Acceptability and Usability of the Family Gene Toolkit for Swiss and Korean Families Harboring BRCA1/BRAC2 Pathogenic Variants: A Web-Based Platform for Cascade Genetic Testing.

The study adapted the Family Gene Toolkit and developed a customized web application for Swiss and Korean families harboring BRCA1 or BRCA2 pathogenic variants to support family communication of genetic testing results and promote cascade genetic testing among at-risk relatives. In the first step, narrative data from 68 women with BRCA1/BRCA2 pathogenic variants and clinician feedback informed a culturally sensitive adaptation of the content consistent with current risk management guidelines. In the second step, the Information Technology team developed the functions and the interface of the web application that will host the intervention. In the third step, a new sample of 18 women from families harboring BRCA1/BRCA2 pathogenic variants tested the acceptability and usability of the intervention using "think-aloud" interviews and a questionnaire. Participants expressed high levels of satisfaction with the intervention. They provided positive feedback for the information regarding active coping, strategies to enhance family communication, interactive elements, and illustrative stories. They reported that the information was useful and the web application was easy to navigate. Findings suggest that the Family Gene Toolkit is well-designed and can increase rates of cascade testing among at-risk relatives. Its efficacy will be tested in a subsequent randomized trial.

A multicenter phase II trial of anti-EGFR-immunoliposomes loaded with doxorubicin in patients with advanced triple negative breast cancer.

Advanced triple negative breast cancer (TNBC) is an aggressive, but initially chemo-sensitive disease. The prognosis is poor and more than three quarters of patients experience progression 12 months after the initiation of conventional first-line chemotherapy. Approximately two thirds of TNBC express epidermal growth factor receptor 1 (EGFR). We have developed an anti-EGFR targeted nanocontainer drug by inserting anti-EGFR antibody fragments into the membrane of pegylated liposomes (anti-EGFR-ILs-dox). The payload consists of doxorubicin, a standard drug for TNBC. In a first-in-human phase I trial in 26 patients with various advanced solid malignancies, anti-EGFR-ILs-dox has shown little toxicity and encouraging efficacy. In this single-arm phase II trial, we assessed the efficacy of anti-EGFR-ILs-dox as first-line therapy in patients with advanced, EGFR + TNBC. The primary endpoint was progression-free survival at 12 months (PFS12m). Secondary endpoints included overall response rate (ORR), duration of response (DOR), time to progression (TTP), overall survival (OS) and adverse events (AEs). 48 patients received anti-EGFR-ILs-dox 50 mg/m2 iv, on day one of a 28 days-cycle until progression. The Kaplan-Meier estimate for PFS12m was 13% (one-sided 90% CI 7%, 95% CI [5%, 25%]), median PFS was 3.5 months (95% CI 1.9, 5.4). The trial has not reached its primary endpoint. There were no new toxicity signals. Based on these results, anti-EGFR-ILs-dox should not be further developed for TNBC. It remains an open question whether anti-EGFR-ILs-dox would offer more opportunities in other EGFR-expressing malignancies, where targeting this receptor has already shown anticancer effects.Trial registration: This trial was registered at clinicaltrials.gov: NCT02833766. Registered 14/07/2016.

Relatives from Hereditary Breast and Ovarian Cancer and Lynch Syndrome Families Forgoing Genetic Testing: Findings from the Swiss CASCADE Cohort.

Cascade genetic testing of relatives from families with pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) or Lynch syndrome (LS) has important implications for cancer prevention. We compared the characteristics of relatives from HBOC or LS families who did not have genetic testing (GT (-) group) with those who had genetic testing (GT (+) group), regardless of the outcome. Self-administered surveys collected cross-sectional data between September 2017 and December 2021 from relatives participating in the CASCADE cohort. We used multivariable logistic regression with LASSO variable selection. Among n = 115 relatives who completed the baseline survey, 38% (n = 44) were in the GT (-) group. Being male (OR: 2.79, 95% CI: 1.10-7.10) and without a previous cancer diagnosis (OR: 4.47, 95% CI: 1.03-19.42) increased the odds of being untested by almost three times. Individuals from families with fewer tested relatives had 29% higher odds of being untested (OR: 0.71, 95% CI: 0.55-0.92). Reasons for forgoing cascade testing were: lack of provider recommendation, lack of time and interest in testing, being afraid of discrimination, and high out-of-pocket costs. Multilevel interventions designed to increase awareness about clinical implications of HBOC and LS in males, referrals from non-specialists, and support for testing multiple family members could improve the uptake of cascade testing.

