Histology Findings after Two Years of Cytology/HPV Co-Testing in Germany.

Introduction: Since 1 January 2020, diagnostic confirmation of abnormalities detected in the context of cytology/HPV co-testing in cervical cancer screening under the statutory health insurance scheme in women aged 35 and over has been performed according to predefined algorithms. A colposcopy is indicated even in the case of borderline/low-grade cytological changes and/or HPV persistence. In this article we compare the histology findings after primary screening examinations in 2020/21 with those from 2018/19, thus also comparing the results of two different screening approaches. Patients and Methods: Our analysis included all of the cytology, HPV, and histology results from all primary screening examinations, as well as the resulting diagnostic confirmation and curative cases, that could be obtained by 30 June 2023. In 2018/19 these comprised 650600 cytology and 1804 histology findings, and in 2020/21 there were 491450 cytology and 7156 histology findings. The absolute numbers of histology findings and the percentage ratios of these to all cytological diagnoses are presented with comparison factors. Results: In 2020/21 there were 5.2 times more histology findings in relation to all previous cytology examinations than in 2018/19, as well as 10.6 times more biopsies, 3.8 times more conizations, and 1.2 times more hysterectomies. There was a particularly high increase in diagnostic confirmation of borderline/low-grade or only HPV-positive findings. With co-testing, 12.7 times more CIN1, 6.4 times more CIN2, and 3.5 times more CIN3 lesions were diagnosed. The proportion of biopsies without dysplasia was 7.6 times higher than in previous years. Cervical carcinomas were diagnosed 1.8 times more frequently, and endometrial carcinomas 0.7 times less frequently. Conclusion: More CIN lesions were found with co-testing, but the increase in histology findings of low-grade or no dysplasia was far greater than findings of CIN3. Lesions not requiring treatment accounted for 94.4% of biopsy results in 2020/21. The use of computer-assisted LBC with progression markers could reduce this.

Comparison of the Hologic Genius Digital Diagnostics System with the ThinPrep Imaging System-A retrospective assessment.

BACKGROUND: Digital cytology (DC) with artificial intelligence (AI) is a new approach. The authors compared DC with liquid-based cytology (LBC) using computer assistance (CAS) in a retrospective, noninterventional study. METHODS: In total, 1994 ThinPrep LBC slides (Hologic), which were previously analyzed in 2020 using an imaging system with CAS in routine cotesting for cytology/human papillomavirus, were reviewed in a blinded mode using the Genius Digital Diagnostics System (Hologic). In 555 cases, a histology result was available. The slides were digitally scanned (volumetric scan) at 14 levels integrated into one. AI algorithms were used to present a gallery of six tiles each (containing objects of interest) in five categories. Six additional tile rows were available, from which the diagnoses were made. All cases with a mismatch between DC and imaging system results were reviewed by an additional cytopathologist. RESULTS: In 86.56% of cases, a complete match between both systems was observed using the same cytology categories. When also considering the histology results, the match was 90.37%. In addition, when a cytology follow-up and/or a retrospective review was applied, the match reached 97.34%. In only 0.65% of cases was a major discrepancy observed (two grades of cytology or a low-grade squamous intraepithelial lesion/high-grade squamous intraepithelial lesion [LSIL/HSIL] shift), and none were identified by DC. Significantly more cases of higher severity (atypical squamous cells cannot exclude high grade [ASC-H], high-grade squamous intraepithelial lesion [HSIL]) were identified with DC, and its negative predictive value was higher. The screening time was significantly shorter with DC. CONCLUSIONS: With the Genius system for DC, the sensitivity for HSIL+/ASC-H and the specificity for LSIL and HSIL were superior to LBC and CAS. Screening time was significantly lower.

Two Years of Cytology and HPV Co-Testing in Germany: Initial Experience.

