Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.

INTRODUCTION: microRNA (miRNA) are short, noncoding RNA that negatively regulate gene expression and may play a causal role in invasive breast cancer. Since many genetic aberrations of invasive disease are detectable in early stages, we hypothesized that miRNA expression dysregulation and the predicted changes in gene expression might also be found in early breast neoplasias. METHODS: Expression profiling of 365 miRNA by real-time quantitative polymerase chain reaction assay was combined with laser capture microdissection to obtain an epithelium-specific miRNA expression signature of normal breast epithelium from reduction mammoplasty (RM) (n = 9) and of paired samples of histologically normal epithelium (HN) and ductal carcinoma in situ (DCIS) (n = 16). To determine how miRNA may control the expression of codysregulated mRNA, we also performed gene expression microarray analysis in the same paired HN and DCIS samples and integrated this with miRNA target prediction. We further validated several target pairs by modulating the expression levels of miRNA in MCF7 cells and measured the expression of target mRNA and proteins. RESULTS: Thirty-five miRNA were aberrantly expressed between RM, HN and DCIS. Twenty-nine miRNA and 420 mRNA were aberrantly expressed between HN and DCIS. Combining these two data sets with miRNA target prediction, we identified two established target pairs (miR-195:CCND1 and miR-21:NFIB) and tested several novel miRNA:mRNA target pairs. Overexpression of the putative tumor suppressor miR-125b, which is underexpressed in DCIS, repressed the expression of MEMO1, which is required for ErbB2-driven cell motility (also a target of miR-125b), and NRIP1/RIP140, which modulates the transcriptional activity of the estrogen receptor. Knockdown of the putative oncogenic miRNA miR-182 and miR-183, both highly overexpressed in DCIS, increased the expression of chromobox homolog 7 (CBX7) (which regulates E-cadherin expression), DOK4, NMT2 and EGR1. Augmentation of CBX7 by knockdown of miR-182 expression, in turn, positively regulated the expression of E-cadherin, a key protein involved in maintaining normal epithelial cell morphology, which is commonly lost during neoplastic progression. CONCLUSIONS: These data provide the first miRNA expression profile of normal breast epithelium and of preinvasive breast carcinoma. Further, we demonstrate that altered miRNA expression can modulate gene expression changes that characterize these early cancers. We conclude that miRNA dysregulation likely plays a substantial role in early breast cancer development.

Early dysregulation of cell adhesion and extracellular matrix pathways in breast cancer progression.

Proliferative breast lesions, such as simple ductal hyperplasia (SH) and atypical ductal hyperplasia (ADH), are candidate precursors to ductal carcinoma in situ (DCIS) and invasive cancer. To better understand the relationship of breast lesions to more advanced disease, we used microdissection and DNA microarrays to profile the gene expression of patient-matched histologically normal (HN), ADH, and DCIS from 12 patients with estrogen receptor positive sporadic breast cancer. SH were profiled from a subset of cases. We found 837 differentially expressed genes between DCIS-HN and 447 between ADH-HN, with >90% of the ADH-HN genes also present among the DCIS-HN genes. Only 61 genes were identified between ADH-DCIS. Expression differences were reproduced in an independent cohort of patient-matched lesions by quantitative real-time PCR. Many breast cancer-related genes and pathways were dysregulated in ADH and maintained in DCIS. Particularly, cell adhesion and extracellular matrix interactions were overrepresented. Focal adhesion was the top pathway in each gene set. We conclude that ADH and DCIS share highly similar gene expression and are distinct from HN. In contrast, SH appear more similar to HN. These data provide genetic evidence that ADH (but not SH) are often precursors to cancer and suggest cancer-related genetic changes, particularly adhesion and extracellular matrix pathways, are dysregulated before invasion and even before malignancy is apparent. These findings could lead to novel risk stratification, prevention, and treatment approaches.

Abnormal anal cytology in HIV-infected women.

