Glycogen synthase 1 targeting reveals a metabolic vulnerability in triple-negative breast cancer

BACKGROUND

Hypoxia-induced glycogen turnover is implicated in cancer proliferation and therapy resistance. Triple-negative breast cancers (TNBCs), characterized by a hypoxic tumor microenvironment, respond poorly to therapy. We studied the expression of glycogen synthase 1 (GYS1), the key regulator of glycogenesis, and other glycogen-related enzymes in primary tumors of patients with breast cancer and evaluated the impact of GYS1 downregulation in preclinical models.

METHODS

mRNA expression of GYS1 and other glycogen-related enzymes in primary breast tumors and the correlation with patient survival were studied in the METABRIC dataset (n = 1904). Immunohistochemical staining of GYS1 and glycogen was performed on a tissue microarray of primary breast cancers (n = 337). In four breast cancer cell lines and a mouse xenograft model of triple-negative breast cancer, GYS1 was downregulated using small-interfering or stably expressed short-hairpin RNAs to study the effect of downregulation on breast cancer cell proliferation, glycogen content and sensitivity to various metabolically targeted drugs.

RESULTS

High GYS1 mRNA expression was associated with poor patient overall survival (HR 1.20, P = 0.009), especially in the TNBC subgroup (HR 1.52, P = 0.014). Immunohistochemical GYS1 expression in primary breast tumors was highest in TNBCs (median H-score 80, IQR 53-121) and other Ki67-high tumors (median H-score 85, IQR 57-124) (P < 0.0001). Knockdown of GYS1 impaired proliferation of breast cancer cells, depleted glycogen stores and delayed growth of MDA-MB-231 xenografts. Knockdown of GYS1 made breast cancer cells more vulnerable to inhibition of mitochondrial proteostasis.

CONCLUSIONS

Our findings highlight GYS1 as potential therapeutic target in breast cancer, especially in TNBC and other highly proliferative subsets.

Validation of the 70-gene signature test (MammaPrint) to identify patients with breast cancer aged ≥ 70 years with ultralow risk of distant recurrence: A population-based cohort study

INTRODUCTION

When risk estimation in older patients with hormone receptor positive breast cancer (HR + BC) is based on the same factors as in younger patients, age-related factors regarding recurrence risk and other-cause mortality are not considered. Genomic risk assessment could help identify patients with ultralow risk BC who can forgo adjuvant treatment. However, assessment tools should be validated specifically for older patients. This study aims to determine whether the 70-gene signature test (MammaPrint) can identify patients with HR + BC aged ≥70 years with ultralow risk for distant recurrence.

MATERIALS AND METHODS

Inclusion criteria: ≥70 years; invasive HR + BC; T1-2N0-3M0.

EXCLUSION CRITERIA

HER2 + BC; neoadjuvant therapy. MammaPrint assays were performed following standardized protocols. Clinical risk was determined with St. Gallen risk classification. Primary endpoint was 10-year cumulative incidence rate of distant recurrence in relation to genomic risk. Subdistribution hazard ratios (sHR) were estimated from Fine and Gray analyses. Multivariate analyses were adjusted for adjuvant endocrine therapy and clinical risk.

RESULTS

This study included 418 patients, median age 78 years (interquartile range [IQR] 73-83). Sixty percent of patients were treated with endocrine therapy. MammaPrint classified 50 patients as MammaPrint-ultralow, 224 patients as MammaPrint-low, and 144 patients as MammaPrint-high risk. Regarding clinical risk, 50 patients were classified low, 237 intermediate, and 131 high. Discordance was observed between clinical and genomic risk in 14 MammaPrint-ultralow risk patients who were high clinical risk, and 84 patients who were MammaPrint-high risk, but low or intermediate clinical risk. Median follow-up was 9.2 years (IQR 7.9-10.5). The 10-year distant recurrence rate was 17% (95% confidence interval [CI] 11-23) in MammaPrint-high risk patients, 8% (4-12) in MammaPrint-low (HR 0.46; 95%CI 0.25-0.84), and 2% (0-6) in MammaPrint-ultralow risk patients (HR 0.11; 95%CI 0.02-0.81). After adjustment for clinical risk and endocrine therapy, MammaPrint-high risk patients still had significantly higher 10-year distant recurrence rate than MammaPrint-low (sHR 0.49; 95%CI 0.26-0.90) and MammaPrint-ultralow patients (sHR 0.12; 95%CI 0.02-0.85). Of the 14 MammaPrint-ultralow, high clinical risk patients none developed a distant recurrence.

DISCUSSION

These data add to the evidence validating MammaPrint's ultralow risk threshold. Even in high clinical risk patients, MammaPrint-ultralow risk patients remained recurrence-free ten years after diagnosis. These findings justify future studies into using MammaPrint to individualize adjuvant treatment in older patients.

Distress, problems, referral wish, and supportive health care use in breast cancer survivors beyond the first year after chemotherapy completion

PURPOSE

We examined distress levels, problems, referral wish, and supportive health care use in a cross-sectional group of breast cancer survivors at two-time points with a 1-year time interval. Also, factors related to continuing elevated distress were explored.

