Long-term Mammography Screening Trends and Predictors of Return to Screening after the COVID-19 Pandemic: Results from a Statewide Registry.

Purpose To evaluate long-term trends in mammography screening rates and identify sociodemographic and breast cancer risk characteristics associated with return to screening after the COVID-19 pandemic. Materials and Methods In this retrospective study, statewide screening mammography data of 222 384 female individuals aged 40 years or older (mean age, 58.8 years ± 11.7 [SD]) from the Vermont Breast Cancer Surveillance System were evaluated to generate descriptive statistics and Joinpoint models to characterize screening patterns during 2000-2022. Log-binomial regression models estimated associations of sociodemographic and risk characteristics with post-COVID-19 pandemic return to screening. Results The proportion of female individuals in Vermont aged 50-74 years with a screening mammogram obtained in the previous 2 years declined from a prepandemic level of 61.3% (95% CI: 61.1%, 61.6%) in 2019 to 56.0% (95% CI: 55.7%, 56.3%) in 2021 before rebounding to 60.7% (95% CI: 60.4%, 61.0%) in 2022. Screening adherence in 2022 remained substantially lower than that observed during the 2007-2010 apex of screening adherence (66.1%-67.0%). Joinpoint models estimated an annual percent change of -1.1% (95% CI: -1.5%, -0.8%) during 2010-2022. Among the cohort of 95 644 individuals screened during January 2018-March 2020, the probability of returning to screening during 2020-2022 varied by age (eg, risk ratio [RR] = 0.94 [95% CI: 0.93, 0.95] for age 40-44 vs age 60-64 years), race and ethnicity (RR = 0.84 [95% CI: 0.78, 0.90] for Black vs White individuals), education (RR = 0.84 [95% CI: 0.81, 0.86] for less than high school degree vs college degree), and by 5-year breast cancer risk (RR = 1.06 [95% CI: 1.04, 1.08] for very high vs average risk). Conclusion Despite a rebound to near prepandemic levels, Vermont mammography screening rates have steadily declined since 2010, with certain sociodemographic groups less likely to return to screening after the pandemic. Keywords: Mammography, Breast, Health Policy and Practice, Neoplasms-Primary, Epidemiology, Screening Supplemental material is available for this article. © RSNA, 2024.

Real-world treatment patterns and clinical outcomes in patients treated with eribulin after prior phosphoinositide 3-Kinase inhibitor treatment for metastatic breast cancer.

PURPOSE: In 2010, the US Food and Drug Administration approved eribulin for the treatment of metastatic breast cancer (MBC). Since then, the treatment landscape has evolved with many new therapy classes, a more recent one being the small molecule inhibitors of phosphoinositide 3 kinase (PI3K). We sought to characterize the treatment patterns and clinical outcomes of patients with MBC who received eribulin following prior treatment with a PI3K inhibitor. METHODS: A retrospective cohort study based on medical record review included MBC patients who initiated eribulin between March 2019 and September 2020 following prior treatment with a PI3K inhibitor was conducted. Patient demographics, treatment characteristics, and clinical outcomes were analyzed descriptively. Real-world progression-free survival (rwPFS) and overall survival (OS) were estimated from the initiation of eribulin therapy using Kaplan-Meier analyses. RESULTS: 82 eligible patients were included. Patients' median age at eribulin initiation was 62 years; 86.5% had hormone receptor-positive, human epidermal growth factor receptor 2-negative tumors. Eribulin was most often administered in the second or third line (82.9%) in the metastatic setting. Best overall response on eribulin was reported as complete or partial response in 72% of the patients. The median rwPFS was 18.9 months (95% confidence interval [CI], 12.4-not estimable); median OS was not reached. The estimated rwPFS and OS rates at 12 months were 63.3% (95% CI, 50.5-73.7) and 82.6% (95% CI, 72.4-89.3), respectively. CONCLUSION: Our real-world study suggests that eribulin may be a potential treatment option for MBC patients who fail a prior PI3K inhibitor.

Early Real-World Treatment Patterns and Clinical Outcomes in Patients with Metastatic Breast Cancer Treated with Eribulin After Prior Immuno-Oncology or Antibody-Drug Conjugate Therapy.

