Abstract 3292: A genetically engineered mouse model for high grade serous “ovarian” carcinoma arising in the fallopian tube

Ovarian cancer is the most lethal gynecologic malignancy because the vast majority of cases are detected in late stage, a finding that has thwarted attempts to understand the pathogenesis and cell-of-origin of this disease. The traditional view of epithelial ovarian pathogenesis asserts that all tumor subtypes share a common origin in the ovarian surface epithelium (OSE). There is robust data to support the OSE as the site of origin for many ovarian tumors, including low-grade carcinomas and borderline tumors. However, the pathogenesis of high-grade serous ovarian carcinoma, the most common type of ovarian cancer, continued to defy explanation by the OSE model. More recent studies suggested that the fallopian tube epithelium (FTE), rather than the OSE, may be the site-of-origin for a majority of pelvic serous carcinomas (PSC, defined as ovarian, peritoneal and tubal high grade serous carcinomas). We show here that the FTE can be site of origin for PSC by genetically engineering a mouse model that specifically targets the FT secretory cell with defined genetic alterations that are characteristic of human PSC. These mice develop tubal intraepithelial serous carcinomas, a precursor to PSC, that are morphologically and immunophenotypically similar to the lesions described in human patients. Furthermore, these intraepithelial lesions progress to widespread peritoneal disease that recapitulates the presentation of high-grade PSC in women. The tumors express common serous markers such as P53, αH2A.X, PAX8 and CA-125. Taken together our model is the first fully genetically engineered mouse model that truly recapitulates human serous carcinoma pathogenesis. Our model serves as proof-of-concept that the FTE can be site-of-origin to PSC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3292. doi:1538-7445.AM2012-3292

Abstract 114: Study of the high-grade ovarian cancer precursors in the oviduct

The discovery that many high-grade ovarian cancers originate in the oviduct has generated a paradigm shift in the field of ovarian cancer. The description of new entities in the oviduct that signify early phases of ovarian carcinogenesis, including both serous tubal intraepithelial carcinomas and their precursors the p53 signatures, has provided a tangible sequence of events leading to malignancy that can be linked to DNA damage and p53 mutations. However, it has become clear that other pathway disturbances also play a critical role in the early development of ovarian cancer. We hypothesize that molecular alterations present in morphologically normal oviductal epithelium from ovarian cancer patients reflect the earliest events in ovarian carcinogenesis and may be markers of increased cancer risk as well as targets for risk reduction. Whole-genome transcriptome analysis of laser microdissected oviductal epithelium from histologically normal ovarian cancer patients and controls was performed. We identified a set of aberrantly expressed genes in the oviductal epithelium from women who developed high-grade ovarian cancer and demonstrated some of these genes are also abnormally expressed in the ovarian cancers due to the genomic alterations. We further examined the function of these genes using three-dimensional cell culture system and mouse models. Our work demonstrates the synergistic effects of defective p53 pathway and other newly found pathways in driving early steps of ovarian cancer development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 114. doi:1538-7445.AM2012-114

Abstract 3297: A cell of origin for cervical cancer

Background Squamous cell carcinoma of the cervix and its precursor [cervical intraepithelial neoplasia (CIN)] are thought to develop either within, or in close proximity to, the squamo-columnar (SC) junction of the ecto and endocervix. Despite this assumption, one issue unresolved in cervical cancer research is the identity of the normal cervical cell type in the SC junction in which tumorigenesis begins. Methods Using GeneChip Human Exon Arrays (Affymetrix), we compared the gene expression profiles of the ecto and endocervical epithelia with the SC junctional cells. Fetal and adult cervical specimens were studied in situ to identify, characterize and determine the dynamics of junctional cell development. CINs and cancers were stained with junction-specific antibodies to ascertain their relationship to the SC junctional cell population. Cervices in which the transformation zone had been excised were analyzed for evidence of the SC junctional immunophenotype. Results Human adult cervices displayed a unique monolayer of cuboidal cells at the SC junction that displayed a unique 77 gene expression signature. Analysis of fetal and postnatal mouse and human cervices using biomarkers from this unique gene signature revealed broad expression in the lining cells of the lower genital tract that, over time, become concentrated in the region of the SC junction. Junction-specific biomarkers consistently immunostained high-grade CINs and squamous and glandular cancers associated with both carcinogenic human papillomaviruses (HPV) and strong expression of p16ink4. Non-carcinogenic HPV-associated CINs and low-grade CINs predominated in the ectocervical location and were usually SC junctional-marker negative. Cervices previously subjected to surgical excision of the SC junction did not remanufacture junctional cells at the new SC junction. Conclusions This study shows, for the first time, that a discrete, residual embryonic cell population in the cervix is uniquely susceptible to carcinogenic HPV infection and is lost following surgical excision of the SC junction. The negative association between the junctional immunophenotype and noncarcinogenic HPV-related CIN may signify different affinities for the SC junction between carcinogenic and non-carcinogenic HPVs. Because junction-specific biomarkers highlight CINs and all cancers with carcinogenic HPVs, they may facilitate interpretation of cervical cancer precursors as well as propose a novel cell type for studies of experimental papillomaviral carcinogenesis. The possibility that unique populations of junctional cells are also involved in the pathogenesis of other HPV-related cancers (anogenital and oropharyngeal) merits investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3297. doi:1538-7445.AM2012-3297

