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George L Mutter

Publications and source records attributed to George L Mutter.

17 recordsLinked to original sources
PubMed2006

Precancer: a conceptual working definition -- results of a Consensus Conference.

BACKGROUND: Precancers are lesions that precede the appearance of invasive cancers. The successful prevention or treatment of precancers has the potential to eliminate deaths due to cancer. METHODS: A National Cancer Institute-sponsored Conference on Precancer was convened on November 8-9, 2004, at The George Washington University Medical Center, Washington, DC. A definition of precancers was developed over 2 days of Conference discussions. RESULTS: The following five criteria define a precancer: (1) evidence must exist that the precancer is associated with an increased risk of cancer; (2) when a precancer progresses to cancer, the resulting cancer arises from cells within the precancer; (3) a precancer differs from the normal tissue from which it arises; (4) a precancer differs from the cancer into which it develops, although it has some, but not all, of the molecular and phenotypic properties that characterize the cancer; (5) there is a method by which the precancer can be diagnosed. CONCLUSIONS: The Conference participants developed a general definition for precancers that would provide a consistent and clinically useful way of distinguishing precancers from all other types of lesions. It was recognized that many precancerous lesions may not meet this strict definition, but the group felt it was necessary to define criteria that will help standardize clinical and biological studies. Furthermore, a set of defining criteria for putative precancer lesions will permit pathologists to build a diagnostically useful taxonomy of precancers based on specified clinical and biological properties. Precancers thus characterized can be classified into clinically relevant sub-groups based on shared properties (i.e. biomarkers, oncogenes, common metabolic pathways, responses to therapy, etc.). Publications that introduce newly described precancer entities should describe how each of the five defining criteria apply. This manuscript reviews the proposed definition of precancers and suggests how pathologists, oncologists and cancer researchers may determine when these criteria are satisfied.

Humans↗
PubMed2006

Molecular and pathologic aspects of endometrial carcinogenesis.

Endometrial cancer is the most common gynecological malignancy, with 41,000 new cases projected in the United States for 2006. Two different clinicopathologic subtypes are recognized: the estrogen-related (type I, endometrioid) and the non-estrogen-related types (type II, nonendometrioid such as papillary serous and clear cell). The morphologic differences in these cancers are mirrored in their molecular genetic profile with type I showing defects in DNA-mismatch repair and mutations in PTEN, K-ras, and beta-catenin, and type II showing aneuploidy and p53 mutations. This article reviews the genetic aspects of endometrial carcinogenesis and progression. We will define the precursor lesion of type I endometrioid cancer and the role of genetics and estrogen in its progression.

Carcinoma, Endometrioid↗
PubMed2006

Regression of latent endometrial precancers by progestin infiltrated intrauterine device.

PTEN tumor suppressor inactivation is the earliest step in endometrial carcinogenesis, occurring in morphologically unremarkable endometrial glands in half of normal women. We test the hypothesis that sex hormones positively or negatively select for these "latent precancers" by examining their emergence, persistence, and regression rates under differing hormonal conditions. Perimenopausal and postmenopausal women had an intake endometrial biopsy and underwent hormonal therapy with progestin-impregnated intrauterine device (IUD; n = 21), cyclic oral progestins (n = 28), or surveillance only (n = 22) with follow-up biopsies. For comparison, premenopausal naturally cycling endometrial biopsies were studied as single time points in 87 patients and multiple surveillance time points in 34 patients. Biopsies in which any PTEN protein-null glands were found by immunohistochemistry were scored as containing a latent endometrial precancer. All groups had a similar proportion of latent precancers at intake but differed after therapy. Emergence rates were highest (21%) for the naturally cycling premenopausal group compared with just 9% for untreated perimenopausal women. The IUD group had the highest rate of regression, with a 62% pretherapy and 5% post-therapy rate of latent precancers. This contrasted to nonsignificant changes for the oral progestin and untreated control groups. Delivery of high doses of progestins locally to the endometrium by IUD leads to ablation of preexisting PTEN-inactivated endometrial latent precancers and is a possible mechanism for reduction of long-term endometrial cancer risk known to occur in response to this hormone.

