Clinicopathologic features, genomic profiles and outcomes of younger vs. older Chinese hormone receptor-positive (HR+)/HER2-negative (HER2-) metastatic breast cancer patients

Background

Poor outcomes have been widely reported for younger vs. older breast cancer patients, but whether this is due to age itself or the enrichment of aggressive clinical features remains controversial. We have evaluated the clinicopathologic characteristics and genomic profiles of real-world hormone receptor-positive (HR+)/HER2-negative (HER2-) metastatic breast cancer (MBC) patients to examine the determinants of outcome for younger vs. older patients in a single clinical subtype undergoing treatment in the same clinic.

Patients and methods

This study included patients presenting at the Peking University Cancer Hospital with primary stage IV or first-line metastatic HR+/HER2- breast cancer who consented to an additional blood draw for genomic profiling prior to treatment. Plasma samples were analyzed with a targeted 152-gene NGS panel to assess somatic circulating tumor DNA (ctDNA) alterations. Genomic DNA (gDNA) extracted from peripheral blood mononuclear cells was analyzed for germline variants using a targeted 600-gene NGS panel. Kaplan-Meier survival analysis was performed to analyze disease free survival (DFS), progression free survival (PFS) and overall survival (OS) in association with clinicopathologic and genomic variables.

Results

Sixty-three patients presenting with HR+/HER2- MBC were enrolled in this study. Fourteen patients were < 40 years, 19 were 40-50 years, and 30 were > 50 years at the time of primary cancer diagnosis. No significant associations were observed between age and DFS, PFS or OS. Shorter OS was associated with de novo Stage IV disease (p = 0.002), Luminal B subtype (p = 0.006), high Ki67 index (p = 0.036), resistance to adjuvant endocrine therapy (p = 0.0001) and clinical stage (p = 0.015). Reduced OS was also observed in association with somatic alterations in FGFR1 (p = 0.008), CCND2 (p = 0.012), RB1 (p = 0.029) or TP53 (p = 0.029) genes, but not in association with germline variants.

Conclusion

In this group of real-world HR+/HER2- MBC breast cancer patients younger age was not associated with poor outcomes. While current guidelines recommend treatment decisions based on tumor biology rather than age, young HR+ breast cancer patients are more likely to receive chemotherapy. Our findings support the development of biomarker-driven treatment strategies for these patients.

Genomic Complexity Predicts Resistance to Endocrine Therapy and CDK4/6 Inhibition in Hormone Receptor-Positive (HR+)/HER2-Negative Metastatic Breast Cancer

PURPOSE

Clinical biomarkers to identify patients unlikely to benefit from CDK4/6 inhibition (CDK4/6i) in combination with endocrine therapy (ET) are lacking. We implemented a comprehensive circulating tumor DNA (ctDNA) analysis to identify genomic features for predicting and monitoring treatment resistance.

EXPERIMENTAL DESIGN

ctDNA was isolated from 216 plasma samples collected from 51 patients with hormone receptor-positive (HR+)/HER2-negative (HER2-) metastatic breast cancer (MBC) on a phase II trial of palbociclib combined with letrozole or fulvestrant (NCT03007979). Boosted whole-exome sequencing (WES) was performed at baseline and clinical progression to evaluate genomic alterations, mutational signatures, and blood tumor mutational burden (bTMB). Low-pass whole-genome sequencing was performed at baseline and serial timepoints to assess blood copy-number burden (bCNB).

RESULTS

High bTMB and bCNB were associated with lack of clinical benefit and significantly shorter progression-free survival (PFS) compared with patients with low bTMB or low bCNB (all P < 0.05). Dominant APOBEC signatures were detected at baseline exclusively in cases with high bTMB (5/13, 38.5%) versus low bTMB (0/37, 0%; P = 0.0006). Alterations in ESR1 were enriched in samples with high bTMB (P = 0.0005). There was a high correlation between bTMB determined by WES and bTMB determined using a 600-gene panel (R = 0.98). During serial monitoring, an increase in bCNB score preceded radiographic progression in 12 of 18 (66.7%) patients.

CONCLUSIONS

Genomic complexity detected by noninvasive profiling of bTMB and bCNB predicted poor outcomes in patients treated with ET and CDK4/6i and identified early disease progression before imaging. Novel treatment strategies including immunotherapy-based combinations should be investigated in this population.

medna-metadata: an open-source data management system for tracking environmental DNA samples and metadata

MOTIVATION

Environmental DNA (eDNA), as a rapidly expanding research field, stands to benefit from shared resources including sampling protocols, study designs, discovered sequences, and taxonomic assignments to sequences. High-quality community shareable eDNA resources rely heavily on comprehensive metadata documentation that captures the complex workflows covering field sampling, molecular biology lab work, and bioinformatic analyses. There are limited sources that provide documentation of database development on comprehensive metadata for eDNA and these workflows and no open-source software.

RESULTS

We present medna-metadata, an open-source, modular system that aligns with Findable, Accessible, Interoperable, and Reusable guiding principles that support scholarly data reuse and the database and application development of a standardized metadata collection structure that encapsulates critical aspects of field data collection, wet lab processing, and bioinformatic analysis. Medna-metadata is showcased with metabarcoding data from the Gulf of Maine (Polinski et al., 2019).

AVAILABILITY AND IMPLEMENTATION

The source code of the medna-metadata web application is hosted on GitHub (https://github.com/Maine-eDNA/medna-metadata). Medna-metadata is a docker-compose installable package. Documentation can be found at https://medna-metadata.readthedocs.io/en/latest/?badge=latest. The application is implemented in Python, PostgreSQL and PostGIS, RabbitMQ, and NGINX, with all major browsers supported. A demo can be found at https://demo.metadata.maine-edna.org/.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Identification of mutation patterns and circulating tumour DNA-derived prognostic markers in advanced breast cancer patients

BACKGROUND

The correlations between circulating tumour DNA (ctDNA)-derived genomic markers and treatment response and survival outcome in Chinese patients with advanced breast cancer (ABC) have not been extensively characterized.

METHODS

Blood samples from 141 ABC patients who underwent first-line standard treatment in Peking University Cancer Hospital were collected. A next-generation sequencing based liquid biopsy assay (PredicineCARE) was used to detect somatic mutations and copy number variations (CNVs) in ctDNA. A subset of matched blood samples and tumour tissue biopsies were compared to evaluate the concordance.