METHODS

Breast cancer survivors, 1-5 years after chemotherapy completion, filled in the Dutch Distress Thermometer/Problem List (DT/PL) and questions on background characteristics at study inclusion (T1). DT/PL responses and health care use were discussed during semi-structured interviews. One year later, re-assessment took place (T2). The data were analyzed by descriptive and univariate analyses. Continuing elevated distress was defined as a DT score ≥ 5 at T1 and T2.

RESULTS

Seventy-three survivors completed all questionnaires (response = 84.6%). Eighteen (25%) experienced continuing elevated distress. Fatigue (T1 N = 48 (66%); T2 N = 41 (56%)) and lack of physical fitness (T1 N = 44 (60%); T2 N = 36 (49%)) were most often reported. Time since diagnosis, health care use, and practical, social, emotional and physical problems were significantly associated with continuing elevated distress. Between diagnosis and T1, N = 49(67%) used supportive healthcare services, mostly a psychologist and/or a physical/lymphedema therapist, and between T1 and T2, 39 (53%) did. At T1, 8 (11%) expressed a referral wish and at T2, 11 (16%) did.

CONCLUSIONS

Screening and management of distress, problems, and referral wish are important, even years after chemotherapy completion as a substantial proportion of breast cancer survivors continue to report elevated distress and problems. Special attention should be paid to survivors reporting physical problems, especially fatigue and lack of physical fitness, since these problems are most strongly related to continuing elevated distress.

Enhanced pulmonary uptake on 18F-FES-PET/CT scans after irradiation of the thoracic area: related to fibrosis?

Rationale

The use of 16α-[¹⁸F]fluoro-17β-estradiol (FES) positron emission tomography (PET) in clinical dilemmas and for therapy decision-making in lesions expressing estrogen receptors is growing. However, on a considerable number of FES PET scans, previously performed in a research and clinical setting in our institution, FES uptake was noticed in the lungs without an oncologic substrate. We hypothesized that this uptake was related to pulmonary fibrosis as a result of radiation therapy. This descriptive study therefore aimed to investigate whether radiation therapy in the thoracic area is possibly related to enhanced pulmonary, non-tumor FES uptake.

Methods

All FES-PET/CT scans performed in our institution from 2008 to 2017 were retrospectively analyzed. Scans from patients who had received irradiation in the thoracic area prior to the scan were compared to scans of patients who had never received irradiation in the thoracic area. The primary outcome was the presence of enhanced non-tumor FES uptake in the lungs, defined as visually increased FES uptake in the absence of an oncologic substrate on the concordant (contrast-enhanced) CT scan. All CT scans were evaluated for the presence of fibrosis or oncologic substrates.

Results

A total of 108 scans were analyzed: 70 scans of patients with previous irradiation in the thoracic area and 38 of patients without. Enhanced non-tumor FES uptake in the lungs was observed in 39/70 irradiated patients (56%), versus in 9/38 (24%) of non-irradiated patients. Fibrosis was present in 37 of the 48 patients with enhanced non-tumor FES uptake (77%), versus in 15 out of 60 (25%) patients without enhanced non-tumor uptake, irrespective of radiotherapy (p < 0.001).

Conclusion

After irradiation of the thorax, enhanced non-tumor uptake on FES-PET can be observed in the radiation field in a significant proportion of patients. This seems to be related to fibrosis. When observing enhanced FES uptake in the lungs, this should not be interpreted as metastases. Information on recent radiation therapy or history of pulmonary fibrosis should therefore be taken into consideration.

89Zr-trastuzumab PET supports clinical decision making in breast cancer patients, when HER2 status cannot be determined by standard work up

Background

Up-to-date information on human epidermal growth factor receptor 2 (HER2) status in breast cancer (BC) is important, as expression can vary during the course of the disease, necessitating anti-HER2 therapy adjustments. Repeat biopsies, however, are not always possible. In this feasibility trial we assessed whether ⁸⁹Zr-trastuzumab PET could support diagnostic understanding and aid clinical decision making, when HER2 status could not be determined by standard work up. Additionally, HER2 status on circulating tumour cells (CTCs) was assessed.

Patients and methods

⁸⁹Zr-trastuzumab PET was performed in patients if disease HER2 status remained unclear after standard work up (bone scan, ¹⁸F-FDG PET, CT and if feasible a biopsy). PET result and central pathologic revision of available tumour biopsies were reported to the referring physician. CTC HER2 status prior to PET was evaluated afterwards and therefore not reported. Diagnostic understanding and treatment decision questionnaires were completed by the referring physicians before, directly after and ≥ 3 months after ⁸⁹Zr-trastuzumab PET.

Results

Twenty patients were enrolled: 8 with two primary cancers (HER2-positive and HER2-negative BC or BC and non-BC), 7 with metastases inaccessible for biopsy, 4 with prior HER2-positive and -negative metastases and 1 with primary BC with equivocal HER2 status. ⁸⁹Zr-trastuzumab PET was positive in 12 patients, negative in 7 and equivocal in 1 patient. In 15/20 patients, ⁸⁹Zr-trastuzumab PET supported treatment decision. The scan altered treatment of 8 patients, increased physicians’ confidence without affecting treatment in 10, and improved physicians’ disease understanding in 18 patients. In 10/20 patients CTCs were detected; 6/10 showed HER2 expression. CTC HER2 status was not correlated to ⁸⁹Zr-trastuzumab PET result or treatment decision.