Administration, Oral↗
PubMed2006

Total-genome analysis of BRCA1/2-related invasive carcinomas of the breast identifies tumor stroma as potential landscaper for neoplastic initiation.

We have shown that the tumor microenvironment of sporadic breast cancer is diverse in genetic alterations and contributes to the cancer phenotype. The dynamic morphology of the mammary gland might be of special interest in hereditary breast/ovarian cancer syndrome (HBOC). We hypothesized that hotspots of loss of heterozygosity or allelic imbalance (LOH/AI) within the tumor stroma of BRCA1/2-related breast cancers provide an impaired mammary stroma that could facilitate later malignant transformation of the breast epithelium. We conducted a total genome LOH/AI scan of DNA derived from the epithelium and stroma of 51 BRCA1/2-related breast cancers, using 372 microsatellite markers. We compared these data with those from a set of 134 sporadic breast cancers. HBOC-related breast cancers accumulated significantly more genetic alterations than did sporadic breast cancers. BRCA1/2-related breast cancer stroma showed LOH/AI at 59.7% of all loci analyzed, similar to the average frequency of LOH/AI observed in the epithelium (66.2%). This is remarkably different from sporadic breast cancers, for which the average epithelial LOH/AI frequency (36.7%) far exceeds the average stromal LOH/AI frequency (28.4%) (P=.03). We identified 11 hotspot loci of LOH/AI in the BRCA1/2 stroma, encompassing genes such as POLD1, which functions in DNA replication, and SDHB. In a subset of samples, enriched for BRCA1 cases, we found 45.0% overall LOH/AI in the stroma, which was significantly higher than the 41.8% LOH/AI observed in corresponding epithelium (P=.04). Together, our data indicate that, in HBOC-related breast cancers, the accumulation of genomic instability in the cancer stroma coincides with that in the neoplastic epithelium, and we postulate that such a genetically unstable stroma might facilitate a microenvironment that functions as a landscaper that promotes genomic instability in the epithelium and, subsequently, neoplastic transformation.

Adult↗
PubMed2005

The molecular genetics and morphometry-based endometrial intraepithelial neoplasia classification system predicts disease progression in endometrial hyperplasia more accurately than the 1994 World Health Organization classification system.

BACKGROUND: The objective of this study was to compare the accuracy of disease progression prediction of the molecular genetics and morphometry-based Endometrial Intraepithelial Neoplasia (EIN) and World Health Organization 1994 (WHO94) classification systems in patients with endometrial hyperplasias. METHODS: A multicenter, multivariate analysis was conducted on 477 patients with endometrial hyperplasia who were required to have a 1-year minimum disease-free interval from the time of the index biopsy (1-18 years of follow-up). The results from that analysis were compared with the results from 197 patients who had < 1 year of follow-up. RESULTS: Twenty-four of 477 hyperplasias (5.0%) progressed to malignant disease over an average of 4 years (maximum, 10 years). According to the WHO94 classification, 16 of 123 atypical hyperplasias (13%) and 8 of 354 nonatypical hyperplasias (2.3%) progressed (hazard ratio [HR] = 7). Twenty-two of 118 EINs (19%) and 2 of 359 non-EINs (0.6%) progressed (HR = 45). EIN was prognostic within each WHO94 subcategory. Progression rates were 3% in simple hyperplasias, 22% in complex hyperplasias, 17% in simple atypical hyperplasias, and 38% in complex atypical hyperplasias with EIN, compared with progression rates of 0.0-2.0% in all hyperplasias if EIN was absent. EIN detected precancerous lesions (sensitivity, 92%) better than WHO94 atypical hyperplasias collectively (67%) or complex atypical hyperplasias alone (46%). In a Cox regression analysis, EIN was the strongest prognostic index of future endometrial carcinoma. The same was true for patients with < 1 year of follow-up (HR for EIN, atypical hyperplasia, and complex atypical hyperplasia: 58, 7, and 8, respectively). CONCLUSIONS: The EIN classification system predicted disease progression more accurately than the WHO94 classification and identified many women with benign changes that would have been regarded as high risk according to the WHO94 classification system.

