High-risk Early Breast Cancer Research Articles

Cost-Effectiveness Analysis of Adjuvant Pertuzumab and Trastuzumab in Human Epidermal Growth Factor Receptor 2-Positive Early Breast Cancer in Japan.

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer presents considerable treatment challenges owing to its aggressive nature. Global guidelines have endorsed a full year of HER2-targeted therapy for early-stage breast cancer. However, previous cost-effectiveness analyses of dual HER2-targeted therapies have been limited. This study aimed to examine the cost effectiveness of dual HER2-targeted therapy for early-stage breast cancer within the Japanese healthcare system context. In the Markov model-based study, the cost effectiveness of dual anti-HER2 therapy, combining pertuzumab and trastuzumab, was assessed in comparison to trastuzumab monotherapy. Patients in whom treatment was initiated at a median age of 51 years were included. The study utilized quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) as comparison units. Subgroup analyses were conducted to explore variations in cost effectiveness, focusing on node-positive and node-negative patients. Both one-way deterministic and broader probabilistic sensitivity analyses using Monte Carlo simulations with 10,000 samples were performed from the Japanese healthcare payers perspective. Dual HER2-targeted therapy led to 0.17 QALYs increment at an additional cost of $US15,289, resulting in an ICER of $US92,232 per QALY. In the subgroup of node-positive patients, the benefit of the dual HER2-targeted therapy was more pronounced, with an increase of 0.64 QALYs and an ICER of $US24,561 per QALY. Sensitivity analyses revealed the model's susceptibility to changes in the transition probabilities from invasive disease-free survival to death, from invasive disease-free survival to first-line metastatic breast cancer, and to costs associated with pertuzumab. Probabilistic sensitivity analysis suggests that for node-positive patients, dual HER2-targeted therapy may be a cost-effective option. The economic viability of dual HER2-targeted therapy was most pronounced in patients with node-positive high-risk early breast cancer. This study highlights the potential of dual HER2-targeted therapy as a cost-effective addition for these cases.

Preclinical study and phase 2 trial of neoadjuvant pyrotinib combined with chemotherapy in luminal/HER2-low breast cancer: PILHLE-001 study.

The prognosis of patients with luminal/human epidermal growth factor receptor 2 (HER2)-low early breast cancer (EBC) needs to be improved. This preclinical study and phase 2 trial (ChiCTR2100047233) aims to explore the efficacy and safety of pyrotinib (a pan-HER tyrosine kinase inhibitor) plus chemotherapy in this population. Our preclinical experiments indicate a synergistic anti-tumor effect of pyrotinib plus chemotherapy in luminal/HER2-low (immunochemistry [IHC] 2+/fluorescent in situ hybridization [FISH]-negative) breast cancer models. Furthermore, 48 women with luminal/HER2-low (IHC 2+/FISH-negative) high-risk EBC are enrolled to receive neoadjuvant pyrotinib plus chemotherapy (epirubicin-cyclophosphamide followed by docetaxel). Ultimately, 26 (54.2%; 95% confidence interval [CI] 39.2%-68.6%) patients achieve the primary endpoint (residual cancer burden [RCB] 0/I). Treatment-related adverse events of grade ≥3 occur in 21 (43.8%) patients, with the most prevalent being diarrhea (10 [20.8%]). In conclusion, neoadjuvant pyrotinib plus chemotherapy has encouraging efficacy and manageable toxicity in women with luminal/HER2-low (IHC 2+/FISH-negative) high-risk EBC. This regimen warrants to be further validated.

Real-World Immune-Related Adverse Events in Patients With Early Triple-Negative Breast Cancer Who Received Pembrolizumab.

The addition of pembrolizumab to chemotherapy in high-risk early triple-negative breast cancer (TNBC) improves cancer outcomes. However, pembrolizumab induces varied immune-related adverse events (irAEs) where some can be severe or lifelong. This retrospective study describes real-world patterns of irAEs in patients with TNBC who received pembrolizumab. We evaluated irAEs in patients with TNBC from a comprehensive cancer center and a community hospital who received pembrolizumab with chemotherapy between 2021 and 2023, excluding those enrolled in clinical trials. We used national guidelines to grade toxicities. Logistic regression assessed the effect of clinicopathologic variables on irAEs adjusting for covariates. We identified 233 patients with a median age of 51 years, 62% had stage II TNBC, 35% had stage III TNBC, 25% were Hispanic, 21% were Black, and 42% were White. Eighty patients (34%) developed 100 separate irAEs. The most common irAEs were endocrinopathies (52%) and GI (23%); there were 26 grade ≥3 irAEs, which all resulted in hospitalization, the most common being GI (13 instances); 45 required systemic steroids, 16 required additional immunosuppressive therapy, and 32 patients discontinued pembrolizumab because of irAEs. Two patients who developed colitis eventually died due to complications. Most (67 instances) irAEs were unresolved at the time of last follow-up, but 55% (37/67) had improved to grade 1. No clinicopathologic factors were associated with the development or severity of irAEs. In this real-world diverse population, we observed rates of irAEs comparable with KEYNOTE-522, where endocrinopathies were the most prevalent, but GI irAEs were also prevalent and severe. This emphasizes a critical issue as pembrolizumab is increasingly being used in early TNBC and could have long-term survivorship implications.

