Secretory Cell Outgrowth Research Articles

Serous tubal intra-epithelial carcinoma: what do we really know at this point?

Serous tubal intra-epithelial carcinoma (STIC) is the earliest morphologically recognisable step in the development of invasive high-grade serous carcinoma of the fallopian tube. Lesions occurring prior to STIC within the carcinogenic sequence for the pathogenesis of invasive high-grade serous carcinoma include the p53 signature and secretory cell outgrowth (SCOUT). Variable histological criteria have been used for diagnosing STIC, but a combination of morphology and immunohistochemistry for p53/Ki-67 improves interobserver agreement. Half of all carcinomas identified in risk-reducing salpingo-oophorectomy specimens are in the form of STIC; however, STIC also may be incidentally found on occasion in specimens from women at low or average risk of ovarian/tubal/peritoneal carcinoma. TP53 mutation is the earliest known DNA sequence alteration in STIC and almost all invasive high-grade serous carcinomas of the ovary and peritoneum. Data on the clinical behaviour of STIC are limited. While the short-term follow-up in the prior literature suggests a low risk of malignant progression, a more recent meta-analysis indicates a 10-year risk of 28%. STIC probably should be best regarded as a lesion with uncertain malignant potential at present, and future molecular analysis will help to classify those with higher risk of dissemination. This review provides an update on the current knowledge of STIC and related issues.

Prevalence of precursor lesions (P53 signature, SCOUT, STIL, STIC) in fallopian tubes resected for non-neoplastic causes.

High-grade pelvic serous carcinoma is a common cause of death in women worldwide and India. Recent evidence has clearly implicated the changes in the mucosa of the fimbrial end of the fallopian tube in its pathogenesis. 1) To study histopathology features of surgically resected specimens of fallopian tubes received with non-neoplastic lesions of the uterus and ovary for the presence of any precursor lesions [secretory cell outgrowth (SCOUT), serous tubal intraepithelial lesion (STIL), p53 signatures, and serous tubal intraepithelial carcinoma (STIC)]. 2) To confirm the findings with immunohistochemistry. 3) To correlate the prevalence of precursor lesions with clinical parameters and benign lesions of the uterus and ovaries. Assessment of histopathological changes in 100 specimens of distal fallopian tubes was done using the sectioning and extensive examination of the fimbrial end (SEE-FIM) protocol. H and E stain followed by immunohistochemistry for Bcl-2, p53, and Ki-67. The statistical significance of the difference in the mean values of precursor areas was evaluated by an unpaired t-test. Among 100 specimens taken on H and E, precursor lesions were suspected in 49% of the cases. SCOUT, suspicious for STIC, suspicious for STIC with areas of SCOUT, and unequivocal for STIC with areas of SCOUT were seen in 8%, 4%, 33%, and 4% of the cases, respectively. However, on IHC, SCOUTS were confirmed in 45% of the cases, p53 signature in 2%, STIL in 9%, and STIC in 4% of the cases. Sectioning and extensive examination of the fimbrial end (SEE-FIM) should be routinely done as it provides the opportunity to detect the early malignant changes. It may help in evolving the strategies for early detection, management, and reducing mortality.

Immunohistochemical Expression Status of p53, CD44v9, and Ki-67 in a Series of Fallopian Tube Lesions of High-grade Serous Carcinoma.