RESULTS

Overall, TP53 (44.0%) and PIK3CA (28.4%) were the top two altered genes. Frequent CNVs included amplifications of ERBB2 (24.8%) and FGFR1 (8.5%) and deletions of CDKN2A (3.5%). PIK3CA/TP53 and FGFR1/2/3 variants were associated with drug resistance in hormone receptor-positive (HR +) and human epidermal growth factor receptor 2-positive (HER2 +) patients. The comparison of genomic variants across matched tumour tissue and ctDNA samples revealed a moderate to high concordance that was gene dependent. Triple-negative breast cancer (TNBC) patients harbouring TP53 or PIK3CA alterations had a shorter overall survival than those without corresponding mutations (P = 0.03 and 0.008). A high ctDNA fraction was correlated with a shorter progression-free survival (PFS) (P = 0.005) in TNBC patients. High blood-based tumor mutation burden (bTMB) was associated with a shorter PFS for HER2 + and TNBC patients (P = 0.009 and 0.05). Moreover, disease monitoring revealed several acquired genomic variants such as ESR1 mutations, CDKN2A deletions, and FGFR1 amplifications.

CONCLUSIONS

This study revealed the molecular profiles of Chinese patients with ABC and the clinical validity of ctDNA-derived markers, including the ctDNA fraction and bTMB, for predicting treatment response, prognosis, and disease progression.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03792529. Registered January 3rd 2019, https://clinicaltrials.gov/ct2/show/NCT03792529 .

Dynamic changes in gene alterations during chemotherapy in metastatic castrate resistant prostate cancer

Docetaxel chemotherapy is a standard treatment option for metastatic castrate resistant prostate cancer (mCRPC) patients. To date, the genomic perturbations underlying the emergence of resistance in mCRPC patients during chemotherapy treatment have not been fully characterized. Previous studies have established that AR, TP53, RB1 and PTEN gene alterations are frequent at this stage of progression and that TP53, RB1 and PTEN, but not AR alterations are associated with poor outcome. However, the clonal dynamics of these key driver cancer genes during chemotherapy in mCRPC patients have not been described. Toward this goal, we performed a retrospective analysis of serially profiled cell-free DNA (cfDNA) alterations in blood samples collected from mCRPC patients before and after starting chemotherapy who were followed for response and clinical outcomes. While AR alterations and measures of mutational load were significantly reduced in patients with stable or decreased PSA levels after 3 cycles of chemotherapy, reductions in RB1, TP53 and PTEN alterations were relatively modest, which may represent the persistence of a clonal signature associated with the emergence of treatment-induced lineage plasticity (TILP) underlying resistance. The ability to monitor these driver gene clonal dynamics during chemotherapy may have utility in the clinical setting.

Circulating Cell-Free DNA-Based Detection of Tumor Suppressor Gene Copy Number Loss and Its Clinical Implication in Metastatic Prostate Cancer

Current liquid biopsy assays lack sufficient sensitivity to detect copy number loss, which limits the interrogation of critical tumor suppressor gene deletions during cancer progression and treatment. Here we describe a liquid biopsy assay with improved sensitivity for detection of copy number loss in blood samples with low levels of circulating tumor DNA, and demonstrate its utility by profiling PTEN, RB1, and TP53 genetic loss in metastatic prostate cancer patients.

Automated Cell Segmentation for Quantitative Phase Microscopy

Automated cell segmentation and tracking is essential for dynamic studies of cellular morphology, movement, and interactions as well as other cellular behaviors. However, accurate, automated, and easy-to-use cell segmentation remains a challenge, especially in cases of high cell densities, where discrete boundaries are not easily discernable. Here, we present a fully automated segmentation algorithm that iteratively segments cells based on the observed distribution of optical cell volumes measured by quantitative phase microscopy. By fitting these distributions to known probability density functions, we are able to converge on volumetric thresholds that enable valid segmentation cuts. Since each threshold is determined from the observed data itself, virtually no input is needed from the user. We demonstrate the effectiveness of this approach over time using six cell types that display a range of morphologies, and evaluate these cultures over a range of confluencies. Facile dynamic measures of cell mobility and function revealed unique cellular behaviors that relate to tissue origins, state of differentiation, and real-time signaling. These will improve our understanding of multicellular communication and organization.

Local estrogen axis in the human bone microenvironment regulates estrogen receptor-positive breast cancer cells

BACKGROUND

Approximately 70% of all breast cancers express the estrogen receptor, and are regulated by estrogen. While the ovaries are the primary source of estrogen in premenopausal women, most breast cancer is diagnosed following menopause, when systemic levels of this hormone decline. Estrogen production from androgen precursors is catalyzed by the aromatase enzyme. Although aromatase expression and local estrogen production in breast adipose tissue have been implicated in the development of primary breast cancer, the source of estrogen involved in the regulation of estrogen receptor-positive (ER+) metastatic breast cancer progression is less clear.

METHODS

Bone is the most common distant site of breast cancer metastasis, particularly for ER+ breast cancers. We employed a co-culture model using trabecular  bone tissues obtained from total hip replacement (THR) surgery specimens to study ER+ and estrogen receptor-negative (ER-) breast cancer cells within the human bone microenvironment. Luciferase-expressing ER+ (MCF-7, T-47D, ZR-75) and ER- (SK-BR-3, MDA-MB-231, MCF-10A) breast cancer cells were cultured directly on bone tissue fragments or in bone tissue-conditioned media, and monitored over time with bioluminescence imaging (BLI). Bone tissue-conditioned media were generated in the presence vs. absence of aromatase inhibitors, and testosterone. Bone tissue fragments were analyzed for aromatase expression by immunohistochemistry.

RESULTS

ER+ breast cancer cells were preferentially sustained in co-cultures with bone tissues and bone tissue-conditioned media relative to ER- cells. Bone fragments analyzed by immunohistochemistry revealed expression of the aromatase enzyme. Bone tissue-conditioned media generated in the presence of testosterone had increased estrogen levels and heightened capacity to stimulate ER+ breast cancer cell proliferation. Pretreatment of cultured bone tissues with aromatase inhibitors, which inhibited estrogen production, reduced the capacity of conditioned media to stimulate ER+ cell proliferation.