Introduction On 1 January 2020 the screening programme for the prevention of cervical cancer in women from the age of 35 years of the Statutory Health Insurance (GKV) in Germany changed from an annual cytology examination to cytological and HPV co-testing carried out every three years. A large standard diagnostics laboratory has been using liquid-based cytology (LBC) with computer-assisted screening (CAS) since 1 January 2020 to assess the samples. Patients and Methods The cytological and HPV results for all cases examined with co-testing from 01.01.2020 to 31.12.2021 (n = 395759) are reported and the cytology results obtained using co-testing are compared with the results obtained using only conventional primary cytology screening from the two previous years (n = 588192). Cytology tests were carried out using LBC and computer-assisted screening. A DNA PCR test which can identify 14 types of HPV was used for HPV testing. The cytology results are reported using the Munich Nomenclature III, which is mandatory in Germany, and converted to The Bethesda System (TBS). Problems occurring during the implementation phase are described here. Results A total of 983951 cases who had primary screening between 01.01.2018 and 31.12.2021 were analysed. The HR HPV-positive rate with co-testing for all age groups was 6.41%. Of this group, 16.31% were positive for HPV-16, 4.43% for HPV-18, and 71.40% had one or more of the other 12 HR HPV types. Several different HPV types were identified in 7.86% of cases. The HPV-positive rate for cases with unremarkable cytological findings was 4.03%. 0.46% of tests were technically invalid. The results of primary cytology screening for 2020/21 (LBC) were: Pap 0 (TBS: unsatisfactory) 0.09%, Pap I and Pap II-a (NILM) 96.82%, Pap II-p/g (~ASC-US/AGC) 1.23%, Pap III-p/g (~ASC-H/AGC) 0.19%, Pap III D1 (LSIL) 1.08%, Pap III D2 (HSIL) 0.31%, Pap IVa/b-p/g (HSIL/AIS) 0.18%, and Pap V-p/g (carcinoma) 0.01%. The rates for 2018/19 (conventional cytology without routine testing for HPV) were significantly higher for Pap II-p/g (1.64%) and significantly lower for Pap III-p/g (0.13%), Pap III D1 (0.45%), Pap III D2 (0.10%) and Pap IVa/b-p/g (0.05%). Conclusion Evaluation of the data for the two first years of cytology and HPV co-testing from a standard diagnostics laboratory found low HR HPV-positive rates. As regards the cytology tests, the Pap II-p/g rate was significantly lower and the ≥ Pap III rate was significantly higher compared to the two previous years. This points to a probable higher sensitivity and specificity of the new method.

Claudin-1 is linked to presence of implants and micropapillary pattern in serous borderline epithelial tumours of the ovary.

AIMS: Expression of Claudin-1 has been associated with prognosis in several cancers. Here we investigated the expression pattern of Claudin-1 in borderline tumours of the ovary (BOT). METHODS: We analysed a cohort of 114 cases of borderline tumour (BOT). Claudin-1 expression was studied by immunohistochemistry using a polyclonal antibody and was compared with clinical and histopathological characteristics. RESULTS: Strong Claudin-1 expression was found in 30 cases (26.3%) independent of histological subtype. Expression was significantly less frequent in International Federation of Gynecology and Obstetrics (FIGO) stage I (p= 0.045), while the presence of microinvasion did not correlate with Claudin-1 expression. In contrast, we detected a highly significant association of Claudin-1 expression with the presence of peritoneal implants (p=0.003) and micropapillary pattern (p=0.047), which are features exclusively seen in serous BOT. Moreover, when we restricted our analysis to the subtype of serous BOT, the association of Claudin-1 expression with peritoneal implants (p<0.001) and micropapillary pattern (p =0.003) remained highly significant. CONCLUSIONS: In conclusion, Claudin-1 expression is associated with the presence of peritoneal implants and micropapillary pattern, which have been shown to be associated with poor prognosis. We speculate that overexpression of Claudin-1 might be linked to the mitogen-activated protein kinase pathway activation in BOT and suggest further studies to define its prognostic and potential therapeutic value.

Prognostic evaluation of the B cell/IL-8 metagene in different intrinsic breast cancer subtypes.

