symptomatic disease and liver metastasis as independent predictors of shorter mPFS (HR; 1.835, 95% CI; 1.146-2.939 and HR; 2.433, 95% CI; 1.329-4.454, respectively).

CONCLUSION

Our analysis revealed that although symptomatic individuals who underwent CDK4/6 inhibitor plus ET experienced a significant reduction in mPFS durations compared to asymptomatic patients, the 22-month mPFS indicated that CDK4/6 inhibitor plus ET is an effective treatment option.

Characteristics, treatment patterns and survival of patients with high-risk early hormone receptor-positive breast cancer in French real-world settings: an exploratory study of the CANTO cohort

BACKGROUND

Patients with hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (HR+ BC) with unfavorable features have an increased risk of relapse and are currently candidate for additional treatment strategies. We evaluated the real-world clinicopathological characteristics, treatment patterns and survival outcomes of these patients within the CANcer TOxicities study (CANTO, NCT01993498).

PATIENTS AND METHODS

This is a retrospective analysis of the prospective data collected within CANTO between 2012 and 2022. Patients with high-risk HR+ BC were defined either by the identification of at least four positive axillary lymph nodes (LNs) or one to three positive axillary LNs with a tumor size ≥5 cm or histologic grade 3 (cohort 1). The definition 1-3 positive LNs with Ki-67 ≥20% was also considered (cohort 2). The Kaplan-Meier method was used for survival analysis.

RESULTS

Patients with high-risk HR+ BC represented 15.0%-19.6% of HR+ BC (cohort 1 and 2, respectively) in the CANTO cohort. Of the 1266 patients in cohort 1, 617 patients (49.0%) had ≥4 LNs, 327 (26.0%) had tumor ≥5 cm and 727 (57.6%) had grade III tumors. 79.9% had a favorable Charlson comorbidity score and 88.1% stage II/IIIA. Patients with ≥10 LNs accounted for 11.8%. (Neo)adjuvant chemotherapy was administered in 94.2%. Endocrine therapy was prescribed in 97.3%, mostly with aromatase inhibitors and discontinued in 34.3%, mainly for adverse events. Patients enrolled at least 6 years before data extraction had a 5-year invasive disease-free survival and 5-year distant relapse-free survival of 79.9% [95% confidence interval (CI) 77.2% to 82.4%] and 83.5% (95% CI 80.9% to 85.7%), respectively.

CONCLUSIONS

This real-world study confirms that patients with HR+ BC and unfavorable clinicopathological features are at risk of relapse early in their adjuvant treatment trajectory, despite (neo)adjuvant chemotherapy. It is imperative to implement innovative treatment approaches for high-risk patients, ideally adding them as early as possible to the adjuvant treatment.

Practical treatment strategies and novel therapies in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2-) advanced breast cancer

Mutations in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway occur in 30%-40% of patients with advanced hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2-) breast cancer. For most patients, endocrine therapy with a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor is the first-line treatment. Recent studies indicate that adding inavolisib, a PI3Kα inhibitor, to palbociclib/fulvestrant benefits patients with endocrine-resistant HR+/HER2- metastatic breast cancer with a PIK3CA mutation. Alpelisib and capivasertib are both US Food and Drug Administration (FDA) approved in combination with fulvestrant in patients with endocrine-resistant HR+/HER2-, PIK3CA-mutant metastatic breast cancer, both with activity in the post-CDK4/6 setting. Capivasertib added to fulvestrant is the first AKT inhibitor to show a significant progression-free survival benefit with a trend for overall survival benefit and the only approved option for patients with phosphate and tensin homolog (PTEN) or AKT alterations. Toxicity profiles of all agents necessitate careful patient selection. Several mutant-selective and pan-mutant-selective novel inhibitors are under investigation with the potential to improve tolerability and efficacy.

The efficacy and safety of CDK4/6 inhibitors combined with endocrine therapy versus endocrine therapy alone in the adjuvant treatment of patients with high-risk invasive HR+/HER2-early breast cancer: A comprehensive updated meta-analysis of randomized clinical trials

BACKGROUND

This paper aimed to evaluate the effectiveness of incorporating CDK 4/6 inhibitors (CDK4/6i) into ET for the adjuvant treatment of HR + HER2-resected early-stage breast cancer (ESBC) patients, employing meta-analysis.

METHODS

In this paper, we compiled randomized clinical trials focusing on CDK4/6i used in the adjuvant treatment of high-risk invasive HR-positive and HER2-ESBC patients. A meta-analysis was performed in line with the PRISMA guidelines.

RESULTS

We identified four clinical trials that met our inclusion criteria and were published between 2020 and 2024. These trials involved a combined sample size of 17,749 patients diagnosed with breast cancer. The data obtained from the pooled analysis revealed a remarkable beneficial trend in terms of invasive disease-free survival (iDFS) for the use of ET in combination with CDK4/6i compared to the group receiving ET alone (HR = 0.81, 95 % CI: 0.67-0.98, p = 0.03). Of note, CDK4/6 inhibitors demonstrated a notably beneficial effect in both grade 2 (HR = 0.69, 95 % CI: 0.59-0.81, p < 0.001) and grade 3 (HR = 0.76, 95 % CI: 0.65-0.89, p < 0.001). Significant improvements were noted in terms of distant relapse-free survival (dRFS) in the groups treated with abemaciclib and ribociclib (HR = 0.65, 95 % CI: 0.56-0.76, p < 0.001; HR = 0.72, 95 % CI: 0.58-0.89, p = 0.003, respectively). CDK4/6i didn't yield a statistically significant difference in overall survival (OS) (HR = 0.96, 95 % CI: 0.77-1.19, p = 0.69). The use of CDK4/6i with ET was associated with an increased risk of adverse events, particularly anemia and neutropenia, compared with ET alone (OR = 9.12, 95 % CI = 5.04-16.48, p < 0.001).