The epidemiology, treatments and outcomes of patients with hormone receptor positive, human epidermal growth factor receptor 2 negative, node-positive early breast cancer in Taiwan.

Aim: Estimate patient counts, treatment patterns and outcomes of a subset of patients with early breast cancer (EBC) presenting with hormone receptor positive, human epidermal growth factor receptor 2 negative, node positive features, who are at high-risk of recurrence, in Taiwan.Materials & methods: Data from Taiwan's National Health Insurance Research Database and Taiwan Cancer Registry from 1 January 2011 to31 December 2020 were analyzed.Results: There were 4500 patients with high-risk EBC (10.4% of all patients with EBC) from 2012 to 2018, with an annual average incidence of 643 that increased over time. Five-year progression was 24.8% in patients with high-risk EBC and 8-year survival was low (69.6%).Conclusion: Patients with hormone receptor positive, human epidermal growth factor receptor 2 negative, node positive high-risk EBC clinical features are an increasing high-risk subset of all patients with EBC.

Is ribociclib plus endocrine therapy effective for high-risk early breast cancer?

Is ribociclib plus endocrine therapy effective for high-risk early breast cancer?

Cost-effectiveness of early vs delayed use of abemaciclib combination therapy for patients with high-risk hormone receptor-positive/human epidermal growth factor receptor 2-negative early breast cancer.

Abemaciclib was newly approved for hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) high-risk early breast cancer (EBC). Clinical guidelines recommended abemaciclib as the first-line treatment for HR+/ HER2- EBC (early use) or HR+/ HER2- metastatic breast cancer (MBC) (delayed use). To compare the cost-effectiveness of early vs delayed use of abemaciclib for treatment of HR+/HER2- high-risk EBC. Early use was defined as combined abemaciclib and endocrine therapy as first-line therapy for EBC, followed by treatment with fulvestrant for MBC. Delayed use was defined as endocrine therapy for EBC, followed by combined abemaciclib and fulvestrant therapy for MBC. A 5-state model was developed to estimate lifetime costs, life-years (LYs), and quality-adjusted life-years (QALYs) of hypothetical patients with HR+/ HER2- EBC from a third-party US payer's perspective. Key clinical and safety data were derived from the monarchE and MONARCH 2 clinical trials. Costs, utilities, and disutility values of adverse events were obtained from the literature. We calculated the incremental cost-effectiveness ratio (ICER) of early vs delayed abemaciclib use and compared it with a willingness-to-pay (WTP) threshold of $100,000 per LY or QALY. Deterministic and probabilistic sensitivity analyses (PSAs) were performed to test the robustness of the base-case model. Base-case analysis showed early use yielded 21.08 LYs and 17.93 QALYs for $586,213 and delayed use yielded 11.14 LYs and 9.38 QALYs for $157,576. The ICER of early vs delayed use was $43,136/LY and $50,104/QALY, which was cost-effective at the WTP threshold of $100,000. The PSA result indicated that a 94.6% likelihood of early use (vs delayed use) was cost-effective at the WTP threshold of $100,000 per QALY. This study suggests that giving abemaciclib in the early stage rather than waiting until patients develop metastatic disease (current standard of care in MBC) is a cost-effective strategy.

The Omission of Anthracycline Chemotherapy in Women with Early HER2-Negative Breast Cancer-A Systematic Review and Meta-Analysis.

Anthracycline-taxane is the standard chemotherapy strategy for treating high-risk early breast cancer despite the potentially life-threatening adverse events caused by anthracyclines. Commonly, the combination of docetaxel and cyclophosphamide (TC) is considered an alternative option. However, the efficacy of TC compared to anthracycline-taxane chemotherapy is unclear. This study compares disease-free survival (DFS), overall survival (OS) and cardiotoxicity between adjuvant TC and anthracycline-taxane for stages I-III, HER2-negative breast cancer. A systematic search on MEDLINE, Embase and Cochrane CENTRAL for randomized-controlled trials published until 11 March 2024, yielded 203 studies with 11,803 patients, and seven trials were included. TC results in little to no difference in DFS (HR 1.09, 95% CI 0.98-1.20; moderate-certainty of evidence); OS (1.02, 95% CI 0.89-1.16; high-certainty of evidence); and cardiotoxicity (RR 0.54, 95% CI 0.16-1.76; high-certainty of evidence), compared to anthracycline-taxane. In the subgroup analysis, patients with ≥4 lymph nodes had improved DFS from anthracycline-taxane over TC. Overall, there was no difference between TC and anthracycline-taxane in DFS, OS and cardiotoxicity. In women with ≥4 nodes, anthracycline-taxane was associated with a substantial reduction in relapse events, compared to TC. Our study supports the current standard of practice, which is to use anthracycline-taxane and TC chemotherapy as a reasonable option in select cases.

