Ribociclib plus letrozole versus chemotherapy for postmenopausal women with hormone receptor-positive, HER2-negative, luminal B breast cancer (CORALLEEN): an open-label, multicentre, randomised, phase 2 trial.

BACKGROUND: In hormone receptor-positive, HER2-negative early stage breast cancer, cyclin-dependent kinases 4 and 6 (CDK4/6) inhibition in combination with endocrine therapy could represent an alternative to multiagent chemotherapy. We aimed to evaluate the biological and clinical activity of neoadjuvant ribociclib plus letrozole in the luminal B subtype of early stage breast cancer. METHODS: CORALLEEN is a parallel-arm, multicentre, randomised, open-label, phase 2 trial completed across 21 hospitals in Spain. We recruited postmenopausal women (≥18 years) with stage I-IIIA hormone receptor-positive, Eastern Cooperative Oncology Group Performance Status 0-1, HER2-negative breast cancer and luminal B by PAM50 with histologically confirmed, operable primary tumour size of at least 2 cm in diameter as measured by MRI. Patients were randomly assigned (1:1) using a web-based system and permuted blocks of 25 to receive either six 28-days cycles of ribociclib (oral 600 mg once daily for 3 weeks on, 1 week off) plus daily letrozole (oral 2·5 mg/day) or four cycles of doxorubicin (intravenous 60 mg/m2) and cyclophosphamide (intravenous 600 mg/m2) every 21 days followed by weekly paclitaxel (intravenous 80 mg/m2) for 12 weeks. The total duration of the neoadjuvant therapy was 24 weeks. Randomisation was stratified by tumour size and nodal involvement. Samples were prospectively collected at baseline (day 0), day 15, and surgery. The primary endpoint was to evaluate the proportion of patients with PAM50 low-risk-of-relapse (ROR) disease at surgery in the modified intention-to-treat population including all randomly assigned patients who received study drug and had a baseline and at least one post-baseline measurement of ROR score. The PAM50 ROR risk class integrated gene expression data, tumour size, and nodal status to define prognosis. This trial was registered at ClinicalTrials.gov, NCT03248427. FINDINGS: Between July 27, 2017 to Dec 7, 2018, 106 patients were enrolled. At baseline, of the 106 patients, 92 (87%) patients had high ROR disease (44 [85%] of 52 in the ribociclib and letrozole group and 48 [89%] of 54 in the chemotherapy group) and 14 (13%) patients had intermediate-ROR disease (eight [15%] and six [11%]). Median follow-up was 200·0 days (IQR 191·2-206·0). At surgery, 23 (46·9%; 95% CI 32·5-61·7) of 49 patients in the ribociclib plus letrozole group and 24 (46·1%; 32·9-61·5) of 52 patients in the chemotherapy group were low-ROR. The most common grade 3-4 adverse events in the ribociclib plus letrozole group were neutropenia (22 [43%] of 51 patients) and elevated alanine aminotransferase concentrations (ten [20%]). The most common grade 3-4 adverse events in the chemotherapy group were neutropenia (31 [60%] of 52 patients) and febrile neutropenia (seven [13%]). No deaths were observed during the study in either group. INTERPRETATION: Our results suggest that some patients with high-risk, early stage, hormone receptor-positive, HER2-negative breast cancer could achieve molecular downstaging of their disease with CDK4/6 inhibitor and endocrine therapy. FUNDING: Novartis, Nanostring, Breast Cancer Research Foundation-AACR Career Development Award.

Cell-cycle inhibition and immune microenvironment in breast cancer treated with ribociclib and letrozole or chemotherapy.

