Ki-67 labeling index as an adjunct in the diagnosis of serous tubal intraepithelial carcinoma

Morphologic and Molecular Heterogeneity of High-grade Serous Carcinoma Precursor Lesions

Serous tubal intraepithelial carcinoma (STIC) is the fallopian tube precursor lesion for most cases of pelvic high-grade serous carcinoma (HGSC). To date, the morphologic, molecular, and clinical heterogeneity of STIC and a less atypical putative precursor lesion, termed serous tubal intraepithelial lesion, has not been well characterized. Better understanding of precursor heterogeneity could impact the clinical management of women with incidental STICs (without concurrent carcinoma) identified in cases of prophylactic or opportunistic salpingectomy. This study analyzed morphologic and molecular features of 171 STICs and 21 serous tubal intraepithelial lesions. We assessed their histologic features, Ki-67 and p53 staining patterns, and genome-wide DNA copy number alterations. We classified all precursor lesions into 2 morphologic subtypes, one with a flat surface (Flat) and the other characterized by budding, loosely adherent, or detached (BLAD) morphology. On the basis of pathology review by a panel of 8 gynecologic pathologists, we found 87 BLAD, 96 Flat, and 9 indeterminate lesions. As compared with Flat lesions, BLAD lesions were more frequently diagnostic of STIC ( P <0.0001) and were found concurrently with HGSC ( P <0.0001). BLAD morphology was also characterized by higher Ki-67 proliferation index ( P <0.0001), presence of epithelial stratification ( P <0.0001), and increased lymphocyte density ( P <0.0001). BLAD lesions also exhibited more frequent DNA copy number gain/amplification at the CCNE1 or CMYC loci canonical to HGSCs ( P <0.0001). Both BLAD morphology and STIC diagnoses are independent risk factors for an elevated Ki-67 proliferation index. No correlation was observed between BLAD and Flat lesions with respect to patient age, presence of germline BRCA1/2 mutation, or p53 staining pattern. These findings suggest that tubal precursor lesions are morphologically and molecularly heterogeneous, laying the foundation for further studies on the pathogenesis of HGSC initiation and identifying histologic features predictive of poor patient outcomes.

Histopathologic and Preneoplastic Changes in Tubal Ligation Materials

Background and Objectives: To investigate histopathological changes and serous carcinoma precursors such as secretory cell outgrowths (SCOUTs) and p53 signature in the bilateral tubal ligation (BTL) materials used during cesarean section (S/C). Materials and Methods: In total, 138 patients underwent S/C and tubal sterilization (TS) between October 2020 and May 2021 at Konya City Hospital. Patients' data were obtained from the hospital's system. All data and findings were investigated and statistically evaluated. Results: The mean age was 34.62 years (22-44), the mean gravity was 4.89 (2-15) and the mean parity was 3.46 (1-10). In total, 5.79% SCOUT, 7.24% atypia and 9.42% p53 signatures were observed. Significant correlations were shown between the epithelial cell lineage and age between Ki-67, SCOUT, and gravity; between the Ki-67 results and gravity and parity; and between the p53 score and age. Conclusions: TS is a common, safe, and effective method worldwide. Today, BTL is increasing along with increasing S/C ratios. In addition to the reduced risk of ovarian cancers with ligation alone, precursor lesions such as hyperplasia, SCOUT, p53 signature, and STIL/Serous tubal intraepithelial carcinoma (STIC) are encountered in the ampulla materials obtained. Considering the low rates of re-anastomosis, tubal excision may be recommended instead of ligation in women of relatively higher gravity and age.

Pathological findings and long-term prognosis in Korean BRCA1/2 mutation carriers undergoing risk-reducing salpingo-oophorectomy

OBJECTIVE

Our study aimed to evaluate the incidence of pathological findings in asymptomatic Korean patients with BRCA1/2 pathogenic variants who underwent risk-reducing salpingo-oophorectomy and to assess their long-term prognosis.

METHODS

We retrospectively analyzed the medical records of patients with a germinal BRCA1/2 pathologic variant who had undergone risk-reducing salpingo-oophorectomy at Asan Medical Center (Seoul, Korea) between January 2013 and December 2020. All pathologic reports were made based on the sectioning and extensively examining the fimbriated end of the fallopian tube (SEE/FIM) protocol.

RESULTS

Out of 243 patients who underwent risk-reducing salpingo-oophorectomy, 121 (49.8%) had a BRCA1 mutation, 119 (48.9%) had a BRCA2 mutation, and three (1.2%) had both mutations. During the procedure, four (3.3%) patients with a BRCA1 mutation were diagnosed with serous tubal intraepithelial carcinoma (STIC) or serous tubal intraepithelial lesion (STIL), and another four patients (3.3%) were diagnosed with occult cancer despite no evidence of malignancy on preoperative ultrasound. In the BRCA2 mutation group, we found one (0.8%) case of STIC, but no cases of STIL or occult cancer. During the median follow-up period of 98 months (range, 44-104) for STIC and 54 months (range, 52-56) for STIL, none of the patients diagnosed with these precursor lesions developed primary peritoneal carcinomatosis.