CONCLUSION

The findings of this paper demonstrate a significant improvement in iDFS when ET is combined with CDK4/6i, compared to ET alone. Specifically, treatments with abemaciclib and ribociclib showed notable enhancements in dRFS.

A comprehensive luminal breast cancer patient-derived xenografts (PDX) library to capture tumor heterogeneity and explore the mechanisms of resistance to CDK4/6 inhibitors

Breast cancer (BC) is marked by significant genetic, morphological and clinical heterogeneity. To capture this heterogeneity and unravel the molecular mechanisms driving tumor progression and drug resistance, we established a comprehensive patient-derived xenograft (PDX) biobank, focusing particularly on luminal (estrogen receptor, ER+) and young premenopausal patients, for whom PDX models are currently scarce. Across all BC subtypes, our efforts resulted in an overall success rate of 17% (26 established PDX lines out of 151 total attempts), specifically 15% in luminal, 12% in human epidermal growth factor receptor 2 positive (HER2+) and 35% in triple negative BC. These PDX mirrored morphologic and genetic features of BC from which they originated, serving as a reliable tool to investigate drug resistance and test therapeutic strategies. We focused on understanding resistance to CDK4/6 inhibitors (CDK4/6i), which are crucial in the treatment of patients with advanced luminal BC. Treating a sensitive luminal BC PDX with the CDK4/6i palbociclib revealed that, despite initial tumor shrinkage, some tumors might eventually regrow under drug treatment. RNA sequencing, followed by gene set enrichment analyses, unveiled that these PDXs have become refractory to CDK4/6i, both at biological and molecular levels, displaying significant enrichment in proliferation pathways, such as MTORC1, E2F and MYC. Using organoids derived from these PDX (PDxO), we observed that acquisition of CDK4/6i resistance conferred cross-resistance to endocrine therapy and that targeting MTORC1 was a successful strategy to overcome CDK4/6i resistance. Considered together, these results indicate that our PDX models may serve as robust tools to elucidate the molecular basis of BC disease progression and, by providing the possibility to simultaneously test different therapies on the same tumor, to surmount treatment resistance. While this approach is of course not feasible in the clinic, its exploitation in PDX may expedite the identification and development of more successful therapies for patients with advanced luminal BC. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Polyphenols as Immunomodulators and Epigenetic Modulators: An Analysis of Their Role in the Treatment and Prevention of Breast Cancer

Breast cancer poses a substantial health challenge for women globally. Recently, there has been a notable increase in scholarly attention regarding polyphenols, primarily attributed to not only the adverse effects associated with conventional treatments but also their immune-preventive impacts. Polyphenols, nature-derived substances present in vegetation, including fruits and vegetables, have received considerable attention in various fields of science due to their probable wellness merits, particularly in the treatment and hindrance of cancer. This review focuses on the immunomodulatory effects of polyphenols in breast cancer, emphasizing their capacity to influence the reaction of adaptive and innate immune cells within the tumor-associated environment. Polyphenols are implicated in the modulation of inflammation, the enhancement of antioxidant defenses, the promotion of epigenetic modifications, and the support of immune functions. Additionally, these compounds have been shown to influence the activity of critical immune cells, including macrophages and T cells. By targeting pathways involved in immune evasion, polyphenols may augment the capacity of the defensive system to detect and eliminate tumors. The findings suggest that incorporating polyphenol-rich foods into the diet could offer a promising, collaborative (integrative) approach to classical breast cancer remedial procedures by regulating how the defense mechanism interacts with the disease.

An innovative approach to the multidisciplinary treatment of uninsured breast cancer patients

PURPOSE

A significant proportion of many populations remain uninsured. The aim of the study was to assess differences in breast cancer outcomes before and after the implementation of an innovative approach to the multidisciplinary treatment of uninsured breast cancer patients.

METHODS

Retrospective review was performed of patients seen at a safety net hospital from January 2000 to December 2020. Beginning July 2006, an innovative approach was implemented to lower patient costs and facilitate care of uninsured patients.

RESULTS

The study included 1,797 patients, 661 patients before the changes (BCS), and 1136 patients after implementation of the new cost saving approach (ACS). The mean age was 53 years. The majority were uninsured (56%) or insured by Medicaid (31%). Only 18% underwent screening mammography. The ACS group had a higher rate of breast conservation (75% vs 47%, p < 0.001). A higher percentage of the ACS group received adjuvant therapy: Chemotherapy (91% vs 70%, p < 0.001), Radiation therapy (91% vs 70%, p < 0.001), and initiated endocrine therapy (87% vs 67%, p < 0.001). After follow-up of 8 years, these changes resulted in lower ipsilateral breast tumor recurrence (2% vs 16%, p < 0.001) and chest wall recurrence (5% versus 8%) and improvement in overall survival (90% vs 81%, p < 0.001).

CONCLUSION

Peer-reviewed literature is replete of studies documenting disparities in breast cancer treatment. The current study describes a successful cost-limiting method which takes advantage of existing financial assistance programs to improve care in uninsured patients.