Conclusion

⁸⁹Zr-trastuzumab PET supports clinical decision making when HER2 status cannot be determined by standard work up. The impact of CTC HER2 status needs to be further explored.

Electronic supplementary material

The online version of this article (10.1007/s00259-018-4099-8) contains supplementary material, which is available to authorized users.

Abstract PD2-12: Molecular imaging for early identification of patients who benefit from palbociclib in addition to letrozole

Palbociclib plus letrozole has improved both progression free survival and overall response rate in metastatic breast cancer (MBC) patients. For response to palbociclib, the best biomarker is ER expression. 16α-[18F]Fluoro-17β-estradiol (FES) -PET allows whole body ER level assessment, and provides insight in the heterogeneity of ER expression throughout the body. We hypothesized that lesions with low uptake on FES-PET are unlikely to respond to letrozole plus palbociclib. METHODS: Post-menopausal women with ER positive MBC were eligible for this pilot study. All patients were staged with fludeoxyglucose (FDG)-PET and CT scan, and in addition a FES-PET was performed at baseline. After 8 weeks treatment an FDG-PET/CT was used for response evaluation. The primary endpoint was the relation between standard uptake value (SUV) per lesion on FES-PET to response, as measured by RECIST 1.1 criteria in case of measurable disease. In case of non-measurable bone lesions, progression was defined as an increase in SUV on FDG-PET of more than 30% per lesion compared to baseline (based on PERCIST). RESULTS: 15 patients were included of which 14 were evaluable for primary endpoint. Mean age was 50 years (range 35-76). Median number of prior therapies was 1. A total of 280 lesions were detected on conventional imaging of which 50 showed low uptake (SUV&lt;1.5) on FES-PET. 29/50 low uptake lesions showed progression based on diagnostic CT (n=9) or FDG PET (n=20). In contrast, 28/230 FES positive lesions showed progression.

 ResponseStable diseaseProgression FES uptake &gt;1.51089428230FES uptake &lt;1.57142950 11510857280

DISCUSSION: this pilot trial indicates negative predictive value of low FES uptake for response to letrozol plus palbociclib in ER positive MBC. The FES-PET may therefore be a biomarker for response for this combination treatment. This will have to be explored further in future clinical trials.

Citation Format: Venema CM, de Vries EFJ, Glaudemans AWJM, Hospers GAP, Schröder CP. Molecular imaging for early identification of patients who benefit from palbociclib in addition to letrozole [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-12.

Abstract P5-23-01: Clinical and biological characterization of male breast cancer (BC) EORTC 10085/TBCRC 029/BOOG 2013-02/BIG 2-07: Baseline results from the prospective registry

BACKGROUND: Through the International Male Breast Cancer Program, a prospective registry for male BC was created with the goals of evaluating 1) the clinical and biological features of this disease and 2) assessing feasibility of a prospective therapeutic clinical trial.

METHODS: All men, with any stage histologically proven invasive breast cancer, age 3 18 years, and newly presenting at the participating institutions (within 3 months prior) were eligible. Patients were enrolled for 30 months after activation of the first center, through February 2017. Per the study design, if &lt;100 men enrolled, the study would be considered a failure and therapeutic trials would not be pursued through this network. Epidemiologic data, staging, pathologic features, and BRCA status were collected. Treatment and outcome data collection is ongoing. Optional collection of FFPE tumor samples, blood, and QOL were performed in the US, the Netherlands, and Latin America. Clinical database lock for this report was May 30, 2017. We currently report patient and disease characteristics and will update with patterns of treatment for the presentation. Outcomes and biological samples will be analyzed in the future.

RESULTS: 557 patients were enrolled: 75% in Europe, 20% in United States, 5% in other countries. 6.3% of patients had missing forms. Median age was 67 years (range 26-92). 93% were diagnosed 2010-2017. Among patients with complete data, 79% presented with a breast mass. 88% were M0 and 12% M1. Among M0 patients: 47%, 39%, 2%, and 11% had T1, T2, T3, and T4 disease respectively; 52% were N0. Overall, 98% had ER+ disease and 11% had HER2+ cancer. 14% had grade 1, 56% had grade 2, and 30% had grade 3 tumors. Among 112 men who underwent BRCA1 testing, 1 was positive. Among 118 men who had BRCA2 testing, 18 (15%) were positive. 21% of men had prior or concurrent malignancies, with the following most common sites: prostate, non-melanoma skin, colorectal, and melanoma. The prevalence of previously identified possible risk factors for male breast cancer were: overweight/obesity (72%), former/current smoker (51%), current alcohol 31 drink daily (41%), family history of breast cancer (35%), gynecomastia (16%), history radiation exposure (8%), use of anti-androgens (1%), and use of estrogens (1%).

CONCLUSION: Through an international collaborative effort, we were able to prospectively accrue 557 patients to a male breast cancer registry. These results demonstrate feasibility of pursuing a therapeutic clinical trial in men with breast cancer. In addition, this study shows the relatively low uptake of BRCA testing, high rates of concurrent/prior malignancy, and the rates of potentially modifiable risk factors in this patient population.