CONCLUSIONS

Risk-reducing salpingo-oophorectomy, in asymptomatic Korean patients with BRCA1/2 pathogenic variants, detected ovarian cancer and precursor lesions, including STIC or STIL. Furthermore, our follow-up period did not reveal any instances of primary peritoneal carcinomatosis, suggesting a limited body of evidence supporting the imperative need for adjuvant treatment in patients diagnosed with these precursor lesions during risk-reducing salpingo-oophorectomy.

A comprehensive immunohistochemical analysis of 26 markers in 250 cases of serous ovarian tumors

BACKGROUND

We examined a large cohort of serous tubo-ovarian tumors with 26 immunohistochemical markers, with the aim to assess their value for differential diagnosis and prognosis.

METHODS

Immunohistochemical analyses with 26 immunomarkers were performed on 250 primary tubo-ovarian tumors including 114 high grade serous carcinomas (HGSC), 97 low grade serous carcinomas (LGSC), and 39 serous borderline tumors (micropapillary variant, mSBT). The associations of overall positivity with clinicopathological characteristics were evaluated using the chi-squared test or Fisher's Exact test.

RESULTS

We found significantly different expression of p53, p16, ER, PR, PTEN, PAX2, Mammaglobin, RB1, Cyclin E1, stathmin, LMP2, L1CAM, CD44, and Ki67 in HGSCs compared to LGSCs. No significant differences were found between LGSC and mSBT. None of the other included markers (PAX8, ARID1A, HNF1B, Napsin A, CDX2, SATB2, MUC4, BRG1, AMACR, TTF1, BCOR, NTRK) showed any differences between the investigated serous tumors. Regarding the prognosis, only PR and stathmin showed a statistically significant prognostic meaning in LGSCs, with better overall survival (OS) and recurrence-free survival (RFS) in cases positive for PR, and worse outcome (RFS) for stathmin. None of the study markers showed prognostic significance in HGSCs.

CONCLUSION

We provided an extensive immunohistochemical analysis of serous ovarian/tubo-ovarian tumors. Although we found some differences in the expression of some markers in HGSCs compared to LGSCs, only p53, p16, and Ki67 seem to be useful in real diagnostic practice. We also suggested the best discriminative cut-off for Ki67 (10% of positive tumor cells) for distinguishing HGSC from LGSC. We found prognostic significance of PR and stathmin in LGSCs. Moreover, the high expression of stathmin could also be of predictive value in ovarian carcinomas as target-specific anti-stathmin effectors are potential therapeutic targets.

Immunobiology of high-grade serous ovarian cancer: lessons for clinical translation

Treatment of high-grade serous ovarian cancer (HGSOC) remains challenging. Although HGSOC can potentially be responsive to immunotherapy owing to endogenous immunity at the molecular or T cell level, immunotherapy for this disease has fallen short of expectations to date. This Review proposes a working classification for HGSOC based on the presence or absence of intraepithelial T cells, and elaborates the putative mechanisms that give rise to such immunophenotypes. These differences might explain the failures of existing immunotherapies, and suggest that rational therapeutic approaches tailored to each immunophenotype might meet with improved success. In T cell-inflamed tumours, treatment could focus on mobilizing pre-existing immunity and strengthening the activation of T cells embedded in intraepithelial tumour myeloid niches. Conversely, in immune-excluded and immune-desert tumours, treatment could focus on restoring inflammation by reprogramming myeloid cells, stromal cells and vascular epithelial cells. Poly(ADP-ribose) polymerase (PARP) inhibitors, low-dose radiotherapy, epigenetic drugs and anti-angiogenesis therapy are among the tools available to restore T cell infiltration in HGSOC tumours and could be implemented in combination with vaccines and redirected T cells.

Serous tubal intraepithelial carcinoma: What Do We Really Know at this Point?

Serous tubal intraepithelial carcinoma (STIC) is the earliest morphologically recognizable 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 histologic 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 behavior 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 classify those with higher risk of dissemination. This review article provides an update on the current knowledge of STIC and related issues.

Focal Serous Tubal Intra-Epithelial Carcinoma Lesions Are Associated With Global Changes in the Fallopian Tube Epithelia and Stroma

Objective

Serous tubal intra-epithelial carcinoma (STIC) lesions are thought to be precursors to high-grade serous ovarian cancer (HGSOC), but HGSOC is not always accompanied by STIC. Our study was designed to determine if there are global visual and subvisual microenvironmental differences between fallopian tubes with and without STIC lesions.