Adult↗
PubMed2005

Lack of PTEN expression in endometrial intraepithelial neoplasia is correlated with cancer progression.

We tested the hypothesis that PTEN inactivation may stratify cancer progression risk among putative endometrial hyperplasias, classified prognostically by means of the morphometric D score (DS). The DS, calculated from 3 morphometric variables measured in routine hematoxylin-eosin-stained endometrial biopsy slides, is the most sensitive and specific method of endometrial cancer risk prediction currently available. Clinical outcomes of 103 women with endometrial hyperplasia on biopsy were tallied according to the DS. Seven (7/103; 7%) patients with carcinoma during follow-up were all distributed within the high-risk prognostic group (ie, DS <1 = endometrial intraepithelial neoplasia [EIN]) (7/21; 33% progression). None of the 82 cases with a DS higher than 1 progressed. All cases that progressed were PTEN null, indicating that this genotype is capable of further stratifying cancer progression risk in hyperplasias irrespective of histological categorization. However, only 16% of the PTEN-null cases progressed. When PTEN expression pattern was combined with EIN, the prognostic power was greatly increased (specificity from 63% for PTEN and 85% for EIN to 93% when combined; positive predictive value from 16% and 33% to 50%). We conclude that loss of PTEN expression is the first biomarker in EIN that increases the accuracy of the prognostic DS to predict cancer progression risk. Unless endometrial hyperplasias are stratified by histological morphometric D-Score, PTEN has a low positive predictive value.

Adult↗
PubMed2005

Prediction of endometrial carcinoma by subjective endometrial intraepithelial neoplasia diagnosis.

Endometrial intraepithelial neoplasia (also known as 'EIN') is a precursor to endometrioid endometrial adenocarcinoma characterized by monoclonal growth of mutated cells, a distinctive histopathologic appearance, and 45-fold elevated cancer risk. We have applied diagnostic criteria for EIN to 97 successive endometrial biopsies classified as hyperplastic according to World Health Organization criteria and correlated results with computer-assisted morphometry (D-score) and clinical cancer outcomes. Three pathologists separately reviewed all cases for presence or absence of EIN using published criteria (gland area>stromal area, cytologic change in focus of altered architecture, lesion size>1 mm, and exclusion of cancer and mimics). Discordant cases were resolved by a consensus review at a multiheaded scope. Clinical outcomes were obtained in 84 patients from patient visit and pathology records. Diagnoses of presence or absence of EIN were unanimous among all three pathologists in 75% of cases, and intraobserver-reproducibility was very good (kappa 0.73-0.90). Cases rediagnosed as EIN encompassed hyperplasias previously diagnosed as atypical (n=18) or nonatypical (eight complex, two simple). Eight follow-up cancers were scattered between hyperplasia types (5/21 atypical, 3/63 nonatypical), but all classified as EIN (8/25) and D-score <or=1 (8/38). Subjective application of criteria for diagnosis of EIN correlates well with objective morphometry and successfully segregates patients into high and low cancer risk subgroups with better reproducibility than atypical hyperplasia diagnosis.

Diagnosis, Computer-Assisted↗
PubMed2004

Comparison of frozen and RNALater solid tissue storage methods for use in RNA expression microarrays.