OBJECTIVE: The purpose of this study was to assess the prevalence of and risk factors for abnormal anal cytology and human papillomavirus (HPV) infections in women who are human immunodeficiency virus (HIV) positive. STUDY DESIGN: We conducted an observational single center study of 100 HIV-infected women with cervical and anal specimens that were obtained for cytologic and high-risk HPV testing with Hybrid Capture 2. RESULTS: Seventeen women had abnormal anal cytology; 16 women had anal HPV; 21 women had abnormal cervical cytology, and 24 women had cervical HPV. Abnormal anal cytology was associated with cervical HPV infection, abnormal cervical cytology, and anal HPV infection in univariate analysis. In multivariate analysis, abnormal anal cytology was associated with a CD4 count <200 cells/mm(3), a history of sexually transmitted disease, and concurrent cervical cytologic abnormality. CONCLUSION: HIV-infected women are at high risk for abnormal cytology and HPV infections of both the anus and cervix. Risk factors for abnormal anal cytology include abnormal cervical cytology, cervical and anal HPV infections, and low CD4 count.

CDKN1C/p57kip2 is a candidate tumor suppressor gene in human breast cancer.

BACKGROUND: CDKN1C (also known as p57KIP2) is a cyclin-dependent kinase inhibitor previously implicated in several types of human cancer. Its family members (CDKN1A/p21CIP1 and B/p27KIP1) have been implicated in breast cancer, but information about CDKN1C's role is limited. We hypothesized that decreased CDKN1C may be involved in human breast carcinogenesis in vivo. METHODS: We determined rates of allele imbalance or loss of heterozygosity (AI/LOH) in CDKN1C, using an intronic polymorphism, and in the surrounding 11p15.5 region in 82 breast cancers. We examined the CDKN1C mRNA level in 10 cancers using quantitative real-time PCR (qPCR), and the CDKN1C protein level in 20 cancers using immunohistochemistry (IHC). All samples were obtained using laser microdissection. Data were analyzed using standard statistical tests. RESULTS: AI/LOH at 11p15.5 occurred in 28/73 (38%) informative cancers, but CDKN1C itself underwent AI/LOH in only 3/16 (19%) cancers (p = ns). In contrast, CDKN1C mRNA levels were reduced in 9/10 (90%) cancers (p < 0.0001), ranging from 2-60% of paired normal epithelium. Similarly, CDKN1C protein staining was seen in 19/20 (95%) cases' normal epithelium but in only 7/14 (50%) cases' CIS (p < 0.004) and 5/18 (28%) cases' IC (p < 0.00003). The reduction appears primarily due to loss of CDKN1C expression from myoepithelial layer cells, which stained intensely in 17/20 (85%) normal lobules, but in 0/14 (0%) CIS (p < 0.00001). In contrast, luminal cells displayed less intense, focal staining fairly consistently across histologies. Decreased CDKN1C was not clearly associated with tumor grade, histology, ER, PR or HER2 status. CONCLUSION: CDKN1C is expressed in normal epithelium of most breast cancer cases, mainly in the myothepithelial layer. This expression decreases, at both the mRNA and protein level, in the large majority of breast cancers, and does not appear to be mediated by AI/LOH at the gene. Thus, CDKN1C may be a breast cancer tumor suppressor.

Allele imbalance, or loss of heterozygosity, in normal breast epithelium of sporadic breast cancer cases and BRCA1 gene mutation carriers is increased compared with reduction mammoplasty tissues.