Distal airway stem cells yield alveoli in vitro and during lung regeneration following H1N1 influenza infection

The extent of lung regeneration following catastrophic damage and the potential role of adult stem cells in such a process remains obscure. Sublethal infection of mice with an H1N1 influenza virus related to that of the 1918 pandemic triggers massive airway damage followed by apparent regeneration. We show here that p63-expressing stem cells in the bronchiolar epithelium undergo rapid proliferation after infection and radiate to interbronchiolar regions of alveolar ablation. Once there, these cells assemble into discrete, Krt5+ pods and initiate expression of markers typical of alveoli. Gene expression profiles of these pods suggest that they are intermediates in the reconstitution of the alveolar-capillary network eradicated by viral infection. The dynamics of this p63-expressing stem cell in lung regeneration mirrors our parallel finding that defined pedigrees of human distal airway stem cells assemble alveoli-like structures in vitro and suggests new therapeutic avenues to acute and chronic airway disease.

Beta-catenin accelerates human papilloma virus type-16 mediated cervical carcinogenesis in transgenic mice

Human papilloma virus (HPV) is the principal etiological agent of cervical cancer in women, and its DNA is present in virtually all of these tumors. However, exposure to the high-risk HPV types alone is insufficient for tumor development. Identifying specific collaborating factors that will lead to cervical cancer remains an unanswered question, especially because millions of women are exposed to HPV. Our earlier work using an in vitro model indicated that activation of the canonical Wnt pathway in HPV-positive epithelial cells was sufficient to induce anchorage independent growth. We therefore hypothesized that constitutive activation of this pathway might function as the "second hit." To address this possibility, we developed two double-transgenic (DT) mouse models, K14-E7/ΔN87βcat and K14-HPV16/ΔN87βcat that express either the proteins encoded by the E7 oncogene or the HPV16 early region along with constitutively active β-catenin, which was expressed by linking it to the keratin-14 (K14) promoter. We initiated tumor formation by treating all groups with estrogen for six months. Invasive cervical cancer was observed in 11% of the K14-ΔN87βcat mice, expressing activated β-catenin and in 50% of the animals expressing the HPV16 E7 oncogene. In double-transgenic mice, coexpression of β-catenin and HPV16 E7 induced invasive cervical cancer at about 7 months in 94% of the cases. We did not observe cervical cancer in any group unless the mice were treated with estrogen. In the second model, K14-HPV16 mice suffered cervical dysplasias, but this phenotype was not augmented in HPV16/ΔN87βcat mice. In summary, the phenotypes of the K14-E7/ΔN87βcat mice support the hypothesis that activation of the Wnt/β-catenin pathway in HPV-associated premalignant lesions plays a functional role in accelerating cervical carcinogenesis.

Abstract A107: Ovarian cancer risk factors by tumor dominance, a surrogate for cell of origin

Although some epidemiologic associations for ovarian cancer are established, such as the risk reduction due to parity or oral contraceptive use, the influence of other characteristics like endometriosis and non-steroidal anti-inflammatory use is less clear. Distinguishing categories of ovarian cancer based on shared pathways of development may clarify these associations and further our understanding of the disease. Traditionally, ovarian cancers have been thought to arise from the ovarian surface epithelium. Recent evidence in BRCA1 or 2 mutation carriers showing synchronous tumors in fallopian tubes and potential precursor lesions with p53 signatures that match tumors suggest that some “ovarian” cancers may originate in the fallopian tube. Tumor origin (e.g., ovarian vs. fallopian) may be classified by rigorous pathologic review protocol, including the identification of tubal lesions and p53 signatures, but this is not practical in population-based studies where the needed tissue is not always available. Alternatively, presence or absence of a two-fold difference in tumor size between ovaries (dominant ovarian mass) can be used to assign a greater or lesser probability of ovarian (versus tubal) origin.

We applied this classification algorithm to ovarian cancer cases in a population based case-control study (NEC) and two prospective cohort studies (NHS/NHSII). Associations between known and suspected ovarian cancer risk factors were evaluated in relation to cases with dominant and non-dominant tumors using polytomous logistic regression (for NEC) and competing risks models (for NHS) adjusted for matching factors, study, oral contraceptive use (never, <5 years, > 5 years), parity (0, 1, 2, 3, 4+), tubal ligation, and family history of breast or ovarian cancer.