Pelvic high-grade serous carcinoma (HGSC) has been postulated to arise via a stepwise accumulation of (epi)genetic alterations from normal epithelium to secretory cell outgrowth (SCOUT), p53 signature, and serous tubal intraepithelial carcinoma (STIC) to invasive HGSC. The aim of this study is to investigate alterations in p53 and CD44v9 expression and the status of Ki-67 labeling index in a series of fallopian tube lesions of HGSC patients. A total of 45 specimens were analyzed in 16 patients with HGSC, and their lesions were categorized as follows: morphologically normal fallopian tube epithelium (FTE, n=6 samples), SCOUT (n=5), p53 signature (n=4), dormant STIC (n=8), active STIC (n=6), and HGSC (n=16). Morphologic features and immunohistochemical expression patterns of the p53 protein, CD44v9 protein, and Ki-67 antigen were blindly evaluated by 2 pathologists. Increased nuclear p53 protein accumulation was observed in p53 signature, dormant STIC, active STIC and HGSC compared with normal FTE and SCOUT (P<0.001). Immunohistochemistry scores of CD44v9 protein expression were significantly higher in normal FTE, SCOUT, and p53 signature than in dormant STIC, active STIC, and HGSC (P<0.001). Both active STIC and HGSC had significantly higher Ki-67 labeling indices than normal FTE, SCOUT, p53 signature and dormant STIC (P<0.001). CD44v9 loss contributes to the stepwise progression of p53 signature to dormant STIC. In conclusion, p53 mutation followed by CD44v9 loss may be involved in the evolution of STIC, which may confer positive clonal selection with a growth and survival advantage.

Secretory Cell OUT growth (SCOUT), Serous Tubal Intraepithelial Carcinoma (STIC) and P53 expression in fallopian fimbriae of ovarian serous tumors- A tertiary care center study

The proposed histopathological precursor lesions of high grade ovarian serous tumors are Secretory Cell OUT growth (SCOUT) and Serous Tubal Intraepithelial Carcinoma (STIC) in fallopian fimbriae. P53 signature in fimbriae is considered as immunohistochemical precursor lesion. This study compared the p53 expression pattern of serous tumors and their fallopian tubes to explore their relationships.To study the histopathological changes in fallopian fimbriae of ovarian serous tumors with p53 expression pattern.A cross-sectional study of 90 cases of serous ovarian tumors were done. (61 benign, 6 borderline and 23 malignant). Their fallopian tubes were examined as per SEE-FIM PROTOCOL. P53 expression pattern of serous tumors and fimbriae were analyzed using SPSS software version 20.Among the 90 cases, SCOUTs were distributed in all categories of serous tumors and 59% of them were in nonmalignant tumors. Only 22.4% of SCOUTs showed p53 signature. STIC were distributed more in high grade tumors (66.6%) and were absent in benign tumors. All the STICs showed aberrant p53 expression pointing mutant p53 gene. Aberrant p53 pattern was high in high grade tumors (91.6%) compared to benign, borderline, low grade tumors (0%, 16.7%,18.2%).STIC and p53 signatures were common in high grade serous carcinoma and their fallopian tubes. SCOUT was present both in benign and malignant tumors but p53 signature was low. Hence it can be presumed that SCOUT is an initial event, later progressing through p53 positive STICs leading to high grade serous carcinoma in ovaries.

Prophylactic risk-reducing salpingo-oophorectomy in BRCA mutation carriers: what is going on in a region of northern Italy?

BackgroundBRCA1 mutation carriers are recommended to undergo prophylactic risk-reducing salpingo-oophorectomy (RRSO) between the ages of 35 and 40 or when child bearing is complete, with a possible delay until age 40–45 for BRCA2 mutation carriers. Study QuestionPrimary outcome was the rate of unsuspected cancer findings during RRSO in a region of northern Italy (Emilia Romagna) and secondary outcomes were details of RRSO: age at surgical intervention, the venue of the procedures in relation to the surgical/pathological quality and the rate/role of concomitant opportunistic hysterectomies. Study DesignMulticentre data collection by invitation to report current RRSO practices. ResultsA total of 222 RRSOs (54.5 % BRCA1, 34.7 % BRCA2, 1.8 % BRCA1 and BRCA2 combined, 5.8 % BRCA-VUS and 3.2 % BRCA not better specified) were reported from 9 different centres, half in non-university hospitals and the remainder in university hospitals.Breast cancer survivors (56.3 %) underwent the RRSO at a younger age (47.8 vs 50.6 years, p = 0.02). The mean and median ages at surgical intervention (49.0 and 48.0, respectively) were similar for BRCA1 and BRCA2 mutation carriers, as was the temporal trend in age distribution, and proportions treated in university and non-university hospitals.A diagnosis of ovarian invasive cancer was reported in 3.5 % of subjects, all BRCA1 or BRCA-combined subjects, at a median and mean age of 57 years (range 42–68). Abnormal tubal findings, such as serous tubal intraepithelial lesions (STIL) (100 %), secretory cell outgrowth (SCOUT) (100 %) and STIC (71.4 %), were mainly reported by pathologists in university hospitals. Of the 222 procedures, 15 (6.7 %) included hysterectomies: in none of these cases was a primitive uterine endometrioid or serous cancer found. ConclusionsThe results from this multicentre regional study should guide future preventive health policies for RRSO in BRCA mutation carriers.