Intention to Inform Relatives, Rates of Cascade Testing, and Preference for Patient-Mediated Communication in Families Concerned with Hereditary Breast and Ovarian Cancer and Lynch Syndrome: The Swiss CASCADE Cohort.

Cascade screening for Tier 1 cancer genetic conditions is a significant public health intervention because it identifies untested relatives of individuals known to carry pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS). The Swiss CASCADE is a family-based, open-ended cohort, including carriers of HBOC- and LS-associated pathogenic variants and their relatives. This paper describes rates of cascade screening in relatives from HBOC- and LS- harboring families, examines carriers' preferences for communication of testing results, and describes theory-based predictors of intention to invite relatives to a cascade screening program. Information has been provided by 304 index cases and 115 relatives recruited from September 2017 to December 2021. On average, 10 relatives per index case were potentially eligible for cascade screening. Approximately 65% of respondents wanted to invite relatives to the cohort, and approximately 50% indicated a preference for patient-mediated communication of testing results, possibly with the assistance of digital technology. Intention to invite relatives was higher for first- compared to second- and third-degree relatives, but was not different between syndromes or based on relatives' gender. The family environment and carrying pathogenic variants predicts intention to invite relatives. Information helps optimize delivery of tailored genetic services.

Using a Tailored Digital Health Intervention for Family Communication and Cascade Genetic Testing in Swiss and Korean Families With Hereditary Breast and Ovarian Cancer: Protocol for the DIALOGUE Study.

BACKGROUND: In hereditary breast and ovarian cancer (HBOC), family communication of genetic test results is essential for cascade genetic screening, that is, identifying and testing blood relatives of known mutation carriers to determine whether they also carry the pathogenic variant, and to propose preventive and clinical management options. However, up to 50% of blood relatives are unaware of relevant genetic information, suggesting that potential benefits of genetic testing are not communicated effectively within family networks. Technology can facilitate communication and genetic education within HBOC families. OBJECTIVE: The aims of this study are to develop the K-CASCADE (Korean-Cancer Predisposition Cascade Genetic Testing) cohort in Korea by expanding an infrastructure developed by the CASCADE (Cancer Predisposition Cascade Genetic Testing) Consortium in Switzerland; develop a digital health intervention to support the communication of cancer predisposition for Swiss and Korean HBOC families, based on linguistic and cultural adaptation of the Family Gene Toolkit; evaluate its efficacy on primary (family communication of genetic results and cascade testing) and secondary (psychological distress, genetic literacy, active coping, and decision making) outcomes; and explore its translatability using the reach, effectiveness, adoption, implementation, and maintenance framework. METHODS: The digital health intervention will be available in French, German, Italian, Korean, and English and can be accessed via the web, mobile phone, or tablet (ie, device-agnostic). K-CASCADE cohort of Korean HBOC mutation carriers and relatives will be based on the CASCADE infrastructure. Narrative data collected through individual interviews or mini focus groups from 20 to 24 HBOC family members per linguistic region and 6-10 health care providers involved in genetic services will identify the local cultures and context, and inform the content of the tailored messages. The efficacy of the digital health intervention against a comparison website will be assessed in a randomized trial with 104 HBOC mutation carriers (52 in each study arm). The translatability of the digital health intervention will be assessed using survey data collected from HBOC families and health care providers. RESULTS: Funding was received in October 2019. It is projected that data collection will be completed by January 2023 and results will be published in fall 2023. CONCLUSIONS: This study addresses the continuum of translational research, from developing an international research infrastructure and adapting an existing digital health intervention to testing its efficacy in a randomized controlled trial and exploring its translatability using an established framework. Adapting existing interventions, rather than developing new ones, takes advantage of previous valid experiences without duplicating efforts. Culturally sensitive web-based interventions that enhance family communication and understanding of genetic cancer risk are timely. This collaboration creates a research infrastructure between Switzerland and Korea that can be scaled up to cover other hereditary cancer syndromes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04214210; https://clinicaltrials.gov/ct2/show/NCT04214210 and CRiS KCT0005643; https://cris.nih.go.kr/cris/. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/26264.