PURPOSE: Normal-appearing breast epithelium can contain genetic abnormalities, including allele imbalance (AI), also referred to as loss of heterozygosity. Whether abnormalities are associated with cancer or cancer risk is unknown. PATIENTS AND METHODS: We performed a miniallelotype, using 20 microsatellites, on each of 460 histologically normal, microdissected breast terminal ducto-lobular units (TDLUs) from three groups of women: sporadic breast cancer patients (SP; n = 18), BRCA1 gene mutation carriers (BRCA1; n = 16), and controls undergoing reduction mammoplasty (RM; n = 18). We analyzed the results using Fisher's exact tests, logistic regression, and generalized estimating equations. RESULTS: AI was increased three-fold in SP and BRCA1 groups compared with RM. Both the number of TDLUs with AI increased (eight [5%] of 162 in the RM group compared with 24 [15%] of 162 in the SP and 22 [16%] of 136 in the BRCA1 groups; P = .0150), and the proportion of patients with AI increased (five [28%] of 18 in the RM group compared with 15 [83%] of 18 in the SP and 13 [81%] of 16 in the BRCA1 groups; P = .0007). The adjusted odds ratios (OR) for AI in TDLU increased in SP (OR = 15.5) and BRCA1 (OR = 13.7) patients compared with RM (P = .0025). This result was particularly evident on chromosome 17q (P = .0393), where more AI was seen in BRCA1 (OR = 12.4) than in SP (OR = 4.9) patients or RM controls. CONCLUSION: Increased prevalence of AI in normal-appearing epithelium is associated with breast cancer and increased breast cancer risk. The increased prevalence may reflect dysregulation, even in normal-appearing epithelium, of genomic processes contributing to cancer development. The clinical significance of genetic alterations in the subset of controls remains to be determined.

Influence of breast cancer margin assessment method on the rates of positive margins and residual carcinoma.

BACKGROUND: We hypothesized that the method of breast cancer margin assessment may be associated with different rates of positive margins and residual carcinoma. METHODS: A total of 178 breast cancer specimens were divided into 2 groups (A and B) based on the margin assessment method used. Rates of positive margins, re-excision, and residual carcinoma at re-excision were compared and analyzed statistically. RESULTS: At least 1 margin was positive in 64.7% in group A and in 65.2% in group B. At directed re-excision 54% in group A and 51% in group B had residual carcinoma. The lateral margin was positive in 44% in group A compared with 26% in group B (P = .06). The posterior margin was positive in 19% in group A and in 51% in group B (P = .001). CONCLUSIONS: Two different breast cancer specimen margin assessment methods had comparable rates of positive margins and residual carcinoma at re-excision. Different patterns of specific margin positivity suggest that the method of margin assessment may alter results.

Quantitative DNA fingerprinting may distinguish new primary breast cancer from disease recurrence.

PURPOSE: Approximately 10% of women with breast cancer develop a second breast tumor, either a new primary or a recurrence. Differentiating between these entities using standard clinical and pathologic criteria remains challenging. Ambiguous cases arise, and misclassifications may occur. We investigated whether quantitative DNA fingerprinting, based on allele imbalance (AI) or loss of heterozygosity (LOH), could evaluate clonality and distinguish second primary breast cancer from recurrence. METHODS: We developed a scoring system based on the AI/LOH fingerprints of 20 independent breast tumors and generated a decision rule to classify any breast tumor pair as related or unrelated. We validated this approach on eight related tumors (cancers and synchronous positive lymph nodes). Finally, we analyzed paired tumors from 13 women (bilateral cancers, primary tumors and contralateral positive axillary lymph nodes, or two ipsilateral tumors). Each pair's genetic classification was compared with their clinical diagnosis and outcome. RESULTS: Each independent cancer had a unique fingerprint. Every tumor pair's relationship was quantifiable. Six of eight related tumor pairs were genetically classified correctly, two were indeterminate, and none were misclassified. Among the 13 women with two cancers, four of five clinically indeterminate pairs could be classified genetically. In three of 13 women, the pair's classification contradicted the clinical diagnosis. These women had bilateral cancers genetically classified as related and disease progression. This challenges the paradigm that bilateral cancers represent independent tumors. Overall, women with tumors genetically classified as related had poorer outcomes. CONCLUSION: Quantitative AI/LOH fingerprinting is a potentially valuable tool to improve diagnosis and optimize treatment for the growing number of second breast malignancies.

Anaplastic thyroid cancer: outcome and the mutation/expression profiles of potential targets.