BACKGROUND: Primary human tissues are an invaluable widely used tool for discovery of gene expression patterns which characterize disease states. Tissue processing methods remain unstandardized, leading to unanswered concerns of how to best store collected tissues and maintain reproducibility between laboratories. We subdivided uterine myometrial tissue specimens and stored split aliquots using the most common tissue processing methods (fresh, frozen, RNALater) before comparing quantitative RNA expression profiles on the Affymetrix U133 human expression array. Split samples and inclusion of duplicates within each processing group allowed us to undertake a formal genome-wide analysis comparing the magnitude of result variation contributed by sample source (different patients), processing protocol (fresh vs. frozen vs. 24 or 72 hours RNALater), and random background (duplicates). The dataset was randomly permuted to define a baseline pattern of ANOVA test statistic values against which the observed results could be interpreted. RESULTS: 14,639 of 22,283 genes were expressed in at least one sample. Patient subjects provided the greatest sources of variation in the mixed model ANOVA, with replicates and processing method the least. The magnitude of variation conferred by processing method (24 hours RNALater vs 72 hours RNALater vs. fresh vs frozen) was similar to the variability seen within replicates. Subset analysis of the test statistic according to gene functional class showed that the frequency of "outlier" ANOVA results within each functional class is overall no greater than expected by chance. CONCLUSIONS: Ambient storage of tissues for 24 or 72 hours in RNALater did not contribute any systematic shift in quantitative RNA expression results relative to the alternatives of fresh or frozen tissue. This nontoxic preservative enables decentralized tissue collection for expression array analysis without a requirement for specialized equipment.

Analysis of Variance↗
PubMed2004

Combined total genome loss of heterozygosity scan of breast cancer stroma and epithelium reveals multiplicity of stromal targets.

Recent breast cancer studies have highlighted the importance of interactions between cancer epithelium and tumor stroma. Recently, the focus of solid tumor investigations has shifted from mutations in carcinomatous epithelium to disturbances of tissue organization in cancer. The genetic basis of this microenvironment, however, remains to be clarified. To begin to resolve this problem, a total genome loss of heterozygosity (LOH) scan was done on epithelial and stromal DNA from 134 sporadic invasive breast carcinomas. In addition to detecting more frequent LOH at three loci in stroma than in epithelium, we found strong evidence that LOH frequencies were significantly elevated in specific regions of each chromosome. We detected 57 markers, which were preferentially lost either in stroma (n = 38) or epithelium (n = 19), relative to the background LOH frequencies on their respective chromosomes. This multiplicity of stromal cell LOH, and hence loss of genetic material, provides a possible mechanism for interpatient variation in host-stromal response to invading adenocarcinoma cells. This is consistent with a model in which initial, random LOH occurs equally among epithelium and stroma, but subsequent clonal selection is driven by factors, which appear to be distinctly different between malignant epithelial and surrounding stromal cells. Genetic alterations in stroma did not mimic those in epithelium, but they could play a different and parallel role in carcinogenesis and tumor progression, probably by modifying some features specific to breast cancer.

Breast Neoplasms↗
PubMed2004

Molecular pathogenesis of uterine smooth muscle tumors from transcriptional profiling.

Uterine smooth muscle tumors range from the very common benign leiomyoma to the uncommon, but frequently lethal, leiomyosarcoma. Morphological and clinical differences between these tumors are presumed to result from differences in gene expression. To test this hypothesis, RNAs from four normal uterine myometria, seven uterine leiomyomas, and nine uterine leiomyosarcomas were profiled using microarrays of oligonucleotides representing about 7,000 unique probe sets. RNAs whose levels distinguished any of the three sample types were selected by analysis of variance (ANOVA). The 153 (2.2% of the total) probe sets representing 146 unique genes with the highest test statistic selected for further analysis met minimum ratio and range thresholds between groups. Cluster analysis distinguished benign and malignant samples at the first node, and myometrium and leiomyoma were resolved in a secondary node. Downregulation of specific genes in uterine leiomyosarcoma was the most common pattern of differential gene expression selected by the three-way ANOVA. Four extrauterine leiomyosarcomas had profiles most similar to that of the uterine leiomyosarcomas. Functional analysis of the 146 genes did not reveal any strong biological theme. These genes were distributed throughout the genome, but there was slight overrepresentation of genes on 1p and 2q. These genes define a tumor signature for uterine smooth muscle neoplasia, and they suggest that the molecular pathways in leiomyoma and leiomyosarcoma are distinct.

Chromosome Banding↗
PubMed2004

Involution of PTEN-null endometrial glands with progestin therapy.