Introduction: Eribulin was approved by the FDA in 2010 for the treatment of metastatic breast cancer (MBC) in the United States (US). More recently, several immuno-oncology (IO) and antibody-drug conjugate (ADC) regimens have been approved for MBC. We assessed the treatment patterns and clinical outcomes in MBC patients treated with eribulin following treatment with an IO or ADC in US clinical practice. Materials and Methods: In a retrospective patient medical chart review study, patients with MBC, aged ≥18 years, who initiated eribulin therapy between March 1, 2019, and September 30, 2020, treated with either prior IO or ADC in the metastatic setting were included. Patient demographics, treatment characteristics, and clinical outcomes were analyzed descriptively. Real-world progression-free survival (rwPFS) and overall survival (OS) were estimated using Kaplan-Meier analyses. Results: In the study population (N=143), median age at eribulin initiation was 62 years; 64% were Caucasian, and 67% had triple-negative MBC (TNBC). Eribulin therapy was used in the second to fifth line of therapy in the metastatic setting; median treatment duration was 7.2 months. The overall response rate for eribulin was 59.4%. Median rwPFS and OS from eribulin initiation were 21.4 months (95% CI, 12.9-not estimable [NE]) and 24.2 months (95% CI, 17.5-NE), respectively. In patients with TNBC, median rwPFS and OS from eribulin initiation were 12.0 months (95% CI, 8.8-NE) and 18.3 months (95% CI, 14.9-NE), respectively. Conclusion: These real-world data provide evidence for the clinical effectiveness outcomes of eribulin treatment among MBC patients previously treated with an IO or ADC.

Landscape of baseline and acquired genomic alterations in circulating tumor DNA with abemaciclib alone or with endocrine therapy in advanced breast cancer.

PURPOSE: To identify potential predictors of response and resistance mechanisms in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) treated with the CDK4/6 inhibitor abemaciclib +/- endocrine therapy (ET), baseline and acquired genomic alterations in circulating tumor DNA (ctDNA) were analyzed and associated with clinical outcomes. PATIENTS AND METHODS: MONARCH 3: postmenopausal women with HR+, HER2- ABC and no prior systemic therapy in the advanced setting were randomized to abemaciclib or placebo plus nonsteroidal aromatase inhibitor (NSAI). nextMONARCH: women with HR+, HER2- metastatic breast cancer that progressed on/after prior ET and chemotherapy were randomized to abemaciclib alone (two doses) or plus tamoxifen. Baseline and end-of-treatment plasma samples from patients in MONARCH 3 and nextMONARCH (monotherapy arms) were analyzed to identify somatic genomic alterations. Association between genomic alterations and median progression-free survival (mPFS) was assessed. RESULTS: Most patients had ≥1 genomic alteration detected in baseline ctDNA. In MONARCH 3, abemaciclib+NSAI was associated with improved mPFS versus placebo+NSAI, regardless of baseline alterations. ESR1 alterations were less frequently acquired in the abemaciclib+NSAI arm than placebo+NSAI. Acquired alterations potentially associated with resistance to abemaciclib +/- NSAI included RB1 and MYC. CONCLUSIONS: In MONARCH 3, certain baseline ctDNA genomic alterations were prognostic for ET but not predictive of abemaciclib response. Further studies are warranted to assess whether ctDNA alterations acquired during abemaciclib treatment differ from other CDK4/6 inhibitors. Findings are hypothesis-generating, further exploration is warranted into mechanisms of resistance to abemaciclib and ET.

Real-world patient characteristics, treatment patterns, and clinical outcomes associated with tucatinib therapy in HER2-positive metastatic breast cancer.

Background: Tucatinib is an oral human epidermal growth factor receptor 2 (HER2)-directed therapy approved in combination with trastuzumab and capecitabine for use in patients with previously treated HER2+ metastatic breast cancer (MBC) with/without brain metastases (BM). To inform clinical decision-making, it is important to understand tucatinib use in real-world clinical practice. We describe patient characteristics, treatment patterns, and clinical outcomes for tucatinib treatment in the real-world setting. Methods: This retrospective cohort study included patients diagnosed with HER2+ MBC (January 2017-December 2022) who received tucatinib treatment in a nationwide, de-identified electronic health record-derived metastatic breast cancer database. Patient demographics and clinical characteristics were described at baseline (prior to tucatinib initiation). Key outcomes included real-world time to treatment discontinuation (rwTTD), time to next treatment (rwTTNT), and overall survival (rwOS). Results: Of 3,449 patients with HER2+ MBC, 216 received tucatinib treatment (n=153 with BM; n=63 without BM) and met inclusion criteria. Median (range) age of patients was 56 (28-84) years, 57.9% were White, and 68.5% had Eastern Cooperative Oncology Group performance status ≤1. Median (IQR) follow-up from start of tucatinib treatment was 12 (6-18) months. Among all patients who received tucatinib treatment, median (95% CI) rwTTD was 6.5 (5.4-8.8) months with 39.8% and 21.4% remaining on treatment at 12 and 24 months, respectively. Median (95% CI) rwTTNT was 8.7 (6.8-10.7) months. Patients who received the approved tucatinib triplet combination after ≥1 HER2-directed regimen in the metastatic setting had a similar median (95% CI) rwTTD (any line: 8.1 [5.7-9.5] months; second-line (2L) and third-line (3L): 9.4 [6.3-14.1] months) and rwTTNT (any line: 8.8 [7.1-11.8] months; 2L and 3L: 9.8 [6.8-14.1] months) to the overall population. Overall, median (95% CI) rwOS was 26.6 (20.2-not reached [NR]) months, with similar findings for patients who received the tucatinib triplet (26.1 [18.8-NR] months) and was NR in the subgroup limited to the 2L/3L population. Conclusion: Tucatinib treatment in the real-world setting was associated with a similar median rwTTD, rwTTNT, and rwOS as in the pivotal HER2CLIMB trial, with particular effectiveness in patients in the 2L/3L setting. These results highlight the importance of earlier use of tucatinib in HER2+ MBC.