We recently reported that a ratio of high B cell and low IL-8 metagene expression identified 32 % of triple negative breast cancers (TNBC) with good prognosis and was the only significant predictor in multivariate analysis including routine clinicopathological variables. However, the clinical relevance of this signature in other breast cancer subtypes remains unclear. We compiled Affymetrix gene expression datasets from 4,467 primary breast cancer samples and excluded 329 triple negative samples which were used as discovery cohort in our previous study. Molecular classification of the remaining 4,138 samples was performed by two methods, including single genes (ER, PgR, HER2, and Ki67) and a centroid-based method using the intrinsic gene list. The prognostic value within the respective subtypes was assessed by analyzing the event-free survival of patients as a function of the B cell/IL-8 metagene ratio using previously published cutoff. ER-negative subtypes had the highest expression of the B cell and the IL-8 metagenes. The IL-8/B cell signature assigned a considerable fraction of samples (range 20.7-42.0 %) into the "good prognosis" group. However, a significant prognostic value was only observed in the subgroup of triple negative breast cancer (P = 0.035). The prognostic value of the B cell/IL-8 ratio is mainly confined to the basal-like and TNBC subtypes of breast cancer. This result underlines the importance of subtype-specific analyses and suggests a sequential multistep approach to developing and applying outcome predictors in the clinic.

Melanoma antigen family A identified by the bimodality index defines a subset of triple negative breast cancers as candidates for immune response augmentation.

BACKGROUND: Molecular markers displaying bimodal expression distribution can reveal distinct disease subsets and may serve as prognostic or predictive markers or represent therapeutic targets. Oestrogen (ER) and human epidermal growth factor receptor 2 (HER2) receptors are strongly bimodally expressed genes in breast cancer. MATERIAL AND METHODS: We applied a novel method to identify bimodally expressed genes in 394 triple negative breast cancers (TNBC). We identified 133 bimodally expressed probe sets (128 unique genes), 69 of these correlated to previously reported metagenes that define molecular subtypes within TNBC including basal-like, molecular-apocrine, claudin-low and immune cell rich subgroups but 64 probe sets showed no correlation with these features. RESULTS: The single most prominent functional group among these uncorrelated genes was the X chromosome derived Cancer/Testis Antigens (CT-X) including melanoma antigen family A (MAGE-A) and Cancer/Testis Antigens (CTAG). High expression of CT-X genes correlated with worse survival in multivariate analysis (HR 2.02, 95% CI 1.27-3.20; P=0.003). The only other significant variable was lymph node status. The poor prognosis of patients with high MAGE-A expression was ameliorated by the concomitant high expression of immune cell metagenes (HR 1.87, 95% CI 0.96-3.64; P=0.060), whereas the same immune metagene had lesser prognostic value in TNBC with low MAGE-A expression. CONCLUSIONS: MAGE-A antigen defines a very aggressive subgroup of TNBC; particularly in the absence of immune infiltration in the tumour microenvironment. These observations suggest a therapeutic hypothesis; TNBC with MAGE-A expression may benefit the most from further augmentation of the immune response. Novel immune stimulatory drugs such as (anti-cytotoxic T-lymphocyte antigen-4 CTLA-4) directed therapies provide a realistic opportunity to directly test this hypothesis in the clinic.

A clinically relevant gene signature in triple negative and basal-like breast cancer.

