Diferencias en las respuestas fisiológicas entre triatletas masculinos y femeninos

Los objetivos de este estudio fueron analizar las diferencias entre triatletas masculinos y femeninos amateurs en el rendimiento en un test incremental máximo y en una competición simulada y describir si existe asociación entre el rendimiento en el test máximo incremental y la prueba simulada de competición. Un total de catorce triatletas recreacionales, 8 mujeres (35,0  8,1  años; 166,8  7,2  cm; 69,4  14,6 kg; 24,7  3,2 kg.m-2) y 6 hombres (47,7  14,3  años; 179,9  8,6  cm; 77,8  5,8  kg; 24,0  1,3 kg.m-2) realizaron un test incremental máximo y en una competición simulada (20 km bici y 5 km carrera a pie). A pesar de que no se observaron diferencias significativas entre el grupo masculino y femenino en el test máximo incremental, a efectos prácticos, el grupo masculino obtuvo valores mayores para VO2max, Pmax, PVT1, PVT2 y VO2VT2 (p > 0,05, ES = -0,8 a -1.9, alto). Con respecto a la competición simulada, si bien no se obtuvieron diferencias en función de sexo en los 5 km de carrera, el grupo femenino obtuvo valores significativamente inferiores para las variables velocidad (media y máxima) (p < 0,05 y p < 0,01, ES = -1,3- -4,1, alto) y potencia (media y máxima) (p < 0,01, ES = -2.4- -2.8, alto) durante los 20 km de ciclismo, así como un tiempo de ejecución del sector ciclista significativamente mayor que el grupo masculino (p < 0,01, ES = 1,6, alto).  Por otro lado, un mejor rendimiento durante el test máximo incremental se asoció a un mejor rendimiento durante los 20 km de ciclismo en el grupo masculino (r = 0,848, p < 0,05), mientras que en el grupo femenino se asoció tanto a los 20 km en bici como a los 5 km corriendo (r = -0,714 a -0,822, p < 0,05). Los resultados obtenidos en el estudio ponen de manifiesto que los triatletas masculinos tienen un mejor rendimiento en un test incremental máximo y en el sector bici en una competición simulada y que la asociación entre el rendimiento en un test incremental y el rendimiento en los sectores de la prueba simulada depende del sexo.

Alterations in PTEN and ESR1 promote clinical resistance to alpelisib plus aromatase inhibitors

Alpelisib is a selective inhibitor of PI3Kα, shown to improve outcomes for PIK3CA mutant, hormone receptor positive (HR+) metastatic breast cancers (MBC) when combined with antiestrogen therapy. To uncover mechanisms of resistance, we conducted a detailed, longitudinal analysis of tumor and plasma circulating tumor DNA among such patients from a phase I/II trial combining alpelisib with an aromatase inhibitor (AI) (NCT01870505). The trial's primary objective was to establish safety with maculopapular rash emerging as the most common grade 3 adverse event (33%). Among 44 evaluable patients, the observed clinical benefit rate was 52%. Correlating genetic alterations with outcome, we identified loss-of-function PTEN mutations in 25% of patients with resistance. ESR1 activating mutations also expanded in number and allele fraction during treatment and were associated with resistance. These data indicate that genomic alterations that mediate resistance to alpelisib or antiestrogen may promote disease progression and highlight PTEN loss as a recurrent mechanism of resistance to PI3Kα inhibition.

Abstract P4-05-11: Methylation profiling of mucinous breast cancer

Introduction: Mucinous carcinoma of the breast (MCB) is a rare histologic form of estrogen receptor (ER)-positive/HER2-negative breast cancer characterized by tumor cells floating in lakes of mucin. As compared to invasive ductal carcinoma of no special type (IDC-NST), we have recently shown that MCBs harbor a lower frequency of PIK3CA mutations and lack concurrent 1q gains and 16q losses, hallmark genetic alterations of ER-positive breast cancer. Despite their distinctive phenotype and previous efforts to characterize their genomic landscape by whole-genome, whole-exome and RNA-sequencing, no pathognomonic somatic mutation or fusion gene underpinning MCBs or the mucinous phenotype have been identified. In this study we sought to determine whether MCBs would be defined by specific epigenetic changes.

Materials and methods: Thirty-six MCBs were subjected to DNA methylation profiling using Infinium MethylationEPIC arrays. Following quantile normalization, low quality probe filtering, and data background and dye bias correction using the ‘noob’ algorithm, methylation profiling data of MCBs were compared to those of ER-positive/HER2-negative IDC-NSTs from The Cancer Genome Atlas (TCGA) lacking concurrent 1q gains/16q losses or PIK3CA hotspot mutations and matched according to age and menopausal status at a 1:2 ratio (n=72). An enrichment analysis of the differentially methylated targets in gene promoters and enhancers was conducted using Minfi and MethylGSEA R packages. A subset of 12 MCBs of this cohort was subjected to RNA-sequencing and compared to age, menopausal status and molecular features-matched ER-positive/HER2-negative IDC-NSTs from TCGA (1:2 ratio; n=24) using gene set enrichment analysis (GSEA).

Results: Enrichment analysis of differentially methylated probes revealed a significant enrichment of targets in promoters and enhancers of mucin-encoding genes and in genes of the mTOR signaling pathway between MCBs and matched IDC-NSTs from TCGA (P&lt;0.01). Compared to matched IDC-NSTs, MCBs displayed promoter/enhancer hypomethylation of mucin-encoding genes, such as MUC1, MUC2 and MUCL1. We also observed promoter/enhancer hypomethylation of mTOR signaling pathway genes including MTOR, which encodes for the catalytic subunit of the mTORC complex, RPTOR, which codes for an mTOR binding protein that positively regulates the downstream effector S6 Kinase 1, EIF4E and EIF4B, key downstream effectors of the mTOR signaling pathway, and the oncogenes PIK3R2 and PIK3R3, which encode for regulatory isoforms of PI3K, in MCBs. Our gene expression analysis revealed that the mucin-encoding genes MUC1, MUC2 and MUCL1, and the mTOR signaling genes MTOR, RPTOR, EIF4E, EPIF4B, PIK3R1 and PIK3R2, found to be hypomethylated in MCBs, displayed a significantly higher gene expression in MCBs (P&lt;0.001, each) compared to clinically and molecularly matched IDC-NSTs.

Conclusions: Taken together, our data suggest that MCBs display a high expression of mucin-encoding genes, due to hypomethylation of promoters and enhancers and could provide the basis for their distinctive phenotype. Moreover, our findings suggest that despite the lack of genetic alterations affecting genes of the PI3K/mTOR signaling pathway in MCBs, mTOR signaling might be constitutively active in these tumors via epigenetic mechanisms, supporting the notion that, in the absence of pathognomonic genetic alterations, a disruption of the epigenetic landscape is a critical driver in the development of this rare breast cancer type.