Near-Infrared Spectral Tomography for Predicting Residual Cancer Burden during Early-Stage Neoadjuvant Chemotherapy for Breast Cancer.

PURPOSE: The aim of this study is to investigate whether near-infrared spectral tomography (NIRST) might serve as a reliable prognostic tool to predict residual cancer burden (RCB) in patients with breast cancer undergoing neoadjuvant chemotherapy (NAC) based upon early treatment response measurements. EXPERIMENTAL DESIGN: A total of thirty-five patients with breast cancer receiving NAC were included in this study. NIRST imaging was performed at multiple time points, including: before treatment, at end of the first cycle, at the mid-point, and post-NAC treatments. From reconstructed NIRST images, average values of total hemoglobin (HbT) were obtained for both the tumor region and contralateral breast at each time point. RCB scores/classes were assessed by a pathologist using histologic slides of the surgical specimen obtained after completing NAC. Logistic regression of the normalized early percentage change of HbT in the tumor region (ΔHbT%) was used to predict RCB and determine its significance as an indicator for differentiating cases within each RCB class. RESULTS: The ΔHbT% at the end of the first cycle, as compared with pretreatment levels, showed excellent prognostic capability in differentiating RCB-0 from RCB-I/II/III or RCB-II from RCB-0/I/III (P < 0.001). Corresponding area under the curve (AUC) values for these comparisons were 0.97 and 0.94, and accuracy values were 0.90 and 0.83, respectively. CONCLUSIONS: NIRST holds promise as a potential clinical tool that can be seamlessly integrated into existing clinical workflow within the infusion suite. By providing early assessment of RCB, NIRST has potential to improve breast cancer patient management strategies.

Alternating 17ß-Estradiol and Aromatase Inhibitor Therapies Is Efficacious in Postmenopausal Women with Advanced Endocrine-Resistant ER+ Breast Cancer.

PURPOSE: Strategies to implement estrogen therapy for advanced estrogen receptor-positive (ER+) breast cancer are underdeveloped. Preclinical data suggest that cycling treatment with 17ß-estradiol followed by estrogen deprivation can control tumor growth long-term. PATIENTS AND METHODS: Postmenopausal women with advanced ER+/HER2- breast cancer with recurrence or progression on ≥ 1 antiestrogen or aromatase inhibitor (AI)-based therapy were eligible. Patients received 17ß-estradiol (2 mg orally, three times a day) for 8 weeks followed by AI (physician's choice) for 16 weeks, alternating treatments on an 8-week/16-week schedule until disease progression. Patients then optionally received continuous single-agent treatment until a second instance of disease progression. Endpoints included 24-week clinical benefit and objective response per RECIST, and tumor genetic alterations. RESULTS: Of 19 evaluable patients, clinical benefit rate was 42.1% [95% confidence interval (CI), 23.1%-63.9%] and objective response rate (ORR) was 15.8% (95% CI, 5.7%-37.9%). One patient experienced a grade 3 adverse event related to 17ß-estradiol. Among patients who received continuous single-agent treatment until a second instance of disease progression, clinical benefit was observed in 5 of 12 (41.7%) cases. Tumor ER (ESR1) mutations were found by whole-exome profiling in 4 of 7 (57.1%) versus 2 of 9 (22.2%) patients who did versus did not experience clinical benefit from alternating 17ß-estradiol/AI therapy. The only two patients to experience objective responses to initial 17ß-estradiol had tumor ESR1 mutations. CONCLUSIONS: Alternating 17ß-estradiol/AI therapy may be a promising treatment for endocrine-refractory ER+ breast cancer, including following progression on CDK4/6 inhibitors or everolimus. Further study is warranted to determine whether the antitumor activity of 17ß-estradiol differs according to ESR1 mutation status.

AMEERA-3: Randomized Phase II Study of Amcenestrant (Oral Selective Estrogen Receptor Degrader) Versus Standard Endocrine Monotherapy in Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer.