INTRODUCTION: Current prognostic gene expression profiles for breast cancer mainly reflect proliferation status and are most useful in ER-positive cancers. Triple negative breast cancers (TNBC) are clinically heterogeneous and prognostic markers and biology-based therapies are needed to better treat this disease. METHODS: We assembled Affymetrix gene expression data for 579 TNBC and performed unsupervised analysis to define metagenes that distinguish molecular subsets within TNBC. We used n = 394 cases for discovery and n = 185 cases for validation. Sixteen metagenes emerged that identified basal-like, apocrine and claudin-low molecular subtypes, or reflected various non-neoplastic cell populations, including immune cells, blood, adipocytes, stroma, angiogenesis and inflammation within the cancer. The expressions of these metagenes were correlated with survival and multivariate analysis was performed, including routine clinical and pathological variables. RESULTS: Seventy-three percent of TNBC displayed basal-like molecular subtype that correlated with high histological grade and younger age. Survival of basal-like TNBC was not different from non basal-like TNBC. High expression of immune cell metagenes was associated with good and high expression of inflammation and angiogenesis-related metagenes were associated with poor prognosis. A ratio of high B-cell and low IL-8 metagenes identified 32% of TNBC with good prognosis (hazard ratio (HR) 0.37, 95% CI 0.22 to 0.61; P < 0.001) and was the only significant predictor in multivariate analysis including routine clinicopathological variables. CONCLUSIONS: We describe a ratio of high B-cell presence and low IL-8 activity as a powerful new prognostic marker for TNBC. Inhibition of the IL-8 pathway also represents an attractive novel therapeutic target for this disease.

Homogeneous datasets of triple negative breast cancers enable the identification of novel prognostic and predictive signatures.

BACKGROUND: Current prognostic gene signatures for breast cancer mainly reflect proliferation status and have limited value in triple-negative (TNBC) cancers. The identification of prognostic signatures from TNBC cohorts was limited in the past due to small sample sizes. METHODOLOGY/PRINCIPAL FINDINGS: We assembled all currently publically available TNBC gene expression datasets generated on Affymetrix gene chips. Inter-laboratory variation was minimized by filtering methods for both samples and genes. Supervised analysis was performed to identify prognostic signatures from 394 cases which were subsequently tested on an independent validation cohort (n = 261 cases). CONCLUSIONS/SIGNIFICANCE: Using two distinct false discovery rate thresholds, 25% and <3.5%, a larger (n = 264 probesets) and a smaller (n = 26 probesets) prognostic gene sets were identified and used as prognostic predictors. Most of these genes were positively associated with poor prognosis and correlated to metagenes for inflammation and angiogenesis. No correlation to other previously published prognostic signatures (recurrence score, genomic grade index, 70-gene signature, wound response signature, 7-gene immune response module, stroma derived prognostic predictor, and a medullary like signature) was observed. In multivariate analyses in the validation cohort the two signatures showed hazard ratios of 4.03 (95% confidence interval [CI] 1.71-9.48; P = 0.001) and 4.08 (95% CI 1.79-9.28; P = 0.001), respectively. The 10-year event-free survival was 70% for the good risk and 20% for the high risk group. The 26-gene signatures had modest predictive value (AUC = 0.588) to predict response to neoadjuvant chemotherapy, however, the combination of a B-cell metagene with the prognostic signatures increased its response predictive value. We identified a 264-gene prognostic signature for TNBC which is unrelated to previously known prognostic signatures.

Data-driven derivation of cutoffs from a pool of 3,030 Affymetrix arrays to stratify distinct clinical types of breast cancer.

Pooling of microarray datasets seems to be a reasonable approach to increase sample size when a heterogeneous disease like breast cancer is concerned. Different methods for the adaption of datasets have been used in the literature. We have analyzed influences of these strategies using a pool of 3,030 Affymetrix U133A microarrays from breast cancer samples. We present data on the resulting concordance with biochemical assays of well known parameters and highlight critical pitfalls. We further propose a method for the inference of cutoff values directly from the data without prior knowledge of the true result. The cutoffs derived by this method displayed high specificity and sensitivity. Markers with a bimodal distribution like ER, PgR, and HER2 discriminate different biological subtypes of disease with distinct clinical courses. In contrast, markers displaying a continuous distribution like proliferation markers as Ki67 rather describe the composition of the mixture of cells in the tumor.

T-cell metagene predicts a favorable prognosis in estrogen receptor-negative and HER2-positive breast cancers.