Citation Format: Fresia Pareja, Lorenzo Ferrando, Edaise M da Silva, Arnaud Da Cruz Paula, Anthe Stylianou, David N Brown, Pier Selenica, Jonathan Serrano, Hannah Y Wen, Hong Zhang, Edi Brogi, Larry Norton, Matjia Snuderl, Jorge S Reis-Filho, Britta Weigelt. Methylation profiling of mucinous breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-05-11.

Abstract P2-10-01: The genomic landscape of breast cancer in African American women

Background: According to several estimates, African American women are 40% more likely to die from breast cancer than white women in the United States. Proposed explanations for this disparity include differential socioeconomic factors and access to care, however some studies have raised the possibility that variation in tumor biology is a contributing factor.

Methods: We prospectively sequenced primary and metastatic breast cancer tumors and their matched normal DNA using the MSK-IMPACT assay. We performed gene enrichment analyses to identify the oncogenic mutations and copy number alterations that were more frequent in patients who self-identified as African American or black (AA/B) compared with patients who self-identified as non-Hispanic white (NHW). Detailed clinicopathologic variables were collected for the full cohort. Mann-Whitney U test, Fisher’s exact test, and multivariate binomial regression models were used for statistical analyses.

Results: Genomic profiling was performed on 339 tumors from 301 AA/B patients (44.6% metastatic), and 2,607 tumors from 2,248 NHW patients (48.5% metastatic). Age of AA/B and NHW patients at diagnosis was similar (51.5 vs. 52.8 years, p = 0.065). However, AA/B patients were more likely to be pre- or peri-menopausal at diagnosis (51.6 vs. 44%, p = 0.013), have triple-negative disease (26.5 vs. 13%, p &lt; 0.001), and have higher stage at diagnosis (p = 0.024). Of note, invasive lobular carcinomas were significantly less frequent in AA/B patients compared to NHW (5.9 vs. 14.5%; p &lt; 0.001), a trend that persisted when controlling for receptor subtype. In the unadjusted analysis, AA/B women were more likely to have TP53 mutations (53.4 vs. 36.5%; q &lt; 0.01) and NF1 loss of function mutations (9.9% vs. 3.7%; q &lt; 0.01), and less likely to have CDH1 mutations (6.3% vs. 15.4%; q &lt; 0.01) and PIK3CA mutations (25.7 vs. 35.6%, q = 0.017). However, in a multivariate analysis adjusted for receptor subtype, histology, and sample type (primary vs. metastatic), NF1 was the only gene found to be more commonly mutated in AA/B women (odds ratio: 2.84; 95% CI: 1.73 - 4.08, q &lt; 0.01). Focusing specifically on ER+/HER2- disease, AA/B women were more likely to have mutations in TP53 (31.6% vs. 24.6%), NF1 (7.7% vs. 3.1%) and FGFR1 amplification (21.4% vs. 13.1%), and less likely to have mutations in CDH1 (9.2% vs. 18.8%) or PIK3CA (29.6% vs. 39.6%), however these results did not retain statistical significance when adjusted for multiple comparisons. In triple-negative breast cancer patients, TP53 was mutated at equal rates in AA/B and NHW patients (88.9% vs. 85.9%; p = 0.59), and there was a numerically higher frequency of NF1 mutations in AA/B patients (11.1% vs. 5%). There was no significant difference in tumor mutational burden between AA/B and NHW women (4.24 vs. 4.87; p = 0.19), and no difference in the frequency of microsatellite instability (defined as MSISensor score &gt; 10, 0.9% vs. 0.5%; p = 0.44).

Conclusions: In this large clinico-genomic analysis, as previously reported, AA/B patients were more likely to have the clinical hallmarks of aggressive disease, as defined by triple-negative subtype, higher stage, and premenopausal status at diagnosis. Our analysis demonstrated trends towards enrichment for some of the genomic alterations previously identified to be associated with poor outcome in the AA/B population, however, after controlling for the aforementioned clinical factors, breast cancer in AA/B did not differ significantly from breast cancer in NHW in terms of their driver genomic alterations, MSI or tumor mutation burden. Further studies are required to fully characterize the genomics of breast cancer in AA/B women, which may play a role in larger efforts to equalize the disparities observed in this population.

Citation Format: Cristian Serna-Tamayo, Joshua Z Drago, Carlos Dos Anjos, Joshua Herbert, Fresia Pareja, Shanu Modi, Komal Jhaveri, Chau Dang, David B Solit, Larry Norton, Mauricio Scaltriti, Jorge S Reis-Filho, Sarat Chandarlapaty, Mark E. Robson, Pedram Razavi. The genomic landscape of breast cancer in African American women [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-10-01.

Abstract GS3-08: Multiplatform analysis of matched primary and metastatic breast tumors from the AURORA US Network

Background: It has become increasingly clear that effective treatment of metastatic breast cancer (MBC) requires an in-depth understanding of the molecular differences between primary tumors and metastases. The AURORA US Network was established to collect primary breast cancer-metastasis pairs for multi-platform genomic profiling in order to identify the molecular drivers of metastatic disease. AURORA US has both a retrospective and prospective phase. This is the first report of the retrospective phase.

Methods: Archived tissue samples from the primary tumor and at least one distant metastasis were retrospectively collected from 83 MBC patients. Following internal quality assessment, samples from 55 pts, including 105 distinct metastatic lesions, were subject to DNA low pass whole genome and exome sequencing, DNA methylation arrays, and RNA sequencing. Early analyses of these multi-platform data include: DNA methylation, tumor gene expression and microenvironmental signatures, somatic and germline variants, DNA copy number changes, and structural variants between breast primaries and matched metastases.

Results: Median age at diagnosis was 49 years (25-76); 32 (58%) were Stage I or II at presentation, 27 (49%) had a family history of breast cancer, and 20 (36%) had a second breast primary. Median disease-free interval before developing MBC was 2 years (range 0-36, 5 patients presented with Stage IV). Median overall survival from initial presentation was 4 years (range 0-37). Median survival after developing MBC was 1 year (range 0-13), with a median of three treatments. Primary tissue samples were banked from 1977-2017 and metastases were banked from 1999-2017. Clinical phenotypes of the primaries included 27 HR+ (49%), 15 triple negative (TNBC, 27%), and 11 HER2+ (20%, 12 missing HER2 status). Intrinsic subtype distribution of the primaries included 17 Basal-like (31%), 17 Luminal A (31%), 7 Normal-like (13%), 5 HER2-enriched (9%), and 1 Luminal B, with 8 pending. All metastases from the Basal-like cases remained Basal-like, while metastases from luminal primaries tended to gain HER2-Enriched subtype features (5/18, p = 0.01). Overall, we identified significant metastasis-enriched alterations in metabolism pathways, an increase in proliferation, and the loss of differentiation signatures and immune infiltrates with progression; the latter being the most pronounced in brain metastases. The most frequent somatic mutations in this cohort were in TP53, NCOR1, and RUNX1. Interestingly, ERBB2, EGFR, and ATM were also mutated in ≥10% of the tumors sequenced. In almost all cases, CpG island hypermethylation was clonally present in the primary tumor and persisted stably in the majority of metastatic lesions. Promoter CpG island hypermethylation was also identified in some metastatic lesions at JAM3, an important cellular adhesion molecule,and this was accompanied by reduced mRNA expression.