CONCLUSIONS

These results suggest that a local estrogen signaling axis regulates ER+ breast cancer cell viability and proliferation within the bone metastatic niche, and that aromatase inhibitors modulate this axis. Although endocrine therapies are highly effective in the treatment of ER+ breast cancer, resistance to these treatments reduces their efficacy. Characterization of estrogen signaling networks within the bone microenvironment will identify new strategies for combating metastatic progression and endocrine resistance.

A retrospective comparison of neoadjuvant chemoradiotherapy regimens for locally advanced esophageal cancer

Preoperative chemoradiotherapy (CRT) with carboplatin/paclitaxel has been shown to increase survival in patients with esophageal cancer, including gastroesophageal junction (GE) junction cancer, over surgery alone; however, there have been no studies comparing the different neoadjuvant CRT regimens. We retrospectively evaluated the long-term results of trimodality therapy for patients with locally advanced esophageal cancer treated on several chemotherapy regimens. Between 1999 and 2014, 215 patients with locally advanced esophageal cancer underwent neoadjuvant CRT followed by surgical resection. The median age was 62 years (range 21-84), 80.5% were men and 86% had adenocarcinoma. The following chemotherapy regimens were administered: cisplatin/5FU (14.9%), cisplatin/irinotecan (35.8%), carboplatin/paclitaxel (35.8%), and other (9.7%). The majority of patients (92.1%) received a radiation dose of 50.4 Gy. Predictors of toxicities and surgical complications were assessed using logistic regression. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method and proportional hazards regression was used to model time-to-event outcomes. The median follow-up among surviving patients was 4.1 years (range 0.4,13). The median OS was 3.0 years from time of diagnosis and OS was 36.8% at 5 years. RFS was 34.9% at 5 years. After neoadjuvant CRT, 34.7% of patients achieved a pathologic complete response including 60.7% of squamous cell carcinoma patients and 18.4% of adenocarcinoma patients (P < 0.001) and 66% were downstaged. Of the variables examined, pathologic stage, preoperative baseline cardiac comorbidity, postoperative cardiac or pulmonary complications, and chemotherapy regimen were associated with OS. Using cisplatin and 5FU as the reference regimen, patients treated with carboplatin/paclitaxel had significantly improved OS (HR = 0.47, P = 0.017 after adjusting for surgery type, radiation modality, baseline cardiac comorbidity, and preoperative stage) with 5-year OS rate of 66%. The most common surgical complications were cardiac in 61 patients (28.5%) and pulmonary in 52 patients (24.3%). Cardiac complications were associated with age (OR 1.05, P = 0.007) and cardiac comorbidity (OR 2.6, P = 0.02) and pulmonary complications with female gender (OR 3.98, P < 0.001). Forty-four patients (20.5%) required readmission within 30 days of discharge, and readmission was associated with cardiac comorbidity (OR 2.7, P = 0.017). Three patients died within 30 days of surgery. We observed an association between neoadjuvant carboplatin/paclitaxel and improved overall survival that requires confirmation in a prospective randomized trial.

Detection of non-melanoma skin cancer by in vivo fluorescence imaging with fluorocoxib A

Non-melanoma skin cancer (NMSC) is the most common form of cancer in the US and its incidence is increasing. The current standard of care is visual inspection by physicians and/or dermatologists, followed by skin biopsy and pathologic confirmation. We have investigated the use of in vivo fluorescence imaging using fluorocoxib A as a molecular probe for early detection and assessment of skin tumors in mouse models of NMSC. Fluorocoxib A targets the cyclooxygenase-2 (COX-2) enzyme that is preferentially expressed by inflamed and tumor tissue, and therefore has potential to be an effective broadly active molecular biomarker for cancer detection. We tested the sensitivity of fluorocoxib A in a BCC allograft SCID hairless mouse model using a wide-field fluorescence imaging system. Subcutaneous allografts comprised of 1000 BCC cells were detectable above background. These BCC allograft mice were imaged over time and a linear correlation (R² = 0.8) between tumor volume and fluorocoxib A signal levels was observed. We also tested fluorocoxib A in a genetically engineered spontaneous BCC mouse model (Ptch1^+/− K14-Cre-ER2 p53^fl/fl), where sequential imaging of the same animals over time demonstrated that early, microscopic lesions (100 μm size) developed into visible macroscopic tumor masses over 11 to 17 days. Overall, for macroscopic tumors, the sensitivity was 88% and the specificity was 100%. For microscopic tumors, the sensitivity was 85% and specificity was 56%. These results demonstrate the potential of fluorocoxib A as an in vivo imaging agent for early detection, margin delineation and guided biopsies of NMSCs.

Methods for culturing human femur tissue explants to study breast cancer cell colonization of the metastatic niche

Bone is the most common site of breast cancer metastasis. Although it is widely accepted that the microenvironment influences cancer cell behavior, little is known about breast cancer cell properties and behaviors within the native microenvironment of human bone tissue.We have developed approaches to track, quantify and modulate human breast cancer cells within the microenvironment of cultured human bone tissue fragments isolated from discarded femoral heads following total hip replacement surgeries. Using breast cancer cells engineered for luciferase and enhanced green fluorescent protein (EGFP) expression, we are able to reproducibly quantitate migration and proliferation patterns using bioluminescence imaging (BLI), track cell interactions within the bone fragments using fluorescence microscopy, and evaluate breast cells after colonization with flow cytometry. The key advantages of this model include: 1) a native, architecturally intact tissue microenvironment that includes relevant human cell types, and 2) direct access to the microenvironment, which facilitates rapid quantitative and qualitative monitoring and perturbation of breast and bone cell properties, behaviors and interactions. A primary limitation, at present, is the finite viability of the tissue fragments, which confines the window of study to short-term culture. Applications of the model system include studying the basic biology of breast cancer and other bone-seeking malignancies within the metastatic niche, and developing therapeutic strategies to effectively target breast cancer cells in bone tissues.

Monitoring dynamic interactions between breast cancer cells and human bone tissue in a co-culture model

PURPOSE

Bone is a preferential site of breast cancer metastasis, and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue.

PROCEDURES

Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell proliferation and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX(®) immunoassays.