INTRODUCTION: Lymphocyte infiltration (LI) is often seen in breast cancer but its importance remains controversial. A positive correlation of human epidermal growth factor receptor 2 (HER2) amplification and LI has been described, which was associated with a more favorable outcome. However, specific lymphocytes might also promote tumor progression by shifting the cytokine milieu in the tumor. METHODS: Affymetrix HG-U133A microarray data of 1,781 primary breast cancer samples from 12 datasets were included. The correlation of immune system-related metagenes with different immune cells, clinical parameters, and survival was analyzed. RESULTS: A large cluster of nearly 600 genes with functions in immune cells was consistently obtained in all datasets. Seven robust metagenes from this cluster can act as surrogate markers for the amount of different immune cell types in the breast cancer sample. An IgG metagene as a marker for B cells had no significant prognostic value. In contrast, a strong positive prognostic value for the T-cell surrogate marker (lymphocyte-specific kinase (LCK) metagene) was observed among all estrogen receptor (ER)-negative tumors and those ER-positive tumors with a HER2 overexpression. Moreover ER-negative tumors with high expression of both IgG and LCK metagenes seem to respond better to neoadjuvant chemotherapy. CONCLUSIONS: Precise definitions of the specific subtypes of immune cells in the tumor can be accomplished from microarray data. These surrogate markers define subgroups of tumors with different prognosis. Importantly, all known prognostic gene signatures uniformly assign poor prognosis to all ER-negative tumors. In contrast, the LCK metagene actually separates the ER-negative group into better or worse prognosis.

Loss of Plexin B1 is highly prognostic in low proliferating ER positive breast cancers--results of a large scale microarray analysis.

Plexins, cell-surface receptors for semaphorins, are involved in cell adhesion and migration. In the previous work, we demonstrated that the loss of Plexin B1 expression is associated with poor outcome in breast cancer patients. The goal of the present study was a validation of Plexin B1 expression in a large scale microarray dataset from n=1086 breast cancer patients. Plexin B1 correlates with ER status (p<0.001) and is of prognostic significance only in ER positive (p=0.024) but not in ER negative samples (p=0.85). Among ER positive tumours, the loss of Plexin B1 expression is associated with a positive ErbB2 status (p=0.05) and a high Ki67 expression (p=0.016) in univariate analysis. Multivariate Cox regression including all standard parameters among ER positive tumours revealed that Plexin B1 (HR 1.59, 95% confidence interval (CI) 1.03-2.47, p=0.036) remains a significant prognostic marker besides tumour size (HR 2.27, 95% CI 1.33-3.89, p=0.0028) and Ki67 (HR 1.78, 95% CI 1.12-2.84, p=0.0149). Interestingly, the prognostic value of Plexin B1 was pronounced in low proliferating ER positive tumours otherwise characterised by a low risk of recurrence. In conclusion, this study confirms our previous observations suggesting Plexin B1 as a new prognostic marker in ER positive breast cancers.

Poor outcome in estrogen receptor-positive breast cancers predicted by loss of plexin B1.

PURPOSE: A common characteristic of mammary carcinomas is an inverse relationship between the estrogen receptor (ER) status and the proliferative activity of the tumor. Yet, a subset of ER-positive breast cancers is characterized by a high proliferation, suggesting malfunctions in ER responsiveness that influence the biological and therapeutic behavior of tumor cells. The expression of several ER-dependent genes seems to be dysregulated among those "uncoupled" tumors. One of those genes is plexin B1, a cell-surface receptor for the semaphorin Sema4D (CD 100). However, the biological role of plexin B1 in breast cancer is largely unknown. EXPERIMENTAL DESIGN: Expression data of plexin B1 were obtained from Affymetrix microarray analysis of n = 119 breast cancer specimens. Validation was done by quantitative real-time PCR and protein expression was evaluated by immunohistochemistry. Expression data were compared with clinical characteristics as well as follow-up data of the disease. RESULTS: Low plexin B1 expression levels characterize a more aggressive tumor phenotype. The expression of plexin B1 is strongly correlated with the ER status. However, even among ER-positive tumors, loss of plexin B1 is associated with an impaired prognosis of breast cancer patients in both univariate (all patients, P = 0.0062; ER positive, P = 0.0107) and multivariate analyses (all patients, P = 0.032; ER positive, P = 0.022). Immunohistochemistry reveals that the tumor cells themselves and not the endothelial cells are the major source of plexin B1 expression in the tumor. CONCLUSION: Plexin B1 acts not only as a new important prognostic but should also represent a predictive marker indicating an endocrine resistance. These data give a new insight in markers that could be involved in endocrine dysregulation of breast cancer.