PURPOSE: Amcenestrant (oral selective estrogen receptor degrader) demonstrated promising safety and efficacy in earlier clinical studies for endocrine-resistant, estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer (aBC). PATIENTS AND METHODS: In AMEERA-3 (ClinicalTrials.gov identifier: NCT04059484), an open-label, worldwide phase II trial, patients with ER+/HER2- aBC who progressed in the (neo)adjuvant or advanced settings after not more than two previous lines of endocrine therapy (ET) were randomly assigned 1:1 to amcenestrant or single-agent endocrine treatment of physician's choice (TPC), stratified by the presence/absence of visceral metastases, previous/no treatment with cyclin-dependent kinase 4/6 inhibitor, and Eastern Cooperative Oncology Group performance status (0/1). The primary end point was progression-free survival (PFS) by independent central review, compared using a stratified log-rank test (one-sided type I error rate of 2.5%). RESULTS: Between October 22, 2019, and February 15, 2021, 290 patients were randomly assigned to amcenestrant (n = 143) or TPC (n = 147). PFS was numerically similar between amcenestrant and TPC (median PFS [mPFS], 3.6 v 3.7 months; stratified hazard ratio [HR], 1.051 [95% CI, 0.789 to 1.4]; one-sided P = .643). Among patients with baseline mutated ESR1; (n = 120 of 280), amcenestrant numerically prolonged PFS versus TPC (mPFS, 3.7 v 2.0 months; stratified HR, 0.9 [95% CI, 0.565 to 1.435]). Overall survival data were immature but numerically similar between groups (HR, 0.913; 95% CI, 0.595 to 1.403). In amcenestrant versus TPC groups, treatment-emergent adverse events (any grade) occurred in 82.5% versus 76.2% of patients and grade ≥3 events occurred in 21.7% versus 15.6%. CONCLUSION: AMEERA-3 did not meet its primary objective of improved PFS with amcenestrant versus TPC although a numerical improvement in PFS was observed in patients with baseline ESR1 mutation. Efficacy and safety with amcenestrant were consistent with the standard of care for second-/third-line ET for ER+/HER2- aBC.

Cumulative 6-Year Risk of Screen-Detected Ductal Carcinoma In Situ by Screening Frequency.

Importance: Detection of ductal carcinoma in situ (DCIS) by mammography screening is a controversial outcome with potential benefits and harms. The association of mammography screening interval and woman's risk factors with the likelihood of DCIS detection after multiple screening rounds is poorly understood. Objective: To develop a 6-year risk prediction model for screen-detected DCIS according to mammography screening interval and women's risk factors. Design, Setting, and Participants: This Breast Cancer Surveillance Consortium cohort study assessed women aged 40 to 74 years undergoing mammography screening (digital mammography or digital breast tomosynthesis) from January 1, 2005, to December 31, 2020, at breast imaging facilities within 6 geographically diverse registries of the consortium. Data were analyzed between February and June 2022. Exposures: Screening interval (annual, biennial, or triennial), age, menopausal status, race and ethnicity, family history of breast cancer, benign breast biopsy history, breast density, body mass index, age at first birth, and false-positive mammography history. Main Outcomes and Measures: Screen-detected DCIS defined as a DCIS diagnosis within 12 months after a positive screening mammography result, with no concurrent invasive disease. Results: A total of 916 931 women (median [IQR] age at baseline, 54 [46-62] years; 12% Asian, 9% Black, 5% Hispanic/Latina, 69% White, 2% other or multiple races, and 4% missing) met the eligibility criteria, with 3757 screen-detected DCIS diagnoses. Screening round-specific risk estimates from multivariable logistic regression were well calibrated (expected-observed ratio, 1.00; 95% CI, 0.97-1.03) with a cross-validated area under the receiver operating characteristic curve of 0.639 (95% CI, 0.630-0.648). Cumulative 6-year risk of screen-detected DCIS estimated from screening round-specific risk estimates, accounting for competing risks of death and invasive cancer, varied widely by all included risk factors. Cumulative 6-year screen-detected DCIS risk increased with age and shorter screening interval. Among women aged 40 to 49 years, the mean 6-year screen-detected DCIS risk was 0.30% (IQR, 0.21%-0.37%) for annual screening, 0.21% (IQR, 0.14%-0.26%) for biennial screening, and 0.17% (IQR, 0.12%-0.22%) for triennial screening. Among women aged 70 to 74 years, the mean cumulative risks were 0.58% (IQR, 0.41%-0.69%) after 6 annual screens, 0.40% (IQR, 0.28%-0.48%) for 3 biennial screens, and 0.33% (IQR, 0.23%-0.39%) after 2 triennial screens. Conclusions and Relevance: In this cohort study, 6-year screen-detected DCIS risk was higher with annual screening compared with biennial or triennial screening intervals. Estimates from the prediction model, along with risk estimates of other screening benefits and harms, could help inform policy makers' discussions of screening strategies.