Funding from Breast Cancer Research Foundation, Susan G. Komen, Dutch Pink Ribbon Foundation, Swedish Breast Cancer Association (BRO) and EBCC Council.

Citation Format: Giordano SH, Schröder CP, Poncet C, van Leeuwen-Stok E, Linderholm B, Abreu MH, Rubio I, Van Poznak C, Morganstern D, Cameron D, Vleugel MM, Smilde TJ, Bozovic-Spasojevic I, Korde L, Russell NS, den Hoed IDM, Honkoop AH, van der Velden AWG, van 't Riet M, Dijkstra N, Bogler O, Goulioti T, Hilsenbeck S, Ruddy KJ, Wolff A, van Deurzen CHM, Martens J, Bartlett JMS, Aalders K, Tryfonidis K, Cardoso F. Clinical and biological characterization of male breast cancer (BC) EORTC 10085/TBCRC 029/BOOG 2013-02/BIG 2-07: Baseline results from the prospective registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-23-01.

Abstract P5-03-06: Clinical value of 89Zr-trastuzumab PET in HER2-positive breast cancer patients with a clinical dilemma

Background: Information on human epidermal growth factor receptor 2 (HER2) is essential for management of metastatic breast cancer (mBC). In patients suspected of HER2-positive mBC, standard work up may fail to clarify whole body HER2 status. We aimed to assess whether 89Zr-trastuzumab PET can support treatment decisions in patients posing this clinical dilemma.

Methods: 89Zr-trastuzumab PET was performed as described earlier (Gaykema et al, Clin Cancer Res 2014) in patients in whom standard work up with bone scan, FDG PET, CT and if feasible a biopsy, failed to evaluate HER2 status of their disease. 89Zr-trastuzumab PET was defined positive, when at least a dominant part of the tumor load showed substantial tracer uptake (Gebhart et al, Ann Oncol 2015), when tumor tracer uptake in single lesions (except brain) was ≥ normal liver uptake or when brain metastases had a tracer uptake &gt; background. Circulating tumor cell (CTC) analysis prior to tracer injectionwas performed using the CellSearch System (Janssen Diagnostics LLC) and CTC HER2 status was assessed immunofluorescently. Questionnaires about treatment decisions were completed before, directly after and ≥3 months after 89Zr-trastuzumab PET.

Results: Twenty patients were enrolled: 8 with two primary cancers (HER2-positive and HER2-negative BC or BC and non-BC), 7 with metastases inaccessible for biopsy, 4 with prior HER2-positive and HER2-negative metastases, 1 with primary BC with equivocal HER2 status (average 4.23 HER2 gene copies/nucleus). 89Zr-trastuzumab PET was positive in 12 patients, negative in 7 and equivocal in one patient. In 15/20 patients 89Zr-trastuzumab PET supported treatment decision. The scan altered treatment of 8 patients, increased physicians' confidence without affecting treatment in 10, and improved physicians' understanding of disease in 18 patients. Ten patients had 1-99 CTCs, 6 with HER2 expression. There was no correlation between HER2 expression by CTCs and 89Zr-trastuzumab PET results or subsequent treatment decision.

Conclusion: 89Zr-trastuzumab PET, but not CTC analysis, supports clinical decision making in BC patients in whom standard work up fails to evaluate HER2 status. (Funded by the Dutch A Sister's Hope).

Citation Format: Schröder CP, Bensch F, Brouwers AH, Lub-de Hooge MN, de Jong JR, van der Vegt B, Sleijfer S, de Vries EG. Clinical value of 89Zr-trastuzumab PET in HER2-positive breast cancer patients with a clinical dilemma [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-03-06.

Abstract P5-01-07: Radiotherapy may induce enhanced uptake on 18F-fluoroestradiol PET scans

Introduction: Whole body imaging of 18F-fluoroestradiol (FES) uptake combined with positron emission tomography (PET) has been applied for diagnosis and prediction of therapy response in estrogen receptor (ER) positive breast cancer patients. A maximal standardized uptake value (SUVmax) of 1.5 has previously been defined as the optimal threshold for FES uptake to differentiate between ER-positive and negative tumor lesions. FES uptake in healthy tissue differs per anatomic site and can be influenced by extrinsic factors. Previous FES PET studies have suggested that radiotherapy (RTx) may cause heterogeneous enhanced uptake in lungs. The cause of this uptake has not been elucidated yet. This is an exploratory study to evaluate whether patients with RTx prior to FES PET show enhanced FES uptake in tissues in the irradiation field.

Methods: Our FES PET database was screened between 2009 and June 2015 for patients who had RTx ≤6 months before FES PET, independent of location of RTx. Irradiation fields were reconstructed and fused with the FES PET scan. The main outcome was the presence of enhanced FES uptake, defined as visually increased FES uptake above background with a SUVmax &gt;1.5 in the irradiation field in the absence of an oncologic substrate on the concordant (contrast enhanced) CT scan.