GAIN2 trial overall survival with intense versus tailored dose dense chemotherapy in early breast cancer

GAIN-2 trial evaluated the optimal intense dose-dense (idd) strategy for high-risk early breast cancer. This study reports the secondary endpoints pathological complete response (pCR) and overall survival (OS). Patients (n = 2887) were randomized 1:1 between idd epirubicin, nab-paclitaxel, and cyclophosphamide (iddEnPC) versus leukocyte nadir-based tailored regimen of dose-dense EC and docetaxel (dtEC-dtD) as adjuvant therapy, with neoadjuvant therapy allowed after amendment. At median follow-up of 6.5 years (overall cohort) and 5.7 years (neoadjuvant cohort, N = 593), both regimens showed comparable 5-year OS rates (iddEnPC 90.8%, dtEC-dtD 90.0%, p = 0.320). In the neoadjuvant setting, iddEnPC yielded a higher pCR rate than dtEC-dtD (51.2% vs. 42.6%, p = 0.045). Patients achieving pCR had significantly improved 5-year iDFS (88.7% vs. 70.1%, HR 0.33, p < 0.001) and OS rates (93.9% vs. 83.1%, HR 0.32, p < 0.001), but OS outcomes were comparable regardless of pCR status. Thus, iddEnPC demonstrates superior pCR rates compared to dtEC-dtD, yet with comparable survival outcomes.

Abemaciclib plus endocrine therapy for HR+, HER2-, node-positive, high-risk early breast cancer: a plain language summary of the monarchE study.

This article summarizes the most recent results of the monarchE study. This study was completed in participants with a type of breast cancer called HR+, HER2-, node-positive, high-risk early breast cancer. In this study, abemaciclib, a non-chemotherapy treatment, was administered with standard of care endocrine therapy after curative surgery. Most participants had received prior chemotherapy and/or radiotherapy. The study investigated if abemaciclib helped participants live longer without their cancer returning compared with participants who only received standard of care endocrine therapy. The study participants were assigned to 1 of 2 treatment groups. Participants in Group A were assigned to receive standard of care endocrine therapy with abemaciclib for 2years, followed by endocrine therapy for a total of at least 5years. Participants in Group B were assigned to receive standard of care endocrine therapy only for at least 5years. The effect of treatment was compared between these 2 groups. Overall, the results showed that the cancer was 34% less likely to come back after surgery in the participants in Group A (abemaciclib plus endocrine therapy) compared with those in Group B (endocrine therapy only). At 4years since the start of the study treatment, more participants who received the combination of abemaciclib plus endocrine therapy remained free of cancer compared with participants who received endocrine therapy alone (86% versus 79%). Participants who received abemaciclib plus endocrine therapy had more side effects than those who received endocrine therapy alone, but most of these effects were mild to moderate and reversible upon the end of therapy. The most common side effects in the abemaciclib group were diarrhea, infections, low number of white blood cells, and tiredness. This study found that administering abemaciclib in combination with standard endocrine therapy after curative breast surgery helped lower the risk of cancer returning in people with HR+, HER2-, node-positive, high-risk early breast cancer. Abemaciclib is a new treatment option for people with this diagnosis. People with high-risk early breast cancer should always talk to their doctors and nurses before making any decisions about their treatment.Clinical Trial Registration: NCT03155997 (monarchE study).

Tailored Dose-Dense Versus Standard Adjuvant Chemotherapy for High-Risk Early Breast Cancer: End-of-Study Results of the Randomized PANTHER 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.Although dose-dense adjuvant chemotherapy administered once every 2 weeks leads to superior outcomes compared with standard regimens once every 3 weeks, the observed improvement is largely limited to studies using the suboptimal paclitaxel schedule once every 3 weeks as control. PANTHER is an international phase III trial which compared sequential epirubicin/cyclophosphamide and docetaxel administered either once every 2 or once every 3 weeks, with tailored dosing at the dose-dense schedule according to hematologic toxicity. In this end-of-study analysis, the median follow-up was 10.3 years. Compared with standard adjuvant chemotherapy, dose-dense treatment improved breast cancer recurrence-free survival (hazard ratio [HR], 0.80 [95% CI, 0.65 to 0.98]; P = .030), event-free survival (HR, 0.78 [95% CI, 0.65 to 0.94]; P = .009), and distant disease-free survival (HR, 0.79 [95% CI, 0.64 to 0.98]; P = .030) while the improvement in overall survival was not statistically significant (HR, 0.82 [95% CI, 0.65 to 1.04]; P = .109). To our knowledge, this is the first trial that confirms the benefit of a dose-dense regimen over a control regimen containing docetaxel once every 3 weeks.