Margetuximab Versus Trastuzumab in Patients With Previously Treated HER2-Positive Advanced Breast Cancer (SOPHIA): Final Overall Survival Results From a Randomized Phase 3 Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Final overall survival (OS) in SOPHIA (ClinicalTrials.gov identifier: NCT02492711), a study of margetuximab versus trastuzumab, both with chemotherapy, in patients with previously treated human epidermal growth factor receptor 2-positive advanced breast cancer, is reported with updated safety. Overall, 536 patients in the intention-to-treat population were randomly assigned to margetuximab (15 mg/kg intravenously once every 3 weeks; n = 266) plus chemotherapy or trastuzumab (6 mg/kg intravenously once every 3 weeks after a loading dose of 8 mg/kg; n = 270) plus chemotherapy. Primary end points were progression-free survival, previously reported, and OS. Final OS analysis was triggered by 385 prespecified events. The median OS was 21.6 months (95% CI, 18.89 to 25.07) with margetuximab versus 21.9 months (95% CI, 18.69 to 24.18) with trastuzumab (hazard ratio [HR], 0.95; 95% CI, 0.77 to 1.17; P = .620). Preplanned, exploratory analysis of CD16A genotyping suggested a possible improvement in OS for margetuximab in CD16A-158FF patients versus trastuzumab (median OS, 23.6 v 19.2 months; HR, 0.72; 95% CI, 0.52 to 1.00) and a possible improvement in OS for trastuzumab in CD16A-158VV patients versus margetuximab (median OS, 31.1 v 22.0 months; HR, 1.77; 95% CI, 1.01 to 3.12). Margetuximab safety was comparable with trastuzumab. Final overall OS analysis did not demonstrate margetuximab advantage over trastuzumab. Margetuximab studies in patients with human epidermal growth factor receptor 2-positive breast cancer with different CD16A allelic variants are warranted.

Cancer Care in the Wake of a Cyberattack: How to Prepare and What to Expect.

PURPOSE: Cyberattacks targeting health care organizations are becoming more frequent and affect all aspects of care delivery. Cancer care is particularly susceptible to major disruptions because of the potential of immediate and long-term consequences for patients who often rely on timely diagnostic testing and regular administration of systemic therapy in addition to other local treatment modalities to cure or control their diseases. On October 28, 2020, a cyberattack was launched on the University of Vermont Health Network with wide-ranging consequences for oncology, including loss of access to all network intranet servers, e-mail communications, and the electronic medical record (EMR). METHODS: This review details the immediate challenges faced by hematology and oncology during the cyberattack. The impact and response on inpatient, outpatient, and special patient populations are described. Steps that other academic- and community-based oncology practices can take to lessen the brunt of such an assault are suggested. RESULTS: The two areas of immediate impact after the cyberattack were communications and lack of EMR access. The oncology-specific impact included loss of the individualized EMR chemotherapy plan templates and electronic safeguards built into multistep treatment preparation and delivery. With loss of access to schedules, basic patient information, encrypted communications platforms and radiology, and laboratory and pharmacy services, clinical outpatient care delivery was reduced by 40%. The infusion visit volume dropped by 52% in the first week and new patients could not access necessary services for timely diagnostic evaluation, requiring the creation of command centers to oversee ethical and transparent triage and allocation of systemic therapies and address new patient referrals. This included appropriate transfer of patients to alternate sites to minimize delays. Inpatient care including transitions of care was particularly challenging and addressing patient populations whose survival might be affected by delays in care. CONCLUSION: Oncology health care leaders and providers should be aware of the potential impact of a cyberattack on cancer care delivery and preventively develop processes to mitigate the impact.

Abemaciclib plus fulvestrant in hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in premenopausal women: subgroup analysis from the MONARCH 2 trial.

BACKGROUND: In MONARCH 2, abemaciclib plus fulvestrant significantly improved median progression-free survival (PFS, 16.4 vs 9.3 months, hazard ratio [HR] 0.553) and overall survival (OS, 46.7 vs 37.3 months; HR 0.757) compared with placebo plus fulvestrant in hormone receptor-positive (HR-positive), human epidermal growth factor receptor 2-negative (HER2-negative) advanced breast cancer (ABC) patients who were endocrine therapy (ET) resistant, regardless of menopausal status. Here, we report findings in the premenopausal subgroup of the MONARCH 2 trial. METHODS: The premenopausal subgroup included patients with natural menstrual bleeding who received a gonadotropin-releasing hormone agonist at least 4 weeks prior to study treatment start date and for the entire study duration. Of the 669 patients enrolled in the MONARCH 2 trial, 114 were premenopausal (abemaciclib plus fulvestrant, n = 72; placebo plus fulvestrant, n = 42), and were included in this analysis. The primary objective was investigator-assessed PFS and secondary objectives were OS, objective response rate, and safety and tolerability. Exploratory analyses included time to second disease progression (PFS2), time to chemotherapy (TTC), and chemotherapy-free survival (CFS). RESULTS: At the primary objective cutoff (February 14, 2017), median PFS was not reached for the abemaciclib plus fulvestrant arm versus 10.52 months for the placebo plus fulvestrant arm (HR 0.415; 95% CI 0.246-0.698). At the pre-specified OS interim cutoff (20-June-2019), median PFS was 28.6 months in the abemaciclib plus fulvestrant arm compared with 10.26 months in the placebo plus fulvestrant arm (HR 0.477; 95% CI 0.302-0.755). A numerical OS benefit was observed with abemaciclib plus fulvestrant compared to fulvestrant alone (HR 0.689; 95% CI 0.379-1.252, median, not reached vs 47.3 months). Improvements were also observed for the exploratory outcomes of PFS2 (HR 0.599), TTC (HR 0.674), and CFS (HR 0.642) with the addition of abemaciclib to fulvestrant. The safety profile was generally consistent with results disclosed previously. CONCLUSIONS: Results of the premenopausal subgroup in the MONARCH 2 trial were consistent with the improved clinical outcomes observed in the intent-to-treat population. The analysis provides support for the use of abemaciclib plus fulvestrant (with ovarian suppression) as an effective treatment option for premenopausal patients with HR+, HER2- ABC who are ET-resistant. CLINICAL TRIAL REGISTRATION: NCT02107703. Registered April 08, 2014- Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02107703 .