Methods

Computational image analyses were used to identify potential morphometric and topologic differences in stromal and epithelial cells in samples from three age-matched groups of fallopian tubes. The Benign group comprised normal fallopian tubes from women with benign conditions while the STIC and NoSTIC groups consisted of fallopian tubes from women with HGSOC, with and without STIC lesions, respectively. For the morphometric feature extraction and analysis of the stromal architecture, the image tiles in the STIC group were further divided into the stroma away from the STIC (AwaySTIC) and the stroma near the STIC (NearSTIC). QuPath software was used to identify and quantitate secretory and ciliated epithelial cells. A secretory cell expansion (SCE) or a ciliated cell expansion (CCE) was defined as a monolayered contiguous run of >10 secretory or ciliated cells uninterrupted by the other cell type.

Results

Image analyses of the tubal stroma revealed gradual architectural differences from the Benign to NoSTIC to AwaySTIC to NearSTIC groups. In the epithelial topology analysis, the relative number of SCE and the average number of cells within SCE were higher in the STIC group than in the Benign and NoSTIC groups. In addition, aging was associated with an increased relative number of SCE and a decreased relative number of CCE. ROC analysis determined that an average of 15 cells within SCE was the optimal cutoff value indicating the presence of a STIC lesion in the tubal epithelium.

Conclusions

Our findings suggest that global stromal alterations and age-associated reorganization of tubal secretory and ciliated cells are associated with STIC lesions. Further studies will need to determine if these alterations precede STIC lesions and provide permissible conditions for the formation of STIC.

Pathologic Classification of Ovarian Cancer

Optimal use of human tissue for research requires an understanding of basic pathologic principles. Given that the physical assessment of tissue must occur as part of standard clinical examination, it cannot be handled directly by investigators unless they are also a part of the care team. The purpose of this chapter is to provide an overview of the clinical analytic process, from initial gross handling to histologic examination by light microscopy and the use of ancillary studies, in order to provide context for samples that are used in research and to highlight specific considerations that are relevant for obtaining appropriate tissue for experimental purposes. Given that they comprise >95% of ovarian malignancies, there is an emphasis on epithelial tumors.

Fallopian tube epithelial cells express androgen receptor and have a distinct hormonal responsiveness when compared with endometrial epithelium

STUDY QUESTION

How does steroid receptor expression, proliferative activity and hormone responsiveness of the fallopian tube (FT) epithelium compare to that of the endometrial epithelium?

SUMMARY ANSWER

Proliferative indices, hormone receptor expression-scores and in vitro response to oestrogen and androgens of the human FT demonstrate a distinct pattern from the matched endometrium.

WHAT IS KNOWN ALREADY

The FT epithelium exists as a continuum of the endometrium, and both express steroid hormone receptors. The ovarian steroid hormones regulate cyclical proliferation and regeneration of the endometrium, but their effects on steroid hormone receptor expression and proliferation in the FT have not yet been fully elucidated.

STUDY DESIGN, SIZE, DURATION

We included women with proven fertility, undergoing hysterectomy and bilateral salpingo-oophorectomy for benign, gynaecological conditions at Liverpool Women's NHS Foundation Trust. They had no known endometrial or tubal pathology and were not on hormonal treatments for at least 3 months preceding sample collection in this prospective observational study (conducted between 2010 and 2018). A full-thickness sample of the endometrium and a sample from the FT were collected from each woman.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The differential protein and mRNA levels of steroid hormone receptors, oestrogen receptors α and β, androgen receptor (AR) and progesterone receptor (PR), and the proliferative marker (Ki67) of the endometrium and the FT tissue samples from 47 healthy women undergoing surgery (37 premenopausal and 10 postmenopausal) were investigated using immunohistochemistry and quantitative real-time PCR. The comparative responsiveness to oestrogen and androgen of the endometrium and the fimbrial end of the FT was analysed using an in vitro short-term explant culture model. The endpoints assessed in the explants were the changes in mRNA and protein levels for AR, PR and the epithelial proliferative index after 24 h treatment with oestradiol (E2) or dihydrotestosterone (DHT).

MAIN RESULTS AND THE ROLE OF CHANCE

The premenopausal endometrial functionalis glands (FG) displayed the well-known cyclic variation in cellular proliferation and steroid receptor scores. Compared with the endometrial FG, the matched FT epithelium (both fimbrial or isthmic ends) displayed a significantly lower proportion of cells expressing Ki67 (2.8% ± 2.2%, n = 18 vs 30.0% ± 26.3%, n = 16, P = 0.0018, respectively) accompanied with a significantly higher AR immunoscores (6.7 ± 2.7, n = 16 vs 0.3 ± 1.0, n = 10, P = 0.0136). The proportion of cells expressing Ki67 and the AR immunoscores of the FT epithelium correlated positively with endometrial luminal epithelium (r = 0.62, P = 0.005, and r = 0.68, P = 0.003, respectively). In vitro experiments suggested the tubal explants to be apparently less responsive to E2 yet more sensitive to DHT compared with the matched endometrium explants.