Prognostic utility of ctDNA detection in the monarchE trial of adjuvant abemaciclib plus endocrine therapy (ET) in HR+, HER2-, node-positive, high-risk early breast cancer (EBC).

LBA507 Background: In monarchE (NCT03155997), 2 years of adjuvant abemaciclib + ET resulted in sustained improvement in invasive disease-free survival (IDFS; HR=0.680, 7.6% absolute benefit at 5 years) in patients (pts) with HR+, HER2-, node-positive, high-risk EBC. Here, we investigate the prognostic value of ctDNA detection and dynamics in pts from monarchE. Methods: Samples were analyzed from a selected pt subset (n=1397; abemaciclib + ET arm, n=685; ET arm, n=712), enriched for overall IDFS events compared to the total monarchE study population (IDFS event rate: 31% [433/1397] vs 18% [992/5637]). Pts had blood collected pre-study treatment (baseline) and at 3, 6, or 24 months. ctDNA detection was performed using the personalized, tumor informed Signatera ctDNA assay (Natera, Inc) and whole exome sequencing (WES) of matched primary tumor and normal required for assay design was performed. Results: Among 1397 pts, 65% (n=910) had sufficient plasma samples and WES performed, and all 910 had successful ctDNA assay testing. Among these 910 pts, the IDFS event rate was 27% (abemaciclib + ET, 23% [101/438]; ET alone, 31% [146/472]). Rates of ctDNA positivity (at baseline and any change from baseline) and associated IDFS events are shown in Table. Among pts with ctDNA positivity, 87% had an IDFS event in comparison to 15% with persistent ctDNA negative (-) status during the study. Conclusions: In a pt subset from monarchE enriched for IDFS events, ctDNA detection was relatively infrequent (&lt;20%); however, its detection at any time during the 24 months of study therapy was adversely prognostic. As compared to pts who had remaining ctDNA positive (+), pts who had clearance of ctDNA on therapy had lower risk of IDFS events, but the event risk still remained clinically meaningful in these pts. Clinical trial information: NCT03155997 . [Table: see text]

Emerging drugs in breast cancer: a focus on antibody–drug conjugates and novel treatment options in luminal disease

SummaryRecent years have seen the introduction of several new drugs and novel treatment approaches in early and advanced-stage breast cancer, leading to relevant improvements in outcome. Still, further reduction of recurrence risk in high-risk early breast cancer is required as is further improvement of disease control in metastatic disease, preferentially with parallel improvement of tolerability. Several antibody–drug conjugates are currently under clinical development, among them drugs targeting HER2, HER3 and TROP2; in addition, bispecific HER2-directed antibodies are a promising class of drugs. In hormone receptor-positive disease, optimizing treatment options in patients progressing on prior CDK4/6-inhibitor-based therapies is a focus of clinical research and recent developments encompass small molecule growth-factor pathway inhibitors such as the AKT inhibitor capivasertib, novel PIK3Ca inhibitors such as inavolisib as well as selective oestrogen receptor degraders and modulators. This article is intended as a short review of promising novel drugs in later clinical development in the field of breast cancer.

Relevance of timing intake of everolimus (EVE) combined with adjuvant endocrine therapy (ET) in patients (pts) with high-risk early breast cancer: Results of a sub-study of the UCBG-UNIRAD trial.