Racial disparities in treatment and outcomes between Hispanic and non-Hispanic black women with triple-negative breast cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) is an aggressive breast cancer (BC) subtype with higher incidence and mortality rates in non-Hispanic Black (NHB) women than non-Hispanic Whites. Studies assessing disparities between NHB and Hispanic women, the two largest US racial/ethnic minorities, are lacking. This study evaluates disparities in the treatment and outcomes between NHB and Hispanic women with non-metastatic TNBC.

METHODS

This observational, population-based study using the SEER database included adult, female patients diagnosed with non-metastatic TNBC between 2010 and 2015 and identified as NHB or Hispanic. Logistic regression analysis was used to examine the adjusted odds of receiving breast cancer-directed treatment. Kaplan-Meier and cumulative incidence of death curves were plotted to assess overall survival (OS) and risk of breast cancer-related death, respectively. Multivariate regression analyses with Cox and Fine-Gray methods were calculated to assess factors associated with OS and breast cancer-related death, respectively.

RESULTS

There were 3426 Hispanic and 5419 NHB patients with non-metastatic TNBC. Hispanics had better 5-year OS relative to NHB (76% vs. 72%). No differences in the odds of receiving chemotherapy or surgery between cohorts was seen. However, the odds of undergoing breast-conserving surgery (BCS) and receiving radiation was higher in NHB than Hispanics, (OR, 1.22; 95% CI, 1.10-1.36) and (OR, 1.50; 95% CI, 1.36-1.66), respectively. Lack of radiation therapy was associated with increased BC-related death in NHB relative to Hispanics (sHR, 1.40; 95% CI, 1.19-1.65). Nevertheless, this difference was not seen when radiation was given, (sHR, 1.03; 95% CI, 0.87-1.23).

CONCLUSIONS

We found racial disparities in treatment and outcomes between NHB and Hispanics. NHB were more likely to receive radiation therapy and have BCS. Still, after adjusting for demographic and treatment-related factors, NHB had worse OS and BCSS relative to Hispanics. Additional research is needed to understand the drivers of these disparities.

Therapeutic benefits of maintaining CDK4/6 inhibitors and incorporating CDK2 inhibitors beyond progression in breast cancer

The combination of CDK4/6 inhibitors (CDK4/6i) and endocrine therapy has revolutionized treatment for hormone receptor-positive (HR+) metastatic breast cancer. However, the emergence of resistance in most patients often leads to treatment discontinuation with no consensus on effective second-line therapies. The therapeutic benefits of maintaining CDK4/6i or incorporating CDK2 inhibitors (CDK2i) after disease progression remain unclear. Here, we demonstrate that sustained CDK4/6i therapy, either alone or combined with CDK2i, significantly suppresses the growth of drug-resistant HR+ breast cancer. Continued CDK4/6i treatment induces a non-canonical pathway for retinoblastoma protein (Rb) inactivation via post-translational degradation, resulting in diminished E2F activity and delayed G1 progression. Importantly, our data highlight that CDK2i should be combined with CDK4/6i to effectively suppress CDK2 activity and overcome resistance. We also identify cyclin E overexpression as a key driver of resistance to CDK4/6 and CDK2 inhibition. These findings provide crucial insights into overcoming resistance in HR+ breast cancer, supporting the continued use of CDK4/6i and the strategic incorporation of CDK2i to improve therapeutic outcomes.

Promoting Apoptosis in MCF-7 Cells via ROS Generation by Quinolino-triazoles Derived from One-Pot Telescopic Synthesis

Inhibition of vascular endothelial growth factor receptor 2 (VEGFR-2) facilitates potent antiangiogenic and anticancer responses. In this regard, the development of effective pharmacophores, i.e., quinoline-based triazole derivatives 6a-j, by a one-pot telescopic approach is our focus. Among all of them, 6f, possessing amide and cyanide substituents, displayed the highest binding ability with VEGFR-2, having high affinity of -8.9 kcal/mol. Further, 6f and 6g (containing amide and bromo groups) exhibited a wide spectrum of anticancer activities due to the presence of active oxidative stress inducers, with cytotoxicity values of 10 ± 0.2 and 12 ± 0.6 μM, respectively. Apoptosis analysis demonstrated the involvement of 6f and 6g in mitochondrial damage and the loss of mitochondrial membrane potential (ΔΨm). Intercellular localization of 6f/6g in MCF-7 revealed the presence of 6g in the cytoplasm along with an increase in ROS production and a reduction in MMP, proving the ability of 6g to target mitochondria.

DLL4-targeted CAR-T therapy sensitizes neoadjuvant chemotherapy via eliminating cancer stem cells and reshaping immune microenvironment in HER2+ breast cancer

BACKGROUND

Neoadjuvant therapy with trastuzumab, pertuzumab and paclitaxel (THP) has significantly improved the prognosis of patients with human epidermal growth factor receptor 2 (HER2)+ breast cancer (BC). However, there remains a subset of non-responsive patients. Thus, this study sought to identify key regulators of THP neoadjuvant therapy resistance and potential targets to sensitize sensitivity.

METHODS

The Cancer Genome Atlas database, Gene Expression Omnibus and membrane protein database were used to identify the key regulator of THP neoadjuvant resistance. The biological functions and mechanisms of delta-like 4 proteins (DLL4) in THP therapy resistance were investigated in vitro and in vivo using the bioinformatic analysis, multiplex immunofluorescence, flow cytometry, sphere formation assays and chromatin immunoprecipitation, etc. Furthermore, DLL4-targeted chimeric antigen receptor (CAR)-T cells were established to sensitize THP therapy.