RESULTS

BLI demonstrated increased MDA-MB-231-fLuc cell proliferation (p < 0.001) in the presence vs. absence of bones and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc cell colonization of bone, and MILLIPLEX(®) profiles of culture supernatants suggested breast/bone crosstalk.

CONCLUSIONS

Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays.

Abstract A48: Optical imaging model for monitoring dynamic interactions of breast cancer cells and bone tissues in ex vivo co-cultures

Purpose: Bone is the most common site of breast cancer metastasis and model systems are needed to study aspects of this process directly at the microenvironmental level. Our goal was to establish optical imaging approaches to monitor and quantitate the dynamics of cell growth, migration and colonization in viable ex vivo co-cultures of breast cancer cells and bone tissue explants.

Experimental Procedures: Femur tissues harvested from CD-1 nude mice and discarded femoral heads from human hip replacement surgeries were cultivated in 6-well tissue culture plates adjacent to 4T1 mouse mammary carcinoma or MDA-MB-231 human breast cancer cells harboring luciferase reporters. Serial bioluminescence imaging (BLI) was performed on an IVIS 50 Imaging System to quantify breast cancer cell growth, track breast cell migration toward bones, and monitor breast cell colonization of bone tissue over a period of days and weeks. Bioluminescence imaging of single breast cancer cells in these cultures was also performed over time using a prototype LV200 Bioluminescent Imaging System from Olympus.

Summary of Results: BLI revealed the directed migration of breast cancer cells toward and into adjacent bone tissues within days, and documented extended colonization of bone tissues for up to several weeks. Quantitative BLI demonstrated variable growth rates for breast cancer cells grown in the presence vs. absence of bone tissues. Growth, migration and colonization varied dramatically and consistently according to the region of femur (epiphysis vs. diaphysis) used for co-culture. The variable patterns of breast cancer cell growth and migration observed in association with different anatomic regions of the femur are consistent with the presence of distinct cell populations within specific microenvironmental compartments of the bone. Migration of bone cells toward adjacent colonies of breast cancer cells was also observed.

Conclusions: Cell behaviors associated with breast cancer metastasis occur reproducibly in viable, dynamic ex vivo co-cultures and can be monitored and quantified using optical imaging approaches. Because of the accelerated time course of interactions, and the immediate quantitation afforded by BLI, this model will facilitate the direct, rapid study of breast cancer cell interactions within the metastatic niche of bone tissues. This approach circumvents the prolonged time course associated with in vivo metastasis models and offers the potential for high throughput perturbation to identify and evaluate therapeutic interventions.

Citation Format: Bonnie L. King, Marie Bammer, Irfan Ali-Khan, Jonathan W. Hardy, Christopher H. Contag. Optical imaging model for monitoring dynamic interactions of breast cancer cells and bone tissues in ex vivo co-cultures. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr A48.

AQUA and FISH analysis of HER-2/neu expression and amplification in a small cell lung carcinoma tissue microarray

AIMS

Most small cell lung carcinoma (SCLC) patients have metastatic disease at the time of diagnosis and are faced with poor prognosis and limited treatment options. Reports of HER-2/neu gene amplification and overexpression in this malignancy have raised the possibility of applying targeted immunotherapy with trastuzumab, the monoclonal antibody used to treat metastatic breast cancer. However, a review of the studies measuring HER-2/neu gene amplification and protein expression in SCLC reveals discordant results. The aim of the present study was to re-examine HER-2/neu expression in SCLC in relation to gene copy number using the new, highly sensitive, immunofluorescence automated quantitative analysis (AQUA) technology.

METHODS AND RESULTS

Fluorescence in situ hybridization (FISH) was used to measure HER-2/neu gene copy number and amplification status and AQUA was used to measure protein expression in a series of 23 SCLC tumours on a tissue microarray. None of the 17 SCLC specimens assessable by FISH exhibited HER-2/neu gene amplification as defined by a HER-2/neu/chromosome 17 ratio = or > 2. Twelve of 17 (70.1%) SCLC samples were polysomic for chromosome 17 with corresponding increases in HER-2/neu gene copy numbers. Intermediate levels of protein expression corresponding to AQUA scores in the range of 4-24 were detected in all 23 specimens. High protein expression levels corresponding to AQUA scores up to 83, observed previously in association with gene amplification and poor prognosis in breast cancer cases, were not detected in the present study. No statistically significant association was observed between absolute chromosome 17 or HER-2/neu gene copy numbers and protein expression levels in tumour cells (P > 0.45).

CONCLUSIONS

The lack of gene amplification and robust HER-2/neu protein expression in SCLC tumour cells in this series does not suggest a prominent role for the HER-2/neu gene in SCLC tumour progression and does not support the general applicability of targeted immunotherapy with trastuzumab to this malignancy.

The intraductal approach to the breast: raison d'être

Opportunities for the detection, prediction, and treatment of breast cancer exist at three biological levels: systemically via the blood, at the whole organ level, and within the individual ductal lobular structures of the breast. This review covers the evaluation of approaches targeted to the ductal lobular units, where breast cancer begins. Studies to date suggest the presence of 5 to 12 independent ductal lobular systems per breast, each harboring complex cellular fluids contributed by local and systemic processes. New techniques for accessing and interrogating these systems offer the potential to gauge the microenvironment of the breast and distill biological risk profiles.

Patterns of reduced nipple aspirate fluid production and ductal lavage cellularity in women at high risk for breast cancer

INTRODUCTION

Nipple aspiration is a noninvasive technique for obtaining breast fluids from the duct openings of the nipple for the evaluation of abnormalities associated with breast cancer. Nipple aspirate fluid (NAF) can be elicited from 48 to 94% of healthy women, and its production has been linked to an increased relative risk for breast cancer development. NAF production has been used in studies to guide the selection of ducts for ductal lavage, a procedure in which ducts are cannulated and flushed with saline to collect cells. In a previous multicenter trial to evaluate intraductal approaches in women at high-risk for breast cancer, NAF production was observed in 84% of the subjects. However, we observed a significantly lower proportion of fluid-yielding subjects in a similar series of high-risk women. The purpose of the present study was to identify variables associated with this reduction.