Among the 1801 invasive epithelial ovarian cancer cases, we observed 1127 tumors (778 NEC, 246 NHS) with a dominant mass, indicating a greater likelihood of ovarian origin, and 674 (534 NEC, 140 NHS) with no dominant mass, indicating a greater likelihood of fallopian tube origin. The dominant cases were more likely to be mucinous, endometrioid, clear cell, or undifferentiated while the non-dominant cases were more likely to be serous ovarian cancers, except for serous borderline tumors which were more likely to be dominant. We observed stronger associations with dominant tumors than non-dominant tumors for tubal ligation, more than two births, and endometriosis (pheterogeneity=0.01, 0.01, and 0.0002, respectively). Interestingly, differences in non-steroidal anti-inflammatory use (pheterogeneity=0.08) suggested inverse associations for non-dominant tumors. These results suggest that risk factors for tumors putatively arising from ovarian versus fallopian tube sites may have different risk factors for disease.

Acknowledgments: Supported by the DOD Ovarian Cancer Academy and National Cancer Institute grants R01CA54419, P50CA105009, P01CA87969, R01CA50385.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A107.

Abstract 4328: Beta-catenin accelerates human papillomavirus type16 -E7 mediated cervical carcinogenesis in transgenic mice

Human papilloma virus (HPV) is the principal etiological agent of cervical cancer in women and its DNA is present and expressed in virtually all cervical cancers. Exposure to the high-risk HPV types is not sufficient for tumor development. Approximately 80% of women will be infected with HPV in their lifetime, however only a small percentage of infected women develop cervical cancer. It is unknown who among the millions of women infected with HPV will go on to develop cervical cancer. Therefore, it remains critical to discover additional cellular changes that lead to malignant transformation. The persistence of viral infection is one critical factor in the predisposition to cancer, presumably providing genetic instability that leads to additional genetic/epigenetic changes. Our earlier work using an in vitro model indicated that activation of the canonical Wnt pathway in HPV-positive epithelial cells was sufficient to induce anchorage independent growth. Therefore, we hypothesized that constitutive activation of the Wnt pathway might function as a second hit. To address this possibility, we generated two new double transgenic (DT) mouse models. The first model, K14-HPV16/ΔN87βcat is established by crossing K14-ΔN87βcat mice with K14-HPV16 mice. These mice express wild type HPV16 early region oncoproteins including E6 and E7 and constitutively active -catenin protein in cervical epithelia under the control of tissue specific K14 promoter. The second model, K14-E7/ΔN87βcat mice were generated by crossing K14-ΔN87cat cat mice with K14-E7 mice and they express only the E7 oncoprotein and constitutively active -catenin under the same K14 promoter. All the transgenic animals in both crosses were maintained as heterozygotes. Within the K14-HPV16/ΔN87βcat model, we did not observe any cervical pathology in the wild type and K14-ΔN87βcat mice, whereas we observed CINIII in 26.7% of K14-HPV16 animals and CINIII and invasive tumors in 30% of the double transgenic animals at an average of 6 months of age. Within the K14-E7/ΔN87βcat model, wild type animals did not develop any cervical pathology. Invasive cervical cancer was observed in 10.5% of the animals expressing activated β-catenin and in 50% of the animals expressing HPV16-E7 oncogene. In double transgenic animals, expression of β-catenin and the HPV16-E7 oncogene induced invasive cervical cancer at an average age of 6 months in 93.75% of the cases. In summary, our data support the hypothesis that activation of the Wnt/β-catenin pathway in HPV pre-malignant lesions has a functional role in accelerating cervical carcinogenesis. These findings may have both preventive and therapeutic applications for cervical cancer patients. HPV positive patients may be screened for activation of Wnt signaling for early intervention. Late stage patients may benefit from novel anti-beta-catenin agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4328. doi:10.1158/1538-7445.AM2011-4328