CONCLUSIONS: Collection of banked primary and metastatic tissue pairs identified a young MBC cohort with a high frequency of breast cancer family history and second breast primaries. Molecular characterization of luminal tumor pairs highlighted acquisition of aggressive traits including increased proliferation and loss of differentiation in the metastases. In contrast, basal-like pairs remained relatively unchanged, except for the loss of immune activation. Ongoing analyses to be presented include clonal heterogeneity and phylogeny, novel metastasis signature discovery, gene fusion, and endogenous retrovirus detection.

Citation Format: Tari A King, Minetta C Liu, Marni B McClure, Toshinori Hinoue, Benjamin J Kelly, Chad J Creighton, Jay Bowen, Kristen Leraas, Robyn T Burns, Sara Coppens, Salma Rezk, Amy L Garrett, Justin M Balko, Joel S Parker, Ben H Park, Ian Krop, Carey Anders, Katherine A Hoadley, Julie Gastier-Foster, Mothaffar F Rimawi, Rita Nanda, Nancy U Lin, Claudine Isaacs, P. Kelly Marcom, Anna Maria Storniolo, Fergus J Couch, Elaine R Mardis, Adrian V Lee, Uma Chandran, Peter W Laird, Susan G Hilsenbeck, Larry Norton, Andrea L Richardson, W. Fraser Symmans, Lisa A Carey, Antonio C Wolff, Nancy E Davidson, Charles M Perou, the AURORA US Network. Multiplatform analysis of matched primary and metastatic breast tumors from the AURORA US Network [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr GS3-08.

Abstract OT1-01-04: A randomized phase 2 study of peri-operative ipilimumab, nivolumab and cryoablation versus standard care in women with residual, early stage/resectable, triple negative breast cancer after standard-of-care neoadjuvant chemotherapy

Background: Local tumor destruction with cryoablation (cryo) induces inflammation and releases antigens that can activate tumor-specific immune responses. Pre-clinically, cryo with checkpoint inhibition augmented tumor-specific immune responses and prevented recurrence. Clinically, we established that peri-operative (peri-op) cryo with ipilimumab (ipi) +/- nivolumab (nivo) was not only safe in patients (pts) with operable, early stage breast cancer (ESBC) but also generated robust intra-tumoral and systemic immune responses. In this randomized phase 2 study, we evaluate the disease specific impact of peri-op ipi/nivo/cryo versus standard care in women with residual triple negative breast cancer (TNBC) after neoadjuvant chemotherapy (NAC), a subset at high risk of early relapse.

Methods: Eligible pts are ≥18y, with ER &lt;10%, PR &lt;10%, HER2 negative (per ASCO/CAP definition), ≥ 1.0 cm, residual operable disease after taxane-based NAC. Approximately 160 pts will be randomized to one of two arms: breast surgery (control arm) or ipi/nivo/cryo followed by breast surgery and adjuvant nivo (intervention arm). Pts in the intervention arm will undergo percutaneous, image-guided cryo with concurrent research core biopsy 7-10 days prior to surgery and will receive ipi (1mg/kg IV) with nivo (240mg IV) 1 to 5 days prior to cryo. After surgery, pts will receive 3 additional doses of nivo at 240mg IV Q2 weeks. Adjuvant capecitabine is recommended for all patients per local standard-of-care. Patients will be stratified by NAC platinum administration, NAC anthracycline administration, and clinical nodal status (positive versus negative). The primary endpoint is 3-year Event Free Survival (EFS). Secondary endpoints include Invasive Disease-Free Survival (IDFS), Distant Disease-Free Survival (DDFS), overall survival (OS) and safety. Exploratory correlative studies will be performed on tumor and serum to characterize the immunologic impact of the intervention and to explore predictors of efficacy and toxicity.

Citation Format: Heather McArthur, Elizabeth Comen, Yolanda Bryce, Stephen B Solomon, Jorge Leal, Micaela Rodine, Christina DiLauro Abaya, Sujita Patil, David Page, Larry Norton. A randomized phase 2 study of peri-operative ipilimumab, nivolumab and cryoablation versus standard care in women with residual, early stage/resectable, triple negative breast cancer after standard-of-care neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-01-04.

Paradigms for Precision Medicine in Epichaperome Cancer Therapy

Alterations in protein-protein interaction networks are at the core of malignant transformation but have yet to be translated into appropriate diagnostic tools. We make use of the kinetic selectivity properties of an imaging probe to visualize and measure the epichaperome, a pathologic protein-protein interaction network. We are able to assay and image epichaperome networks in cancer and their engagement by inhibitor in patients' tumors at single-lesion resolution in real time, and demonstrate that quantitative evaluation at the level of individual tumors can be used to optimize dose and schedule selection. We thus provide preclinical and clinical evidence in the use of this theranostic platform for precision medicine targeting of the aberrant properties of protein networks.

Efficacy and Safety of Gemcitabine With Trastuzumab and Pertuzumab After Prior Pertuzumab-Based Therapy Among Patients With Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer: A Phase 2 Clinical Trial

IMPORTANCE

Taxanes with trastuzumab and pertuzumab for initial treatment of human epidermal growth factor receptor 2 (ERBB2, formerly HER2)-positive metastatic breast cancer is associated with improved progression-free survival (PFS) and overall survival. While continued use of trastuzumab in therapeutic combinations after disease progression is standard, the efficacy of continuing pertuzumab is unknown.

OBJECTIVE

To evaluate the efficacy and safety of pertuzumab in combination with gemcitabine and trastuzumab after prior treatment with pertuzumab for ERBB2-positive metastatic breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This is a phase 2 single-arm clinical trial of dual anti-ERBB2 therapy after prior treatment with pertuzumab. The study took place at a single academic center from March 2015 to April 2017 among women with ERBB2-positive metastatic breast cancer, prior pertuzumab-based treatment, and 3 or fewer prior chemotherapy regimens. Data were analyzed between January 2019 and March 2019.

INTERVENTION

Treatment consisted of gemcitabine, 1200 mg/m2 (later amended to 1000 mg/m2) on days 1 and 8 every 3 weeks, plus trastuzumab (8-mg/kg loading dose, then 6 mg/kg) and pertuzumab (840-mg loading dose, then 420 mg) once every 3 weeks.