542 Background: We reported the benefit of taking evening tamoxifen compared to morning/afternoon as adjuvant treatment for high-risk breast cancers in the UNIRAD phase III trial (NCT01805271) (1). Here, we examine the relevance of EVE timing intake in this trial. Methods: 1,277 pts with high-risk HR+/ HER2- primary BC were randomly assigned to adjuvant ET with placebo or EVE (1). Patients prospectively reported in a diary the daily timing for ET and EVE intake among four 6-h slots (06:00 to 11:59 (morning), 12:00 to 17:59 (afternoon), 18:00 to 23:59 (evening), or 24:00 to 05:59 (night). The association between EVE, ET timing and disease-free survival (DFS) was a prespecified secondary endpoint of the trial. Results: EVE timing was recorded by 513 of 632 patients (81.2%). Patients declaring EVE intake in the morning (n= 248, 48 %) or in the afternoon (n=52, 10%) were older than those declaring evening (n=207, 40 %) or night (n=6,1%) intakes ( p&lt;0.001). They were more likely to be postmenopausal (p=0.001) and to take AI rather than tamoxifen (p = 0.03). Only 17 patients (3%) changed EVE intake timing throughout the study. EVE intake dialy times were binned into 2 categories for analyses: morning/afternoon group (n=300) and evening/night group (n = 213). The patients who took morning/afternoon EVE chose another timing for ET in 38% of the cases compared to 17.1% in evening/Night EVE group (p&lt;0.01). The timing of EVE intake was not significantly associated with definitive EVE withdrawal ( p=0.62) in the whole population. Time to EVE withdrawal was significantly longer in the patients taking tamoxifen rather than AI (17.2 vs 10.9 months, p = 0.0047). Prolonged duration of EVE treatment was associated with evening/night intakes of both EVE and tamoxifen, compared to other drug timing modalities (p = 0.04). With a median follow-up of 85months, 15 patients relapsed locally (3%), 55 developed metastases (11%), 36 patients died (7%). Overall, EVE intake timing was not associated with DFS (HR=0.84 [95% CI, 0.53 - 1.35], p=0.4). There was a significant interaction between EVE timing intake and ET type ( P interaction= 0.001). Patients on evening/night EVE combined with tamoxifen had a reduced likelihood of relapse compared to those taking morning/afternoon EVE (HR = 0.17 [0.05- 0.59], p = 0.005). In contrast, no significant EVE effect was found in the AI group (HR = 1.56 [0.92 2.64], p = 0.1). Evening/Night intake of EVE plus tamoxifen was independently associated with DFS (HR 0.13 [0.03-0.6], p = 0.002) after adjustment for age, nodal status, tumor size, ET timing intake, and EVE dose (2.5, 5 or 10 mg). Conclusions: These exploratory results are consistent with a role of circadian rhythm in the efficacy of EVE when given with tamoxifen in pts with high risk early breast cancer. 1. S. Giacchetti et al, Abst 546, ASCO 2023. Clinical trial information: NCT01805271 .

Dose-dense adjuvant chemotherapy in patients with HER2-low early breast cancer: An exploratory analysis of the GIM2 trial.

532 Background: Dose-dense (DD) adjuvant chemotherapy represents the standard treatment for patients with node-positive early-stage HER2-negative breast cancer, but its role in HER2-low disease is unknown. In this exploratory analysis of the Gruppo Italiano Mammella 2 (GIM2) trial, we investigated efficacy of DD chemotherapy among patients affected by HER2-negative breast cancer according to HER2 immunohistochemistry (IHC) score (low vs. zero). Methods: Patients with node-positive early breast cancer were randomly assigned to receive either DD or standard schedule anthracycline- and taxane-based chemotherapy. HER2 status was assessed locally. Tumours with HER2 score 0 were classified as HER2-zero, while those with a HER2 score 1+ or 2+ without fluorescence in situ hybridization (FISH) amplification were defined as HER2-low. Some tumours were classified as HER2-negative with unknown IHC score. Survival outcomes were compared between patients with HER2-zero vs HER2-low tumours. Results: Among 2003 patients enrolled in the GIM2 trial, 1243 subjects were eligible for this analysis. Median age was 52 years (interquartile range [IQR] 44-59) and 604 patients (48.6%) were pre-menopausal. Hormone receptor status was positive in 87.9% of cancers. 475 tumours were classified as HER2-zero (38.2%), 446 (35.9%) were defined HER2-low and 322 (25.9%) were HER2-negative with unknown IHC score. No significant differences were found in terms of baseline characteristics between these three subgroups. At a median follow-up of 14.9 years (IQR 8.4-16.2), no significant interaction was observed between treatment effect and HER2 status in invasive disease-free survival (iDFS) (p for interaction=0.46) nor in overall survival (OS) (p for interaction=0.43). Comparing patients with HER2-zero breast cancer with those affected by HER2-low tumours, no significant differences in iDFS were observed (15yr iDFS were 61% vs. 54%, respectively, p=0.25), nor OS differences (15yr OS were 75% vs. 72%, respectively, p=0.19). When investigating DD schedule efficacy among patients with HER2-zero tumours, hazard ratio (HR) for iDFS was 0.64 (95% confidence interval [CI] 0.46-0.87) and HR for OS was 0.57 (95%CI 0.38-0.88). Similarly, within patients affected by HER2-low breast cancer, HR was 0.83 (95%CI 0.62-1.11) for iDFS and 0.83 (95%CI 0.57-1.22) for OS. These results were consistent with the findings of efficacy of DD chemotherapy in the overall population included in this analysis (HR for iDFS 0.73 [95%CI 0.61-0.89]; HR for OS 0.69 [95%CI 0.54-0.88]). Conclusions: In this exploratory analysis of a large phase III adjuvant trial, HER2 status (i.e. HER2-zero vs HER2low) did not show prognostic value. In patients with high-risk early breast cancer, the benefit of DD chemotherapy was observed irrespective of HER2 status. Clinical trial information: NCT00433420 .

A phase II trial comparing dalpiciclib in combination with letrozole versus standard chemotherapy as neoadjuvant therapy in patients with high-risk HR- positive HER-2 negative breast cancer: DARLING-02.