Abstract 104: PAX2 dysregulation in the fallopian tube and pelvic serous cancer

High grade ovarian serous cancer in women has been linked to the distal fallopian tube via a carcinogenic sequence of p53 mutations in both a clonally-derived precursor (p53 signature) and an early malignancy (tubal intraepithelial carcinoma)(Lee 2007). Dysregulation of additional genes, including PTEN and PAX2, has been associated with this early carcinogenic sequence and advanced ovarian serous cancers. Dysregulation of PAX2 has not been linked to genetic mutations, and has been recently documented throughout the tube within discrete secretory cell outgrowths (SCOUTs), particularly in fallopian tubes of women with serous cancer (Chen 2010). This study explored the frequency of PAX2-null SCOUTs in the fallopian tube and other potential molecular and cell kinetic correlates of this phenomenon. Fallopian tubes from a wide range of subjects, including (1) pre-adolescents (n=20), women undergoing (2) post-partum tubal ligation (n=25), (3) salpingectomy during surgery for benign disease (n=20), surgery for (4) endometriosis (n=47), (5) low grade endometrioid adenocarcinomas of the ovary (n=42), and (6) high-grade ovarian serous carcinomas (n=12) were immunostained and scored blindly for PAX2-null SCOUTs. Extracted tubal DNA from cancers and controls was analyzed for hypermethylation of the PAX2 promotor by real-time PCR and fallopian tube epithelial cultures were established from cancers and controls to assess clonogenic capacity. Review of over 350 tissue blocks revealed a frequency (%) of PAX2-null SCOUTs of 0, 0.5, 11, 5, 4.5 and 56.2 for groups 1-6 above, respectively, yielding a 5-50-fold increase in the tubes of patients with serous cancer (p < .001). A preliminary analysis of DNA from one cancer-associated fallopian tube revealed a relative increase in PAX2 promotor methylation. A striking increase in cell growth (clonogenic) capacity was observed in tubes from cancer patients versus controls. This study reveals, for the first time, that functional loss of PAX2 expression is linked to a morphologically defined entity (SCOUT) in the fallopian tube that is absent in pre-adolescent fallopian tubes and post-partum tubal ligations, increases with age, and is exquisitely linked to co-existing high grade ovarian serous carcinoma. This unique dysregulation of PAX2 appears to segregate with a markedly higher in vitro clonogenic potential of tubal epithelium in women with serous cancer. The potential that this highly prevalent entity (PAX2-null SCOUT) and its milieu in fallopian tube epithelium of women with serous cancer can be exploited as a predictor of concurrent or future ovarian serous carcinoma is under investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 104. doi:10.1158/1538-7445.AM2011-104

STICS, SCOUTs and p53 signatures; a new language for pelvic serous carcinogenesis

The events leading to the most common and most lethal ovarian carcinoma - high grade serous carcinoma - have been poorly understood. However, the detailed pathologic study of asymptomatic women with germ-line BRCA 1 or BRCA2 (BCRA+) mutations has unearthed an early malignancy, serous tubal intraepithelial carcinomas (STIC), which has linked many peritoneal and ovarian serous carcinomas to the fimbria. The distinction between high-grade serous and endometrioid carcinomas continues to narrow, with shared alterations in expression of pTEN, PAX2 and p53. Moreover, the discovery of clonal alterations in p53 in benign tubal epithelium, - p53 signatures - has established a foundation for a serous cancer precursor in the fimbria. We have expanded this concept to include a generic secretory cell outgrowth (SCOUT) in the fallopian tube that is associated with altered PAX2 expression. As the repertoire of gene alterations is expanded and its link to serous carcinogenesis clarified, a cogent pathway to high-grade Mullerian carcinomas will emerge. This will challenge conventional thinking about ovarian carcinogenesis but will provide a new template for studies of ovarian cancer prevention.

High-grade and low-grade pelvic serous neoplasms demonstrate differential p53 immunoreactivity in peritoneal washings

OBJECTIVE

Serous neoplasms of the female pelvis share a müllerian phenotype. Unlike low-grade serous neoplasms (LGSNs), high-grade serous carcinomas (HGSCs) commonly display p53 mutations. The current study correlates p53 immunoreactivity in peritoneal washings with the cytologic interpretation and histology of the corresponding serous neoplasm.

STUDY DESIGN

Peritoneal washings from consecutive cases of pelvic serous neoplasms were identified (n=45, 31 HGSCs and 14 LGSNs), with a control population selected from benign resections. Immunoreactivity for p53 was scored as a percentage of positive epithelioid cells by blinded manual cell count.

RESULTS

Washings from LGSNs and HGSCs were cytomorphologically positive with similar frequency (57 vs. 77%, respectively, p=0.15, Fisher's exact test). Immunoreactivity for p53 was not predictive of morphologic positivity. The percentage of p53-positive cells was higher in HGSCs (47±42%), compared to LGSNs (9±9%) and negative controls (2±2%, n=10). The difference in p53 immunoreactivity was statistically significant (p<0.00009, ANOVA).

CONCLUSIONS

The proportion of p53 immunoreactive cells was higher in cases of HGSCs, reflecting the importance of p53 mutations in high-grade serous tumorigenesis. The presence of p53 staining is not diagnostic for neoplastic cells; however, peritoneal washings are potential specimens in the investigation of serous neoplasia.