In this study, we performed genomic analyses of cell cycle and tumor microenvironment changes during and after ribociclib and letrozole or chemotherapy in the CORALLEEN trial. 106 women with untreated PAM50-defined Luminal B early breast cancers were randomly assigned to receive neoadjuvant ribociclib and letrozole or standard-of-care chemotherapy. Ki67 immunohistochemistry, tumor-infiltrating lymphocytes quantification, and RNA sequencing were obtained from tissue biopsies pre-treatment, on day 14 of treatment, and tumor specimens from surgical resection. Results showed that at surgery, Ki67 and the PAM50 proliferation scores were lower after ribociclib compared to chemotherapy. However, consistent reactivation of tumor cell proliferation from day 14 to surgery was only observed in the ribociclib arm. In tumors with complete cell cycle arrest (CCCA) at surgery, PAM50 proliferation scores were lower in the ribociclib arm compared to chemotherapy (p < 0.001), whereas the opposite was observed with tumor cellularity (p = 0.002). Gene expression signatures (GES) associated with antigen-presenting cells (APCs) and innate immune system activity showed increased expression post-chemotherapy but decreased expression post-ribociclib. Interferon-associated GES had decreased expression with CCCA and increased expression with non-CCCA. Our findings suggest that while both treatment strategies decreased proliferation, the depth and the patterns over time differed by treatment arm. Immunologically, ribociclib was associated with downregulated GES associated with APCs and the innate immune system in Luminal B tumors, contrary to existing preclinical data. Further studies are needed to understand the effect of CDK4/6 inhibition on the tumor cells and microenvironment, an effect which may vary according to tumor subtypes.

Comparison of ultrasound guided surgery and radio-guided occult lesions localization (ROLL) for nonpalpable breast cancer excision.

Background: There is little literature comparing intraoperative ultrasound (IOUS) with radio-guided occult lesions localization (ROLL) in nonpalpable invasive tumors in breast conserving surgery (BCS). There is a need to compare these two methods in terms of safety and efficacy. Methods: This is an observational cohort study. All patients treated with BCS for nonpalpable invasive breast cancer using IOUS from March 2016 to March 2020 were included and compared with a historical reference control group operated on using ROLL from March 2013 to March 2017. For each detection method, the ability to locate tumors intraoperatively, tumor and surgical specimen sizes, total resection volume (TRV), optimal resection volume, excess of healthy tissue resected (ETR), margin status, re-excision rate, surgical time, complications and costs were studied. Results: One hundred and fifty-eight were included, 83 with IOUS and 75 with ROLL. The mean tumor size is equivalent in both groups (11.88 mm IOUS vs. 12.29 mm ROLL, P=0.668). TRV is significantly lower with IOUS (24.92 vs. 60.32 cm3, P<0.001), and the ETR is also significantly lower in the IOUS group (21.74 vs. 58.37 cm3, P<0.001). The rate of positive margins did not differ (10.98% vs. 12.16%, P=1), nor did re-excision rate (10.98% vs. 8.11%, P=0.597). Complication rate did not differ (12.2% IOUS vs. 10.81% ROLL, P=0.808). Surgical time was shorter in IOUS (45.5 vs. 57 min, P>0.05). Conclusions: IOUS in BCS for nonpalpable invasive breast cancer is more accurate than ROLL because it decreases excision volumes with the same rate of free margins and re-excision. Also, IOUS is a more efficient and comfortable technique, and just as safe as ROLL.

Trastuzumab Deruxtecan in HER2-Positive Metastatic Breast Cancer Patients with Brain Metastases: A DESTINY-Breast01 Subgroup Analysis.

DESTINY-Breast01 (NCT03248492) evaluated trastuzumab deruxtecan (T-DXd; DS-8201) in patients with heavily pretreated HER2-positive metastatic breast cancer (mBC). We present a subgroup of 24 patients with a history of treated brain metastases (BM), a population with limited treatment options. In patients with BMs, the confirmed objective response rate (cORR) was 58.3% [95% confidence interval (CI), 36.6%-77.9%], and the median progression-free survival (mPFS) was 18.1 months (95% CI, 6.7-18.1 months). In patients without BMs (n = 160), cORR was 61.3% and mPFS was 16.4 months. Eight patients (47.1%) experienced a best overall intracranial response of partial response or complete response. Seven patients (41.2%) had a best percentage change in brain lesion diameter from baseline consistent with stable disease. Two patients (8.3%) with BMs and two (1.3%) without BMs experienced progression in the brain. The safety profile of T-DXd was consistent with previous studies. The durable clinical activity of T-DXd in this population warrants further investigation. SIGNIFICANCE: Advances in treating HER2-positive metastatic breast cancer have greatly improved patient outcomes, but intracranial progression remains an important risk for which few therapeutic options are currently available. T-DXd demonstrated durable efficacy in patients with stable, treated BMs. This article is highlighted in the In This Issue feature, p. 2711.