Results: A total of 133 patients were identified in the database; 29 were eligible for the study. Mean age at the first FES PET scan was 57 (SD 9) years. 28/29 patients had breast cancer, 2/28 had a concurrent other malignancy. Seventeen patients (59%) showed enhanced uptake in the RTx field. 15/17 patients were irradiated in the thoracic area, and 2/17 at the hip. Enhanced uptake was mostly located at the dorsomedial side of the lungs, or subcutaneously after thoracic- or hip RTx, respectively. Patients with normal FES uptake in the radiation field were irradiated in the pelvic/lumbal spine area (n=5), hip (n=3) or thorax (n=4). Time range between RTx and FES PET did not differ between patients with and without enhanced FES uptake (mean 50.9 days [range 0-156] vs. mean 56.8 days [range 0-178]). Systemic treatment at the time of FES PET did not differ between the patients with and without enhanced uptake. Radiation dosage in gray (Gy) was related to enhanced FES uptake, after RTx in the thoracic area or at the hip.

Conclusion: RTx can induce enhanced uptake in the irradiation field on the FES PET scan in part of the patients. Irradiation-induced FES uptake most frequently occurs in lung tissue. Therefore, physicians should keep the possibility of radiation-induced aspecific enhanced tracer uptake in mind, when interpreting FES PET scan of patients that have recently received RTx.

Citation Format: Venema CM, van der Veen SJ, Glaudemans AWJM, Schröder CP, de Vries EFJ, Hospers GAP. Radiotherapy may induce enhanced uptake on 18F-fluoroestradiol PET scans. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-07.

Abstract P6-08-01: Inverse relationships between high somatic copy number load and immune phenotypes in breast cancer

Introduction

Currently, there is no clear biomarker to predict which breast cancer patient may benefit from immunotherapy. High somatic point mutational load is thought to lead to immune activation and CD8+ T cell activation and infiltration. In addition, pre-existing CD8+ T cells distinctly located at the invasive tumor margin are associated with expression of the PD-1/PD-L1 immune inhibitory axis and may predict response to PD-1 targeted therapy. However, breast tumors are considered copy number-driven rather than mutational-driven cancers. Therefore, in order to identify which breast cancer patients may potentially benefit from immunotherapy, we investigated relations between copy number load and CD8+ T cell abundance, immune pathways and immune activation scores in a large set of publically available breast cancer expression profiles.

Methods

Functional genomic mRNA-profiling (Fehrmann et al., Nat Genet, 2015) was used to capture the downstream effect of somatic copy number alterations on gene expression levels. This method allowed using gene expression profiles to quantify somatic copy number load occurring in tumor samples in a univariate measurement called the copy number load index (CNL-index). Immune activation scores were calculated according to two known gene immune signatures (Teschendorff et al., Genome Biol, 2007 and Desmedt et al., Clin Cancer Res, 2008). Cibersort (Newman et al., Nat Methods, 2015) was applied to estimate CD8+ T cell abundance. Publicly available gene expression profiles of 7,270 primary breast cancer samples were used. The relation between CNL-index, immune activation scores and disease-free survival (DFS), defined as time from diagnosis until distant metastasis development, was assessed by multivariate cox-regression analysis including age, ER and HER2 status, tumor size, lymph node involvement, tumor grade and treatment regimen. Gene set enrichment analysis (GSEA) was applied to assess relations between immune pathways and CNL-index.

Results

In primary breast cancer, low CNL-index was found in 1,796 samples (24.7%) versus 5,474 samples with a high CNL-index (75.3%). Higher CNL-index was correlated with shorter DFS (HR 2.51, P = 1.6x10-4), whereas higher immune activation scores were associated with prolonged DFS (HR 0.199, P = 0.003 and HR 0.347, P = 0.017). CD8+ T cell abundance was negatively correlated with the CNL-index (Spearman R = -0.14, P = 8.11x10-34). GSEA showed enrichment of immune pathways amongst genes that negatively correlated with CNL-index. Subset analysis in 1,555 TNBC samples showed low CNL-index in 287 samples (18.5%) versus high CNL-index in 1,268 samples (81.5%). Similar to the entire breast cancer set, CD8+ T cell abundance and CNL-index were negatively correlated in TNBC (Spearman R = -0.11, P = 4.11x10-05). Immune pathway enrichment in genes in TNBC also negatively correlated to CNL-index.

Conclusion

High CNL-index (i.e. high copy number load) is inversely related to immunoactivation, immune pathways and CD8+ T cell abundance. This implies that in breast cancer, tumors with low CNL-index may be intrinsically sensitive to immune modulation, which warrants further confirmation in prospective trials.

This research was supported by Dutch Cancer Society Grants RUG 2010-4739 and RUG 2013-5960.

Citation Format: Bense RD, van der Vegt B, de Vries EGE, van Vugt MATM, Schröder CP, Fehrmann RSN. Inverse relationships between high somatic copy number load and immune phenotypes in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-08-01.

Molecular imaging as a tool to investigate heterogeneity of advanced HER2-positive breast cancer and to predict patient outcome under trastuzumab emtansine (T-DM1): the ZEPHIR trial

BACKGROUND

Only human epidermal growth factor receptor (HER)2 status determined by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) has been validated to predict efficacy of HER2-targeting antibody-drug-conjugate trastuzumab emtansine (T-DM1). We propose molecular imaging to explore intra-/interpatient heterogeneity in HER2 mapping of metastatic disease and to identify patients unlikely to benefit from T-DM1.