Obstetric and perinatal complications in placentas with fetal thrombotic vasculopathy

Fetal thrombotic vasculopathy (FTV) is a placental lesion characterized by regionally distributed avascular villi and is often accompanied by upstream thrombosis in placental fetal vessels. Previous studies, using preselected populations, have shown associations of this lesion with adverse neurodevelopmental outcomes and potentially obstructive lesions of the umbilical cord. We investigated the prevalence of obstetric complications, perinatal disease, and placental abnormalities in cases with FTV. One hundred thirteen cases of placentas with FTV were identified in our pathology database over an 18-year period. Two hundred sixteen placentas without the diagnosis of FTV, frequency matched on year of birth, were selected as controls. Electronic medical records and pathology reports were used to extract maternal and gestational age, method of delivery, neonatal outcome, lesions of the umbilical cord, obstetric complications, and fetal abnormalities. Placentas with FTV were associated with a 9-fold increase in rate of stillbirth and a 2-fold increase in intrauterine growth restriction. The increase in pregnancy-induced hypertension/preeclampsia was not significant when adjusted for maternal and gestational age. Although the rate of potentially obstructive cord lesions was similar in both groups, there was an almost 6-fold increase in the presence of oligohydramnios in FTV placentas, compared with controls. Finally, FTV was associated with a 6-fold increase in fetal cardiac abnormalities. Fetal thrombotic vasculopathy is associated with a significantly higher rate of obstetric and perinatal complications. This study points to abnormal fetal circulation, either in the form of congenital heart disease or oligohydramnios predisposing to cord compression, as a risk factor for FTV.

Clinical outcome in diagnostically ambiguous foci of 'gland crowding' in the endometrium

Premalignant endometrial lesions (endometrial intraepithelial neoplasia (EIN)) are clonal neoplasms that arise focally and can be diagnosed using specific criteria: (1) area of glands exceeds that of stroma (glands/stroma >1), (2) nuclear and/or cytoplasmic features of epithelial cells differ between architecturally abnormal glands and normal background glands, and (3) maximum linear dimension exceeds 1 mm. However, localized groups of crowded endometrial glands may be encountered that do not fulfill all of the criteria for EIN, are interpreted as ambiguous, and are reported as 'focal gland crowding'. We conducted a retrospective study of gland crowding using a free-text index search for this term in our pathology files. The age of the patients, number of subsequent specimens, the duration, and the outcome of the follow-ups were recorded. Of the 71,579 consecutive gynecological pathology reports, 206 (0.3%) 'gland crowding' cases were identified, in which 69% (143/206) had follow-up sampling. Of these, 33 (23%) had an outcome diagnosis of EIN (27 cases; 19%) or carcinoma (6 cases; 4%). Included were 18 cases (55%) diagnosed within the first year and presumed concurrent, and an additional 15 (45%) discovered after 1 year and interpreted as a later phase of disease or new events. The term 'crowded glands' is a highly significant finding that carries a substantial risk of an outcome of EIN and occasionally malignancy. It underscores the importance of follow-up when some but not all of the criteria for EIN are encountered in the appropriate clinical setting.

CA125 immune complexes in ovarian cancer patients with low CA125 concentrations

BACKGROUND

About 20% of women with ovarian cancer have low concentrations of serum cancer antigen 125 (CA125), and this important tumor marker cannot be used to monitor their disease. The measured concentration for mucin 1 (MUC1), or CA15-3, another tumor marker, can be lowered in breast and ovarian cancer patients when circulating immune complexes (CICs) containing antibodies bound to the free antigen are present. Because CA125 and MUC1 are related members of the mucin family, we sought to determine whether CICs might also exist for CA125 and interfere with its clinical assay.

METHODS

We developed an antigen capture-based assay to determine the presence of CICs for CA125. We spotted mouse antibodies to CA125 onto nanoparticle slides, incubated them with patient serum, and added Cy5-tagged goat antihuman IgG antibodies. Fluorescence intensities were read and normalized to the intensities for glutathione S-transferase A1 as a control.

RESULTS

Assay results for 23 ovarian cancer cases with high CA125 concentrations, 43 cases with low CA125 concentrations, and 19 controls (mean CA125 concentrations, 2706, 23, and 11 kilounits/L, respectively) revealed mean fluorescence intensities for CA125 CIC of 2.30, 2.72, and 1.99 intensity units (iu), respectively. A generalized linear model adjusted for batch and age showed higher CA125 CIC fluorescence intensities in low-CA125 cases than in high-CA125 cases (P = 0.03) and controls (P = 0.0005). Four ovarian cancer patients who had recurrent disease and always had low CA125 values had a mean CA125 CIC value of 3.06 iu (95% CI, 2.34-4.01 iu).

CONCLUSIONS

These preliminary results suggest the existence of CICs involving CA125, which may help explain some ovarian cancer cases with low CA125 concentrations.