When Is Sentinel Node Biopsy Indicated in High-Risk Ductal Carcinoma in situ? Four Hundred Sixty-Eight Cases from Three Institutions.

INTRODUCTION: Sentinel lymph node biopsy (SLNB) in ductal carcinoma in situ (DCIS) is not indicated. However, in certain cases (size >3 cm, high grade, mass effect on mammography, or palpable mass), it may be possible to find incidental invasive carcinoma (IC) that requires an SLNB. We studied the correlation of the aforesaid factors with the probability of finding IC in the surgical specimen. METHODS: Data was collected from 3 different institutions between 2010 and 2016, recording characteristics such as, but not limited to: high grade, size >3 cm, mass effect on mammography, and palpable mass. RESULTS: On the whole, 468 "high-risk" DCIS cases were identified, 139 (29%) of which had IC. When the DCIS was high grade or the size was >3 cm, there was no significant difference in the probability of finding IC in the surgical specimen (OR = 1.13; 95% CI 0.84-1.51; OR = 1.2; 95% CI 0.85-1.40). Nevertheless, when a high grade and size (>3 cm) were combined, IC was more likely to exist (72.7 vs. 27.3%; p = 0.001). In addition, mass effect and palpation were independently associated with a significantly greater degree of IC (OR = 12.76; 95% CI 6.93-23.52). CONCLUSIONS: The results suggest that high-grade DCIS or DCIS with a size >3 cm, independently, does not require SLNB. Nonetheless, in the event that both factors are found in the same case, SLNB may be indicated. Additionally, SLNB is advisable for DCIS cases that are palpable or show a mass effect on mammography.

Efficacy and Determinants of Response to HER Kinase Inhibition in HER2-Mutant Metastatic Breast Cancer.

HER2 mutations define a subset of metastatic breast cancers with a unique mechanism of oncogenic addiction to HER2 signaling. We explored activity of the irreversible pan-HER kinase inhibitor neratinib, alone or with fulvestrant, in 81 patients with HER2-mutant metastatic breast cancer. Overall response rate was similar with or without estrogen receptor (ER) blockade. By comparison, progression-free survival and duration of response appeared longer in ER+ patients receiving combination therapy, although the study was not designed for direct comparison. Preexistent concurrent activating HER2 or HER3 alterations were associated with poor treatment outcome. Similarly, acquisition of multiple HER2-activating events, as well as gatekeeper alterations, were observed at disease progression in a high proportion of patients deriving clinical benefit from neratinib. Collectively, these data define HER2 mutations as a therapeutic target in breast cancer and suggest that coexistence of additional HER signaling alterations may promote both de novo and acquired resistance to neratinib. SIGNIFICANCE: HER2 mutations define a targetable breast cancer subset, although sensitivity to irreversible HER kinase inhibition appears to be modified by the presence of concurrent activating genomic events in the pathway. These findings have implications for potential future combinatorial approaches and broader therapeutic development for this genomically defined subset of breast cancer.This article is highlighted in the In This Issue feature, p. 161.

Incidence of chemotherapy-induced nausea and vomiting associated with docetaxel and cyclophosphamide in early breast cancer patients and aprepitant efficacy as salvage therapy. Results from the Spanish Breast Cancer Group/2009-02 study.