Outcome of preterm and term neonates of mothers with malignant diseases diagnosed during pregnancy.

OBJECTIVE: To investigate the outcome of preterm and term neonates born to mothers with malignant diseases diagnosed during pregnancy. METHODS: A retrospective analysis with a matched-paired control group in a third level obstetric department and third level neonatal department of the University Hospital Frankfurt. Patients were preterm and term neonates from mothers with oncologic diseases diagnosed during pregnancy and matched-paired preterm and term neonates from healthy mothers. MEASUREMENTS AND RESULTS: Nineteen preterm and three term (1 x twins) neonates from 21 mothers with oncologic diseases and matched-paired neonates from 21 healthy mothers were included. With the exception of one case, pregnancy was terminated because of the necessity for maternal oncological treatment. Children from mothers with malignant diseases had a significantly lower birth weight and a tendency towards a higher incidence of high-grade respiratory distress syndrome. No significant differences concerning Apgar scores, red blood cell (RBC), white blood cell (WBC), and platelet (PLT) counts postpartum, and duration of hospital days between the two groups of neonates were observed. CONCLUSION: Direct perinatal outcome of preterm or term neonates from mothers with malignant diseases diagnosed during ongoing intact pregnancy does not differ from the outcome of a comparable group of neonates from healthy mothers. This might be in contrast to the long-term outcome of this special patient group. In our study we could find no elevated mortality in neonates where pregnancy was terminated because of the need for maternal chemotherapeutic therapy.

Uterine contractility and directed sperm transport assessed by hysterosalpingoscintigraphy (HSSG) and intrauterine pressure (IUP) measurement.

BACKGROUND: Uterine peristalsis sustains sperm transport and can be detected by hysterosalpingoscintigraphy (HSSG). This study is the first to be designed to investigate utero-tubal transport function by HSSG and uterine contractility by intrauterine pressure measurement (IUP) consecutively on the same day in the periovulatory phase. METHODS: Twenty-one female subjects (mean age 28.4 years) without a gynecologic history were examined sequentially by HSSG and IUP on the same day to evaluate uterine contractility in relation to the utero-tubal transport function. In HSSG, intact transport function was visualized by the rapid uptake of 99m-technetium-marked albumin aggregates through the female genital tract. In IUP, the frequency of uterine contractions (UC/min), amplitude of uterine contractions and basal pressure tone were detected via a intrauterine catheter. HSSG and IUP were embedded in cycle monitoring with measurement of LH and estradiol. RESULTS: In HSSG, a positive transport of inert particles was assessed in 20 of 21 subjects, in 76% to the side of the dominant follicle or on both sides of the oviduct, and in 19% a strict contralateral transport could be observed. In only one subject (5%), no transport was assessed. The mean value of uterine contractions was 3.4 UC/min (SD +/- 0.7), the mean amplitude was 12.0 mmHg (SD +/- 4.25 mmHg). Basal pressure tone was 70.7 mmHg. There was a statistically significant correlation with estradiol levels: none of the subjects with less than 3 UC/min showed an estradiol level higher than 100 pg/mL; nearly every patient (one exception) with more than 3 UC/min had an estradiol level higher than 100 pg/mL (p < 0.0001, Fisher's exact test). CONCLUSIONS: Intact periovulatory utero-tubal transport function can be documented by HSSG and is caused by directed uterine contractility, measured consecutively by IUP. Uterine contractility is influenced by rising estradiol levels. Directed uterine contractility and intact utero-tubal transport function are considered necessary for intact sperm transport, mainly to the side bearing the dominant follicle to maximize fertility.