Patterns of care and economic consequences of using bone-targeted agents for castration-sensitive prostate cancer patients with bone metastases to prevent skeletal-related events in Switzerland - the SAKK 95/16 prostate study.

BACKGROUND: International guidelines state that bone-targeted agents such as denosumab or zoledronic acid at doses used for bone metastasis are not indicated for patients with metastatic castration-sensitive prostate cancer (mCSPC) with bone metastases. Whereas denosumab has never been studied in this patient population, zoledronic acid has been shown to be ineffective in decreasing the risk for skeletal-related events. This study estimates the prevalence and economic consequences of real-world use of bone-targeted agents for mCSPC patients in Switzerland. METHODS: To estimate the frequency of bone-targeted agent administration and skeletal-related events, data from a non-interventional, cross-sectional survey involving oncologists across Switzerland (SAKK 95/16) was combined with data from the Swiss National Institute for Cancer Epidemiology and Registration (NICER). Economic parameters were calculated from the perspective of the healthcare system over the median time to prostate-specific antigen (PSA) progression for the extrapolated patient group, using data from NICER. The cost calculation covered costs for bone-targeted agents, their administration and skeletal-related events. The time to PSA progression (33.2 months), as well as the probability and cost of skeletal-related events were derived from the literature. RESULTS: The survey was answered by 86 physicians treating 417 patients, of whom 106 (25.4%) had prostate cancer, with 36 (34.0%) of these mCSPC. The majority of mCSPC patients (52.8%, n = 19) received bone-targeted agents monthly. Denosumab was the treatment of choice in 84.2% of patients (n = 16). Extrapolation using data from NICER indicated that 568 mCSPC patients may be treated with bone-targeted agents at doses used for bone metastasis  every year in Switzerland, leading to estimated total costs of more than CHF 8.3 million over 33.2 months. Because of its more frequent prescription and higher price, it appears that almost 93% of the total costs can be attributed to denosumab. For both denosumab and zoledronic acid, the most expensive components were the cost of administration and the drug cost, making up more than 90% of the total costs, with the rest being costs of skeletal-related events. CONCLUSIONS: This study found that the administration of bone-targeted agents in doses used for bone-metastatic diseases to prevent skeletal-related events is frequent in the setting of mCSPC and results in significant costs for the healthcare system.

Quality of life and pain in patients with metastatic bone disease from solid tumors treated with bone-targeted agents- a real-world cross-sectional study from Switzerland (SAKK 95/16).

BACKGROUND: Bone-targeted agents (BTAs) are widely used in the management of patients with bone metastases from solid tumors. Knowledge of the impact of their routine care use on patient-reported pain and bone pain-related quality of life (QoL) is limited. METHODS: This real world, cross-sectional study enrolled patients over a 3-month period through oncologists across Switzerland. Patients were ≥ 18 years, had solid tumors and at least one bone metastasis, and received routine care for bone metastases. Physicians provided data on BTA-related practices, risk of bone complications and BTA regimen. Patients completed questionnaires about pain (BPI-SF), general and bone pain-related QoL (FACT-G, FACT-BP) and treatment satisfaction (FACIT-TS-G). RESULTS: Eighteen sites recruited 417 patients. Based on the FACT-BP, 42% of the patients indicated not having bone pain. According to the BPI-SF, 28% reported no, 43% mild, 14% moderate, and 15% severe pain, respectively. Patients not treated with a BTA had better overall QoL (FACT-G: p = 0.031) and bone pain-related QoL (FACT-BP, p = 0.007) than those treated with a BTA. All pain and other QoL scales did not differ between groups. Patients perceived at 'low risk of bone complications' by their physician not receiving a BTA reported less pain and better QoL than those considered at 'low risk' but receiving BTA treatment or those considered at 'high risk' regardless of BTA treatment. Overall satisfaction with the treatment was good; almost 50% of patients reporting that they were completely satisfied. CONCLUSIONS: Overall, pain and QoL did not differ according to BTA treatment or physicians' risk perception. Patient with low risks not receiving BTA treatment reported least pain and highest QoL scores. These results may suggest that treating physicians assess bone complication risk appropriately and treat patients accordingly, but they need to be confirmed by objective determination of longitudinal skeletal complication risk.