Serous tubal intraepithelial carcinoma: diagnostic reproducibility and its implications

Serous tubal intraepithelial carcinoma (STIC) is detected in between 5% and 7% of women undergoing risk-reduction salpingooophorectomy for mutations in the BRCA1 or 2 genes (BRCA+), and seems to play a role in the pathogenesis of many ovarian and "primary peritoneal" serous carcinomas. The recognition of STIC is germane to the management of BRCA+ women; however, the diagnostic reproducibility of STIC is unknown. Twenty-one cases were selected and classified as STIC or benign, using both hematoxylin and eosin and immunohistochemical stains for p53 and MIB-1. Digital images of 30 hematoxylin and eosin-stained STICs (n=14) or benign tubal epithelium (n=16) were photographed and randomized for blind digital review in a Powerpoint format by 6 experienced gynecologic pathologists and 6 pathology trainees. A generalized kappa statistic for multiple raters was calculated for all groups. For all reviewers, the kappa was 0.333, indicating poor reproducibility; kappa was 0.453 for the experienced gynecologic pathologists (fair-to-good reproducibility), and kappa=0.253 for the pathology residents (poor reproducibility). In the experienced group, 3 of 14 STICs were diagnosed by all 6 reviewers, and 9 of 14 by a majority of the reviewers. These results show that interobserver concordance in the recognition of STIC in high-quality digital images is at best fair-to-good for even experienced gynecologic pathologists, and a proportion cannot be consistently identified even among experienced observers. In view of these findings, a diagnosis of STIC should be corroborated by a second pathologist, if feasible.

MOLECULAR MARKERS OF EARLY CERVICAL NEOPLASIA

Pure morphological distinction of high-grade squamous intraepithelial lesions (HSILs) from their mimics can be challenging. Diagnosis can be difficult with nonconventional HSILs associated with a metaplastic phenotype, squamous intraepithelial lesions (SILs) that defy precise classification such as "eosinophilic dysplasias", and those that overlap with columnar neoplasms, including stratified variants of adenocarcinoma in situ ("SMILE"). Gene expression and protein profiling have identified biomarkers with the potential to decrease diagnostic variability and increase specificity of histological and cytological analysis. Among the ones clinically useful for HSIL detection are p16(INK4A) and MIB-1 which complement each other, differentiating SIL from normal/atrophic (MIB-1 low) or reactive/immature metaplastic (p16(INK4A) scattered) epithelium. Additional markers, including ProEx(TM) C, have been proposed but their added value is yet to be established. In the final analysis, biomarkers are most helpful for distinguishing benign immature or atrophic proliferations from HSIL. The distinction of LSIL from HSIL must be made on the hematoxylin and eosin-stained section and should be made with care, given the potential consequences of a diagnosis of CIN2 or CIN3.

A weakly positive human papillomavirus Hybrid Capture II result correlates with a significantly lower risk of cervical intraepithelial neoplasia 2,3 after atypical squamous cells of undetermined significance cytology

OBJECTIVE

The Hybrid Capture II assay (hc2; QIAGEN, Inc) for high-risk human papillomavirus (hrHPV) is an in vitro nucleic acid hybridization assay using chemiluminescence for the qualitative detection of hrHPV DNA in cervical samples. Results are reported as a ratio of relative light units (RLUs) to a cutoff value based on a positive control. Specimens with RLU ratios of 1.0 or higher are scored positive for hrHPV. We tested the hypothesis that hrHPV positives with low-positive RLU ratios (1-10) had a lower prevalence of cervical intraepithelial neoplasia 2,3 (CIN 2,3) on histologic follow-up.

MATERIALS AND METHODS

Relative light unit ratios for 388 consecutive hrHPV-positive cervical cytologic specimens interpreted as atypical squamous cells of undetermined significance (ASCUS) were reviewed. Individual RLU ratios were compared with outcome histologic diagnosis in cases with colposcopic follow-up and tissue sampling (biopsy and/or endocervical curettage; n = 236).

RESULTS

Of 236 cases with histologic follow-up, 63 had RLU ratios in the range of 1 to 10; of these, 53 (84.1%) were negative for CIN, 7 (11.1%) had CIN 1, 1 (1.6%) had CIN of uncertain grade, and 2 (3.2%) had CIN 2,3. The difference in CIN 2,3 outcome between RLU ratios of 1 to 10 (3.2%) versus over 10 (17.3%) was significant (p =.0047). The difference in prevalence of CIN 1 was not significant (p =.67).

CONCLUSIONS

An RLU ratio of 10 or less was associated with a significantly lower prevalence of CIN 2,3 on biopsy outcome after a Pap test result of ASCUS. The much lower prevalence of underlying CIN 2,3 in patients who are weakly HPV-positive may justify modification of the management algorithm for this subset of women with ASCUS.