Acute ethanol intoxication during pregnancy and consecutive fetal cardiac arrest: a case report.

Chronic alcohol exposure during pregnancy and the resulting toxic effects for the fetus has been the subject of many investigations. In contrast, acute alcohol intoxication during pregnancy is a rare event and less is known about the consequences for fetal life. We report a case of the acute ethanol intoxication of a pregnant woman at the 35th week of gestation and the consecutive cardiac arrest of the neonate. Despite the life threatening event, the newborn recovered after resuscitation and intensive care treatment and could be discharged from hospital in good physical condition. We suggest that acute alcoholized pregnant women should be transferred to Perinatal Centers to cater for the possible need for emergency cesarean section and resuscitation of the newborn.

From latent disseminated cells to overt metastasis: genetic analysis of systemic breast cancer progression.

According to the present view, metastasis marks the end in a sequence of genomic changes underlying the progression of an epithelial cell to a lethal cancer. Here, we aimed to find out at what stage of tumor development transformed cells leave the primary tumor and whether a defined genotype corresponds to metastatic disease. To this end, we isolated single disseminated cancer cells from bone marrow of breast cancer patients and performed single-cell comparative genomic hybridization. We analyzed disseminated tumor cells from patients after curative resection of the primary tumor (stage M0), as presumptive progenitors of manifest metastasis, and from patients with manifest metastasis (stage M1). Their genomic data were compared with those from microdissected areas of matched primary tumors. Disseminated cells from M0-stage patients displayed significantly fewer chromosomal aberrations than primary tumors or cells from M1-stage patients (P < 0.008 and P < 0.0001, respectively), and their aberrations appeared to be randomly generated. In contrast, primary tumors and M1 cells harbored different and characteristic chromosomal imbalances. Moreover, applying machine-learning methods for the classification of the genotypes, we could correctly identify the presence or absence of metastatic disease in a patient on the basis of a single-cell genome. We suggest that in breast cancer, tumor cells may disseminate in a far less progressed genomic state than previously thought, and that they acquire genomic aberrations typical of metastatic cells thereafter. Thus, our data challenge the widely held view that the precursors of metastasis are derived from the most advanced clone within the primary tumor.

Anti-epidermal growth factor receptor-antibody therapy for treatment of breast cancer.

Recent studies demonstrated that tumors overexpressing the epidermal growth factor receptor (EGF-R, erbB-1) are associated with poor clinical outcome. This led to the development of a variety of monoclonal antibodies targeting the extracellular domain of this receptor tyrosine kinase. The aim of our study was the evaluation of anti-EGF-R antibody EMD 55900 therapy for treatment of breast cancer. On the basis of 299 tumor specimens derived from breast cancer patients, we investigated EGF-R expression and generated a collective of primary xenotransplants in athymic nude mice. The animals received therapy in 2 treatment schedules to investigate the therapeutic response in early stages of tumor formation as well as on well established tumors. Using 6 different tumors with EGF-R expression levels between 10-300 fmol/mg total protein, we found a therapeutic effect when the EGF-R expression of the tumors was at least 40 fMol/mg. On the basis of these experimental data and our EGF-R expression analysis of breast cancer specimens, we conclude that up to 15% of breast cancer patients could benefit from this monotherapy with EMD 55900.

Identification of high risk breast-cancer patients by gene expression profiling.

We previously used DNA array analyses in the molecular profiling of breast cancers. By cluster analysis of 55 patients, we identified a subpopulation of breast cancers-designated class A-that contained a high number of nodal-positive tumours and that had frequently developed distant metastases at the time of diagnosis. We have now analysed follow-up data from these patients. We found that, despite a median of only 23.5 months of follow-up, 11 of 22 patients in class A progressed to metastatic disease, and three of five patients classified as having a nodal status of N0 in this subpopulation developed distant metastases. Our analysis identifies breast-cancer patients with a high risk of disease recurrence, and could act as a first step towards improved patient-adapted therapy.