E2112: Randomized Phase III Trial of Endocrine Therapy Plus Entinostat or Placebo in Hormone Receptor-Positive Advanced Breast Cancer. A Trial of the ECOG-ACRIN Cancer Research Group.

PURPOSE: Endocrine therapy resistance in advanced breast cancer remains a significant clinical problem that may be overcome with the use of histone deacetylase inhibitors such as entinostat. The ENCORE301 phase II study reported improvement in progression-free survival (PFS) and overall survival (OS) with the addition of entinostat to the steroidal aromatase inhibitor (AI) exemestane in advanced hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. PATIENTS AND METHODS: E2112 is a multicenter, randomized, double-blind, placebo-controlled phase III study that enrolled men or women with advanced HR-positive, HER2-negative breast cancer whose disease progressed after nonsteroidal AI. Participants were randomly assigned to exemestane 25 mg by mouth once daily and entinostat (EE) or placebo (EP) 5 mg by mouth once weekly. Primary end points were PFS by central review and OS. Secondary end points included safety, objective response rate, and lysine acetylation change in peripheral blood mononuclear cells between baseline and cycle 1 day 15. RESULTS: Six hundred eight patients were randomly assigned during March 2014-October 2018. Median age was 63 years (range 29-91), 60% had visceral disease, and 84% had progressed after nonsteroidal AI in metastatic setting. Previous treatments included chemotherapy (60%), fulvestrant (30%), and cyclin-dependent kinase inhibitor (35%). Most common grade 3 and 4 adverse events in the EE arm included neutropenia (20%), hypophosphatemia (14%), anemia (8%), leukopenia (6%), fatigue (4%), diarrhea (4%), and thrombocytopenia (3%). Median PFS was 3.3 months (EE) versus 3.1 months (EP; hazard ratio = 0.87; 95% CI, 0.67 to 1.13; P = .30). Median OS was 23.4 months (EE) versus 21.7 months (EP; hazard ratio = 0.99; 95% CI, 0.82 to 1.21; P = .94). Objective response rate was 5.8% (EE) and 5.6% (EP). Pharmacodynamic analysis confirmed target inhibition in entinostat-treated patients. CONCLUSION: The combination of exemestane and entinostat did not improve survival in AI-resistant advanced HR-positive, HER2-negative breast cancer.

MONARCH 2: Subgroup Analysis of Patients Receiving Abemaciclib Plus Fulvestrant as First-Line and Second-Line Therapy for HR+, HER2--Advanced Breast Cancer.

PURPOSE: In MONARCH 2, abemaciclib plus fulvestrant significantly prolonged progression-free survival (PFS) and overall survival (OS) versus placebo plus fulvestrant in patients with hormone receptor positive (HR+), HER2- advanced breast cancer. This exploratory analysis assessed the efficacy of abemaciclib plus fulvestrant across subgroups of patients receiving study therapy as first- or second-line treatment for metastatic disease. PATIENTS AND METHODS: Improvements were estimated using Cox models, and a test of interactions of subgroups with treatment was performed. RESULTS: The benefit in PFS [first-line, HR, 0.57; 95% confidence interval (CI), 0.45-0.73; second-line, HR, 0.48; 95% CI, 0.36-0.64] and OS (first-line, HR, 0.85; 95% CI, 0.64-1.14; second-line, HR, 0.66; 95% CI, 0.46-0.94) was observed across both subgroups, consistent with the intent-to-treat (ITT) population. In first-line patients (abemaciclib arm, n = 265; placebo arm, n = 133), the numerically largest effect on PFS and OS was observed in patients with primary resistance to endocrine therapy (ET; PFS, HR, 0.40; 95% CI, 0.26-0.63; OS, HR, 0.58; 95% CI, 0.35-0.97) and visceral disease (PFS, HR, 0.54; 95% CI, 0.39-0.73; OS, HR, 0.82; 95% CI, 0.58-1.20). In second-line patients (abemaciclib arm, n = 170; placebo arm, n = 86), a numerical benefit in PFS and OS was observed across primary and secondary ET resistance, with numerically more pronounced effects observed in patients with visceral disease (PFS, HR, 0.39; 95% CI, 0.27-0.57; OS, HR, 0.51; 95% CI, 0.33-0.81). Prolongation of time to second disease progression, time to chemotherapy, and chemotherapy-free survival was observed in both subgroups. CONCLUSIONS: Consistent with the ITT population, a benefit in PFS and OS was observed across the first- and second-line subgroups in MONARCH 2.