RESULTS

DLL4 was identified as a key target in THP neoadjuvant therapy resistance for HER2+ BC. Mechanistically, DLL4+ tumor cells exhibited enhanced stemness and resistance to the THP neoadjuvant chemotherapy. Additionally, soluble DLL4 can split away from tumor cells and diffuse into the stroma, where it can activate the Notch signaling pathway in neutrophils, inducing the formation and release of neutrophil extracellular traps (NETs) by regulating the transcription of MPO, PDIA4 and ELANE. This led to the exclusion of lymphocyte infiltration, thereby enhancing therapy resistance. What is more, we designed a DLL4-targeted CAR-T to eliminate DLL4+ tumor cells and reverse the resistant status.

CONCLUSIONS

Our study revealed novel functions of DLL4 in cell stemness and immune infiltration, including NET formation and T cell exclusion, which collectively contributed to THP neoadjuvant therapy resistance in HER2+ BC. Furthermore, we provided a CAR-T-based therapy to sensitize the THP neoadjuvant therapy.

Worse Clinical and Survival Outcomes in Breast Cancer Patients Living in Puerto Rico Compared to Hispanics, Non-Hispanic Blacks, and Non-Hispanic Whites from Florida

BACKGROUND

Herein, we report the characterization of four cohorts of breast cancer patients including (1) non-Hispanic Whites in Florida, (2) non-Hispanic Blacks in Florida, (3) Hispanics in Florida, and (4) Hispanics in Puerto Rico.

METHODS

Data from female breast cancer patients were collected from cancer registry (n = 9361) and self-reported patient questionnaires (n = 4324). Several statistical tests were applied to identify significant group differences.

RESULTS

Breast cancer patients from Puerto Rico were least frequently employed and had the lowest rates of college education among the groups. They also reported more live births and less breastfeeding. Both Hispanic groups reported a higher fraction experiencing menstruation at age 11 or younger (Floridian Hispanics [38%] and Puerto Ricans [36%]) compared to non-Hispanic Whites (20%) and non-Hispanic Blacks (22%). Non-Hispanic Black and Puerto Rican women were significantly older at breast cancer diagnosis than their non-Hispanic White and Floridian Hispanic counterparts. The Puerto Rican and non-Hispanic Black groups more frequently had pathology stage T2 or higher primary breast tumors at diagnosis (non-Hispanic Whites [29%], non-Hispanic Blacks [39%], Floridian Hispanics [33%], Puerto Ricans [46%]). The Puerto Rican (73%, 95% CI [66, 82]) and non-Hispanic Black (79%, 95% CI [75, 84]) groups demonstrate reduced 5-year survival compared to non-Hispanic Whites (89%, 95% CI [86, 92]) and Floridian Hispanics (89%, 95% CI [86, 90]).

CONCLUSIONS

These findings demonstrate that Puerto Rican breast cancer patients suffer significant breast cancer health disparities relative to non-Hispanic Whites and Hispanics from Florida similar to the disparities observed for non-Hispanic Blacks. Future work must seek to better understand and address these disparities.

Are All Prognostic Stage IB Breast Cancers Equivalent?

Background/Objectives: The 8th edition of the American Joint Committee on Cancer integrates histology and biomarker status with anatomic extent in breast cancer (BC) pathologic prognostic staging (PPS). However, PPS IB includes anatomic locally advanced hormone-receptor-positive/HER2-negative (LA-HR+/HER2-) and early-stage triple-negative BC (ES-TNBC). Previous research shows that increased nodal involvement is a critical predictor of worse prognosis, raising questions about whether biological subtype or anatomic stage has a greater influence on outcomes in these discordant cases. We hypothesized that overall survival (OS) remains worse for LA-HR+/HER2- BC compared to ES-TNBC, despite both being classified as PPS IB. Methods: Using the National Cancer Database, we identified patients with LA-HR+/HER2- BC (pT3N1 or pT1-3N2, grade 1-2) and ES-TNBC (T1N0, grade 2-3) treated between 2004 and 2017. Patients without complete primary tumor stage, biomarker status, grade, TNM staging, or treated with neoadjuvant therapy were excluded. The primary endpoint was OS. Multivariable Cox regression evaluated OS between LA-HR+/HER2- BC and ES-TNBC. Results: Among 45,818 patients (17,359 LA-HR+/HER2- BC and 28,459 ES-TNBC), LA-HR+/HER2- BC had significantly worse 6-year OS (86.1% vs. 90.4%; HR = 1.63; p < 0.0001). Among patients receiving appropriate therapies, patients with LA-HR+/HER2- BC had 35% relatively higher risk of death (HR = 1.35; 1.24-1.48; p < 0.0001). These results highlight that LA-HR+/HER2- breast cancer has worse survival compared to ES-TNBC, despite both being classified as PPS IB and receiving all appropriate treatments. Conclusions: Anatomic disease extent remains an important factor in patients with discordant AS and PPS. Future iterations of PPS should re-classify LA-HR+/HER2- breast cancer from PPS IB to ensure more accurate prognostic and survival information.

Racial Differences in Breast Cancer Survival Between Black and White Women According to Tumor Subtype: A Systematic Review and Meta-Analysis

PURPOSE

Despite effective early-detection approaches and innovative treatments, Black women in the United States have higher breast cancer mortality rates compared with White women. The purpose of this systematic review and meta-analysis is to determine the extent of disparities in breast cancer survival between Black and White women according to tumor subtype.