Anaplastic thyroid cancer (ATC) is a rare but aggressive malignancy of the thyroid. No effective treatment modalities are currently available. Targeted therapy against protein kinases showed promising results in preclinical studies. Our goal was to assess the mutational status of potential therapeutic targets, as well as the biomarker for immunotherapy in the clinical context. Using allele specific PCR, Sanger sequencing, fragment analysis and immunohistochemistry, we assessed BRAF, KRAS, EGFR mutations and protein overexpression of C-KIT and PDL1 in anaplastic thyroid cancer specimens. Results were compared to clinical information and patient outcome to assess the utility of these biomarkers. There were 13 patients in our study with a median overall survival of 19 weeks. Of the 13 ATC patients, 3 (23 %) had BRAF V600E mutation. C-KIT overexpression was found in 1 (8 %) patient who responded well to a tyrosine kinase inhibitor. PDL1 expression was seen in 3 (23 %) patients, none of them were surgical candidates due to unresectability and poor performance status. KRAS codon 12/13 and EGFR exon 18, 19, 20 and 21 were all wild type in our patients. Protein kinase inhibitors and immunotherapy may be useful adjuvant therapies for ATC.

Hypercalcemia from metastatic pancreatic neuroendocrine tumor secreting 1,25-dihydroxyvitamin D.

Malignant hypercalcemia occurs in about 20-30% of patients with cancer, both solid tumors and hematologic malignancies. The secretion of parathyroid hormone-related protein (PTH-rP) is the most common cause and has been shown to be the etiology of hypercalcemia associated with neuroendocrine tumors. Here we report the case of a patient with metastatic pancreatic neuroendocrine tumor who developed hypercalcemia more than 4 years after the initial diagnosis as a result of secretion of 1,25-dihydroxyvitamin D, a mechanism only commonly seen in lymphomas. The successful control of the patient's disease with capecitabine and temozolomide led to the alleviation of this paraneoplastic syndrome.

Early detection of high-grade squamous intraepithelial lesions in the cervix with quantitative spectroscopic imaging.

Quantitative spectroscopy has recently been extended from a contact-probe to wide-area spectroscopic imaging to enable mapping of optical properties across a wide area of tissue. We train quantitative spectroscopic imaging (QSI) to identify cervical high-grade squamous intraepithelial lesions (HSILs) in 34 subjects undergoing the loop electrosurgical excision procedure (LEEP subjects). QSI's performance is then prospectively evaluated on the clinically suspicious biopsy sites from 47 subjects undergoing colposcopic-directed biopsy. The results show the per-subject normalized reduced scattering coefficient at 700 nm (An) and the total hemoglobin concentration are significantly different (p<0.05) between HSIL and non-HSIL sites in LEEP subjects. An alone retrospectively distinguishes HSIL from non-HSIL with 89% sensitivity and 83% specificity. It alone applied prospectively on the biopsy sites distinguishes HSIL from non-HSIL with 81% sensitivity and 78% specificity. The findings of this study agree with those of an earlier contact-probe study, validating the robustness of QSI, and specifically An, for identifying HSIL. The performance of An suggests an easy to use and an inexpensive to manufacture monochromatic instrument is capable of early cervical cancer detection, which could be used as a screening and diagnostic tool for detecting cervical cancer in low resource countries.

In thyroid fine-needle aspiration, use of bedside-prepared slides significantly increased diagnostic adequacy and specimen cellularity relative to solution-based samples.

BACKGROUND: In the United States, the prevalence among adults of palpable thyroid nodules is 4%-7%, of which 5%-10% may represent thyroid carcinoma. Despite the success of fine-needle aspiration in reducing the need for thyroidectomy, aspirates are inadequate to render a diagnosis in 20% of cases. Minimizing nondiagnostic samples is an important goal in improving this technique. Our objective was to determine whether bedside-prepared slides improve diagnostic adequacy over standard solution-based samples. We further sought to determine the role of needle size. METHODS: One hundred sixty-two patients were prospectively enrolled. For each, both bedside slides and standard cytology solutions were prepared; the order of preparation alternated from subject to subject. Needle size (21- or 25-gauge) also alternated from subject to subject. Slides were evaluated by pathologists blinded to needle size. The study took place in the endocrinology clinic at Boston Medical Center, the tertiary referral hospital of the Boston University School of Medicine. Key outcomes were diagnostic adequacy and specimen cellularity. RESULTS: Compared to standard solution-based samples, bedside slides provided more cellular specimens (p < 0.01) and fewer nondiagnostic samples (p = 0.016). When standard solution-based samples were used as the sole method of preparation, 21-gauge needles provided improved diagnostic adequacy. CONCLUSIONS: Bedside-prepared slides offer improved diagnostic adequacy and specimen cellularity over solution-based samples. The difference may be especially important when using smaller (25-gauge) needles to perform fine-needle aspiration. When solution-based samples are used, larger (21-gauge) needles provide more diagnostic specimens.