PATIENTS AND METHODS

HER2-positive mBC patients with IHC3+ or FISH ≥ 2.2 scheduled for T-DM1 underwent a pretreatment HER2-positron emission tomography (PET)/computed tomography (CT) with (89)Zr-trastuzumab. [(18)F]2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT was performed at baseline and before T-DM1 cycle 2. Patients were grouped into four HER2-PET/CT patterns according to the proportion of FDG-avid tumor load showing relevant (89)Zr-trastuzumab uptake (>blood pool activity): patterns A and B were considered positive (>50% or all of the tumor load 'positive'); patterns C and D were considered negative (>50% or all of the tumor load 'negative'). Early FDG-PET/CT was defined as nonresponding when >50% of the tumor load showed no significant reduction of FDG uptake (<15%). Negative (NPV) and positive predictive values (PPV) of HER2-PET/CT, early FDG response and their combination were assessed to predict morphological response (RECIST 1.1) after three T-DM1 cycles and time-to-treatment failure (TTF).

RESULTS

In the 56 patients analyzed, 29% had negative HER2-PET/CT while intrapatient heterogeneity (patterns B and C) was found in 46% of patients. Compared with RECIST1.1, respective NPV/PPV for HER2-PET/CT were 88%/72% and 83%/96% for early FDG-PET/CT. Combining HER2-PET/CT and FDG-PET/CT accurately predicted morphological response (PPV and NPV: 100%) and discriminated patients with a median TTF of only 2.8 months [n = 12, 95% confidence interval (CI) 1.4-7.6] from those with a TTF of 15 months (n = 25, 95% CI 9.7-not calculable).

CONCLUSIONS

Pretreatment imaging of HER2 targeting, combined with early metabolic response assessment holds great promise for improving the understanding of tumor heterogeneity in mBC and for selecting patients who will/will not benefit from T-DM1.

CLINICALTRIALSGOV IDENTIFIER

NCT01565200.

Impact of primary local treatment on the development of distant metastases or death through locoregional recurrence in young breast cancer patients

In this study, we tested the hypothesis whether breast conserving therapy (BCT) compared with mastectomy is associated with a negative outcome in terms of distant metastases or death (DMD) and investigated the relation between locoregional recurrence (LRR) and DMD in young breast cancer (BC) patients. This study included a consecutive series of 536 patients ≤40 years of age at diagnosis with pathological T1N0-3M0 BC, treated between 1989 and 2005. A multistate survival model was used to evaluate the influences of local treatment and LRR on DMD, adjusted for potential prognostic factors. Patients were treated with mastectomy (N = 213) or BCT (N = 323). Median age at diagnosis was 36.3 years, with a median follow-up of 9.0 years. The 10-year actuarial cumulative incidence of DMD was 30.6 % after mastectomy and 26.3 % after BCT (P = 0.04). In total, 81 (15 %) LRRs were observed. After BCT, patients had a threefold higher risk of LRR than after mastectomy (HR 2.9; 95 % CI 1.6-5.3). Patients with LRR had a higher risk of DMD compared with patients without LRR (HR 5.5; 95 % CI 2.1-14.5). However, BCT was not negatively associated with DMD-after-LRR (HR 0.47; 95 % CI 0.2-1.1, BCT vs mastectomy). In conclusion, although LRR significantly affected DMD, the increased risk of LRR after BCT compared with mastectomy did not lead to a worse DMD outcome in BC patients ≤40 years of age.

Lapatinib: clinical benefit in patients with HER 2-positive advanced breast cancer

BACKGROUND

Lapatinib, a tyrosine kinase inhibitor of human epidermal growth factor receptor 2 (HER2), has shown activity in combination with capecitabine in patients with HER2-positive advanced breast cancer progressive on standard treatment regimens. We present results on preapproval drug access for this combination in such patients occurring in the general oncology practice in the Netherlands.

METHODS

Patients with HER2-positive advanced breast cancer progressive on schedules containing anthracyclines, taxanes, and trastuzumab were eligible. Brain metastases were allowed if stable. Lapatinib 1250 mg÷day was given continuously in combination with capecitabine 1000 mg÷m2 twice daily for two weeks in a three-week cycle. Efficacy was assessed by use of response evaluation criteria in solid tumours version 1.0. Progression-free survival (PFS) and overall survival (OS) were calculated.

RESULTS

Eighty-three patients were enrolled from January 2007 until July 2008. The combination was generally well tolerated and the most common drug-related serious adverse events were nausea and÷or vomiting (5%) and diarrhoea (2%). Seventy-eight patients were evaluable for response. Clinical benefit (response or stable disease for at least 12 weeks) was observed in 50 patients (64%) of whom 15 had a partial response and 35 stable disease. The median PFS and OS were 17 weeks (95% CI: 13 to 21) and 39 weeks (95% CI: 24 to 54), respectively. For OS, higher Eastern Cooperative Oncology Group (ECOG) status (p=0.016), brain metastases at study entry (p=0.010) and higher number of metastatic sites (p=0.012) were significantly negative predictive factors.