Reduced PAX2 expression in murine fallopian tube cells enhances estrogen receptor signaling

High-grade serous ovarian cancer (HGSOC) is thought to progress from a series of precursor lesions in the fallopian tube epithelium (FTE). One of the preneoplastic lesions found in the FTE is called a secretory cell outgrowth (SCOUT), which is partially defined by a loss of paired box 2 (PAX2). In the present study, we developed PAX2-deficient murine cell lines in order to model a SCOUT and to explore the role of PAX2 loss in the etiology of HGSOC. Loss of PAX2 alone in the murine oviductal epithelium (MOE) did not induce changes in proliferation, migration and survival in hypoxia or contribute to resistance to first line therapies, such as cisplatin or paclitaxel. RNA sequencing of MOE PAX2shRNA cells revealed significant alterations in the transcriptome. Silencing of PAX2 in MOE cells produced a messenger RNA expression pattern that recapitulated several aspects of the transcriptome of previously characterized human SCOUTs. RNA-seq analysis and subsequent qPCR validation of this SCOUT model revealed an enrichment of genes involved in estrogen signaling and an increase in expression of estrogen receptor α. MOE PAX2shRNA cells had higher estrogen signaling activity and higher expression of putative estrogen responsive genes both in the presence and absence of exogenous estrogen. In summary, loss of PAX2 in MOE cells is sufficient to transcriptionally recapitulate a human SCOUT, and this model revealed an enrichment of estrogen signaling as a possible route for tumor progression of precursor lesions in the fallopian tube.

The conceptual advances of carcinogenic sequence model in high-grade serous ovarian cancer.

The present review focuses on the current status of molecular pathology in high-grade serous cancer (HGSC) and preneoplastic conditions. This article reviews the English-language literature on HGSC, precursor, fallopian tubal epithelium, secretory cells, ciliated cells, secretory cell expansion, secretory cell outgrowth (SCOUT), p53 signature, serous tubal intraepithelial carcinoma (STIC), DNA damage and immunohistochemistry in an effort to identify the precursor-carcinoma sequence in HGSC. The majority of HGSC originates from the fimbriated end of the fallopian tube secretory epithelial cells, while the small part of this disease may develop from ovarian cortical inclusion cyst (CIC). A series of morphological changes from normal fallopian epithelium to preneoplastic to neoplastic lesions were concomitant with the multistep accumulation of molecular and genetic alterations. Recent studies provide a stepwise progression of fallopian tubal epithelium to precursor lesions to carcinoma, with the aid of a 'secretory cell-SCE-SCOUT-p53 signature-STIC-HGSC sequence' model. Immunohistochemical markers, including p53, STMN1, EZH2, CCNE1, Ki67 and γ-H2AX, were gradually increased during the SCOUT-p53 signature-STIC-HGSC sequence. Conversely, PAX2 expression was decreased during the early phase of SCOUT development. Potential genes and proteins are involved in the evolutionary trajectory of the precursor-cancer lineage model. In the present review we examined detailed aspects of the molecular changes involved in malignant transformation from fallopian tube epithelium to HGSC. A precursor condition originating in 'field cancerization' may gain a growth advantage, leading to HGSC.