METHOD

Nipple aspiration was performed on 33 high-risk women (defined as having a 5-year Gail model index of more than 1.7, a personal or family history of breast cancer, and/or a BRCA1 or BRCA2 germline mutation) to identify ductal orifices for lavage procedures. Lavage was performed on all fluid-yielding ducts and on nine non-fluid-yielding ducts.

RESULTS

Fluid-yielding ducts were identified in 12 of 33 (36%) of the subjects in the present series, compared with 16 of 19 (84%) of the subjects undergoing identical procedures at our facility during a multicenter trial (P = 0.001). Reduced NAF yields were associated with postmenopausal status (P = 0.02), BRCA germline mutations (P = 0.004), and risk reduction therapies, including bilateral salpingo-oophorectomy (BSO) and/or selective estrogen receptor modulators (SERMs; P = 0.009). All nine (100%) of the ductal lavage specimens collected from non-fluidyielding ducts were acellular, in comparison with 3 of 13 specimens from fluid-yielding ducts (P < .001).

CONCLUSION

Analysis of high-risk women in the present series revealed patterns of reduced NAF production and ductal lavage cellularity compared with a previous multicenter trial. The present series included more BRCA-positive women, many of whom had undergone BSO and/or were using SERMs. Our data suggest that endocrine mechanisms associated with these risk-reducing therapies may be related to patterns of diminished breast fluid production.

The Fourth International Symposium on the Intraductal Approach to Breast Cancer, Santa Barbara, California, 10-13 March 2005

Intraductal approaches encompass procedures and technologies that are designed to access and interrogate the ductal–alveolar systems of the human breast, and include nipple aspiration, ductal lavage, random periareolar fine needle aspiration, and ductoscopy. These approaches are being used to collect and analyze fluids and cells to develop methods for breast cancer detection and risk assessment; to introduce imaging technologies to explore the mammary tree for abnormalities; to administer therapeutic and/or preventive agents directly to the breast tissue; and to explore the biology of the normal mammary gland. The latest research findings in these areas, presented at The 4th International Symposium on the Intraductal Approach to Breast Cancer in 2005, are summarized in this report.

The Mouse Genome Database (MGD): integrating biology with the genome

The Mouse Genome Database (MGD) is one component of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a community database resource for the laboratory mouse. MGD strives to provide a comprehensive knowledgebase about the mouse with experiments and data annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genetic, genotype (sequence) and phenotype information including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships between genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent developments in MGD discussed here include an extensive integration of the mouse sequence data and substantial revisions in the presentation, query and visualization of sequence data.

A comparison of five immunohistochemical biomarkers and HER-2/neu gene amplification by fluorescence in situ hybridization in white and Korean patients with early-onset breast carcinoma

BACKGROUND

The objective of this article was to compare five tumor markers between white women in the U.S. and native Korean women with early-onset breast carcinoma.

METHODS

Sixty Korean women who were diagnosed with breast carcinoma at age 45 years or younger and 60 white women with breast carcinoma who were matched by age were selected for this study. The median age of both groups was 37 years. Paraffin embedded blocks of the primary tumor were processed for immunohistochemical staining of estrogen receptor (ER), progesterone receptor (PR), p53, cyclin D1, and HER-2/neu.

RESULTS

The proportion of tumors that stained positive for ER, PR, p53, and cyclin D1 in the Korean women were 47.5%, 42.4%, 28.8%, and 40.9%, respectively; in the white women, the proportions were 43.9%, 52.6%, 21.1%, and 59.1%, respectively. The differences between the white patients and the Korean patients were not statistically significant with respect to any of those variables. A significant difference was found in the expression of HER-2/neu. Specifically, positive HER-2/neu status was observed in 47.5% of Korean women, compared with overexpression in only 15.8% of white women (P < 0.001). Fluorescence in situ hybridization analysis for HER-2/neu gene amplification on all HER-2/neu positive samples that scored 2 + and 3 + demonstrated a significant difference (P = 0.007) in gene amplification between the two populations. Differences in HER-2/neu positivity were observed for the entire cohort as well as among the subsets of patients with negative and positive lymph node status. No association was found between immunoreactivity for the five markers and axillary lymph node metastasis.

CONCLUSIONS

The findings of high positivity of HER-2/neu expression and gene amplification in Korean women with early-onset breast carcinoma may have potential implications for local and systemic management of breast carcinoma, especially anti-HER-2/neu therapy for patients with hormone receptor negativity. Further research will be needed to identify biologic and genetic factors and their effects on the survival between different racial groups.

Detection of chromosomal instability in paired breast surgery and ductal lavage specimens by interphase fluorescence in situ hybridization

PURPOSE

Ductal lavage is a new modality for collecting exfoliated breast cells with the goal of detecting early neoplasia. The purpose of our study was to evaluate the correlation between cancer-associated abnormalities in breast lesions and exfoliated breast cells collected by ductal lavage.

EXPERIMENTAL DESIGN

We performed histopathologic, cytologic, and molecular cytogenetic analyses on 39 paired cases of surgically excised breast lesions and ductal lavage specimens collected immediately before surgery.

RESULTS

Abnormal cytology was detected in 7 of 15 (47%) of the evaluable lavages collected from malignant cases, versus 4 of 19 (21%) of the evaluable lavages harvested from benign cases for a sensitivity and specificity of 47 and 79%, respectively. Interphase fluorescence in situ hybridization analysis of all evaluable lavages revealed numeric changes on chromosomes 1, 8, 11, and/or 17 in 10 of 14 (71%) specimens from malignant cases versus 2 of 18 (11%) from benign cases for a sensitivity and specificity of 71 and 89%, respectively.

CONCLUSIONS

Our study demonstrates that cytologic and genetic abnormalities associated with breast cancer progression can be detected in ductal lavage cells collected from women with in situ and invasive breast cancer and suggests that fluorescence in situ hybridization may have superior sensitivity and specificity compared with conventional cytology.