A requirement for p120-catenin in the metastasis of invasive ductal breast cancer.

We report here the effects of targeted p120-catenin (encoded by CTNND1; hereafter denoted p120) knockout (KO) in a PyMT mouse model of invasive ductal (mammary) cancer (IDC). Mosaic p120 ablation had little effect on primary tumor growth but caused significant pro-metastatic alterations in the tumor microenvironment, ultimately leading to a marked increase in the number and size of pulmonary metastases. Surprisingly, although early effects of p120-ablation included decreased cell-cell adhesion and increased invasiveness, cells lacking p120 were almost entirely unable to colonized distant metastatic sites in vivo The relevance of this observation to human IDC was established by analysis of a large clinical dataset of 1126 IDCs. As reported by others, p120 downregulation in primary IDC predicted worse overall survival. However, as in the mice, distant metastases were almost invariably p120 positive, even in matched cases where the primary tumors were p120 negative. Collectively, our results demonstrate a strong positive role for p120 (and presumably E-cadherin) during metastatic colonization of distant sites. On the other hand, downregulation of p120 in the primary tumor enhanced metastatic dissemination indirectly via pro-metastatic conditioning of the tumor microenvironment.

Activity of Platinum-Based Chemotherapy in Patients With Advanced Prostate Cancer With and Without DNA Repair Gene Aberrations.

Importance: DNA repair gene aberrations occur in 20% to 30% of patients with castration-resistant prostate cancer (CRPC), and some of these aberrations have been associated with sensitivity to poly(ADP-ribose) polymerase (PARP) inhibition platinum-based treatments. However, previous trials assessing platinum-based treatments in patients with CRPC have mostly included a biomarker-unselected population; therefore, efficacy in these patients is unknown. Objective: To characterize the antitumor activity of platinum-based therapies in men with CRPC with or without DNA repair gene alterations. Design, Setting, and Participants: In this case series, data from 508 patients with CRPC treated with platinum-based therapy were collected from 25 academic centers from 12 countries worldwide. Patients were grouped by status of DNA repair gene aberrations (ie, cohort 1, present; cohort 2, not detected; and cohort 3, not tested). Data were collected from January 1986 to December 2018. Data analysis was performed in 2019, with data closure in April 2019. Exposure: Treatment with platinum-based compounds either as monotherapy or combination therapy. Main Outcomes and Measures: The primary end points were as follows: (1) antitumor activity of platinum-based therapy, defined as a decrease in prostate-specific antigen (PSA) level of at least 50% and/or radiological soft tissue response in patients with measurable disease and (2) the association of response with the presence or absence of DNA repair gene aberrations. Results: A total of 508 men with a median (range) age of 61 (27-88) years were included in this analysis. DNA repair gene aberrations were present in 80 patients (14.7%; cohort 1), absent in 98 (19.3%; cohort 2), and not tested in 330 (65.0%; cohort 3). Of 408 patients who received platinum-based combination therapy, 338 patients (82.8%) received docetaxel, paclitaxel, or etoposide, and 70 (17.2%) received platinum-based combination treatment with another partner. A PSA level decrease of at least 50% was seen in 33 patients (47.1%) in cohort 1 and 26 (36.1%) in cohort 2 (P = .20). In evaluable patients, soft tissue responses were documented in 28 of 58 patients (48.3%) in cohort 1 and 21 of 67 (31.3%) in cohort 2 (P = .07). In the subgroup of 44 patients with BRCA2 gene alterations, PSA level decreases of at least 50% were documented in 23 patients (63.9%) and soft tissue responses in 17 of 34 patients (50.0%) with evaluable disease. In cohort 3, PSA level decreases of at least 50% and soft tissue responses were documented in 81 of 284 patients (28.5%) and 38 of 185 patients (20.5%) with evaluable disease, respectively. Conclusions and Relevance: In this study, platinum-based treatment was associated with relevant antitumor activity in a biomarker-positive population of patients with advanced prostate cancer with DNA repair gene aberrations. The findings of this study suggest that platinum-based treatment may be considered an option for these patients.