Abstract MIP-052: THE ROLES OF CD24 IN OVARIAN CANCER DEVELOPMENT

Abstract OBJECTIVES: CD24 is recently reported as ovarian cancer stem cell markers, and the expression of CD24 is increased from borderline tumors to invasive ovarian carcinomas. However, the underlying pathways controlled by CD24 in ovarian pathogenesis were poorly understood. We investigated the potential roles of CD24 in normal fallopian tube epithelial (FTE) cells and ovarian cancer development. METHODS: Lentiviral particles harboring CD24 shRNAs targeting CD24 expression were used to establish FTE cell lines and ovarian cancer cell lines with CD24 knockdown. The resulting cell lines were compared with the correspondent cells with non target shRNA control in colony formation assay, BrdU incorporation, cell growth and drug resistance. Western blot was used for analyzing downstream pathways affected by the knockdown of CD24. Expression of CD24 and its downstream effectors identified from western blot, including Pax 2 and Gli1 were studied in normal FTE, non–serous and serous tumor tissues by immunohistochemistry (IHC) to confirm whether the in vitro study is clinically relevant. RESULTS: Western blot analysis showed that CD24 expression was absent in normal ovarian surface epithelial (OSE) cells but was relatively high in normal FTE cells. In addition, serous cancer cell lines have a lower CD24 expression when compared to non–serous cancer cell lines. Knockdown of CD24 in FTE cells caused slower growth, lower ability in colony formation, reduced percentage of cells in S phase and decrease in expression of p–stat3 in JAK pathway and the JAK downstream targets Nanog and OCT3/4; and Pax2, which is normally expressed in FTE but lost in FTE secretory cell outgrowth (SCOUT). The loss of Pax2 in SCOUT is associated with serous carcinoma. IHC showed cytoplasmic co–localized expression of CD24 and Pax2 in the normal FTE tissue, suggesting the possibility of interaction between these two proteins in vivo. In contrast, knockdown of CD24 in ovarian cancer cells caused faster growth, higher ability in colony formation, increased percentage of cells in S phase, more resistant to carboplatin and higher expression of Shh and Gli1 in Sonic hedgehog (SHH) pathway. The above effects were more obvious in the non–serous cancer cell line. Activation of SHH pathway requires translocation of Gli1 into the nucleus. Concurrent with the in vitro results, IHC showed that the expression of Gli1 was found inside the nucleus in the non–serous tumor tissues but in the cytoplasm in serous–tissue, suggesting that the effect brought by SHH pathway is more prominent in the non–serous cancer cells. CONCLUSION: Our study is the first study revealing the linkage between CD24 and PAX2, and suggesting normal FTE cells depends on CD24/JAK pathway for growth and the loss of CD24 expression and hence, the loss of PAX2 may be associated with serous type tumor development, basing on other studies that SCOUTs were significantly associated with serous carcinoma. Moreover, the study also suggests CD24 pathway affects Type I and Type II (HGSOC) tumors differently. The CD24/SHH pathways may be responsible in controlling cell growth and drug resistance in ovarian cancer cells, hence, warrant further studies. Citation Format: Pui–Wah Choi, Brooke E. Howitt, Christopher P. Crum, Ross S. Berkowitz, and Shu–Wing Ng. THE ROLES OF CD24 IN OVARIAN CANCER DEVELOPMENT [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr MIP-052.

Secretory cell expansion with aging: Risk for pelvic serous carcinogenesis

ObjectiveRecent advances suggest that precancerous lesions of pelvic serous carcinoma (PSC) originate from tubal secretory cells. The purpose of our study was to determine if increased number of secretory cells shows difference in age and location and to examine their association with serous neoplasia. Materials and methodsThree groups (benign control, high-risk, and PSC) of patients with matched ages were studied. The age data was stratified into 10-year intervals ranging from age 20 to older than 80. The number of secretory and ciliated cells from both tubal fimbria and ampulla segments was counted by microscopy and immunohistochemical staining methods. The data was analyzed by standard contingency table and Poisson distribution methods after age justification. ResultsWe found that the absolute number of tubal secretory cells increased significantly with age within each age group. Age remained a significant risk factor for serous neoplasia after age adjustment. In addition, a dramatic increase of secretory cells was observed in high-risk and PSC patients. Further, secretory cell expansion (SCE) was more prevalent than secretory cell outgrowth in both fimbria and ampulla tubal segments and was significantly associated with serous neoplasia (p<0.001). ConclusionsThese findings suggest that SCE could potentially serve as a sensitive biomarker for early serous carcinogenesis within the fallopian tube. Findings support a relationship between serous neoplasia and increased secretory to ciliated cell ratios. Findings also support a relationship between frequency of SCE and increasing age, presence of high-risk factors and co-existing serous cancers.