Quantitative analysis of breast cancer tissue microarrays shows that both high and normal levels of HER2 expression are associated with poor outcome

Using a tissue microarray cohort of 300 breast cancers and 84 samples of normal breast epithelium, we analyzed HER2/neu expression and compared traditional clinical (manual) scoring with a recently developed system for the quantitative measurement of immunohistochemical stains (AQUA). As expected, both methods identified a population (10-15%) of high-HER2-expressing tumors with poor 30-year disease-related survival. Using AQUA analysis, we found that normal epithelium expresses a low but detectable level of HER2 and that 17.5% of tumors exhibit similar low-level HER2 expression. This low group was not definable by manual scoring. Surprisingly, HER2-normal tumors were as aggressive as HER2-overexpressing tumors. Our studies suggest that in situ quantitative measurement of HER2 stratifies breast tumors into three expression levels: normal, intermediate, and high, where both normal and high levels are associated with a worse outcome.

Analysis of the mouse transcriptome based on functional annotation of 60,770 full-length cDNAs

Only a small proportion of the mouse genome is transcribed into mature messenger RNA transcripts. There is an international collaborative effort to identify all full-length mRNA transcripts from the mouse, and to ensure that each is represented in a physical collection of clones. Here we report the manual annotation of 60,770 full-length mouse complementary DNA sequences. These are clustered into 33,409 'transcriptional units', contributing 90.1% of a newly established mouse transcriptome database. Of these transcriptional units, 4,258 are new protein-coding and 11,665 are new non-coding messages, indicating that non-coding RNA is a major component of the transcriptome. 41% of all transcriptional units showed evidence of alternative splicing. In protein-coding transcripts, 79% of splice variations altered the protein product. Whole-transcriptome analyses resulted in the identification of 2,431 sense-antisense pairs. The present work, completely supported by physical clones, provides the most comprehensive survey of a mammalian transcriptome so far, and is a valuable resource for functional genomics.

Immunocytochemical analysis of breast cells obtained by ductal lavage

BACKGROUND

Intraductal breast fluids containing exfoliated mammary epithelial cells can be harvested from the breast by ductal lavage to screen for disease-associated cytologic abnormalities. In addition to epithelial cells, breast fluids contain large numbers of mammary foam cells, and the tissue of origin of these foam cells has been the subject of controversy for many years. Immunocytochemical, morphologic, and molecular studies variously have supported a mammary epithelial origin versus a histiocytic origin for this cell type. In the current study, the authors performed immunocytochemical analysis with epithelial specific and macrophage specific antibodies to characterize and quantify breast cells obtained by ductal lavage.

METHODS

Breast fluids were harvested from 19 individual breast ducts in 15 female patients by ductal lavage. Cells from each specimen were processed for immunocytochemical staining using the AE1/AE3 multicytokeratin and CD68 (clone KP1) monoclonal antibodies. Cells were classified as mammary epithelial cells or mammary foam cells on the basis of morphologic criteria, and the cells were counted and evaluated for immunoreactivity with epithelial specific and macrophage specific antibodies.

RESULTS

The CD68 macrophage specific antibody stained all ductal lavage cells that exhibited foam cell morphology. The AE1/AE3 multicytokeratin antibody demonstrated strong, positive staining of cells that exhibited epithelial morphology but failed to demonstrate significant staining of mammary foam cells. The lavage specimens contained a range of 3040-278,850 epithelial cells and 2230-90,480 foam cells. The median numbers of epithelial cells and foam cells per lavage sample were 15,680 and 29,200, respectively. The ratio of epithelial cells to foam cells varied among specimens ranging from 3.4 to 0.09 (median, 0.8). Seven of 19 lavage specimens contained more epithelial cells than foam cells, whereas 12 samples contained a greater proportion of foam cells.

CONCLUSIONS

Immunocytochemical analysis using the AE1/AE3 multicytokeratin and CD68 antibodies supports a histiocytic origin for the majority of mammary foam cells harvested from the ductal system of the human breast by ductal lavage. Although mammary foam cells constitute a significant proportion of the cellular population obtained by ductal lavage, thousands of epithelial cells also are harvested.

Characterization of the HER-2/neu oncogene by immunohistochemical and fluorescence in situ hybridization analysis in oral and oropharyngeal squamous cell carcinoma

PURPOSE

The role of HER-2/neu in squamous cell carcinoma (SCC) of the head and neck is not well defined. The purpose of the current study is to measure the frequency of HER-2/neu expression, to demonstrate HER-2/neu gene amplification in the cases found to be positive for protein overexpression, and to investigate the prognostic significance of overexpression and/or amplification in SCC of the head and neck.

EXPERIMENTAL DESIGN

A cohort of 77 patients with SCC of the oral cavity or oropharynx, with stage III or IV disease and uniformly treated with surgical resection and postoperative radiation, served as the primary patient population for the study. Of these, 56 patients had adequate follow-up and paraffin-embedded specimens available for analysis. Median follow-up was 6.1 years. Each of the paraffin-embedded specimens were immunohistochemically stained for HER-2/neu expression and graded for intensity of staining by a pathologist. All cases that demonstrated positive staining by immunohistochemistry were analyzed by fluorescence in situ hybridization (FISH) to assess HER-2/neu amplification status.

RESULTS

Five-year survival for the 56 evaluable patients was 40%, with 25% experiencing local relapse, 18% regional relapse, and 25% distant relapse. The percentage of tumors staining positive for HER-2/neu by immunohistochemistry was 17%. There was no statistically significant correlation between HER-2/neu and T stage, N stage, tumor grade, survival, or disease-free survival. HER-2/neu expression did correlate with vascular endothelial growth factor expression. FISH analysis revealed four cases that were amplified for HER-2/neu. Of note, of the 4 amplified cases, 2 suffered regional relapse, 1 suffered distant metastasis, and all 4 expired by 5 years of follow-up.

CONCLUSIONS

This is the first demonstration of HER-2/neu gene amplification by FISH in SCC of the head and neck. FISH validates a previously contested controversial role for HER-2/neu gene overexpression in SCC of the head and neck. The prognostic significance and clinical implications of HER-2/neu expression and amplification in head and neck cancer will require additional studies.

Ductal lavage for detection of cellular atypia in women at high risk for breast cancer

BACKGROUND

Breast cancer originates in breast epithelium and is associated with progressive molecular and morphologic changes. Women with atypical breast ductal epithelial cells have an increased relative risk of breast cancer. In this study, ductal lavage, a new procedure for collecting ductal cells with a microcatheter, was compared with nipple aspiration with regard to safety, tolerability, and the ability to detect abnormal breast epithelial cells.