BACKGROUND: Docetaxel-cyclophosphamide (TC) has become a common regimen in moderate-high-risk early breast cancer (EBC), but the incidence of chemotherapy-induced nausea and vomiting (CINV) with this regimen is not well established. This trial investigates the effect of guideline-consistent prophylaxis on CINV related to TC regimen and explores the efficacy of aprepitant among resistant patients. PATIENTS AND METHODS: This prospective multicentre study enrolled 212 chemotherapy-naïve EBC patients receiving T-75 mg/m(2) and C-600 mg/m(2). Antiemetic therapy on the first cycle consisted of dexamethasone for 3 d plus 5-hydroxytryptamine (5-HT3) antagonists on day 1, according to Multinational Association of Supportive Care in Cancer guidelines. The primary end-point was complete response (CR) (no emesis and no need of rescue treatment within the initial 120 h). Patients failing CR on cycle 1 entered in a single-arm study exploring the efficacy of aprepitant on the second cycle. Patients' diaries and Functional Living Index-Emesis (FLIE) questionnaires were collected in cycles 1 and 2. RESULTS: Among the 185 evaluable patients on cycle 1, 161 (87%, 95% confidence interval [CI]: 82.2-91.8) achieved a CR. Twenty-three patients received aprepitant on cycle 2, and 12 reached a CR (52.2%, 95% CI: 31.8-72.6). The absence of CR had a very substantial impact on quality of life on cycles 1 (FLIE before and after: 23.8-38.1, p = 0.0124) and 2 (18.3-42.9, p = 0.0059). CONCLUSIONS: Guideline-consistent antiemetic prophylaxis for the TC regimen is associated with a low incidence of CINV. Aprepitant is effective as secondary prevention of CINV and should be considered as rescue therapy in patients treated with moderate emetogenic chemotherapy.

Inference of tumor evolution during chemotherapy by computational modeling and in situ analysis of genetic and phenotypic cellular diversity.

Cancer therapy exerts a strong selection pressure that shapes tumor evolution, yet our knowledge of how tumors change during treatment is limited. Here, we report the analysis of cellular heterogeneity for genetic and phenotypic features and their spatial distribution in breast tumors pre- and post-neoadjuvant chemotherapy. We found that intratumor genetic diversity was tumor-subtype specific, and it did not change during treatment in tumors with partial or no response. However, lower pretreatment genetic diversity was significantly associated with pathologic complete response. In contrast, phenotypic diversity was different between pre- and posttreatment samples. We also observed significant changes in the spatial distribution of cells with distinct genetic and phenotypic features. We used these experimental data to develop a stochastic computational model to infer tumor growth patterns and evolutionary dynamics. Our results highlight the importance of integrated analysis of genotypes and phenotypes of single cells in intact tissues to predict tumor evolution.

Substance P autocrine signaling contributes to persistent HER2 activation that drives malignant progression and drug resistance in breast cancer.

ERBB receptor transmodulation by heterologous G-protein-coupled receptors (GPCR) generates functional diversity in signal transduction. Tachykinins are neuropeptides and proinflammatory cytokines that promote cell survival and cancer progression by activating several GPCRs. In this work, we found that the pain-associated tachykinin Substance P (SP) contributes to persistent transmodulation of the ERBB receptors, EGFR and HER2, in breast cancer, acting to enhance malignancy and therapeutic resistance. SP and its high-affinity receptor NK-1R were highly expressed in HER2(+) primary breast tumors (relative to the luminal and triple-negative subtypes) and were overall correlated with poor prognosis factors. In breast cancer cell lines and primary cultures derived from breast cancer samples, we found that SP could activate HER2. Conversely, RNA interference-mediated attenuation of NK-1R, or its chemical inhibition, or suppression of overall GPCR-mediated signaling, all strongly decreased steady-state expression of EGFR and HER2, establishing that their basal activity relied upon transdirectional activation by GPCR. Thus, SP exposure affected cellular responses to anti-ERBB therapies. Our work reveals an important oncogenic cooperation between NK-1R and HER2, thereby adding a novel link between inflammation and cancer progression that may be targetable by SP antagonists that have been clinically explored.