Morphologic changes of fallopian tubal epithelium in ovarian serous tumors

To study the morphologic changes of fallopian tubal epithelium in patients with ovarian serous epithelial tumors and to explore the relationship between the tubal epithelial changes and tumorigenesis of serous ovarian carcinoma. The fallopian tubes in 79 cases of high-grade serous ovarian carcinoma, 12 cases of low-grade serous ovarian carcinoma, 16 cases of serous borderline ovarian tumor and 11 cases of non-ovarian benign tumors were serially examined under light microscope. Immunohistochemical study with EnVision method was used to detect the expression of p53 and bcl-2 protein in the fallopian tubal epithelium in all cases. The occurrences of secretory cell outgrowth (SCOUT), p53 signature, serous tubal intraepithelial carcinoma (STIC) and serous invasive carcinoma were analyzed. SCOUT in tubal epithelium was observed in 60.8% (48/79) of the high-grade serous carcinoma group, 4/12 of the low-grade serous carcinoma group, 3/16 of the serous borderline tumor group and 2/11 of the non-ovarian benign tumor group (P = 0.001). P53 signature, STIC and serous invasive carcinoma occurred only in the fallopian tubal epithelium of patients with high-grade serous ovarian carcinoma, with the positive rates being 29.1% (23/79), 15.2% (12/79) and 44.3% (35/79), respectively. Of the 23 cases with p53 signature, 17 cases had solitary lesion and 6 cases involved more than two sites. A total of 33 p53 signature positive foci were found, with 22 foci located at fimbria and 11 at ampulla. Bcl-2 expression was demonstrated in 90.9% of those foci (30/33). Of the 12 patients with STIC, 7 cases were solitary and 5 cases involved more than two sites. A total of 18 STIC foci were found, with 16 foci located at fimbria and 2 at ampulla. All of them were positive for bcl-2. SCOUT is found in fallopian tubal epithelium in patients with serous ovarian epithelial tumors, especially high-grade serious carcinoma. On the other hand, p53 signature, STIC and invasive serous carcinoma of tubal epithelium are observed only in patients with high-grade serous ovarian carcinoma, with a predilection of fimbrial involvement. Correlation exists between SCOUT, p53 signature, STIC and high-grade serous ovarian carcinomas. Bcl-2 and p53 immunostaining is helpful for demonstrating such lesions.

Trompe de Fallope : le côté obscur de la carcinogenèse pelvienne

Ovarian carcinomas are a heterogeneous group of lesions, among which serous histologic subtype is the most frequent. Ovarian and peritoneal serous carcinomas are subdivided into low- and high-grade tumors. Low-grade carcinomas derive from serous tumors of low malignant potentiel, while high-grade carcinomas were thought to derive de novo from ovarian surface epithelium. Studies from prophylactic salpingo-oophorectomy in women with BRCA mutations revealed a precursor to pelvic serous carcinomas that originates in the distal fallopian tube, called STIC (serous tubal intraepithelial carcinoma). This review reports new findings on serous carcinogenesis in the tube (SCAT). It brings an explanation in French on different terminologies used in the English literature these last years such as SCOUT (secretory cell outgrowth), p53 signature, TILT (tubal intraepithelial lesion in transition), STIC and SCAT and on the macroscopic protocol of Brigham and Women's Hospital of annexectomies specially in the setting of BRCA mutation, the SEE-FIM (sectioning and extensively examining the fimbriated end of the fallopian tube).

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.

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.