METHODS

A comprehensive database search was performed for full-text, English-language articles published from January 1, 2000, to December 31, 2022. Included studies compared survival between Black and White female patients with breast cancer within subtypes defined by hormone receptor and human epidermal growth factor receptor 2 (HER2)/neu (HER2; now known as ERBB2) status. Random-effects models were used to combine study-specific results and generate pooled relative risks (RRs) and 95% CIs for breast cancer-specific or overall survival (OS). A protocol for this review was registered in PROSPERO (CRD42021268212).

RESULTS

Eighteen studies including 228,885 (34,262 Black; 182,466 White) patients with breast cancer were identified. Compared with White women, Black women had a higher risk of breast cancer death for all tumor subtypes. The summary risk of breast cancer death was 50% higher among hormone receptor-positive HER2-negative [HER2-] tumors (RR, 1.50 [95% CI, 1.30 to 1.72]), 34% higher for hormone receptor+/HER2+ (RR, 1.34 [95% CI, 1.10 to 1.64]), 20% higher for hormone receptor-negative (-)/HER2+ (RR, 1.29 [95% CI, 1.00 to 1.43]), and 17% higher among individuals with hormone receptor-/HER2- tumors (hazard ratio, 1.17; 95% CI, 1.10 to 1.25). Black women also had poorer OS than White women for all subtypes.

CONCLUSION

These results suggest there are both subtype-specific and subtype-independent mechanisms that contribute to disparities in breast cancer survival between Black and White women, which require multilevel interventions to address and achieve health equity.

C-Peptide and BMi predict anti-hyperglycemic treatment lines in breast cancer patients treated with Alpelisib

PURPOSE

Alpelisib is a PI3K (Phosphoinositide 3-kinases) inhibitor used for breast cancer which develops hyperglycemia based on its action on glucose metabolism regulation. This study aims to identify potential risk factors predicting hyperglycemia development and the need for multiple treatments for hyperglycemia in patients receiving Alpelisib.

METHODS

Fourteen women diagnosed with metastatic hormone receptor-positive breast cancer carrying PI3K mutations who initiated treatment with Alpelisib were monitored through consultations in the Oncology and Endocrinology departments. Non-parametric ROC curves were generated to assess the need for three or more antidiabetic medications to achieve glycemic control.

RESULTS

The study population had a median age of 64 years (range:48-69) with a median body mass index (BMI) of 26.6 kg/m2 (range: 22.9-29.4). Overweight was observed in 35.7% of the participants and obesity in 21.4%. Fifty percent of the participants had prediabetes, and 85.7% developed hyperglycemia requiring pharmacological treatment, although none of them needed to discontinue treatment for this reason. Baseline C-peptide levels and BMI were associated with the number of antidiabetic drugs used (Spearman's Rho 0.553, p = 0.040; Spearman's Rho 0.581, p = 0.030, respectively). ROC curve analysis showed and area under the curve (AUC) of 0.819 for the variable risk profile (defined as baseline C-peptide >10.5 ng/ml and BMI > 27 kg/m2), whereas AUC values were 0.556 and 0.514 for HbA1c and baseline glucose, respectively, (p = 0.012).

CONCLUSION

A joint follow-up by an Oncology department and a Diabetes Unit can prevent treatment discontinuation in patients under Alpelisib therapy. Baseline BMI and plasma C-peptide levels can predict an increased need for anti-hyperglycemic treatment.

Dissecting the immune infiltrate of primary luminal B-like breast carcinomas in relation to age

The impact of aging on the immune landscape of luminal breast cancer (Lum-BC) is poorly characterized. Understanding the age-related dynamics of immune editing in Lum-BC is anticipated to improve the therapeutic benefit of immunotherapy in older patients. To this end, here we applied the 'multiple iterative labeling by antibody neo-deposition' (MILAN) technique, a spatially resolved single-cell multiplex immunohistochemistry method. We created tissue microarrays by sampling both the tumor center and invasive front of luminal breast tumors collected from a cohort of treatment-naïve patients enrolled in the prospective monocentric IMAGE (IMmune system and AGEing) study. Patients were subdivided into three nonoverlapping age categories (35-45 = 'young', n = 12; 55-65 = 'middle', n = 15; ≥70 = 'old', n = 26). Additionally, depending on localization and amount of cytotoxic T lymphocytes, the tumor immune types 'desert' (n = 22), 'excluded' (n = 19), and 'inflamed' (n = 12) were identified. For the MILAN technique we used 58 markers comprising phenotypic and functional markers allowing in-depth characterization of T and B lymphocytes (T&B-lym). These were compared between age groups and tumor immune types using Wilcoxon's test and Pearson's correlation. Cytometric analysis revealed a decline of the immune cell compartment with aging. T&B-lym were numerically less abundant in tumors from middle-aged and old compared to young patients, regardless of the geographical tumor zone. Likewise, desert-type tumors showed the smallest immune-cell compartment and were not represented in the group of young patients. Analysis of immune checkpoint molecules revealed a heterogeneous geographical pattern of expression, indicating higher numbers of PD-L1 and OX40-positive T&B-lym in young compared to old patients. Despite the numerical decline of immune infiltration, old patients retained higher expression levels of OX40 in T helper cells located near cancer cells, compared to middle-aged and young patients. Aging is associated with important numerical and functional changes of the immune landscape in Lum-BC. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Abemaciclib increases the risk of venous thromboembolism in breast cancer: Integrate meta-analysis, pharmacovigilance database analysis, and in vitro validation

BACKGROUND

Recently, cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have emerged as a novel treatment strategy for breast cancer. However, increasing reports of CDK4/6i-associated venous thromboembolism (VTE) have garnered attention. This study assessed CDK4/6i-associated VTE in breast cancer, and examined the effect of CDK4/6i on platelet/coagulation function for the first time in vitro.