Gene expression profiles of estrogen receptor-positive and estrogen receptor-negative breast cancers are detectable in histologically normal breast epithelium.

PURPOSE: Previously, we found that gene expression in histologically normal breast epithelium (NlEpi) from women at high breast cancer risk can resemble gene expression in NlEpi from cancer-containing breasts. Therefore, we hypothesized that gene expression characteristic of a cancer subtype might be seen in NlEpi of breasts containing that subtype. EXPERIMENTAL DESIGN: We examined gene expression in 46 cases of microdissected NlEpi from untreated women undergoing breast cancer surgery. From 30 age-matched cases [15 estrogen receptor (ER)+, 15 ER-] we used Affymetryix U133A arrays. From 16 independent cases (9 ER+, 7 ER-), we validated selected genes using quantitative real-time PCR (qPCR). We then compared gene expression between NlEpi and invasive breast cancer using four publicly available data sets. RESULTS: We identified 198 genes that are differentially expressed between NlEpi from breasts with ER+ (NlEpiER+) compared with ER- cancers (NlEpiER-). These include genes characteristic of ER+ and ER- cancers (e.g., ESR1, GATA3, and CX3CL1, FABP7). qPCR validated the microarray results in both the 30 original cases and the 16 independent cases. Gene expression in NlEpiER+ and NlEpiER- resembled gene expression in ER+ and ER- cancers, respectively: 25% to 53% of the genes or probes examined in four external data sets overlapped between NlEpi and the corresponding cancer subtype. CONCLUSIONS: Gene expression differs in NlEpi of breasts containing ER+ compared with ER- breast cancers. These differences echo differences in ER+ and ER- invasive cancers. NlEpi gene expression may help elucidate subtype-specific risk signatures, identify early genomic events in cancer development, and locate targets for prevention and therapy.

Effect of anatomy on spectroscopic detection of cervical dysplasia.

It has long been speculated that underlying variations in tissue anatomy affect in vivo spectroscopic measurements. We investigate the effects of cervical anatomy on reflectance and fluorescence spectroscopy to guide the development of a diagnostic algorithm for identifying high-grade squamous intraepithelial lesions (HSILs) free of the confounding effects of anatomy. We use spectroscopy in both contact probe and imaging modes to study patients undergoing either colposcopy or treatment for HSIL. Physical models of light propagation in tissue are used to extract parameters related to tissue morphology and biochemistry. Our results show that the transformation zone, the area in which the vast majority of HSILs are found, is spectroscopically distinct from the adjacent squamous mucosa, and that these anatomical differences can directly influence spectroscopic diagnostic parameters. Specifically, we demonstrate that performance of diagnostic algorithms for identifying HSILs is artificially enhanced when clinically normal squamous sites are included in the statistical analysis of the spectroscopic data. We conclude that underlying differences in tissue anatomy can have a confounding effect on diagnostic spectroscopic parameters and that the common practice of including clinically normal squamous sites in cervical spectroscopy results in artificially improved performance in distinguishing HSILs from clinically suspicious non-HSILs.

Expression of cytokeratin 19 in the diagnosis of thyroid papillary carcinoma by quantitative polymerase chain reaction.