MAIN OUTCOMES AND MEASURES

The primary end point was 3-month PFS. Based on prior trials, a target rate of 70% or higher was selected as the promising progression-free rate at 3 months. Secondary outcomes included safety, tolerability, and overall survival.

RESULTS

A total of 45 patients (median [range] age, 57.1 [31.7-77.2] years) were enrolled; 22 (49%) were treated in the second-line setting, and 23 (51%) were treated in the third-line setting or beyond. Of these, 22 (49%) received prior trastuzumab emtansine (T-DM1). At a median (range) follow-up of 27.6 (8.3-36.0) months, 3-month PFS was 73.3% (95% CI, 61.5%-87.5%). Overall, median PFS was 5.5 months (95% CI, 5.4-8.2 months). Treatment was well tolerated, with no occurrences of febrile neutropenia or symptomatic left ventricular systolic dysfunction.

CONCLUSIONS AND RELEVANCE

In this phase 2 trial, treatment with gemcitabine, trastuzumab, and pertuzumab after prior pertuzumab-based therapy for ERBB2-positive metastatic breast cancer was associated with a 3-month PFS rate of 73.3% and was well tolerated. Continuation of pertuzumab beyond progression was associated with apparent clinical benefit.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02252887.

Impact of the 2018 American Society of Clinical Oncology/College of American Pathologists HER2 Guideline Updates on HER2 Assessment in Breast Cancer With Equivocal HER2 Immunohistochemistry Results With Focus on Cases With HER2/CEP17 Ratio <2.0 and Average HER2 Copy Number ≥4.0 and <6.0

CONTEXT.—

The American Society of Clinical Oncology/College of American Pathologists HER2 testing guideline in breast cancer was updated in 2018 to address issues on interpretation of uncommon results using dual-probe in situ hybridization according to the 2013 guideline.

OBJECTIVE.—

To assess impact of the 2018 guideline on breast cancer with equivocal HER2 immunohistochemistry results.

DESIGN.—

We retrospectively reviewed HER2 fluorescence in situ hybridization (FISH) data (HER2/CEP17 ratio and average HER2 copy number per cell) of HER2 immunohistochemistry-equivocal (2+ or 1+ to 2+) breast cancers at our center between January 2014 and May 2018 and compared HER2 FISH results according to 2013 and 2018 guidelines.

RESULTS.—

A total of 1666 HER2 FISH results from 1421 patients with equivocal HER2 immunohistochemistry were reviewed. Based on the 2013 guideline, HER2 FISH results were amplified in 346 cases (20.8%), equivocal in 242 (14.5%), and nonamplified in 1078 (64.7%). Using the 2018 guideline, 258 cases (16%) were reclassified, including 242 previously equivocal test results (15%) and 16 previously positive results (1%) reclassified as negative. The subset of 2013 HER2-equivocal and 2018 HER2-nonamplified cases with HER2/CEP17 ratio lower than 2.0 and average HER2 copy number 4.0 or higher and lower than 6.0 showed higher incidence of micropapillary morphology compared with HER2-amplified cases. Despite most patients in this group not receiving HER2-targeted treatment, 96% had no evidence of disease at follow-up.

CONCLUSIONS.—

The 2018 guideline eliminated HER2 FISH-equivocal cases by reclassifying HER2-equivocal cases and cases with nonclassical amplification without HER2 overexpression as HER2 negative. As a consequence, we observed a considerable increase in HER2 FISH-negative cases and a slight decrease in HER2 FISH-positive cases.

A Small-Molecule Pan-Id Antagonist Inhibits Pathologic Ocular Neovascularization

Id helix-loop-helix (HLH) proteins (Id1-4) bind E protein bHLH transcription factors, preventing them from forming active transcription complexes that drive changes in cell states. Id proteins are primarily expressed during development to inhibit differentiation, but they become re-expressed in adult tissues in diseases of the vasculature and cancer. We show that the genetic loss of Id1/Id3 reduces ocular neovascularization in mouse models of wet age-related macular degeneration (AMD) and retinopathy of prematurity (ROP). An in silico screen identifies AGX51, a small-molecule Id antagonist. AGX51 inhibits the Id1-E47 interaction, leading to ubiquitin-mediated degradation of Ids, cell growth arrest, and reduced viability. AGX51 is well-tolerated in mice and phenocopies the genetic loss of Id expression in AMD and ROP models by inhibiting retinal neovascularization. Thus, AGX51 is a first-in-class compound that antagonizes an interaction formerly considered undruggable and that may have utility in the management of multiple diseases.

Homologous recombination DNA repair defects in PALB2-associated breast cancers

Mono-allelic germline pathogenic variants in the Partner And Localizer of BRCA2 (PALB2) gene predispose to a high-risk of breast cancer development, consistent with the role of PALB2 in homologous recombination (HR) DNA repair. Here, we sought to define the repertoire of somatic genetic alterations in PALB2-associated breast cancers (BCs), and whether PALB2-associated BCs display bi-allelic inactivation of PALB2 and/or genomic features of HR-deficiency (HRD). Twenty-four breast cancer patients with pathogenic PALB2 germline mutations were analyzed by whole-exome sequencing (WES, n = 16) or targeted capture massively parallel sequencing (410 cancer genes, n = 8). Somatic genetic alterations, loss of heterozygosity (LOH) of the PALB2 wild-type allele, large-scale state transitions (LSTs) and mutational signatures were defined. PALB2-associated BCs were found to be heterogeneous at the genetic level, with PIK3CA (29%), PALB2 (21%), TP53 (21%), and NOTCH3 (17%) being the genes most frequently affected by somatic mutations. Bi-allelic PALB2 inactivation was found in 16 of the 24 cases (67%), either through LOH (n = 11) or second somatic mutations (n = 5) of the wild-type allele. High LST scores were found in all 12 PALB2-associated BCs with bi-allelic PALB2 inactivation sequenced by WES, of which eight displayed the HRD-related mutational signature 3. In addition, bi-allelic inactivation of PALB2 was significantly associated with high LST scores. Our findings suggest that the identification of bi-allelic PALB2 inactivation in PALB2-associated BCs is required for the personalization of HR-directed therapies, such as platinum salts and/or PARP inhibitors, as the vast majority of PALB2-associated BCs without PALB2 bi-allelic inactivation lack genomic features of HRD.

Randomized Trial of Standard Adjuvant Chemotherapy Regimens Versus Capecitabine in Older Women With Early Breast Cancer: 10-Year Update of the CALGB 49907 Trial

PURPOSE

Older women with breast cancer remain under-represented in clinical trials. The Cancer and Leukemia Group B 49907 trial focused on women age 65 years and older. We previously reported the primary analysis after a median follow-up of 2.4 years. Standard adjuvant chemotherapy showed significant improvements in recurrence-free survival (RFS) and overall survival compared with capecitabine. We now update results at a median follow-up of 11.4 years.