TPS626 Background: Dalpiciclib is a CDK4/6 inhibitor that has shown promising efficacy and safety when in combination with endocrine in the treatment of advanced HR+ HER2- breast cancer. Building on preliminary findings from our previous study (Geng, 2023SABCS PO2-02-05), we aim to evaluate the efficacy and safety of dalpiciclib combined with letrozole versus standard chemotherapy as neoadjuvant treatment in patients with high-risk early breast cancer (EBC). Methods: This is a prospective, multicenter, randomized phase II non-inferiority trial. Main eligibility criteria include: female patients ≥18 years, ECOG performance status of 0-1, histologically confirmed invasive breast cancer, clinical stage T1c-T2, cN1–2 or T3-4, cN0-2, ER≥50%, HER2-negative, and Ki67 ≤ 20%. Participants are randomized 1:1 to receive either 24-week experimental intervention (oral dalpiciclib 150mg once daily for 3 weeks on, 1 week off and oral letrozole 2.5 mg/day) or 24-week standard intervention (intravenous epirubicin 100 mg/m² and intravenous cyclophosphamide 500 mg/m² on day 1 for three 3-week cycles, followed by intravenous docetaxel 100 mg/m2 on day 1 for three 3-week cycles). The primary endpoint is the objective response rate (ORR) assessed by RECIST v1.1. Secondary endpoints include patient-reported outcomes (EORTC QLQ-C30, EORTC QLQ-BR23), residual cancer burden 0–I rate, preoperative endocrine prognostic index score 0 rate, pathological complete response rate , 2-year invasive disease-free survival rate, and safety. Exploratory endpoints include biomarker analysis. The hypothesis is that the experimental group will not be inferior to control group. Assuming an ORR of 70% for both groups, a sample size of 65 patients per group is required to achieve 80% power to detect a non-inferiority margin of up to 20% at a two-sided significance level of 5%. A total of 130 patients are needed (65 per group). Considering a dropout rate of 10% per group, the total sample size is approximately 144 patients. The trial was registered at ClinicalTrials.gov (NCT06107673) and is actively recruiting. Clinical trial information: NCT06107673 .

PARPi eligibility amongst women with newly diagnosed invasive breast cancer enrolled in the GREAT universal genetic testing study.

531 Background: Poly(ADP-ribose) polymerase inhibitors (PARPi) are approved for the treatment of BRCA-associated metastatic and high-risk early breast cancer. Recent guidelines have endorsed the use of BRCA1/2 testing for all patients with breast cancer who may be eligible for PARPi therapy, however it is unclear what proportion of patients are impacted by these recommendations. Methods: We sought to evaluate pre-test and post-test eligibility for PARPi in women aged &gt;18 years old with a first diagnosis of stage I-IV invasive breast cancer who enrolled in a prospective, multicentered universal genetic testing study between 2019-2022. All enrolled patients underwent pre-test counselling and an obligatory primary panel of BRCA1, BRCA2, and PALB2 at the time of diagnosis. Candidacy for PARPi was determined by biologic subtype, clinical stage, pathologic stage, and/or response to neoadjuvant chemotherapy. Results: Of 1017 patients referred for the study, 805 were eligible and 729 (90.6%) consented to participate. The median age at diagnosis was 53 years (IQR, 45-62 years) and 96.2% had stage I-III disease. Overall, 32 (4.4%) patients had a germline pathogenic variant (GPV) in BRCA1/2, and 7 (1.0%) had a GPV in PALB2. Of 112 (15.4%) patients with triple negative breast cancer (TNBC), 19.6% had a GPV in BRCA1/2 or PALB2, whereas in 487 (66.8%) with ER+HER2- disease, 2.9% had a GPV (p&lt;0.001). Among the 112 patients with TNBC, 64 (57%) were candidates for PARPi pre-genetic testing, and 12 (10.7%) remained eligible due to a GPV in BRCA1/2. Among the 487 patients with ER+HER2- breast cancer, 37 (5.1%) were candidates for PARPi pre-genetic testing, and 1 (0.2%) remained eligible due to a BRCA1 GPV identified on testing. All patients who were PARPi eligible were &lt;65 years of age or &gt;65 years with TNBC. Conclusions: In women with newly diagnosed invasive breast cancer, approximately 14% are candidates for PARPi prior to genetic testing, and 1.8% remain PARPi eligible due to a confirmed pathogenic variant in BRCA1/2. Consequently, genetic testing impacts systemic therapy decisions for PARPi in 10% of TNBC patients and fewer than 1% of women with ER+HER2- breast cancer. [Table: see text]

Incidence and time to onset of immunotherapy-related adrenal insufficiency in the I-SPY2 trial.