Patterns of care for patients with metastatic bone disease in solid tumors: A cross-sectional study from Switzerland (SAKK 95/16).

BACKGROUND: Bone-targeted agents (BTAs) are widely used in the management of patients with bone metastases from solid tumors, but knowledge of their routine care use and the therapeutic implications remains limited. This non-interventional study aimed to characterize real-world BTA patterns of care in Switzerland. MATERIALS AND METHODS: Non-interventional, cross-sectional study involving oncologists from across Switzerland who completed a Treating Physician questionnaire, providing data on their clinical setting and BTA-related practices, and a Patient Characteristics and Treatment questionnaire, providing data on their patients' disease status, risk of bone complications, BTA regimen and related outcomes. Eligible patients were aged ≥ 18 years, with solid tumors and at least one bone metastasis and were receiving routine management at the participating physician's center over the 3-month study period. RESULTS: A total of 86 oncologists recruited 417 patients from across 18 centers in Switzerland (80% public hospitals; 20% private clinics). The majority of physicians (70.9%) reported prescribing BTAs in line with international guidelines; denosumab was the treatment of choice in 78.5% of patients. BTAs were widely administered (94.2%) according to a 3-4-weekly dosing regimen; 33.7% of physicians reported extending intervals to 12 weeks after an initial 2 years of treatment. Physicians appeared to use clinical judgement, as well as formal risk assessment, to guide treatment for symptomatic skeletal events. No association was seen between either BTA use, or risk of complications, and incidence of skeletal complications. Only 4.3% of patients were reported to be experiencing severe bone pain at the time of the study. CONCLUSIONS: This cross-sectional, non-interventional study found high implementation of guideline-recommended BTA prescribing, good pain control and low incidence of skeletal-related events. Long-term BTA randomized controlled trials have the potential to further optimize routine care outcomes for patients.

Acute toxicity associated with the recreational use of the novel dissociative psychoactive substance methoxphenidine.

INTRODUCTION: Methoxphenidine is a novel dissociative designer drug of the diarylethylamine class which shares structural features with phencyclidine (PCP), and is not at present subject to restrictive regulations. There is very limited information about the acute toxicity profile of methoxphenidine and the only sources are anonymous internet sites and a 1989 patent of the Searle Company. We report a case of analytically confirmed oral methoxphenidine toxicity. CASE DETAILS: A 53-year-old man was found on the street in a somnolent and confusional state. Observed signs and symptoms such as tachycardia (112 bpm), hypertension (220/125 mmHg), echolalia, confusion, agitation, opisthotonus, nystagmus and amnesia were consistent with phencyclidine-induced adverse effects. Temperature (99.1°F (37.3°C)) and peripheral oxygen saturation while breathing room air (99%) were normal. Laboratory analysis revealed an increase of creatine kinase (max 865 U/L), alanine aminotransferase (72 U/L) and gamma-glutamyl transpeptidase (123 U/L). Methoxphenidine was identified by a liquid chromatography tandem mass spectrometry toxicological screening method using turbulent flow online extraction in plasma and urine samples collected on admission. The clinical course was favourable and signs and symptoms resolved with symptomatic treatment. CONCLUSION: Based on this case report and users' web reports, and compatible with the chemical structure, methoxphenidine produces effects similar to those of the arylcyclohexylamines, as PCP.