PATIENTS AND METHODS

Patients age 65 years or older with early breast cancer were randomly assigned to either standard adjuvant chemotherapy (physician's choice of either cyclophosphamide, methotrexate, and fluorouracil or cyclophosphamide and doxorubicin) or capecitabine. An adaptive Bayesian design was used to determine sample size and test noninferiority of capecitabine. The primary end point was RFS.

RESULTS

The design stopped accrual with 633 patients at its first sample size assessment. RFS remains significantly longer for patients treated with standard chemotherapy. At 10 years, in patients treated with standard chemotherapy versus capecitabine, the RFS rates were 56% and 50%, respectively (hazard ratio [HR], 0.80; P = .03); breast cancer-specific survival rates were 88% and 82%, respectively (HR, 0.62; P = .03); and overall survival rates were 62% and 56%, respectively (HR, 0.84; P = .16). With longer follow-up, standard chemotherapy remains superior to capecitabine among hormone receptor-negative patients (HR, 0.66; P = .02), but not among hormone receptor-positive patients (HR, 0.89; P = .43). Overall, 43.9% of patients have died (13.1% from breast cancer, 16.4% from causes other than breast cancer, and 14.1% from unknown causes). Second nonbreast cancers occurred in 14.1% of patients.

CONCLUSION

With longer follow-up, RFS remains superior for standard adjuvant chemotherapy versus capecitabine, especially in patients with hormone receptor-negative disease. Competing risks in this older population dilute overall survival benefits.

Phase I Study of Intermittent High-Dose Lapatinib Alternating with Capecitabine for HER2-Positive Breast Cancer Patients with Central Nervous System Metastases

PURPOSE

Lapatinib and capecitabine cross the blood-tumor barrier in breast cancer brain metastasis but have modest clinical efficacy. Administration of high-dose tyrosine kinase inhibitor has been evaluated in brain metastases and primary brain tumors as a strategy to improve drug exposure in the central nervous system (CNS). We derived a rational drug scheduling of intermittent high-dose lapatinib alternating with capecitabine based on our preclinical data and Norton-Simon mathematical modeling. We tested this intermittent, sequential drug schedule in patients with breast cancer with CNS metastasis.

PATIENTS AND METHODS

We conducted a phase I trial using an accelerated dose escalation design in patients with HER2-positive (HER2+) breast cancer with CNS metastasis. Lapatinib was given on day 1-3 and day 15-17 with capecitabine on day 8-14 and day 22-28 on an every 28-day cycle. Lapatinib dose was escalated, and capecitabine given as a flat dose at 1,500 mg BID. Toxicity and efficacy were evaluated.

RESULTS

Eleven patients were enrolled: brain only (4 patients, 36%), leptomeningeal (5 patients, 45%), and intramedullary spinal cord (2 patients, 18%). Grade 3 nausea and vomiting were dose-limiting toxicities. The MTD of lapatinib was 1,500 mg BID. Three patients remained on therapy for greater than 6 months.

CONCLUSIONS

High-dose lapatinib is tolerable when given intermittently and sequentially with capecitabine. Antitumor activity was noted in both CNS and non-CNS sites of disease. This novel administration regimen is feasible and efficacious in patients with HER2+ breast cancer with CNS metastasis and warrants further investigation.

Abstract 1993: Gluthathione peroxidase 2 downregulation in the PyMT mammary tumor model leads to an aggressive phenotype due to stimulation of angiogenesis and tumor stemness via HIF1 alpha signaling

Breast tumors are known to undergo high levels of mitochondrial oxidative phosphorylation leading to accumulation of reactive oxygen species (ROS), which in turn potentiate cancer stem cells and chemoresistance. This was shown to be due to HIF1α stabilization by ROS; however, the signaling events downstream of HIF1α regulating the cancer stem cell (CSC) phenotype remain unknown. Kaplan Meier survival curves upon the gene profiling database of breast cancer patients showed that reduced levels of the ROS scavenging enzyme, glutathione peroxidase 2 (GPx2) in breast cancers was associated with shorter patient survival duration. Consistent with this idea, we found that GPx2 was downregulated in metastatic mammary tumor cells, suggesting GPx2 loss enhances metastasis. Indeed, GPx2 knockdown in poorly metastatic cells increased ROS production, shortened tumor latency, and stimulated dramatic mammary tumor growth and metastasis. These effects were associated with marked increases in angiogenesis, CSC-like properties, and chemoresistance. Here, we show that GPx2 downregulation in mammary epithelial cells increases ROS production and HIF1α stabilization which were accompanied by VEGF upregulation and enhanced angiogenesis. On the other hand, GPx2 loss caused dramatic mammosphere formation and resistance to doxorubicin, implying effects on stemness leading to chemoresistance. These data suggest that GPx2 loss is a critical event that drives mammary tumorigenesis and metastasis via HIF1α signaling leading to stimulation of angiogenesis and stemness properties. Understanding the ramifications of GPx2 loss in breast cancer will allow us to identify key regulators of stemness and chemoresistance, with the goal of identifying novel drug targets in metastasis.

Citation Format: Zuen Ren, Huizhi Liang, Outhiriaradjou Benard, Kimita Suyama, Joseph M. Albanese, Larry Norton, Wei Zheng, Rachel B. Hazan. Gluthathione peroxidase 2 downregulation in the PyMT mammary tumor model leads to an aggressive phenotype due to stimulation of angiogenesis and tumor stemness via HIF1 alpha signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1993.

A Tribute to John Mendelsohn: A Pioneer in Targeted Cancer Therapy

Cancer scientists and clinicians are mourning the death of one of the most accomplished members of their community: Dr. John Mendelsohn. He was a pioneer in targeted cancer therapy and was instrumental for the discovery and deployment of the first antagonist epidermal growth factor receptor (EGFR) therapeutic antibodies, broadening the concept of targeted EGFR therapy to encompass other receptor tyrosine kinases, such as HER2, and developing blocking antibody-combination therapy with chemotherapies or radiotherapy. Dr. Mendelsohn, who died on January 7, 2019, always led by the strength of his accomplishments and the humility of his character. Above all, he was a well-revered mentor and clinician, who extended compassion and the gift of his time to patients, colleagues, and mentees alike. In tribute to Dr. Mendelsohn, Cancer Research has invited his former mentees and colleagues who were associated with Dr. Mendelsohn for over three decades to reflect on the broad impact of his work. Here, we discuss Dr. Mendelsohn's illustrious career at three elite academic cancer institutions and hospitals in the United States, his acumen to build, grow, and uplift institutions, and train a generation of medical oncologists, physician scientists, and cancer biologists. His profound legacy on targeted therapy and cancer research and treatment continue to prolong and save the lives of cancer patients globally.