Eribulin Plus Pembrolizumab in Patients with Metastatic Triple-Negative Breast Cancer (ENHANCE 1): A Phase Ib/II Study.

PURPOSE: As monotherapies, eribulin (chemotherapy) and pembrolizumab (immunotherapy) have shown promise for patients with metastatic triple-negative breast cancer (mTNBC). This phase Ib/II study examined eribulin plus pembrolizumab as a potential mTNBC treatment in first-line and later-line settings. PATIENTS AND METHODS: In this open-label, single-arm, phase Ib/II study, eligible patients had mTNBC, measurable disease, and ≤2 prior systemic anticancer therapies in the metastatic setting. Patients were enrolled by number of prior systemic anticancer therapies (stratum 1: 0 vs stratum 2: 1-2) in the metastatic setting and further analyzed by tumor programmed death-ligand 1 (PD-L1) expression status. All patients received intravenous eribulin 1.4 mg/m2 on day 1 and day 8, plus intravenous pembrolizumab 200 mg on day 1, of 21-day cycles. The primary objectives were the safety, tolerability, and objective response rate (ORR) of this combination. RESULTS: The study included 167 patients (phase Ib, n = 7; phase II, n = 160). The most common treatment-emergent adverse events were fatigue (66%), nausea (58%), peripheral sensory neuropathy (41%), alopecia (40%), and constipation (37%). ORRs were 25.8% [95% confidence interval (CI): 15.8-38.0] for stratum 1 (n = 66) and 21.8% (95% CI: 14.2-31.1) for stratum 2 (n = 101). Patients with PD-L1-positive tumors (combined positive score ≥1) had numerically higher ORR than those with PD-L1-negative tumors, particularly in stratum 1 [stratum 1: 34.5% (95% CI: 17.9-54.3) vs 16.1% (95% CI: 5.5-33.7); stratum 2, 24.4% (95% CI: 12.9-39.5) vs 18.2% (95% CI: 8.2-32.7)]. CONCLUSIONS: Eribulin plus pembrolizumab was generally well tolerated and showed promising antitumor activity in mTNBC. Efficacy outcomes appeared influenced by line of therapy and PD-L1 status.

Baseline characteristics and first-line treatment patterns in patients with HER2-positive metastatic breast cancer in the SystHERs registry.

BACKGROUND: Systemic Therapies for HER2-Positive Metastatic Breast Cancer Study (SystHERs, NCT01615068) was a prospective, observational disease registry designed to identify treatment patterns and clinical outcomes in patients with HER2-positive metastatic breast cancer (MBC) in real-world treatment settings. METHODS: SystHERs enrolled patients aged ≥ 18 years with recently diagnosed HER2-positive MBC. Treatment regimens and clinical management were determined by the treating physician. In this analysis, patients were compared descriptively by first-line treatment, age, or race. Multivariate logistic regression was used to examine the associations between baseline variables and treatment selections. Clinical outcomes were assessed in patients treated with trastuzumab (Herceptin [H]) + pertuzumab (Perjeta [P]). RESULTS: Patients were enrolled from June 2012 to June 2016. As of February 22, 2018, 948 patients from 135 US treatment sites had received first-line treatment, including HP (n = 711), H without P (n = 175), or no H (n = 62) (with or without chemotherapy and/or hormonal therapy). Overall, 68.7% received HP + taxane and 9.3% received H without P + taxane. Patients aged < 50 years received HP (versus H without P) more commonly than those ≥ 70 years (odds ratio 4.20; 95% CI, 1.62-10.89). Chemotherapy was less common in patients ≥ 70 years (68.2%) versus those < 50 years (88.0%) or 50-69 years (87.4%). Patients treated with HP had median overall survival of 53.8 months and median progression-free survival of 15.8 months. CONCLUSIONS: Our analysis of real-world data shows that most patients with HER2-positive MBC received first-line treatment with HP + taxane. However, older patients were less likely to receive dual HER2-targeted therapy and chemotherapy.

Overall survival analysis in patients with metastatic breast cancer and liver or lung metastases treated with eribulin, gemcitabine, or capecitabine.