Slug and Sox9 cooperatively determine the mammary stem cell state.

Regulatory networks orchestrated by key transcription factors (TFs) have been proposed to play a central role in the determination of stem cell states. However, the master transcriptional regulators of adult stem cells are poorly understood. We have identified two TFs, Slug and Sox9, that act cooperatively to determine the mammary stem cell (MaSC) state. Inhibition of either Slug or Sox9 blocks MaSC activity in primary mammary epithelial cells. Conversely, transient coexpression of exogenous Slug and Sox9 suffices to convert differentiated luminal cells into MaSCs with long-term mammary gland-reconstituting ability. Slug and Sox9 induce MaSCs by activating distinct autoregulatory gene expression programs. We also show that coexpression of Slug and Sox9 promotes the tumorigenic and metastasis-seeding abilities of human breast cancer cells and is associated with poor patient survival, providing direct evidence that human breast cancer stem cells are controlled by key regulators similar to those operating in normal murine MaSCs.

Designed ankyrin repeat proteins: a novel tool for testing epidermal growth factor receptor 2 expression in breast cancer.

Designed ankyrin repeat proteins are a novel class of specific binding molecules, which display increased thermodynamic stability, smaller size and at least equal target affinity compared to immunoglobulins, making them potentially powerful tools in diagnostic pathology and therapeutic oncology. Here, we investigated whether designed ankyrin repeat proteins can reliably identify the amplification status of the epidermal growth factor receptor 2 in breast cancer. Designed ankyrin repeat proteins specific for epidermal growth factor receptor 2 were tested in paraffin-embedded tissue sections. Detection using enzymatic biotinylation proved to be most specific and sensitive. The affinity of the designed ankyrin repeat proteins was found crucial, but for a picomolar binder no further gain was found by making it multivalent. The best designed ankyrin repeat protein, G3 (K(D) 90 pM) was compared on breast cancer tissue microarrays (n=792) to an FDA-approved rabbit monoclonal antibody against epidermal growth factor receptor 2 (clone 4B5; Ventana Medical Systems) and correlated with corresponding epidermal growth factor receptor 2 amplification status measured by fluorescent in situ hybridization. Amplification status and epidermal growth factor receptor 2 expression measured by designed ankyrin repeat protein and antibody correlated strongly with each other (P<0.0001 each), the correlation between designed ankyrin repeat protein and amplification status being the strongest (0.87 compared to 0.77 for the antibody, Kendall's tau-beta). Using a modified scoring system for the designed ankyrin repeat protein, we show that the designed ankyrin repeat protein detects a positive epidermal growth factor receptor 2 amplification status with similar sensitivity and significantly higher specificity than the antibody (P=0.0005). This study suggests that designed ankyrin repeat proteins provide a valuable alternative to antibodies for the detection of epidermal growth factor receptor 2 expression in breast cancer and adds further compelling evidence for the use of designed ankyrin repeat proteins in diagnostic pathology and therapeutic oncology.

IGFBP2 and IGFBP3 protein expressions in human breast cancer: association with hormonal factors and obesity.

PURPOSE: The insulin-like growth factor (IGF) signaling system is involved in breast cancer initiation and progression. The prognostic relevance of tumor expression patterns of IGFI-related proteins remains poorly understood. This study associates the expression of selected IGF proteins with breast tumor and patient characteristics. EXPERIMENTAL DESIGN: IGFI, IGFI receptor, IGF-binding protein (IGFBP)2, and IGFBP3 expression was measured in 855 primary breast carcinomas by immunohistochemistry using tissue microarrays. We investigated the association of tumor and nodal stage, grade, hormone receptor status, HER2 gene amplification, menopausal status, body mass index, and survival with IGF protein expression. RESULTS: In contrast to IGFI, the expression of IGFI receptor, IGFBP2, and IGFBP3 was associated with estrogen receptor status. In addition, IGFBP3 was positively correlated with body mass index and premenopausal status. Importantly, IGFBP2 was an independent and positive predictor of overall survival (hazard ratio, 0.48; 95% confidence interval, 0.24-0.95; P = 0.04). There was a weak suggestion for IGFBP2 and overweight to modify each other's effect on survival. CONCLUSIONS: According to these results, which need confirmation in larger patient series, the prognostic relevance of IGFBP2 and IGFBP3 protein expressions in breast cancer may depend on the hormonal context and body weight.