Assessment of Quality of Life and Treatment Outcomes of Patients With Persistent Postchemotherapy Alopecia

Importance

Persistent alopecia occurs in a subset of patients undergoing chemotherapy, yet the quality of life (QOL) of these patients and their response to therapy have not been described in a large patient cohort.

Objective

To characterize the clinical presentation of patients with persistent chemotherapy-induced alopecia (pCIA) or endocrine therapy-induced alopecia after chemotherapy (EIAC) and their QOL and treatment outcomes.

Design, Setting, and Participants

A retrospective multicenter cohort of 192 women with cancer treated with cytotoxic agents who received a clinical diagnosis of persistent alopecia (98 with pCIA and 94 with EIAC) between January 1, 2009, and July 31, 2017, was analyzed. All patients were from the dermatology service in 2 comprehensive cancer centers and 1 tertiary-care hospital. Data on demographics, chemotherapy regimens, severity, clinical patterns, and response to hair-growth promoting agents were assessed. Data from the Hairdex questionnaire were used to assess the QOL of patients with alopecia.

Main Outcomes and Measures

The clinical presentation, response to dermatologic therapy, and QOL of patients with pCIA were assessed and compared with those of patients with EIAC.

Results

A total of 98 women with pCIA (median age, 56.5 years [range, 18-83 years]) and 94 women with EIAC (median age, 56 years [range, 29-84 years]) were included. The most common agents associated with pCIA were taxanes for 80 patients (82%); the most common agents associated with EIAC were aromatase inhibitors for 58 patients (62%). Diffuse alopecia was predominant in patients with pCIA compared with patients with EIAC (31 of 75 [41%] vs 23 of 92 [25%]; P = .04), with greater severity (Common Terminology Criteria for Adverse Events, version 4.0, grade 2) among patients with pCIA (29 of 75 [39%] vs 12 of 92 [13%]; P < .001). A negative emotional effect was reported by both groups. After treatment with topical minoxidil or spironolactone, moderate to significant improvement was observed for 36 of 54 patients with pCIA (67%) and for 32 of 42 patients with EIAC (76%).

Conclusions and Relevance

Persistent chemotherapy-induced alopecia is frequently more severe and diffuse when compared with EIAC, and both groups of patients experienced a negative effect. A modest benefit was observed with dermatologic therapy. Additional studies are warranted to develop effective strategies for prevention and effective therapy for pCIA and EIAC.

Pathologic complete response rate according to HER2 detection methods in HER2-positive breast cancer treated with neoadjuvant systemic therapy

PURPOSE

Human epidermal growth factor receptor 2 (HER2)-positive breast cancers are known to have significant clinical and pathological response to neoadjuvant systemic therapy (NST). The aim of this study was to identify factors associated with pathological complete response (pCR), defined as no residual invasive carcinoma in the breast and axillary lymph nodes (ypT0/is ypN0), among patients with HER2-positive breast cancer and to compare pCR rates between breast cancers with HER2 protein overexpression by immunohistochemistry (IHC) versus HER2 gene amplification by fluorescence in situ hybridization (FISH) in the absence of protein overexpression by IHC.

METHODS

We conducted a retrospective review of HER2-positive breast cancer patients treated with NST and surgery at Memorial Sloan Kettering Cancer Center between January 2013 and May 2018. Estrogen receptor (ER), progesterone receptor (PR), and HER2 status were assessed according to the 2018 ASCO/CAP guidelines.

RESULTS

During the study period, 560 patients were identified. Of 531 patients with IHC results available, 455 patients had HER2 IHC 3+, and 76 had IHC < 3+ but HER2 amplification detected by FISH. The overall pCR rate was 59% (330/560). The pCR rate among patients with HER2 protein overexpression (IHC 3+) was 67%, compared to 17% among patients with HER2 amplification by FISH (IHC < 3+). On univariate and multivariate analyses, HER2 protein overexpression by IHC (IHC 3+) was a significant predictor of pCR, along with grade 3 histology, PR-negative status, and dual anti-HER2 therapy.

CONCLUSION

Although both HER2 IHC and FISH are standard HER2 testing methods in breast cancer, achievement of pCR is associated with HER2 IHC expression level, among other factors.

A large retrospective analysis of CDK 4/6 inhibitor retreatment in ER+ metastatic breast cancer (MBC)

1053

Background: Sequential retreatment with endocrine therapy (ET) has been the clinical paradigm for ER+ MBC due to persistent dependence on hormone signaling. Recently CDK4/6i + ET have improved PFS and are routinely utilized in the first/second- line setting. Whether this paradigm of sequential retreatment holds for CDK 4/6i is unknown. To evaluate the potential benefit of CDK4/6i re-treatment we conducted this retrospective analysis. Methods: We identified ER+/HER2- MBC pts treated with ≥ 2 lines of CDK4/6i at our institution between 2015-2018. We categorized pts based on reason for discontinuation of their first CDK4/6i: cohort 1 – switch to alternate CDK4/6i due to toxicity; cohort 2 – retreatment with same CDK4/6i beyond progression with change of ET and cohort 3- switch to alternate CDK4/6i as monotherapy or with same or another ET. We analyzed pt demographics, imaging reports and time to subsequent therapy (TTST) for every CDK4/6i line for each cohort. If a pt received > 2 lines of CDK4/6i, then that pt was evaluated for every CDK4/6i exposure. Results: 135 pts received ≥ 2 lines of CDK4/6i treatment (Tx). Cohorts 1, 2 and 3 had 23, 43 pts and 84 pts respectively. In Cohort 2, 95% of pts received 2 subsequent CDK 4/6i + ET Tx; 56% had the second CDK4/6i in second-line met setting. TTST1 (1st CDK4/6i Tx) was 9.6m (95% CI 4.9 - 11 m), TTST2 (second CDK4/6i Tx) was 4.5m (95% CI 3.3 – 7.6 m) and 35% had TTST2 ≥ 24 weeks. For Cohort 3, 48% were retreated with a different CDK 4/6i in ≥ fifth-line. 51% received 2 subsequent CDK 4/6i Tx with 18% in second-line met setting. TTST1 was 9.6 m (95% CI 5.9 – 12 m), TTST2 was 4.4 m (95% CI 3.8 – 5.9 m) and 29% had TTST2 ≥ 24 weeks. In cohort 3, 29% (n=24) pts had PD as best response at the time of first CDK4/6i exposure but 29% (7/24) achieved a radiologic response to their second CDK4/6i Tx. Pts had tumor sequencing using MSK-IMPACT which will be correlated with TTST. Conclusions: This large single institution retrospective analysis suggests that retreatment with a CDK4/6i regimen should be evaluated in prospective trials. Additionally, despite PD as best response with the first CDK4/6i (palbociclib/ribociclib) regimen, a subset of pts had radiologic response to a subsequent abemaciclib-containing regimen, which is an hypothesis generating observation.