Secretory cell outgrowth, PAX2 and serous carcinogenesis in the Fallopian tube

The 'p53 signature' is a benign secretory cell outgrowth in the distal Fallopian tube that shares properties with ovarian serous cancer-including p53 mutations-and is a putative serous cancer precursor. We expanded the precursor definition to all secretory cell outgrowths (SCOUTs) of 30 or more cells and scored normal (N) and altered (A) expression of both p53 and PAX2, a gene down-regulated in ovarian and endometrial cancer. SCOUTs were identified by BCL2/p73 staining in tubes from women with serous carcinoma, inherited mutations in BRCA1 or BRCA2 and controls. SCOUTs were prevalent in both proximal and distal tube and significantly associated with serous carcinoma versus the others (p < 0.001); 89% were PAX2 (A) and 26% were PAX2 (A)/p53 (A) (p53 signatures). PAX2 (A)/p53 (N) SCOUTs were free of p53 mutations; however, 12 of 13 p53 signatures were PAX2 (A). A tubal carcinoma and contiguous SCOUT were p53 (A)/PAX2 (A) and shared the same p53 mutation. SCOUTs are discretely localized alterations commonly containing altered expression of multiple genes within histologically benign tubal epithelium. Geographic distribution in the tube varies by genotype and immunophenotype, from regionally unrestricted (PAX2) to greater likelihood specific area (fimbria) of shared prevalence (PAX2 and p53). This study reveals, for the first time, an entity (SCOUT) that is associated with serous cancer, expands the topography of altered PAX2 expression in the female genital tract mucosa and highlights another potential pathway disturbance involved in early serous carcinogenesis in the Fallopian tube.

PD-1 on immature and PD-1 ligands on migratory human Langerhans cells regulate antigen-presenting cell activity

Langerhans cells (LCs) are known as "sentinels" of the immune system that function as professional antigen-presenting cells (APCs) after migration to draining lymph node. LCs are proposed to have a role in tolerance and the resolution of cutaneous immune responses. The Programmed Death-1 (PD-1) receptor and its ligands, PD-L1 and PD-L2, are a co-inhibitory pathway that contributes to the negative regulation of T-lymphocyte activation and peripheral tolerance. Surprisingly, we found PD-1 to be expressed on immature LCs (iLCs) in situ. PD-1 engagement on iLCs reduced IL-6 and macrophage inflammatory protein (MIP)-1alpha cytokine production in response to TLR2 signals but had no effect on LC maturation. PD-L1 and PD-L2 were expressed at very low levels on iLCs. Maturation of LCs upon migration from epidermis led to loss of PD-l expression and gain of high expression of PD-L1 and PD-L2 as well as co-stimulatory molecules. Blockade of PD-L1 and/or PD-L2 on migratory LCs (mLCs) and DDCs enhanced T-cell activation, as has been reported for other APCs. Thus the PD-1 pathway is active in iLCs and inhibits iLC activities, but expression of receptor and ligands reverses upon maturation and PD-L1 and PD-L2 on mLC function to inhibit T-cell responses.

Polymerase chain reaction detection of HPV in squamous carcinoma of the oropharynx

Human papillomavirus (HPV) testing is routinely performed on oropharyngeal carcinomas. We compared the Access Genetics (Minneapolis, MN) polymerase chain reaction (PCR) assay (AGPCR), DNA-DNA in situ hybridization (ISH; Ventana, Tucson, AZ), and HPV-16 E7 PCR amplification in consecutively accessioned oropharyngeal cancers. We tested 126 cases by both PCR methods; 102 were positive by either for a maximum positive rate (MPR) of 81.0%. Relative to the MPR, the sensitivities of AGPCR and E7 PCR were 90.2% and 72.5%, respectively. Of 17 AGPCR+ cases tested by ISH, 14/14 unequivocally positive/negative were concordant. All cases (97/97) positive by either PCR assay were positive for p16. There was no relationship between level of histologic differentiation and HPV status. ISH and AGPCR have comparable performance for the detection of HPV in oropharyngeal carcinomas. PCR is a suitable and economical assay that is comparable to ISH in sensitivity and may provide logistical advantages relative to ISH for assessing HPV status in oropharyngeal malignancies. However, it is imperative that appropriate sensitivity controls be in place for such assays.