584 Background: I-SPY2 was the first randomized trial to demonstrate an improvement in pCR and EFS when Immune Checkpoint Inhibitors (ICI) were added to standard neoadjuvant chemotherapy. This finding was validated in the phase 3 KEYNOTE 522 trial for triple-negative breast cancer, leading to approval of pembrolizumab (pembro) in this setting. ICIs add the risk of immune-related adverse events (irAEs); while most irAEs are reversible, endocrinopathies appear to persist. Higher rates of adrenal insufficiency (AI), either from primary adrenalitis or hypophysitis, have been reported with ICI-based therapy (tx) in early breast cancer (EBC) compared to advanced disease. Here we describe the incidence and time of onset of AI with ICI-based tx in I-SPY2. Methods: I-SPY2 is a multicenter, phase 2 trial using response-adaptive randomization within biomarker subtypes defined by hormone receptor, HER2, and MammaPrint status to evaluate novel agents in the neoadjuvant setting in patients (pts) with high-risk EBC. Treatment included weekly paclitaxel (T) plus ICI-based tx x 4 cycles, followed by doxorubicin/cyclophosphamide (AC) every 2-3 weeks x 4. 6 completed investigational arms included ICIs: T+pembro x 4, T+pembro x 8 (+/- AC), T+pembro+SD101 (TLR9 agonist), T+durvalumab+olaparib, T+cemiplimab (cemi), and T+cemi+REGN3767 (anti-LAG-3). AI diagnoses were made by treating providers with review from two board certified endocrinologists. AI was defined as AM serum cortisol level &lt; 3 mcg/dl in absence of recent glucocorticoid treatment. If ACTH was low or normal, pt was dx with hypophysitis; if ACTH was elevated, pt was dx with primary AI. Results: 442 pts in I-SPY2 received ICI-based tx; 11.8% (n=52) developed AI (primary+hypophysitis). Mean age of pts who developed AI was 47.3 vs 48.6 yrs in those who did not (p=0.44). Incidence of AI was highest in arms with dual immune modulation (18.1%) as compared to single ICI tx (8.5%). Median time to onset varied by arm, ranging from 92-204 days from first ICI dose. While some cases occurred during ICI tx (13.5%), the majority occurred between 12-24 wks after tx initiation, with 21.2% diagnosed after completion of all tx. The majority (94.2%) of pts with AI were symptomatic; the most common presenting symptoms included fatigue (59.6%), nausea (48.1%), and vomiting (34.6%). All pts with AI remain on glucocorticoid replacement tx. Conclusions: The incidence of AI in EBC is higher than has previously been reported in advanced disease, with higher rates observed in those tx with dual immune modulation. No correlation was observed with age; correlation of AI with response predictive subtype and other clinicopathologic features is ongoing and will be presented. Given the high incidence of AI in EBC, close monitoring in the peri/postoperative setting and education of pts and providers is critical, as risk persists even after completion of tx. Work to identify risk factors for AI is ongoing. Clinical trial information: NCT01042379 .

Real-world immune-related adverse events in patients with early triple negative breast cancer who received pembrolizumab.

1099 Background: The addition of pembrolizumab to chemotherapy (KEYNOTE-522 regimen) in high risk early triple negative breast cancer (TNBC) has improved clinical outcomes. However, this treatment can result in immune-related adverse events (irAEs) involving any organ and in some cases, life-long toxicities or even death. This retrospective study describes real-world patterns of irAEs in patients (pts) with early TNBC who received pembrolizumab at two academic centers. Methods: We evaluated irAEs in pts with stage II-III TNBC from MD Anderson Cancer Center and Lyndon B Johnson diagnosed between January 2018 and May 2023 who received neoadjuvant pembrolizumab plus chemotherapy. We excluded those enrolled on clinical trials. We utilized ASCO irAE and CTCAE v5 guidelines for toxicity grading. Logistic regression assessed the effect of clinical variables on irAEs, adjusting for covariates. Results: We identified 233 pts with a median age of 51 ± 12 years; 62% with stage II and 35% with stage III TNBC; 25% were Hispanic/Latino, 21% non-Hispanic Black and 42% were non-Hispanic White. In total, 80 pts (34%) developed 100 separate irAEs (94 with definite and 6 with possible/probable attribution). The most common irAEs were endocrine (52%) followed by gastrointestinal (23%). Grade ≥ 3 irAE occurred in 26 instances, with the most common being gastrointestinal (13 instances). A fatal irAE occurred in 2 pts where both were colitis. A total of 26 irAEs resulted in hospitalization, 45 required systemic steroids, and 15 required additional immunosuppressive therapy. Most (66) irAEs were unresolved at last follow up, although the majority had improved to grade 1 (37/66) and 32 patients discontinued pembrolizumab early due to irAEs. No clinical factor (race, stage, tumor grade, age, body mass index) was associated with development of an irAE. Conclusions: In this real-world diverse population, we identified a similar rate and severity of irAEs as reported in the KEYNOTE-522 trial. Hospitalizations occurred in 26% of irAEs while most developed persistent immune toxicity. Gastrointestinal irAEs were more common compared to KEYNOTE-522 reported data. Research is needed to better predict and mitigate the burden of irAEs and to improve the long-term survivorship care of pts with early TNBC pts who receive pembrolizumab. [Table: see text]