Preoperative checkpoint inhibition (CPI) and cryoablation (Cryo) in women with early-stage breast cancer (ESBC)

592

Background: Checkpoint inhibition (CPI) combined with local strategies that cause local tumor destruction, such as cryo may augment tumor specific immunity and improve survival. We previously demonstrated in 18 ESBC patients (pts) that pre-operative (pre-op) cryo with ipilimumab (ipi) is not only safe but also generates robust local and systemic immune responses (NCT01502592). Given the added activity of dual CPI in other tumors, we undertook a second pilot study of pre-op ipi/nivolumab (nivo)/cryo to confirm the safety of this combination and the impact on immune biomarkers. Methods: In both pilot studies, eligible pts had operable ≥1.5cm invasive HER2 negative ESBC. CPI was administered 8-15d prior to, and cryo was performed 7-10d prior to, standard-of-care (SOC) surgery. Toxicity evaluation continued for 12wks after drug administration. Blood for immune correlates was obtained at baseline, cryo, surgery and 2-4 weeks thereafter. Tumor samples were obtained at cryo and surgery. Flow-cytometry of peripheral lymphocytes was compared to previously reported ipi/cryo responses. Results: After a median follow-up of 66 months all 18 ESBC ipi/cryo pts, including 3 TNBC pts, are recurrence free. In the ipi/nivo/cryo study, the safety primary endpoint was met when 5 pts underwent SOC surgery without delay. Ipi/nivo/cryo was well tolerated overall. One pt on an aromatase inhibitor had grade 4 liver toxicity 8 weeks after surgery. One pt, 3 weeks after her SOC surgery, developed grade 1 hyperthyroidism, preventing a secondary axillary dissection from proceeding as scheduled. Robust activation of peripheral CD4+ and CD8+ T cells peaked at week 2 post ipi/nivo with the majority of activated CD8+ T cells expressing PD1. Comparing the correlatives of the ipi/nivo/cryo study with the prior ipi/cryo study, we observed higher expression of activation markers (Ki-67, ICOS, CTLA-4, LAG-3) on peripheral T cells and downregulation of suppressor cells. Conclusions: Ipi/cryo-treated pts, including 3 TNBC pts, remain recurrence free after > 5y. Combining cryo with ipi/nivo preop is feasible, safe, and associated with greater T cell activation than ipi/cryo alone. These results informed an ongoing randomized phase 2 study of pre-op ipi/nivo/cryo versus SOC in women with residual TNBC after neoadjuvant chemotherapy (NCT03546686). Clinical trial information: NCT02833233.

Molecular profiling of ER+ metastatic breast cancers to reveal association of genomic alterations with acquired resistance to CDK4/6 inhibitors

1009

Background: Genomic profiling of ER+ metastatic breast cancer (MBC) has revealed highly prevalent genomic alterations (e.g. ESR1, NF1, ERBB2) associated with exposure to antiestrogen therapy and endocrine resistance. It is not known whether any such acquired genomic alterations are observed after exposure to now standard CDK4/6 inhibitors (CDK4/6i). Methods: To identify genomic alterations associated with acquired resistance to CDK4/6i + antiestrogen combinations, we prospectively performed tumor and matched normal sequencing on 1059 ER+ breast cancers from 845 MBC patients collected prior to (n = 838) or post-treatment with CDK4/6i (n = 221), including 110 pre- and post-treatment pairs. We performed gene enrichment analyses to identify the oncogenic mutations and copy number alterations that were more frequent in post-CDK4/6i samples compared to CDK4/6i-naïve samples and further compared these results to those of post-hormone alone therapy datasets. Results: The post-CDK4/6i samples were collected following exposure to CDK4/6i plus aromatase inhibitors (51%), plus fulvestrant (28%), or multiple/other (21%). Along with alterations previously associated with resistance to hormonal therapy alone, our analysis identified multiple genes to be specifically enriched in the post-CDK4/6i tumors. Among these, loss-of-function alterations in RB1 were significantly enriched in the post-CDK4/6i compared to CDK4/6i-naïve samples (7.9% vs. 2.7%, p-value = 1.5e-5). The majority of the RB1 mutations in the post-CDK4/6i tumors had loss of heterozygosity (LOH), while LOH was uncommon in the CDK4/6i-naive tumors. Additionally, multiple alterations in effectors of PI3K/AKT signaling (excluding PIK3CA), cell cycle (such as CDKN2A loss) and in Hippo signaling were more frequent in the post-CDK4/6i tumors. Conclusions: This large clinico-genomic analysis of the post- and pre-CDK4/6i MBCs reveals multiple genomic lesions to be enriched after exposure to CDK4/6i, highlighting therapy-related genomic evolution as a recurrent phenomenon and identifying unique genomic subsets that have strong potential to alter the benefit of subsequent lines of therapies.

The Landscape of Somatic Genetic Alterations in Breast Cancers from CHEK2 Germline Mutation Carriers

Pathogenic germline variants in checkpoint kinase 2 (CHEK2), which plays pivotal roles in DNA damage response and cell cycle regulation, confer an increased breast cancer (BC) risk. Here, we investigated the phenotypic and genomic characteristics of 33 BCs from CHEK2 germline mutation carriers (16 high-risk variants and 17 low-risk p.Ile157Thr variants). CHEK2-associated BCs from patients with high-risk germline variants were largely hormone receptor-positive (87%, 13/15), and 81% (13/16) exhibited loss of heterozygosity (LOH) of the CHEK2 wild-type allele. Conversely, CHEK2-associated BCs from patients with the low-risk p.Ile157Thr variant displayed less-frequent loss of heterozygosity (5/17, 29%) and higher levels of CHEK2 protein expression than those with high-risk germline variants. CHEK2-associated BCs lacked a dominant mutational signature 3, a genomics feature of homologous recombination DNA repair deficiency (HRD). Our findings indicate that CHEK2-associated BCs are generally hormone receptor-positive and lack HRD-related mutational signatures, recapitulating the features of ATM-associated BCs. Specific CHEK2 germline variants may have a distinct impact on tumor biology.

p21CIP1 Promotes Mammary Cancer-Initiating Cells via Activation of Wnt/TCF1/CyclinD1 Signaling

Cancer stem cells (CSC) generate and sustain tumors due to tumor-initiating potential, resulting in recurrence or metastasis. We showed that knockout of the cell-cycle inhibitor, p21CIP1, in the PyMT mammary tumor model inhibits metastasis; however the mechanism remained unknown. Here, we show a pivotal role for p21 in potentiating a cancer stem-like phenotype. p21 knockout in PyMT mammary tumor cells caused dramatic suppression of CSC properties involving tumorsphere formation, ALDH1 activity, and tumor-initiating potential, which were in turn rescued by p21 overexpression into PyMT/p21 knockout cells. Interestingly, p21 knockout dramatically suppresses Wnt/β-catenin signaling activity, leading to striking inhibition of LEF1 and TCF1 expression. TCF1 knockdown in PyMT cells suppressed tumorsphere formation due to Cyclin D1 attenuation. These data demonstrate that p21 promotes a CSC-like phenotype via activation of Wnt/TCF1/Cyclin D1 signaling. IMPLICATIONS: p21 is a strong promoter of mammary CSCs.