OBJECTIVE: To examine cytokeratin 19 (CK19) expression levels by immunostaining for protein and quantitative reverse-transcription polymerase chain reaction (qPCR) for messenger RNA in thyroid surgical specimens from patients with papillary carcinoma (PC) and other types of thyroid lesions. METHODS: A total of 54 randomly selected postoperative thyroid tissue samples were collected for formalin-fixed paraffin-embedded sectioning or flash-frozen total RNA extraction for complementary DNA synthesis (or both). Tissue sections were stained for CK19 expression with use of a specific monoclonal antibody. qPCR was performed on synthesized complementary DNA with sequence-specific primers for human CK19 in conjunction with ribonucleoprotein S18 for normalization. RESULTS: CK19 immunostaining was diffuse and intense in all PC lesions and considerably less in specimens that harbored both Hashimoto thyroiditis (HT) and PC. CK19 immunostaining was mostly absent in areas of multinodular goiter (MNG), with occasional focal staining. HT and Hürthle cell adenoma were essentially negative for CK19 immunostaining, except for weak staining in focal areas. Analysis of CK19 gene expression by qPCR revealed that the PC samples tested (n = 21) had significantly higher levels in comparison with all other groups (P < 0.0001). Furthermore, PC had a 32-fold mean level increase in CK19 expression in comparison with CK19 expression in MNG. Hürthle cell adenoma (n = 5) and HT (n = 7) lesions were similar to MNG in CK19 expression, with some overlap of CK19 between HT and PC. CONCLUSION: The data indicate that expression of CK19 by qPCR is a quantitative method for distinguishing PC lesions from other types of thyroid lesions, in contrast to the more qualitative immunohistochemistry. Moreover, qPCR of CK19 is a valid method that could be used as an ancillary tool in diagnosing thyroid cancer. The expression of CK19 by qPCR may be adopted, in combination with other markers, for molecular definition of the various subtypes of thyroid lesions assessed by fine-needle aspiration biopsy in the preoperative diagnosis of thyroid lesions.

In utero exposure to diethylstilbestrol (DES) does not increase genomic instability in normal or neoplastic breast epithelium.

BACKGROUND: In 1992, the National Cancer Institute (NCI) established the Continuation of Follow-Up of DES-Exposed Cohorts to study the long-term health effects of exposure to diethylstilbestrol (DES). Genetic effects on human breast tissue have not been examined. The authors investigated whether breast tissue of women exposed in utero to DES might exhibit the genetic abnormalities that characterize other DES-associated tumors. METHODS: Subjects enrolled in the NCI Cohort were queried about breast biopsies or breast cancer diagnoses. Available tissue blocks were obtained for invasive cancers (IC), in situ cancers (CIS), or atypical hyperplasia (AH). Exposure status was blinded, lesions were microdissected, and their DNA was analyzed for microsatellite instability (MI) and loss of heterozygosity (LOH), or allele imbalance (AI), at 20 markers on 9 chromosome arms. RESULTS: From 31 subjects (22 exposed, 9 unexposed), 273 samples were analyzed (167 normal epithelium, 16 AH, 30 CIS, 60 IC). Exposed and unexposed subjects exhibited no differences in breast cancer risk factors or demographic characteristics, except for age at diagnosis (exposed vs. unexposed: 43.2 vs. 48.8 years of age, P = .02). The authors found that MI was rare and that AI was common, with frequencies consistent with previous reports. The global age-adjusted relative rate (RR) of AI was 1.3, 95% CI = 0.8-2.4. No statistically significant associations were observed after adjustment for risk factors or after stratification by histology or by chromosome arm. CONCLUSIONS: In utero DES exposure does not appear to significantly increase genomic instability in breast epithelium, as measured by MI and AI. Breast tissue may respond differently from that of the reproductive tract to in utero DES exposure. Consequences of in utero DES exposure on the breast may be mediated by proliferative effects of estrogen.

Loss of heterozygosity or allele imbalance in histologically normal breast epithelium is distinct from loss of heterozygosity or allele imbalance in co-existing carcinomas.