PURPOSE: The purpose of this study was to estimate the overall survival (OS) in real-world clinical practice in patients with metastatic breast cancer (MBC) and visceral metastases (liver or lung) treated in the third-line setting with eribulin, gemcitabine or capecitabine overall and in the major clinical categories of MBC (TNBC, HR+/HER2-, and HER2+). METHODS: A retrospective, observational study was conducted with de-identified patient electronic health records from the Cancer Treatment Centers of America (CTCA). Patients with a diagnosis of metastatic breast with lung or liver metastases, and treated with eribulin, gemcitabine, or capecitabine as third-line therapy were included in the analysis. Landmark survival was calculated as percentage of patients alive at 6, 12, 24, and 36 months. Overall survival was compared between treatment arms within TNBC and HR+/HER2- using log-rank analysis. Cox regression analyses was performed to estimate hazard ratios for comparison of treatments within TNBC and HR+/HER2- subtype. RESULTS: 443 patients with liver or lung metastases received third-line therapy with eribulin (n = 229), gemcitabine (n = 134), or capecitabine (n = 80). Eribulin patients had a higher percentage of patients alive at all landmark timepoints vs. gemcitabine, and a higher percentage of patients alive until 36 months vs. capecitabine. Median survival times showed that overall, and within the TNBC and HR+/HER2- subtype, patients receiving eribulin had a numerically higher median overall survival. CONCLUSIONS: This real-world evidence study is consistent with randomized clinical trial data and demonstrates consistency of eribulin effectiveness in MBC patients with lung or liver metastases overall and in TNBC and HR+/HER2- disease.

Plasma DNA as a "liquid biopsy" incompletely complements tumor biopsy for identification of mutations in a case series of four patients with oligometastatic breast cancer.

PURPOSE: Circulating tumor DNA in plasma may present a minimally invasive opportunity to identify tumor-derived mutations to inform selection of targeted therapies for individual patients, particularly in cases of oligometastatic disease where biopsy of multiple tumors is impractical. To assess the utility of plasma DNA as a "liquid biopsy" for precision oncology, we tested whether sequencing of plasma DNA is a reliable surrogate for sequencing of tumor DNA to identify targetable genetic alterations. METHODS: Blood and biopsies of 1-3 tumors were obtained from 4 evaluable patients with advanced breast cancer. One patient provided samples from an additional 7 tumors post-mortem. DNA extracted from plasma, tumor tissues, and buffy coat of blood were used for probe-directed capture of all exons in 149 cancer-related genes and massively parallel sequencing. Somatic mutations in DNA from plasma and tumors were identified by comparison to buffy coat DNA. RESULTS: Sequencing of plasma DNA identified 27.94 ± 11.81% (mean ± SD) of mutations detected in a tumor(s) from the same patient; such mutations tended to be present at high allelic frequency. The majority of mutations found in plasma DNA were not found in tumor samples. Mutations were also found in plasma that matched clinically undetectable tumors found post-mortem. CONCLUSIONS: The incomplete overlap of genetic alteration profiles of plasma and tumors warrants caution in the sole reliance of plasma DNA to identify therapeutically targetable alterations in patients and indicates that analysis of plasma DNA complements, but does not replace, tumor DNA profiling. TRIAL REGISTRATION: Subjects were prospectively enrolled in trial NCT01836640 (registered April 22, 2013).

Effect of neuromuscular electrical stimulation on skeletal muscle size and function in patients with breast cancer receiving chemotherapy.

Exercise has numerous benefits for patients with cancer, but implementation is challenging because of practical and logistical hurdles. This study examined whether neuromuscular electrical stimulation (NMES) can serve as a surrogate for classic exercise by eliciting an exercise training response in skeletal muscle of women diagnosed with breast cancer undergoing chemotherapy. Patients (n = 22) with histologically confirmed stage I, II, or III breast cancer scheduled to receive neoadjuvant or adjuvant chemotherapy were randomized to 8 wk of bilateral neuromuscular electrical stimulation (NMES; 5 days/wk) to their quadriceps muscles or control. Biopsy of the vastus lateralis was performed at baseline and after 8 wk of intervention to assess muscle fiber size, contractility, and mitochondrial content. Seventeen patients (8 control/9 NMES) completed the trial and were included in analyses. NMES promoted muscle fiber hypertrophy (P < 0.001), particularly in fast-twitch, myosin heavy chain (MHC) IIA fibers (P < 0.05) and tended to induce fiber type shifts in MHC II fibers. The effects of NMES on single-muscle fiber contractility were modest, and it was unable to prevent declines in the function in MHC IIA fibers. NMES did not alter intermyofibrillar mitochondrial content/structure but was associated with reductions in subsarcolemmal mitochondria. Our results demonstrate that NMES induces muscle fiber hypertrophy and fiber type shifts in MHC II fibers but had minimal effects on fiber contractility and promoted reductions in subsarcolemmal mitochondria. Further studies are warranted to evaluate the utility of NMES as an exercise surrogate in cancer patients and other conditions.NEW & NOTEWORTHY This is the first study to evaluate whether neuromuscular electrical stimulation (NMES) can be used as an exercise surrogate to improve skeletal muscle fiber size or function in cancer patients receiving treatment. We show that NMES promoted muscle fiber hypertrophy and fiber type shifts but had minimal effects on single-fiber contractility and reduced subsarcolemmal mitochondria.