METHODS

Women at high risk for breast cancer who had nonsuspicious mammograms and clinical breast examinations underwent nipple aspiration followed by lavage of fluid-yielding ducts. All statistical tests were two-sided.

RESULTS

The 507 women enrolled included 291 (57%) with a history of breast cancer and 199 (39%) with a 5-year Gail risk for breast cancer of 1.7% or more. Nipple aspirate fluid (NAF) samples were evaluated cytologically for 417 women, and ductal lavage samples were evaluated for 383 women. Adequate samples for diagnosis were collected from 111 (27%) and 299 (78%) women, respectively. A median of 13,500 epithelial cells per duct (range, 43-492,000 cells) was collected by ductal lavage compared with a median of 120 epithelial cells per breast (range, 10-74,300) collected by nipple aspiration. For ductal lavage, 92 (24%) subjects had abnormal cells that were mildly (17%) or markedly (6%) atypical or malignant (<1%). For NAF, corresponding percentages were 6%, 3%, and fewer than 1%. Ductal lavage detected abnormal intraductal breast cells 3.2 times more often than nipple aspiration (79 versus 25 breasts; McNemar's test, P<.001). No serious procedure-related adverse events were reported.

CONCLUSIONS

Large numbers of ductal cells can be collected by ductal lavage to detect atypical cellular changes within the breast. Ductal lavage is a safe and well-tolerated procedure and is a more sensitive method of detecting cellular atypia than nipple aspiration.

Genomic-sequence comparison of two unrelated isolates of the human gastric pathogen Helicobacter pylori

Helicobacter pylori, one of the most common bacterial pathogens of humans, colonizes the gastric mucosa, where it appears to persist throughout the host's life unless the patient is treated. Colonization induces chronic gastric inflammation which can progress to a variety of diseases, ranging in severity from superficial gastritis and peptic ulcer to gastric cancer and mucosal-associated lymphoma. Strain-specific genetic diversity has been proposed to be involved in the organism's ability to cause different diseases or even be beneficial to the infected host and to participate in the lifelong chronicity of infection. Here we compare the complete genomic sequences of two unrelated H. pylori isolates. This is, to our knowledge, the first such genomic comparison. H. pylori was believed to exhibit a large degree of genomic and allelic diversity, but we find that the overall genomic organization, gene order and predicted proteomes (sets of proteins encoded by the genomes) of the two strains are quite similar. Between 6 to 7% of the genes are specific to each strain, with almost half of these genes being clustered in a single hypervariable region.

Repeat expansion detection analysis of (CAG)n tracts in tumor cell lines, testicular tumors, and testicular cancer families

The mutational expansion of triplet repeat microsatellite sequences underlies the transmission of a number of heritable neurological disorders. However, this form of microsatellite instability has not previously been observed in association with malignant disease. Because trinucleotide expansions can dramatically alter gene expression and protein function, we hypothesized that they might occur in neoplastic cells as a mechanism through which to alter cancer genes. Accordingly, we used the repeat expansion detection technique to determine whether (CAG)n triplet repeat expansions were present in DNA from malignant cells. No expansions were observed in a survey of 20 tumor cell lines derived from neoplasms of the breast, ovary, cervix, endometrium, lung, colon, placenta, or hematopoietic system. However, we did observe expanded (CAG)n tracts in DNA from 5 of 11 testicular tumor cell lines and in 1 of 11 sporadic testicular tumors. Examination of the corresponding normal DNA, when available, revealed that some of the expansions were germline in nature. To assess the possibility that (CAG)n expansions underlie some cases of inherited testicular cancer, we also analyzed germline DNA from members of five kindreds predisposed to this malignancy. An increase in (CAG)n tract size was observed in all five families and was particularly striking in one large pedigree in which expansions were observed in three of four affected siblings. These observations raise the possibility that the germline transmission of expanded (CAG)n tracts may play a role in testicular tumorigenesis.

Empirical free energy as a target function in docking and design: application to HIV-1 protease inhibitors

Structure-based drug design requires the development of efficient computer programs for exploring the structural compatibility of various flexible ligands with a given receptor. While various algorithms are available for finding docked conformations, selecting a target function that can reliably score the conformations remains a serious problem. We show that the use of an empirical free energy evaluation method, originally developed to characterize protein-protein interactions, can substantially improve the efficacy of search algorithms. In addition to the molecular mechanics interaction energy, the function takes account of solvation and side chain conformational entropy, while remaining simple enough to replace the incomplete target functions used in many drug docking and design procedures. The free energy function is used here in conjunction with a simple site mapping-fragment assembly algorithm, for docking the MVT-101 non-peptide inhibitor to HIV-1 protease. In particular, we predict the bound structure with an all atom RMSD of 1.21 A, compared to 1.69 A using an energy target function, and also accurately predict the free energy shifts obtained with a series of five trimeric hydroxyethylene isostere analogs.

Microsatellite instability in ovarian neoplasms

Microsatellite instability has been observed in a variety of sporadic malignancies, but its existence in sporadic ovarian cancer has been the subject of conflicting reports. We have performed a polymerase chain reaction-based microsatellite analysis of DNAs extracted from the neoplastic and non-neoplastic tissues of 41 ovarian cancer patients. Tumour-associated alterations were observed in seven (17%) of these cases. Clinicopathological correlations revealed that: (1) alterations among tumours classified as serous adenocarcinomas occurred with relatively low frequency (2/24 or 8%); (2) most of the tumours with microsatellite alterations (5/7 or 71%) were of less common histopathological types (epithelial subtypes such as endometrioid and mixed serous and mucinous, or non-epithelial types such as malignant mixed Müllerian or germ cell tumours); (3) tumour-associated alterations were observed in 3/4 (75%) of the patients with stage I tumours vs 4/37 (11%) of the patients with stage II, III and IV tumours (P = 0.01); (4) tumour-associated microsatellite instability was found to occur with similar frequencies among patients with and without clinical features suggestive of familial disease, including positive family history, early onset, or multiple primary tumours. In summary, we have observed microsatellite alterations in the neoplastic tissues of ovarian cancer patients with diverse genetic backgrounds and clinicopathological features. The pattern of alterations is consistent with the possibility that multiple mechanisms may be responsible for microsatellite instability in ovarian neoplasms.