OBJECTIVES: Loss of PTEN tumor suppressor gene function characterizes most (63%) endometrial precancerous lesions (endometrial intraepithelial neoplasia, EIN) and up to 83% of endometrioid endometrial cancers. Because systemic progestins are known to promote involution of precancerous endometrial lesions, we tested the hypothesis that this therapy preferentially leads to clearance of immunohistochemically detected PTEN-null endometrial glands in a variety of histopathologic settings. METHODS: PTEN immunohistochemistry of pre and postprogestin-treated endometria was successfully performed on 17 women presenting with an intake endometrial biopsy diagnosis of "hyperplasia". Intake biopsies were rediagnosed using EIN criteria as 5 normal (proliferative or secretory), 4 anovulatory, 3 polyps, and 5 EIN endometria. The persistence of PTEN-null glands in progestin-treated patients was compared to that seen previously in rebiopsied normal proliferative endometrium of endogenously cycling premenopausal women. RESULTS: Ten of 17 women prehormonal therapy had PTEN-null glands in the initial biopsy, and 90% (9/10) of these disappeared in the postprogestin sample. This contrasts with only 17% (2/12) involution in the endometria of normal cycling women (Fishers exact test P=0.002, Odds Ratio 45). CONCLUSIONS: We conclude that progestin therapy promotes involution, or disappearance, of PTEN-null endometrial glands relative to the persistence rate seen for normal cycling women. This effect occurs among PTEN-null glands having a variety of histopathologic presentations.

Adult↗
PubMed2003

Factors associated with disposition of cryopreserved reproductive tissue.

OBJECTIVE: To study patient characteristics associated with the preferences for the disposition of cryopreserved semen and embryos in the event of death or divorce. DESIGN: Retrospective exploratory study. SETTING: Tertiary care academic medical center. PATIENT(S): One hundred twelve men banking sperm, 54 female patients (partners of men banking sperm) undergoing in vitro fertilization (IVF), and 112 women undergoing IVF who were not partners of men banking sperm. INTERVENTION(S): Male patients banking sperm and couples undergoing IVF completed a standard consent form detailing their desired dispositions (disposal or release to a surviving party) of cryopreserved sperm and embryos in the event of death or divorce. MAIN OUTCOME MEASURE(S): Effect of marital status, age, reason for sperm banking, infertility diagnosis, partner status (single or significant-other partner) on sperm, and embryo disposition choice. RESULT(S): In the event of death, married men were 5.5 times more likely to release banked sperm to a surviving party than were single men. The estimated odds of giving sperm to a survivor were 1.07 times greater with every 1-year increase in age. The choice of sperm disposal was significantly related to the banking reason for the case of banking prior to chemotherapy and/or radiation for malignancy. In the case of male death, the decisions of couples undergoing IVF for embryo disposition agreed with choices of male patients for sperm disposition approximately 33% of the time more often than by chance alone. CONCLUSION(S): Decisions surrounding disposition of cryopreserved sperm are significantly associated with marital status, age, and reason for banking sperm. Respective choices of sperm and embryo disposition in couples undergoing IVF were similar in the situation of male death.

Adolescent↗
PubMed2003

Biomarkers in diagnostic obstetric and gynecologic pathology: a review.

Until recently, the histologic diagnosis of obstetrical and gynecologic neoplasia was based principally on morphologic criteria. However, interobserver reproducibility for entities such as squamous intraepithelial, endometrial, and trophoblastic disease varies widely between observers. This inherent variability in interpretation between individuals has led to wide ranges in diagnostic precision between practices, and in many cases, between recognized experts. The advent of immunohistochemistry, and the more recent accelerated discovery of new genes and their functions has resulted in the discovery of cellular proteins or nucleic acids that are differentially expressed in tumors. When applied in conjunction with existing histologic criteria, these "biomarkers" have the potential to enhance diagnostic consistency and reproducibility. The gains expected are to practicing diagnostic pathologists (who will enjoy greater diagnostic consistency) and to academics (for whom biomarkers may uncover new pathways unappreciated by histologic diagnosis alone). However, fundamental to the success in both arenas will be critical analysis of the potential pitfalls in immunohistochemistry, strict validation of new markers as they arrive in the field, and a realistic view of their value in the laboratory management of obstetrical and gynecologic diseases.