Abstract 2054: A microRNA hypothesis for the precursor lesions of ovarian cancer

Ovarian cancer is the leading cause of death among gynecologic diseases in Western countries. Ovarian surface epithelial (OSE) cells were previously considered as the cells of origin of ovarian cancer. The ovarian surface epithelium is derived from the coelomic layer, which is consisted of peritoneal mesothelial cells. Malignant ovarian cancer cells, however, are found to be associated with epithelial phenotypes resembling cells from fallopian tube, uterus, and cervix. Recent studies have suggested that significant percentages of familial and sporadic high-grade serous ovarian carcinomas could be explained by an origin in the distal fallopian tube. We and others have identified overexpression of miR-200 family members in ovarian caner cells. In order to investigate whether the miR-200 pathway is involved in the early stages of ovarian pathogenesis, we have studied the expression levels of the pathway components in a panel of samples isolated from primary cultures and laser microdissection. The ovarian samples included OSEs, epithelial tumor cells from benign tumors, borderline tumors, nonserous invasive tumors, serous invasive tumors, ovarian cancer cell lines, and tumor-associated stromal fibroblasts. Fallopian tube samples included normal fallopian tubal epithelial (FTE) cells, tumor cells and stromal fibroblasts from frozen tubal intraepithelial carcinomas (TICs) of fallopian tube. Gene expression was determined using quantitative real-time polymerase chain reactions (qRT-PCRs). The reactions for the 4 target genes of miR-200s (ZEB1, ZEB2, TGFb1 and TGFb2), and 21 effector genes that were regulated by the target genes, were performed using a high-throughput BioMark array platform (Fluidigm). qRT-PCR of epithelial tumor cells from ovarian tumors and fallopian TICs showed concurrent up-regulation of miR-200s, down-regulation of the target genes, and up-regulation of several effector genes. To confirm the role of miR-200 family in regulating gene expression, synthetic miRNA precursors were transfected into normal OSE and FTE cells and qRT-PCRs were performed to determine the expression of target and effector genes. The results showed similar reduced expression of target genes and elevated levels of CDH1 and EpCAM effector genes in both normal OSE and FTE cells. However, the most interesting finding was the specific induction of tumor marker, CA125, in the normal FTE cells. Immunocytochemistry confirmed the induced CA125 proteins in FTE cells. In conclusion, the activation of the miR-200 pathway may be an early lesion that renders the OSE and FTE cells more susceptible to oncogenic mutations and histologic differentiation. As high-grade serous ovarian tumors usually express higher levels of CA125, the greater capacity of FTE cells to express CA125 by miR-200 induction is consistent with the notion that high-grade serous ovarian tumors have an origin in the distal fallopian tube.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2054.

p63 in epithelial survival, germ cell surveillance, and neoplasia

The p53homolog p63has emerged as a gene with an enormously complex function that is distinct from that of p53. It encodes two distinct transcript isoforms that have a dramatic impact on replenishment of cutaneous epithelial stem cells and on ovarian germ cell survival. However, although these two fundamental roles of p63 attest to its powerful place in development, its other functions-specifically the apparent capacity of p63, when induced, to supervise the emergence of new cell populations in the breast, prostate, cervix, and upper reproductive tract-are shared by embryo and adult. These observed functions may only scratch the surface of a repertoire that has been postulated to encompass a range of cellular activities, as evidenced by the fact that p63 proteins have been shown to potentially bind to over 5800 target sites. Whether tumorigenic pathways are also involved, and to what extent, is a subject of both promise and controversy that remains to be resolved.

p53 autoantibodies as potential detection and prognostic biomarkers in serous ovarian cancer

BACKGROUND

This study examined the value of serum p53 autoantibodies (p53-AAb) as detection and prognostic biomarkers in ovarian cancer.

METHODS

p53-AAb were detected by ELISA in sera obtained preoperatively from women undergoing surgery for a pelvic mass. This group included women subsequently diagnosed with invasive serous ovarian cancer (n = 60), nonserous ovarian cancers (n = 30), and women with benign disease (n = 30). Age-matched controls were selected from the general population (n = 120). Receiver operating characteristic curves were constructed to compare the values of p53-AAb, CA 125, and HE4 as a screening biomarker. Kaplan-Meier curves and Cox proportional hazards modeling were used to assess its prognostic value on survival.

RESULTS

p53-AAb were detected in 25 of 60 (41.7%) of serous cases, 4 of 30 (13.3%) nonserous cases, 3 of 30 (10%) benign disease cases, and 10 of 120 (8.3%) controls (combined P = 0.0002). p53-AAb did not significantly improve the detection of cases [area under the curve (AUC), 0.69] or the discrimination of benign versus malignant disease (AUC, 0.64) compared with CA 125 (AUC, 0.99) or HE4 (AUC, 0.98). In multivariate analysis among cases, p53-AAb correlated only with a family history of breast cancer (P = 0.01). Detectable p53 antibodies in pretreatment sera were correlated with improved overall survival (P = 0.04; hazard ratio, 0.57; 95% confidence interval, 0.33-0.97) in serous ovarian cancer.

CONCLUSIONS

Antibodies to p53 are detected in the sera of 42% of patients with advanced serous ovarian cancer.

IMPACT

Although their utility as a preoperative diagnostic biomarker, beyond CA 125 and HE4, is limited, p53-AAb are prognostic for improved overall survival.