METHODS

PubMed and Embase databases were searched for studies published from the establishment of the database to December 31, 2022 for randomized controlled trials (RCTs) and real-world studies of CDK4/6i in patients with breast cancer, and the data obtained from the included studies were used for meta-analysis. A disproportionality analysis by extracting adverse drug reaction signals of CDK4/6i-associated VTE from the FDA Adverse Event Reporting System (FAERS) database was also conducted. Additionally, the in vitro effect of CDK4/6i on platelet function was assessed based on platelet aggregation tests and flow cytometry, and coagulation function was assessed based on the blood clotting function test.

FINDINGS

A total of 16,903 patients in 13 RCTs and 6,490 patients in 9 real-world studies were included in the meta-analysis. In RCTs, VTE occurred in 193 (2.1 %) and 55 (0.7 %) patients in the CDK4/6i and control groups, respectively. In real-world studies, the aggregate incidence rate of VTE was 4.2 % (95 % CI: 2.1, 6.3). The meta-analysis of RCTs revealed that abemaciclib (Odds ratio [OR]: 4.40 [95 % CI: 2.74,7.05], p < 0.001) and palbociclib (OR: 2.35 [95 % CI: 1.34, 4.12], p < 0.01) significantly increased the risk of VTE in patients with breast cancer compared to placebo. FAERS database analysis revealed that abemaciclib (reporting odds ratio [ROR]: 1.63 [95 % CI: 1.36, 1.97]; IC025: 0.67) and ribociclib (ROR: 1.17 [95 % CI: 1.0, 1.39]; IC025: 0.18) demonstrated a significantly increased signal of VTE. Similarly, findings from in vitro experiments demonstrated that abemaciclib enhanced agonist-induced platelet activation, especially when collagen was used as the inducer, and this effect became more prominent with increasing its concentration.

INTERPRETATION

Use of abemaciclib may increase the risk of VTE in patients with breast cancer, which may be partially attributed to the effect of abemaciclib on platelet function. Close monitoring of VTE occurrence is highly recommended while using abemaciclib, especially in patients at a high risk of VTE.

Gastrin-releasing peptide receptor as theranostic target in estrogen-receptor positive breast cancer: A preclinical study of the theranostic pair [55Co]Co- and [177Lu]Lu-DOTA-RM26

BACKGROUND

Patients with advanced metastatic estrogen receptor-positive breast cancer often develop resistance to standard treatments, leading to uncontrolled progression. Thus, innovative therapies are urgently needed. The gastrin-releasing peptide receptor (GRPR) is overexpressed in various cancers, including breast cancer, making it an interesting theranostic target. RM26, a GRPR-targeting antagonist, has demonstrated promising in vivo kinetics in prostate cancer models. This study evaluated the theranostic capabilities of [55Co]Co-/[177Lu]Lu-DOTA-RM26 in vitro in estrogen receptor-positive breast cancer cells and assessed the diagnostic potential of [55Co]Co-DOTA-RM26 in vivo in a breast cancer mouse model.

METHODS

We analyzed the binding specificity of [57Co]Co-/[177Lu]Lu-DOTA-RM26 in T47D breast cancer cells, using [57Co]Co-DOTA-RM26 as a surrogate for [55Co]Co-DOTA-RM26. The therapeutic efficacy of increasing [177Lu]Lu-DOTA-RM26 concentrations was determined via viability assay in vitro. Ex vivo biodistribution of [57Co]Co-DOTA-RM26 (17.2 ± 2.7 kBq, 33 ± 5.2 pmol/mouse) was investigated in 12 mice (n= 4/group) with orthotopic breast cancer tumors. The mice were sacrificed at 4 and 24 h post-injection (pi), including a blocking group (20 nmol of unlabeled [Tyr4]-Bombesin) at 4 h pi. For imaging, two tumor-bearing mice underwent [55Co]Co-DOTA-RM26 PET/CT, 4 and 24 h pi (2.8 ± 0.2 MBq, 167.5 ± 0.5 pmol/mouse), with or without GRPR blocking.

RESULTS

In vitro studies revealed high, specific binding of [57Co]Co-DOTA-RM26 (43 ± 1 % of total added activity per 106 cells (%IA/106)) and [177Lu]Lu-DOTA-RM26 (37 ± 4 %IA/106). The activity was predominantly localized at the cell surface: 71 ± 3 % and 80 ± 6 % for [57Co]Co-DOTA-RM26 and [177Lu]Lu-DOTA-RM26, respectively. [177Lu]Lu-DOTA-RM26 significantly reduced cell viability at all activity concentrations >0.625 MBq/mL (p < 0.0001), with cell viability below 1 % at concentrations ≥5 MBq/mL. Biodistribution data (n = 12) indicated a high, specific tumor uptake of [57Co]Co-DOTA-RM26, surpassing all other tissues significantly at both time points, 3.7 ± 0.6 % of the injected activity per gram (%IA/g) 4 h pi and 0.98 ± 0.05 %IA/g 24 h pi. The kidneys showed the second-highest uptake (2.0 ± 0.1 %IA/g 4 h pi), followed by the pancreas (1.4 ± 0.4 %IA/g 4 h pi). PET/CT imaging with [55Co]Co-DOTA-RM26 supported the biodistribution data and, distinctly visualized the tumor 24 h pi and showed an improved tumor-to-background compared to the earlier time points. Effective GRPR blocking significantly reduced tumor uptake in the PET images 24 h pi.

