CDK4/6-Inhibitors Versus Chemotherapy in Advanced HR+/HER2-Negative Breast Cancer: Results and Correlative Biomarker Analyses of the KENDO Randomized Phase II Trial.

BACKGROUND: The optimal treatment approach for hormone receptor-positive/HER2-negative metastatic breast cancer (HR+/HER2-negative MBC) with aggressive characteristics remains controversial, with lack of randomized trials comparing cyclin-dependent kinase (CDK)4/6-inhibitors (CDK4/6i) + endocrine therapy (ET) with chemotherapy + ET. MATERIALS AND METHODS: We conducted an open-label randomized phase II trial (NCT03227328) to investigate whether chemotherapy + ET is superior to CDK4/6i + ET for HR+/HER2-negative MBC with aggressive features. PAM50 intrinsic subtypes (IS), immunological features, and gene expression were assessed on baseline samples. RESULTS: Among 49 randomized patients (median follow-up: 35.2 months), median progression-free survival (mPFS) with chemotherapy + ET (11.2 months, 95% confidence interval [CI]: 7.7-15.4) was numerically shorter than mPFS (19.9 months, 95% CI: 9.0-30.6) with CDK4/6i + ET (hazard ratio: 1.41, 95% CI: 0.75-2.64). Basal-like tumors under CDK4/6i + ET exhibited worse PFS (mPFS: 11.4 months, 95% CI: 3.00-not reached [NR]) and overall survival (OS; mOS: 18.8 months, 95% CI: 18.8-NR) compared to other subtypes (mPFS: 20.7 months, 95% CI: 9.00-33.4; mOS: NR, 95% CI: 24.4-NR). In the chemotherapy arm, luminal A tumors showed poorer PFS (mPFS: 5.1 months, 95% CI: 2.7-NR) than other IS (mPFS: 13.2 months, 95% CI: 10.6-28.1). Genes/pathways involved in BC cell survival and proliferation were associated with worse outcomes, as opposite to most immune-related genes/signatures, especially in the CDK4/6i arm. CD24 was the only gene significantly associated with worse PFS in both arms. Tertiary lymphoid structures and higher tumor-infiltrating lymphocytes also showed favorable survival trends in the CDK4/6i arm. CONCLUSIONS: The KENDO trial, although closed prematurely, adds further evidence supporting CDK4/6i + ET use in aggressive HR+/HER2-negative MBC instead of chemotherapy. PAM50 IS, genomic, and immunological features are promising biomarkers to personalize therapeutic choices.

Serum Biomarkers to Dynamically Predict the Risk of Cardiovascular Events in Patients under Oncologic Therapy. A Multicenter Observational Study.

Background: Serum biomarkers have been investigated as predictive risk factors for cancer-related cardiovascular (CV) risk, but their analysis is limited to their baseline level rather than their overtime change. Besides historically validated causal factors, inflammatory and oxidative stress (OS) related markers seem to be correlated to CV events but this association needs to be further explored. We conducted an observational study to determine the predictive role of the longitudinal changes of commonly used and OS-related biomarkers during the cancer treatment period. Methods: Patients undergoing anticancer therapies, either aged 75+ years old or younger with an increased CV risk according to European Society of Cardiology guidelines, were enrolled. We assessed the predictive value of biomarkers for the onset of CV events at baseline and during therapy using Cox model, Subpopulation Treatment-Effect Pattern Plot (STEPP) method and repeated measures analysis of longitudinal data. Results: From April 2018 to August 2021, 182 subjects were enrolled, of whom 168 were evaluable. Twenty-eight CV events were recorded after a median follow up of 9.2 months (Interquartile range, IQR: 5.1-14.7). Fibrinogen and troponin levels were independent risk factors for CV events. Specifically, patients with higher than the median levels of fibrinogen and troponin at baseline had higher risk compared with patients with values below the medians, hazard ratio (HR) = 3.95, 95% CI, 1.25-12.45 and HR = 2.48, 0.67-9.25, respectively. STEPP analysis applied to Cox model showed that cumulative event-free survival at 18 and 24 months worsened almost linearly as median values of fibrinogen increased. Repeated measure analysis showed an increase over time of D-Dimer (p-interaction event*time = 0.08), systolic (p = 0.07) and diastolic (p = 0.05) blood pressure and a decrease of left ventricular ejection fraction (p = 0.15) for subjects who experienced a CV event. Conclusions: Higher levels of fibrinogen and troponin at baseline and an increase over time of D-Dimer and blood pressure are associated to a higher risk of CV events in patients undergoing anticancer therapies. The role of OS in fibrinogen increase and the longitudinal monitoring of D-dimer and blood pressure levels should be further assessed.