A polymerase chain reaction-based microsatellite typing assay used for tumor cell line identification

In this report we describe the application of a polymerase chain reaction (PCR)-based DNA typing assay to the analysis of tumor cell line identity. We have applied the technique to analyze four tumor cell lines purchased from the American Type Culture Collection (SK-OV-3, SK-BR-3, OVCAR, HeLa) and four lines isolated from the ascites fluids of ovarian cancer patients (YAOVBIX1, YAOVBIX3, OC194, and OC346). In this assay, three polymorphic tetranucleotide microsatellite loci (GABARB1, TH01, and HPRTB) were amplified from tumor cell line DNAs in radioactive PCR-reactions. The products were resolved in polyacrylamide gels and exposed to film to produce individual-specific patterns for five of the cell lines (HeLa, SK-BR-3, OVCAR, YAOVBIX3, and OC194). However, three of the cell lines, SK-OV-3, YAOVBIX1, and OC436 had identical "fingerprints" at all three loci. The probability that the observed profile match could occur between three randomly selected heterologous cell lines was calculated to be 1.32 x 10(-13). On the basis of this analysis, we have identified two independent cross-contamination events involving the SK-OV-3 ovarian adenocarcinoma cell line. The PCR-based analysis of tetranucleotide microsatellite loci is technically straightforward and produces discrete allelic bands associated with known population frequencies, allowing for the unequivocal interpretation of typing patterns.

Alcohol and other drug abuse among social work colleagues and their families: impact on practice

This article presents data from a 1987 random sample survey mailed to the membership of the New York City chapter of the National Association of Social Workers. The purpose of the study was to determine the prevalence of alcohol and other drug problems as perceived by social workers among their colleagues and their family members and friends. Forty-three percent of the 198 respondents said that they had known at least one social worker who had a problem with alcohol or other drugs. The large number of social workers with close personal involvement with substance abuse was significant: 60 percent had close friends or family members with a problem, 39 percent had a nuclear family member with a problem, and 11 percent were adult children of alcoholics. The latter group reported a significantly higher impact on job functioning than did the other groups. Implications of these findings and recommendations for dealing with them are discussed.

Graphical representations of the class I MHC cleft

We describe computer graphics and computer aided manufacture of three-dimensional models designed specifically to elucidate the cleft in the class I human leukocyte antigen. The models evolve from computer graphical representations and provide a geometrically and chemically concise and detailed view of the antigen binding site. The techniques provide a new approach to representations of binding sites. The model provides sufficient detail to support binding specificities analysis of active sites involved in protein and DNA binding.

NEU protein overexpression in benign, borderline, and malignant ovarian neoplasms

In situ hybridization (ISH) analysis of 24 benign, borderline, and malignant ovarian tumor specimens revealed NEU transcript expression by epithelial elements in approximately two-thirds of the samples and high-level expression in 3 grade 3 adenocarcinomas. Immunohistochemical staining (IHC) of a total of 86 specimens (including 17 of those studied by ISH) localized NEU antigen expression to epithelial cells in 36 of 86 samples with strong membrane staining observed in 12, including 1 benign, 1 borderline serous carcinoma, 3 clear cell/endometrioid carcinomas, and 7 predominantly papillary serous carcinomas with areas of clear cell/endometrioid histology. Clinical correlation of the IHC results for the 72 Stage I-IV invasively malignant neoplasms revealed no statistically significant association of the intensity of NEU IHC staining with either relapse-free or overall survival. However, more of the patients whose tumors showed strong membrane staining for NEU antigen suffered relapses of disease by 3 and 4 years than did patients whose tumors showed weak or no membrane staining. These results suggest a role for the NEU gene product in the physiology of benign ovarian surface epithelium and the neoplastic epithelium of preinvasive borderline and some invasively malignant adenocarcinomas.

Neu proto-oncogene amplification and expression in ovarian adenocarcinoma cell lines

In this communication, the authors summarize their characterization of eight ovarian adenocarcinoma-derived cell lines for level of neu gene amplification, expression of neu transcripts and protein, and intraperitoneal tumorigenicity in nude mice. Two of the eight cell lines in our study (SKOV3 and YAOVBIX1) exhibited five- to ninefold neu DNA sequence amplification, accompanied by up to 200-fold overexpression of transcripts and protein (p185). Both of these cell lines expressed a major approximately 7.5 kb neu-complementary transcript not previously reported in other neu-positive tumor cell lines. One pair of cell lines (YAOVBIX1 and YAOVBIX3), isolated from a single ovarian carcinoma patient's ascites sample differed dramatically in regard to level of neu gene amplification and expression. Immunohistochemical staining of the primary ovarian tumor from which these two lines were derived demonstrated populations of both neu-positive and neu-negative malignant epithelial cells. Seven of the eight ovarian carcinoma lines produced intra-abdominal tumors after intraperitoneal injection into nude mice, irrespective of level of neu gene expression. This study demonstrates tumor cell heterogeneity with regard to neu gene amplification and expression in an ovarian adenocarcinoma, reveals the overexpression of novel neu-complementary transcripts in two independently isolated ovarian adenocarcinoma cell lines, and suggests that neu gene expression is not required for intraperitoneal tumorigenicity of ovarian carcinoma xenografts in a nude mouse model system.

FMS (CSF-1 receptor) and CSF-1 transcripts and protein are expressed by human breast carcinomas in vivo and in vitro

The expression in vivo of FMS transcripts and antigen by neoplastic epithelial cells was demonstrated immunohistochemically or by in situ hybridization in sixteen of seventeen human breast carcinoma specimens and one case of sclerosing adenosis. Expression of CSF-1 receptor (FMS) transcripts and protein was also observed in vitro in two or three breast carcinoma-derived cell lines and was dramatically increased by dexamethasone, a potent glucocorticoid and inducer of mammary epithelial cell differentiation. Immunohistochemical staining with an anti-CSF-1 antibody identified neoplastic epithelial cell co-expression of fms and CSF-1 antigens in more than one-third of the fms-positive invasive carcinoma specimens. These results suggest that autocrine and paracrine interactions of the lymphohematopoietic cytokine CSF-1 and its receptor may participate in the biology of human mammary neoplasms.