CONCLUSION

In a patient population with heavily pretreated HER2-positive advanced breast cancer lapatinib plus capecitabine was well tolerated and offered clinical benefit.

Molecular imaging of breast cancer

Molecular imaging of breast cancer can potentially be used for breast cancer screening, staging, restaging, response evaluation and guiding therapies. Techniques for molecular breast cancer imaging include magnetic resonance imaging (MRI), optical imaging, and radionuclide imaging with positron emission tomography (PET) or single photon emission computed tomography (SPECT). This review focuses on PET and SPECT imaging which can provide sensitive serial non invasive information of tumor characteristics. Most clinical data are gathered on the visualization of general processes such as glucose metabolism with the PET-tracer [(18)F]fluorodeoxyglucose (FDG) and DNA synthesis with [18F]fluoro-L-thymidine (FLT). Increasingly more breast cancer specific targets are imaged such as the estrogen receptor (ER), growth factors and growth factor receptors. Imaging of the ER with the PET tracer 16-alpha-[(18)F]fluoro-17-beta-estradiol (FES) has shown a good correlation between FES tumor uptake and ER density. (111)In-trastuzumab SPECT to image the human epidermal growth factor receptor 2 (HER2) showed that in most patients with metastatic HER2 overexpressing disease more lesions were detected than with conventional staging procedures. The PET tracer (89)Zr-trastuzumab showed excellent, quantifiable, and specific tumor uptake. (111)In-bevacizumab for SPECT and (89)Zr-bevacizumab for PET-imaging have been developed for vascular endothelial growth factor (VEGF) imaging as an angiogenic marker. Lastly, tracers for the receptors EGFR, IGF-1R, PDGF-betaR and the ligand TGFbeta are under development. Although molecular imaging of breast cancer is still not commonly used in daily clinical practice, its application portfolio is expanding rapidly.

An in vitro model for purging of tumour cells from ovarian tissue

BACKGROUND

Cryopreservation and autografting of ovarian tissue may preserve fertility after cancer treatment, but could be hampered by tumour cell contamination. Epithelial tumour cell lysis can be obtained with cytotoxic T cell retargeting through the bispecific antibody BIS-1, with combined affinity for the T-cell receptor and epithelial glycoprotein-2 (EGP-2). Our aim was to study the concept of tumour cell purging in the setting of a suspension of ovarian tissue.

METHODS

Human ovarian tissue was brought into suspension by mechanical and enzymatic treatment. Cells of the MCF-7 breast cancer cell line and activated human lymphocytes were co- incubated for 4 h with or without BIS-1 and with or without ovarian suspension. After incubation, MCF-7 cell death and cell growth were evaluated by fluorescent cell detection and MTT assay, respectively. Ovarian tissue morphology was evaluated immunohistochemically.

RESULTS

MCF-7 cell death and cell growth inhibition increased with increasing ratios of lymphocytes to MCF-7 cells. BIS-1 addition gave further augmentation, with a maximum depletion of growing MCF-7 cells of 89% (SD 11%) versus without BIS-1, 23% (SD 15%; P < 0.001). Follicles remained morphologically intact.

CONCLUSIONS

Purging of added epithelial tumour cells from ovarian tissue with BIS-1 is possible in vitro. Morphologically, follicles remain intact after this procedure. This method may contribute to safer replacement of ovarian tissue in female cancer survivors.

Telomere length in breast cancer patients before and after chemotherapy with or without stem cell transplantation

High-dose chemotherapy and peripheral blood stem cell transplantation (PBSCT) may accelerate telomere length loss in haematopoietic stem cells. As data including pre-and post-treatment samples are lacking, we studied leukocyte telomere length and telomerase activity before and after treatment in breast cancer patients randomized to receive 5 adjuvant courses FEC (5-FU, epirubicin and cyclophosphamide) (n= 17), or 4 × FEC followed by high-dose cyclophosphamide, thiotepa, carboplatin and autologous PBSCT (n= 16). Haemoglobin, MCV, leukocyte-and platelet numbers were assessed prior to (t₀), 5 months after (t₁) and 9 months after chemotherapy (t₂); these parameters were decreased at t₁ and t₂ compared to t₀(high-dose: all parameters; standard-dose: leukocytes and platelets), and all parameters were lower after high-dose than standard-dose treatment at t₁. Paired individual leukocyte samples of t₀ and t₁ showed telomere length change (determined by telomere restricted fragment (TRF) assay) ranging from +0.8 to –2.2 kb, with a decreased TRF length in 9 patients of both groups. Telomerase activity (determined by TRAP assay) was below detection limit in leukocyte samples of t₀ and t₁. Thus, standard-and high-dose chemotherapy negatively affect haematological reconstitution in this setting. In individual patients, telomere length can be remarkably changed following haematological proliferative stress after treatment. © 2001 Cancer Research Campaign www.bjcancer.com

Purging of epithelial tumor cells from peripheral blood stem cells by means of the bispecific antibody BIS-1