Real life comparison between doxorubicin and cyclophosphamide (AC) dose-dense (dd) and conventional dose AC in patients with triple negative breast cancer (TNBC) under neoadjuvant treatment.

e12662 Background: High-risk early triple-negative breast cancer (TNBC) is frequently associated with early recurrence and high mortality. Studies suggest a sustained clinical benefit in patients with TNBC who have a pathological complete response (PCR) after neoadjuvant chemotherapy (NACT). The dose-dense (dd) regimen demonstrated improved survival regardless of hormone receptor expression or HER2 status. The doxorubicin and cyclophosphamide (AC) regimen can be performed in (dd), therefore it must include granulocyte growth factors, which may increase costs and toxicities. The object of the study was to evaluate their clinical characteristics and treatment, patients with TNBC, stage I-III who received ACdd in neoadjuvant treatment versus patients who received AC dose conventional (dc). Methods: We performed a retrospective observational cohort study of patients with early TNBC, stage I-III who received neoadjuvant treatment with chemotherapy based on doxorubicin, cyclophosphamide, paclitaxel and carboplatin associated with pembrolizumab. Results: All 82 patients were women 57.3% received ACdd, 30.4% received AC dc. In group ACdd 59.5% had intercurrence related with chemotherapy, in which 17.8% were neutropenic fever and 21.4% had developed different types of infections (ex: diarrhea, pneumonia and others). In these 2 groups all of them had received antibiotic. About 50% of the patients had developed intercurrence because of treatment toxicity and just 3.5% had disease progression. The other group that we evaluated is composed by patients who ACdc, dose Regarding to these group 48% developed any intercurrence during the neoadjuvant treatment, in which 8.3% had neutropenic fever and 25% had different types of infections. All of them earned antibiotic. About clinical and pathological response, the group that earned ACdd 61.7% got complete clinical response and 8.5% had a disease progression during the treatment. In the other arm 68% got complete clinical response and 4% had a progression. Conclusions: AC dd was more prevalent in our series, despite the additional use of granulocyte growth factor, there were more complications in this group and it did not demonstrate better results than those who received conventional dose AC.

The SURVIVE study: Liquid biopsy guided surveillance after intermediate- to high-risk early breast cancer.

TPS620 Background: Current guidelines limit routine breast cancer (BC) follow-up to clinical examinations and breast imaging. This is based on the results of two large cohort studies conducted in the 1980s that showed no improvement in overall survival (OS) by an intensified screening for distant metastases. Thus, imaging for distant metastases should currently only be performed in patients with specific symptoms. To detect distant relapse in a pre-symptomatic stage, we suggest the evaluation of a liquid biopsy-guided intensified surveillance, analyzing tumor markers (CA 27.29, CA 125 and CEA), circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). Methods: Funded by the German Federal Ministry of Education and Research, the SURVIVE study is the first large, randomized BC surveillance trial to investigate the potential survival benefit of a liquid biopsy guided follow-up care in intermediate- to high-risk early breast cancer patients. The trial is a German multicenter, controlled phase 3 superiority study, in which 3500 patients are randomized in a 1:1 ratio to standard vs. liquid biopsy guided intensified follow-up care. Eligible patients are adults with confirmed primary invasive intermediate to high-risk early BC, defined as an indication for (neo-)adjuvant chemotherapy, and/or large tumor size (&gt; 50 mm), and/or positive lymph nodes (≥ pN1mi), and/or high grade (≥ G3). Primary anti-tumor therapy (surgery, adjuvant chemo- or radiotherapy) must have been completed previously. Patient enrollment during adjuvant endocrine, antibody- or targeted therapy is allowed. The total study duration is 144 months. Stratification factors are study site as well as HR-, HER2- and nodal status at surgery.Both study arms receive standard follow-up according to national guidelines, and the intensified surveillance arm will be tested for standard tumor markers, CTCs and ctDNA via tumor-informed approach (RaDaR assay). Pre-specified abnormal findings of any of the liquid biopsy markers indicative of minimal residual disease trigger complete staging. In the event of confirmed disease recurrence, guideline-based treatment follows, otherwise, liquid biopsy testing continues. If applicable, study participants may enter interventional trials. Statistics:The two primary objectives are to determine whether intensified, liquid biopsy-guided surveillance leads to better OS or an overall lead-time effect, compared to standard surveillance. OS will be analyzed in the ITT population using Kaplan Meier methods and cox regression models, the overall lead time effect is a purely descriptive composite measure. Secondary objectives include IDFS, DDFS, DRFS, BCSS and quality of life (QoL). Aims: We propose a liquid biopsy guided follow-up method, with high sensitivity and specificity for the earlier detection of distant (oligo-)metastases, to enable earlier initiation of therapy. Clinical trial information: NCT05658172 .