Biomarkers, Tumor↗
PubMed2003

Hertig and beyond: a systematic and practical approach to the endometrial biopsy.

Evaluation of the endometrial biopsy is a challenge to practicing pathologists, largely due to the wide range of morphologic patterns resulting from both normal and abnormal cyclic changes, exogenous hormones, infections, and intrauterine tumors. Successfully addressing these challenges requires that the practitioner (i) understand the clinical questions being asked, (ii) have a realistic expectation for answering these questions, and (iii) have a systematic approach to resolving these questions in the context of these expectations. The approach outlined begins with the subdividing of women with endometrial alterations into three general categories: (i) women in their fourth decade undergoing evaluation for infertility, (ii) women in their fifth decade who experience abnormal uterine bleeding, and (iii) women in their sixth decade and beyond who experience postmenopausal bleeding. The clinical expectations for each group are unique, as are the morphologic patterns most commonly encountered. Algorithms for the laboratory management of cyclic changes, dysfunctional bleeding, and mixed-pattern endometria are provided, as are pitfalls in interpretation and exclusion of neoplasia.

Adult↗
PubMed2003

Identification of differentially expressed genes in high-density oligonucleotide arrays accounting for the quantification limits of the technology.

In DNA microarray analysis, there is often interest in isolating a few genes that best discriminate between tissue types. This is especially important in cancer, where different clinicopathologic groups are known to vary in their outcomes and response to therapy. The identification of a small subset of gene expression patterns distinctive for tumor subtypes can help design treatment strategies and improve diagnosis. Toward this goal, we propose a methodology for the analysis of high-density oligonucleotide arrays. The gene expression measures are modeled as censored data to account for the quantification limits of the technology, and two gene selection criteria based on contrasts from an analysis of covariance (ANCOVA) model are presented. The model is formulated in a hierarchical Bayesian framework, which in addition to making the fit of the model straightforward and computationally efficient, allows us to borrow strength across genes. The elicitation of hierarchical priors, as well as issues related to parameter identifiability and posterior propriety, are discussed in detail. We examine the performance of our proposed method on simulated data, then present a detailed case study of an endometrial cancer dataset.

Biometry↗
PubMed2002

p63 Coordinates anogenital modeling and epithelial cell differentiation in the developing female urogenital tract.

p63 is a p53 homologue required for cutaneous development that is expressed in immature squamous epithelium and reserve cells of the cervix. Humans with p63 mutations exhibit defects in limb, accessory organ (skin appendage, breast, prostate), and genitourinary development. Because p63 expression patterns imply a strong role of the gene in the female genital tract development, newborn female p63-/-, +/-, and +/+ mice were examined in situ, dissected, and compared. Nuclear p63 protein was localized to the skin, vagina, bladder, urethra, and basal columnar cells of the caudal uterus in p63+/+ and +/- animals. p63-/- mice exhibited abnormal genital morphogenesis with hypoplastic genitalia, a single cloacal opening, and persistence of columnar epithelium at lower genital tract sites that normally undergo squamous and urothelial differentiation. The defects observed support p63-dependent pathways of genital tract development that permit externally, ectodermal basal cell replenishment integral to reciprocal epithelial stromal signaling, urorectal septation, and modeling of the external genitalia; and internally, the emergence of basal epithelial cell populations capable of divergent epithelial cell differentiation in the vagina, cervix, and urinary tract. Defects in the first pathway explain imperforate anus, vaginal septum, genital hypoplasia, and micropenis reported in humans with p63 mutations. The second is necessary for the generation of multipotential reserve cells in the cervix and may be operative in other epithelial stromal interactions integral to the emergence of uterine basal cells later in life.

Anal Canal↗