Peripheral blood stem cell (PBSC) support in breast cancer patients allows high-dose chemotherapy, but tumor cell contamination of the PBSCs is a potential source of relapse. Specific carcinoma cell killing can be obtained by retargeting activated T cells with bispecific antibody BIS-1, directed against epithelial glycoprotein-2 and CD3. To purge epithelial tumor cells from the PBSCs of breast cancer patients, activation of T cells in PBSCs and T-cell retargeting by BIS-1 was studied. PBSCs, obtained by leukapheresis after chemotherapy and recombinant human granulocyte colony-stimulating factor, were cultured in the presence of PBS, interleukin-2, OKT3, or interleukin-2/OKT3 for induction of T-cell activation. Subsequently, lysis of epithelial tumor cell lines by activated T cells of PBSCs in the presence or absence of BIS-1 was assessed with the 51Cr-release assay or immunocytochemical staining. The effect on PBSC hematopoietic colony formation (HCF) was evaluated by the granulocyte macrophage colony-stimulating units assay. Prior to activation, PBSCs from breast cancer patients contained higher levels of CD8+ T cells than peripheral blood from healthy volunteers (P < 0.05). The potential of PBSCs to sustain tumor cell lysis was increased after all prior activations and was further enhanced by BIS-1. Maximal BIS-1 effect was observed after OKT3 activation of PBSCs for 72 h (P < 0.0005), inducing a >3 log depletion of tumor cells. HCF was not affected by prior OKT3 activation and/or BIS-1. In conclusion, specific tumor cell lysis by PBSCs can be obtained in vitro by OKT3 activation and BIS-1 retargeting of T cells, without affecting HCF. At present, studies are evaluating this format for future clinical application.

Prevention of febrile leucopenia after chemotherapy in high-risk breast cancer patients: no significant difference between granulocyte-colony stimulating growth factor or ciprofloxacin plus amphotericin B

In a prospective randomized trial, 40 stage IV breast cancer patients undergoing intermediate high-dose chemotherapy (cyclophosphamide, 5-fluorouracil plus epirubicin or methotrexate), received either recombinant human G-CSF (rhG-CSF, group I) or ciprofloxacin and amphotericin B (CAB, group II) for prevention of febrile leucopenia (FL). In group I, seven of 18 patients developed FL (after 10/108 courses); in group II, seven of 22 patients (7/98 courses) (P = NS). Median hospitalization duration and costs were not different. RhG-CSF was 6.6 times more expensive per course than CAB. In conclusion, prophylactic CAB has similar efficacy to rhG-CSF in this setting, and is more cost-effective.

Serotonin metabolism following platinum-based chemotherapy combined with the serotonin type-3 antagonist tropisetron

The administration of platinum-based chemotherapy induces serotonin release from the enterochromaffin cells, causing nausea and vomiting. This study was conducted to evaluate parameters of serotonin metabolism following platinum-based chemotherapy given in combination with the serotonin type-3 antagonist tropisetron as an antiemetic agent. In nine chemotherapy-naive patients with disseminated germ-cell tumors, parameters of serotonin metabolism in both blood and urine were evaluated during two consecutive courses of platinum-based chemotherapy. Serotonin concentrations in platelet-rich plasma and platelet-poor plasma as well as urinary 5-hydroxyindoleacetic acid (5-HIAA) and serotonin levels were measured during the full length of the courses. By means of comparison with the antiemetic agent chlorpromazine, used on day 1 of the first course only, the effect of the serotonin type-3 antagonist tropisetron, the antiemetic agent used during the rest of the courses, on these parameters was studied. Clinical effects were also recorded. No change in the parameters of serotonin metabolism could be demonstrated during either course by the serotonin type-3 antagonist tropisetron. Also in vitro, no effect of tropisetron on the active serotonin uptake by platelets was found. Serotonin levels in platelets showed no correlation with emetic response. However, the platelet serotonin content decreased significantly between the first and the second course (P < 0.01). The significant reduction in platelet serotonin content observed between the first and the second course indicates a depletion of total body serotonin. The role of a serotonin type-3 antagonist might be affected by the altered serotonin equilibrium during later courses of chemotherapy.

Ultramicro-electrophoresis of protein in sweat from patients with cystic fibrosis of the pancreas and controls

46 sweat-samples from 32 children with cystic fibrosis of the pancreas (C.F.) and 35 samples from 23 control-children were collected with glass micro-capillaries. Protein was determined by ultramicro-electrophoresis.

RESULTS

1. Protein was detected in 48% of the samples (C.F. and controls). 2. At pH 2.3, C.F.-sweat showed at least one more band than control-sweat. 3. At pH 8.9, C.F.-sweat occasionally showed one more band than the control-group. 4. At pH 2.3, more protein was found at the electrophoresis start point using C.F.-sweat, whereas at pH 8.9 the opposite was found. 5. At pH 2.3, protein was found in fewer samples than at pH 8.9. The "C.F.-factor" is postulated to represent a basic polyelectrolyte which induces the following pathogenic mechanisms: a) Aggregation of proteins giving rise to a high viscosity of secretions, such as saliva. b) Binding to the cell-membrane of the glandular epithelium, thus inducing a disturbance of active NaCl-reabsorption (e.g. by reduction of luminal passive Na+-influx).