Distinct expression patterns of the immunogenic differentiation antigen NY-BR-1 in normal breast, testis and their malignant counterparts.

NY-BR-1 is a differentiation antigen and a potential target for cancer immunotherapy. Its mRNA expression is restricted to breast, testis, prostate and breast cancer by RT-PCR. In this study, we correlated NY-BR-1 protein and mRNA expression on tissue microarrays of mammary, prostatic and testicular malignancies using immunohistochemistry and in situ hybridization with probes for exon 4-7 and 30-33. NY-BR-1 mRNA was confined to primary spermatocytes, suggesting a role in spermatogenesis. Exon 4-7 and 30-33 were equally expressed this cell type. However, NY-BR-1 was absent in all germ cell tumours analyzed (n = 475) and present in one of 56 (2%) prostate carcinomas. In breast, NY-BR-1 mRNA expression was detected in 307 of 442 (70%) primary carcinomas, with strong correlation to its protein expression (p < 0.0001). mRNA expression was significantly stronger and more frequently detected by the exon 30-33 probe than by the exon 4-7 probe (70% vs. 35%, p < 0.0001), indicating the presence of alternative splice variants that lack 5-prime sequences. A similar restricted mRNA pattern was also observed in the normal breast epithelium. NY-BR-1 protein and mRNA correlated significantly with estrogen receptor alpha (ER alpha) protein expression (p < 0.0001), with stronger association to NY-BR-1 mRNA than protein (odds ratio 7.7 compared to 4.6). We identified 4 estrogen response elements (ERE)-like sequences nearby the promoter region, suggesting that NY-BR-1 transcription might be controlled by ER alpha. Accordingly, analysis of matching pairs of primary tumors with their recurrences showed a marked decrease of NY-BR-1 expression in recurrences after tamoxifen treatment (p < 0.0001).

NY-BR-1 protein expression in breast carcinoma: a mammary gland differentiation antigen as target for cancer immunotherapy.

NY-BR-1 is a recently identified differentiation antigen of the mammary gland. To use NY-BR-1 for T-cell-based immunotherapy, analysis of its co-expression with HLA class I antigens is required. In the present tissue microarray study, primary breast cancers (n = 1,444), recurrences (n = 88), lymph node (n = 525) and distant metastases (n = 91) were studied for NY-BR-1 expression using a novel monoclonal antibody. NY-BR-1 expression was compared with prognosis, estrogen receptor, HER2-status, EGFR and HLA class I antigen expression. NY-BR-1 was more frequently expressed in grade 1 (82%) than in grade 2 (69%) and grade 3 (46%) carcinomas (P < 0.0001). Moreover, NY-BR-1 expression correlated directly with estrogen receptor expression (P < 0.0001) and inversely correlated with HER2-status and EGFR expression (P < 0.0001 for both). Considering high expression level of co-expression, 198/1,321 (15%) primary breast carcinomas and 4/65 (6%) distant metastases expressed NY-BR-1 and HLA class I, suggesting that active immunotherapy can be applied to about 10% of breast cancer patients. Survival analysis showed an association of NY-BR-1 expression with better patient outcome (P = 0.015). No difference between NY-BR-1 expression of primary tumors and metastases could be found, indicating that the presence of NY-BR-1 in metastases can be deduced from their corresponding primary. Forty-three paired biopsies taken from patients before and after chemotherapy suggest that NY-BR-1 expression is not influenced by preceding chemotherapy (kappa = 0.89, P < 0.0001). In summary, the co-expression of NY-BR-1 with HLA class I antigens and its expression in metastases without modification by chemotherapy suggest that NY-BR-1 targeted immunotherapy represents a viable strategy in addition to other targeted cancer drug therapies of breast cancer.