Computed tomography based analyses of body mass composition in HER2 positive metastatic breast cancer patients undergoing first line treatment with pertuzumab and trastuzumab.

Body composition parameters (BCp) have been associated with outcome in different tumor types. However, their prognostic value in patients with HER2-positive metastatic breast cancer (BC) receiving first line treatment with dual anti-HER2 antibody blockade is unknown. Preclinical evidences suggest that adipocytes adjacent to BC cells can influence response to anti-HER2 treatments. We retrospectively analyzed Computed Tomography (CT)-based BCp from 43 patients with HER2-positive metastatic BC who received first line pertuzumab/trastuzumab-based treatment between May 2009 and March 2020. The impact of baseline CT-based BCp on progression-free survival (PFS) was tested using Kaplan-Meier estimates and univariate and multivariate Cox regression models. We found a significantly worse PFS for patients with high baseline subcutaneous fat index (median 7.9 vs 16.1 months, p = 0.047, HR = 2.04, 95%CI 1-4.17) and for those with high total abdominal fat index (8.1 vs 18.8 months, p = 0.030, HR = 2.17, 95%CI 1.06-4.46). Patients with baseline sarcopenia did not show shorter PFS compared to those without sarcopenia (10.4 vs 9.2 months, p = 0.960, HR = 0.98, 95%CI 0.47-2.03). Total abdominal fat index remained a significant predictor of PFS at multivariate analysis. Our findings suggest that a high quantity of total abdominal fat tissue is a poor prognostic factor in patients receiving trastuzumab/pertuzumab-based first-line treatment for HER2-positive metastatic BC.

Ki67 and PR in Patients Treated with CDK4/6 Inhibitors: A Real-World Experience.

CDK4/6 inhibitors (CDK4/6i) are recommended in patients with estrogen receptor (ER)-positive, HER2-negative advanced breast cancer (ABC). Up to now, no prognostic biomarkers have been identified in this setting. We retrospectively analyzed the expression of progesterone receptor (PR) and Ki67, assessed by immunohistochemistry, in 71 ABC patients treated with CDK4/6i and analyzed the impact of these markers on progression-free survival (PFS). The majority of patients 63/71 (88.7%) received palbociclib, 4 (5.6%) received ribociclib, and 4 (5.6%) received abemaciclib. A higher median value of Ki67 was observed in cases undergoing second-line treatment (p = 0.047), whereas the luminal B subtype was more prevalent (p = 0.005). In the univariate analysis of the first-line setting, luminal A subtype showed a trend towards a correlation with a longer PFS (p = 0.053). A higher continuous Ki67 value led to a significantly shorter PFS. When the interaction between pathological characteristics and line of treatment was considered, luminal B subtype showed a significantly (p = 0.043) worse outcome (Hazard Ratio (HR) 2.84; 1.03-7.82 95% Confidence Interval (CI)). PFS in patients undergoing endocrine therapy plus CDK4/6i was inversely correlated with Ki67 expression but not with PR, suggesting that tumor proliferation has a greater impact on cell cycle inhibitors combined with endocrine therapy than PR expression.