CONCLUSION

These findings suggest that the theranostic pair [55Co]Co-/[177Lu]Lu-DOTA-RM26 holds significant promise as a theranostic agent for estrogen receptor-positive breast cancer.

Predictors of abemaciclib discontinuation in patients with breast cancer: a multicenter retrospective cohort study

OBJECTIVE

This study explored the predictors of abemaciclib discontinuation, a cyclin-dependent kinase 4 and 6 inhibitor, in patients with breast cancer.

MATERIAL AND METHODS

Between November 2018 and March 2023, 147 patients with breast cancer treated with abemaciclib at Osaka Medical and Pharmaceutical University Hospital and Kindai University Nara Hospital were included. The exclusion criteria were as follows: lack of blood testing within 2 weeks prior to starting abemaciclib therapy, transfer to another facility after the commencement of abemaciclib therapy, and discontinuation of abemaciclib therapy due to the diagnosis of another cancer. The duration from the initiation of abemaciclib to discontinuation for any reason and to temporary suspension or dose reduction due to adverse events were analyzed as outcome variables using multivariate Cox regression analysis.

RESULTS

Baseline weight < 54 kg, bone metastases, and hemoglobin level ≤ 12.4 g/dL were independent predictors of abemaciclib discontinuation for any reason. The main adverse events leading to abemaciclib discontinuation were liver enzyme elevation and gastrointestinal symptoms. Additionally, focusing on the adverse event of abemaciclib, a baseline weight < 54 kg was an independent predictor of temporary suspension or dose reduction due to adverse events. The most common adverse events leading to temporary suspension or dose reduction were neutropenia and diarrhea.

CONCLUSION

Patients with lower body weight are more susceptible to the adverse events of abemaciclib, increasing their risk of treatment discontinuation. In such patients, strict monitoring of adverse events and consideration of more frequent medical visits are necessary from the start of abemaciclib therapy.

Hormone Receptor Positive Breast Cancer in Young Women: A Review

The global incidence of hormone-positive breast cancer (HR+ BC) in young women is rising, though the underlying reasons remain unclear. HR+ disease in younger women appears to represent a distinct clinical entity compared to that in older women, exhibiting distinct clinicopathological characteristics, outcomes and responses to treatment. Despite these differences, there is a paucity of large-volume data focusing on young women with HR+ in contemporary literature. Hormone receptor positive breast cancer in young women is associated with poorer prognoses compared to older women. Additionally, early age onset breast cancer presents unique challenges, including concerns related to fertility, the toxic effects of therapeutic agents, and specific surgical considerations. The purpose of this review is to report the existing literature on HR+ disease in young women.

Systemic and local chronic inflammation and hormone disposition promote a tumor-permissive environment for breast cancer in older women

Estrogen receptor positive (ER+) breast cancer is the most common subtype of breast cancer and is an age-related disease. The peak incidence of diagnosis occurs around age 70, even though these post-menopausal patients have low circulating levels of estradiol (E2). Despite the hormone sensitivity of age-related tumors, we have a limited understanding of the interplay between systemic and local hormones, chronic inflammation, and immune changes that contribute to the growth and development of these tumors. Here, we show that aged F344 rats treated with the dimethylbenz(a)anthracene / medroxyprogestrone acetate (DMBA/MPA) carcinogen develop more tumors at faster rates than their younger counterparts, suggesting that the aged environment promotes tumor initiation and impacts growth. Single-nuclei RNA-seq (snRNA-seq) of the tumors showed broad local immune dysfunction that was associated with circulating chronic inflammation. Across a broad cohort of specimens from patients with ER+ breast cancer and age-matched donors of normal breast tissue, we observe that even with an estrone (E1)-predominant estrogen disposition in the systemic circulation, tumors in older patients increase HSD17B7 expression to convert E1 to E2 in the tumor microenvironment (TME) and have local E2 levels similar to pre-menopausal patients. Concurrently, trackable increases in several chemokines, defined most notably by CCL2, promote a chronically inflamed but immune dysfunctional TME. This unique milieu in the aged TME, characterized by high local E2 and chemokine-enriched chronic inflammation, promotes both accumulation of tumor-associated macrophages (TAMs), which serve as signaling hubs, as well as polarization of TAMs towards a CD206+/PD-L1+, immunosuppressive phenotype. Pharmacologic targeting of estrogen signaling (either by HSD17B7 inhibition or with fulvestrant) and chemokine inflammation both decrease local E2 and prevent macrophage polarization. Overall, these findings suggest that chronic inflammation and hormonal disposition are critical contributors to the age-related nature of ER+ breast cancer development and growth and offer potential therapeutic insight to treat these patients.

Translational Summary

We uncover the unique underpinnings establishing how the systemic host environment contributes to the aged breast tumor microenvironment, characterized by high local estradiol and chronic inflammation with immune dysregulation, and show that targeting avenues of estrogen conversion and chronic inflammation work to restore anti-tumor immunity.