To better understand early steps in human breast carcinogenesis, we examined allele imbalance or loss of heterozygosity (LOH), in co-existing normal-appearing breast epithelium and cancers. We microdissected a total of 173 histologically normal ducts or terminal ductolobular units (TDLUs) and malignant epithelial samples from 18 breast cancer cases, and examined their DNA for LOH at 21 microsatellite markers on 10 chromosome arms. Fourteen of 109 (13%) normal ducts/TDLUs, from 8 of 18 (44%) cases, contained LOH. The location of these 14 ducts/TDLUs appeared unrelated to distance from the cancer. LOH in normal-appearing epithelium involved only single markers, whereas LOH in cancers commonly encompassed all informative markers on a chromosome arm. In only 1 of 14 (7%) ducts/TDLUs with LOH, was the same LOH seen in the co-existing cancer. Global differences in LOH per arm in normal-appearing tissue were not demonstrated, but less LOH was seen at 11q and 17p than at 1q (P = 0.002), 16q (P = 0.01), and possibly 17q (P = 0.06). These results indicate that in a large fraction of women with breast cancer, histologically normal breast epithelium harbors occult aberrant clones. Individual clones rarely are precursors of co-existing cancers. However, they might constitute a reservoir from which proliferative lesions or second cancers develop once additional genetic abnormalities occur, they could contribute to intratumoral genetic heterogeneity, and they are consistent with a role for genetic instability early in tumorigenesis.

Loss of heterozygosity in serial plasma DNA samples during follow-up of women with breast cancer.

We evaluated the potential utility of occult circulating tumor DNA as a molecular marker of disease in subjects previously diagnosed with breast cancer. Using 24 microsatellite markers located at sites of frequent loss of heterozygosity (LOH) or allele imbalance in breast cancer, we analyzed DNA from 16 primary tumors (Stage IIA or more advanced) and 30 longitudinally collected plasma specimens. Clinical data at the time of plasma collection were obtained. All 16 tumors were characterized by an individual pattern of LOH. LOH was detected in 12 of 30 (40%) plasma samples, taken from 8 of 14 (57%) subjects. However, the number of LOH in plasma was small (n = 15), and the mean proportion of LOH was much lower than in the tumors (0.05 vs. 0.52). Although infrequent, 12 of 15 (80%) plasma LOH were concordant with abnormalities in the paired tumors, and the mean percent LOH was higher than in normal plasmas, suggesting that they were authentic tumor-derived abnormalities. We found, despite this, no association, between plasma LOH and tumor stage or clinical status at time of blood collection (i.e., LOH was as common in subjects with no evident disease as in those with evident disease). In addition, detection of LOH was not consistent between serial samples from 5 of 11 subjects (45%), despite stable clinical conditions. No association with clinical outcome was evident, although the sample size was small. Microsatellite instability in plasma was infrequent, nonconcordant with paired tumor and inconsistent in serial samples. This pilot study suggests that identifying tumor-specific LOH in the plasma of breast cancer subjects may not be useful for detecting occult metastases or for monitoring disease. Other detection techniques may be more promising, but circulating tumor DNA may not be a sufficiently accurate reflection of breast cancer clinical status or tumor activity.

Interim analysis of a prospective, randomized trial of vacuum-assisted closure versus the healthpoint system in the management of pressure ulcers.

Twenty-eight patients with 41 full-thickness decubitus ulcers were randomized to compare the Vacuum-Assisted Closure device (VAC) with the Healthpoint System (HP) of wound gel products in promoting ulcer healing. A total of 22 patients with 35 full-thickness ulcers completed the 6-week trial of treatment, during which time 2 patients (10%) in the VAC group (N =20) and 2 patients (13%) in the HP group (N = 15) healed completely. The mean percent reduction in ulcer volume was 42.1% with HP and 51.8% with VAC (p = 0.46). The mean number of PMNs and lymphocytes per high-power field decreased in the VAC group and increased in the HP group (p = 0.13, p = 0.41 respectively). The mean number of capillaries per high-power field was greater in the VAC group (p = 0.75). There were 15 cases of biopsy-proven osteomyelitis underlying the ulcers; three (37.5%) improved with VAC and none improved with HP (p = 0.25). VAC promotes an increased rate of wound healing and favorable histological changes in soft tissue and bone compared with HP.