Increasing the dose intensity of chemotherapy by more frequent administration or sequential scheduling: a patient-level meta-analysis of 37 298 women with early breast cancer in 26 randomised trials

BACKGROUND

Increasing the dose intensity of cytotoxic therapy by shortening the intervals between cycles, or by giving individual drugs sequentially at full dose rather than in lower-dose concurrent treatment schedules, might enhance efficacy.

METHODS

To clarify the relative benefits and risks of dose-intense and standard-schedule chemotherapy in early breast cancer, we did an individual patient-level meta-analysis of trials comparing 2-weekly versus standard 3-weekly schedules, and of trials comparing sequential versus concurrent administration of anthracycline and taxane chemotherapy. The primary outcomes were recurrence and breast cancer mortality. Standard intention-to-treat log-rank analyses, stratified by age, nodal status, and trial, yielded dose-intense versus standard-schedule first-event rate ratios (RRs).

FINDINGS

Individual patient data were provided for 26 of 33 relevant trials identified, comprising 37 298 (93%) of 40 070 women randomised. Most women were aged younger than 70 years and had node-positive disease. Total cytotoxic drug usage was broadly comparable in the two treatment arms; colony-stimulating factor was generally used in the more dose-intense arm. Combining data from all 26 trials, fewer breast cancer recurrences were seen with dose-intense than with standard-schedule chemotherapy (10-year recurrence risk 28·0% vs 31·4%; RR 0·86, 95% CI 0·82-0·89; p<0·0001). 10-year breast cancer mortality was similarly reduced (18·9% vs 21·3%; RR 0·87, 95% CI 0·83-0·92; p<0·0001), as was all-cause mortality (22·1% vs 24·8%; RR 0·87, 95% CI 0·83-0·91; p<0·0001). Death without recurrence was, if anything, lower with dose-intense than with standard-schedule chemotherapy (10-year risk 4·1% vs 4·6%; RR 0·88, 95% CI 0·78-0·99; p=0·034). Recurrence reductions were similar in the seven trials (n=10 004) that compared 2-weekly chemotherapy with the same chemotherapy given 3-weekly (10-year risk 24·0% vs 28·3%; RR 0·83, 95% CI 0·76-0·91; p<0·0001), in the six trials (n=11 028) of sequential versus concurrent anthracycline plus taxane chemotherapy (28·1% vs 31·3%; RR 0·87, 95% CI 0·80-0·94; p=0·0006), and in the six trials (n=6532) testing both shorter intervals and sequential administration (30·4% vs 35·0%; RR 0·82, 95% CI 0·74-0·90; p<0·0001). The proportional reductions in recurrence with dose-intense chemotherapy were similar and highly significant (p<0·0001) in oestrogen receptor (ER)-positive and ER-negative disease and did not differ significantly by other patient or tumour characteristics.

INTERPRETATION

Increasing the dose intensity of adjuvant chemotherapy by shortening the interval between treatment cycles, or by giving individual drugs sequentially rather than giving the same drugs concurrently, moderately reduces the 10-year risk of recurrence and death from breast cancer without increasing mortality from other causes.

FUNDING

Cancer Research UK, Medical Research Council.

Abstract OT2-06-05: A randomized phase II study of peri-operative ipilimumab, nivolumab and cryoablation versus standard peri-operative care in women with residual triple negative early stage/resectable breast cancer after standard-of-care neoadjuvant chemotherapy

Background: Triple negative breast cancer (TNBC) is a biologically distinct subtype with high risk of early relapse, particularly for patients who do not achieve a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC), with an event free survival of &lt; 60% at 3 years. Physical disruption of tumors with cryoablation (cryo) induces inflammation and releases antigens that can activate tumor-specific immune responses. In pre-clinical studies, the combination of cryo with checkpoint inhibition augmented tumor-specific immune responses and prevented cancer recurrence. In clinical studies, the combination of pre-operative ipilimumab (ipi)- +/- nivolumab (nivo)-mediated checkpoint blockade with cryo was safely administered in women with operable, early stage breast cancer and generated intra-tumoral and systemic immune responses (NCT01502592, NCT02833233). In this multi-center, randomized study, we evaluate the disease specific impact of peri-operative ipi, nivo and cryo versus standard care in women with residual TNBC after neoadjuvant taxane-based chemotherapy (NCT03546686).

Methods:Eligible pts are aged ≥18 years, with ER, PR and HER2 negative operable tumors ≥ 1.0 cm after neoadjuvant taxane-based chemotherapy. Approximately 160 patients will be randomized to one of two arms: standard-of-care breast surgery (control arm) or ipi/nivo/cryo followed by standard-of-care breast surgery (intervention arm). Subjects randomized to the intervention arm will undergo percutaneous, ultrasound- (or MRI-) guided cryoablation with concurrent research core biopsy 7-10 days prior to surgery, and will receive a pre-operative infusion with ipilimumab at the dose of 1mg/kg IV, and nivolumab 240mg flat dose IV (1 to 5 days prior to cryoablation). After surgery, patients will receive three additional doses of nivolumab 240mg flat dose IV Q2 weeks. Adjuvant capecitabine is recommended for all participants and will be administered per standard-of-care at the treating physician's discretion. Patients will be stratified by prior platinum administration, prior anthracycline administration, and clinical nodal status (positive versus negative) at enrollment. The primary endpoint is 3-year Event Free Survival (EFS). Secondary end points include Invasive Disease-Free Survival (IDFS), Distant Disease-Free Survival (DDFS), overall survival (OS) and safety. Exploratory correlative studies will be performed on tumor and serum to characterize the immunologic impact of the intervention and to explore predictors of efficacy and toxicity.

Citation Format: McArthur HL, Comen EA, Solomon S, Rodine M, DiLauro Abaya C, Leal JHS, Patil S, Norton L. A randomized phase II study of peri-operative ipilimumab, nivolumab and cryoablation versus standard peri-operative care in women with residual triple negative early stage/resectable breast cancer after standard-of-care neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-06-05.