Irish national real-world analysis of the clinical and economic impact of 21-gene oncotype DX® testing in early-stage, 1-3 lymph node-positive, oestrogen receptor-positive, HER2-negative, breast cancer

PURPOSE

The treatment landscape of Oestrogen receptor-positive (ER-positive) breast cancer is evolving, with declining chemotherapy use as a result of Oncotype DX Breast Recurrence Score® testing. Results from the SWOG S1007 RxPONDER trial suggest that adjuvant chemotherapy may benefit some premenopausal women with ER-positive, HER2-negative disease with 1-3 positive lymph nodes (N1), and a Recurrence Score® (RS) of ≤ 25. Postmenopausal women with similar characteristics did not benefit from adjuvant chemotherapy. We examine the clinical and economic impact of Oncotype DX® testing on treatment decisions in patients with N1 disease in Ireland using real world data.

METHODS

From March 2011 to October 2022, a retrospective, cross-sectional observational study was performed of patients with ER-positive, HER2-negative N1 breast cancer, who had Oncotype DX testing across 5 of Ireland's largest cancer centres. Patients were classified into low risk (RS 0-13), intermediate risk (RS 14-25) and high risk (RS > 25). Data were collected via electronic patient records. Information regarding costing was provided primarily by pre-published sources.

RESULTS

A total of 828 N1 patients were included in this study. Post Oncotype DX testing, 480 patients (58%) were spared chemotherapy. Of the patients who had a change in chemotherapy recommendation based on Oncotype DX testing, 271 (56%), 205 (43%), 4 (1%) had a RS result of 0-13, 14-25 and > 25 respectively. Use of Oncotype DX testing was associated with a 58% reduction in chemotherapy administration overall. This resulted in estimated savings of over €6 million in treatment costs. Deducting the assay cost, estimated net savings of over €3.3 million were achieved. Changes in the ordering demographics of Oncotype DX tests were identified after RxPONDER data were presented, with increased testing in women ≥ 50 years and a reduction in proportion of tests ordered for women < 50 years.

CONCLUSION

Between 2011 and 2022, assay use resulted in a 58% reduction in chemotherapy administration and net savings of over €3.3 million.

Mammary adipocytes promote breast tumor cell invasion and angiogenesis in the context of menopause and obesity

The mechanism(s) underlying obesity-related postmenopausal (PM) breast cancer (BC) are not clearly understood. We hypothesized that the increased local presence of 'obese' mammary adipocytes within the BC microenvironment promotes the acquisition of an invasive and angiogenic BC cell phenotype and accelerates tumor proliferation and progression. BC cells, treated with primary mammary adipocyte secretome from premenopausal (Pre-M) and PM obese women (ObAdCM; obese adipocyte conditioned-media) upregulated the expression of several pro-tumorigenic factors including VEGF, lipocalin-2 and IL-6. Both Pre-M and PM ObAdCM stimulated endothelial cell recruitment and proliferation and significantly stimulated BC cell proliferation, migration and invasion. IL-6 and LCN2 induced STAT3/Akt signaling in BC cells and STAT3 inhibition abrogated the ObAdCM-stimulated BC cell proliferation and migration. Expression of proangiogenic regulators including VEGF, NRP1, NRP2, IL8RB, TGFβ2, and TSP-1 were found to be differentially regulated in mammary adipocytes from obese PM women. Comparative RNAseq indicated an upregulation of PI3K/Akt signaling, ECM-receptor interactions and lipid/fatty acid metabolism in PM versus Pre-M mammary adipocytes. Our results demonstrate that irrespective of menopausal status, cross-talk between obese mammary adipocytes and BC cells promotes tumor aggressiveness and suggest that targeting the LCN2/IL-6/STAT3 signaling axis may be a useful strategy in obesity-driven breast tumorigenesis.

Correlating Predicted Adjuvant Therapy Benefit and Risk of Recurrence Between Breast Cancer Index (BCI) and the 21-Gene Oncotype DX Recurrence Score (RS)

INTRODUCTION

Breast Cancer Index (BCI) is a genomic assay that evaluates the benefit of extending endocrine therapy (ET) from 5 to 10 years and predicts recurrence risk (RR). We evaluated the association between BCI and Oncotype DX (ODX).

PATIENTS

Women with hormone receptor (HR)-positive early-stage breast cancer (EBC) who had BCI and ODX performed were included.

METHODS

We performed a retrospective review of women with HR-positive EBC. BCI was categorized as predictive of extended ET versus not and ODX recurrence score (RS) as low (0-10), intermediate (11-25), and high (26-100). Univariate and multivariable logistic and linear regression models assessed the relationship between BCI and ODX, factors associated with each, and discordance between scores.

RESULTS

We identified 153 women, 22% were premenopausal and 18% were lymph node positive. The univariate logistic and linear models revealed an association between BCI predictive score and ODX RS (OR 7.84, CI, 2.63-23.36, P < .001) and log of BCI RR (Beta 0.04, CI, 0.02-0.06, P < .001). Seventy-four percent of BCI predictive scores were concordant with ODX RS and 83% of BCI RR was concordant with ODX RR. In a univariate logistic regression model, BCI predictive of ET benefit was associated with discordance (OR 28.00, CI, 10.58-74.02, P < .001). Higher ODX RR was associated with discordance (OR 1.92, CI, 1.42-2.59, P < .001).

CONCLUSION

We found a significant association between ODX and BCI predictive and prognostic scores. BCI predictive of extended ET benefit was associated with discordance with ODX RS. Higher predicted RR on ODX was associated with discordance with BCI predicted RR.