LIMITATIONS, REASONS FOR CAUTION

The short-term in vitro nature of the tissue explant cultures used in the study may not be representative of how different anatomical regions of the endometrium and FT behave in vivo. Our study included a high proportion of older premenopausal women with a regular menstrual cycle, which may therefore affect extrapolation of findings to a younger group.

WIDER IMPLICATIONS OF THE FINDINGS

Advancing our understanding of tubal and endometrial epithelial cell function has important implications for the diagnosis and treatment of diseases such as infertility, ectopic pregnancy, endometriosis and cancer.

STUDY FUNDING/COMPETING INTEREST(S)

The work included in this article was funded by Wellbeing of Women project grants RG1073 and RG2137 (D.K.H.) and Wellbeing of Women Entry-Level Scholarship ELS706 (A.M). A.M. was also supported by an NIHR ACF fellowship grant. Further support received from Liverpool Women's Hospital NHS Trust (S.M.), University of Liverpool (E.B. and A.W.). All authors declare there are no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

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.

The organoid: A research model for ovarian cancer

Epithelial ovarian cancer (EOC) is a heterogeneous disease with a variety of distinct clinical and molecular characteristics. The currently available and common research models for EOC include tumor cell lines and patient-derived xenografts. However, these models have certain shortcomings: establishing a cell line is time-consuming, loss of genetic traits after long-term culture is a possibility, and investment is required in terms of animal care facilities. Therefore, better research models are required. Organoid technology was originally developed from colorectal cancer. Tumor organoid is a three-dimensional culture system and can help accurately recapture the tumor phenotype from the original tumor. Tumor organoid systems can overcome the above-mentioned shortcomings of the currently available research models. The organoid model can be used for culturing ovarian cancer subtypes, screening drugs, assessing genomes, and establishing biobanks. However, the currently available organoid models can only culture one type of cells, epithelial cells. Therefore, an organoid-on-a-chip device can be developed in the future to provide a microenvironment for cell–cell, cell–matrix, and cell–media interactions. Thus, organoid models can be used in ovarian cancer research and can generate a simulated in vivo system, enabling studies on the heterogeneity of ovarian cancer.

The Origin of Ovarian Cancer Species and Precancerous Landscape

Unlike other human cancers, in which all primary tumors arise de novo, ovarian epithelial cancers are primarily imported from either endometrial or fallopian tube epithelium. The prevailing paradigm in the genesis of high-grade serous carcinoma (HGSC), the most common ovarian cancer, posits to its development in fallopian tubes through stepwise tumor progression. Recent progress has been made not only in gathering terabytes of omics data but also in detailing the histologic-molecular correlations required for looking into, and making sense of, the tissue origin of HGSC. This emerging paradigm is changing many facets of ovarian cancer research and routine gynecology practice. The precancerous landscape in fallopian tubes contains multiple concurrent precursor lesions, including serous tubal intraepithelial carcinoma (STIC), with genetic heterogeneity providing a platform for HGSC evolution. Mathematical models imply that a prolonged time (decades) elapses from the development of a TP53 mutation, the earliest known molecular alteration, to an STIC, followed by a shorter span (6 years) for progression to an HGSC. Genetic predisposition accelerates the trajectory. This timeline may allow for the early diagnosis of HGSC and STIC, followed by intent-to-cure surgery. This review discusses the recent advances in this tubal paradigm and its biological and clinical implications, alongside the promise and challenge of studying STIC and other precancerous lesions of HGSC.

Analysis of Telomere Lengths in p53 Signatures and Incidental Serous Tubal Intraepithelial Carcinomas Without Concurrent Ovarian Cancer

Telomere alterations represent one of the major molecular changes in the development of human cancer. We have previously reported that telomere lengths in most serous tubal intraepithelial carcinomas (STIC) are shorter than they are in ovarian high-grade serous carcinomas (HGSC) or in normal-appearing fallopian tube epithelium from the same patients. However, it remains critical to determine if similar telomere alterations occur in TP53-mutated but histologically unremarkable "p53 signature" lesions, as well as incidental STICs without concurrent HGSC. In this study, we quantitatively measured telomere lengths by performing telomere-specific fluorescence in situ hybridization in conjunction with p53 immunolabeling in 15 p53 signatures and 30 incidental STICs without concurrent HGSC. We compared these new results with our previous data in paired STICs and concurrent HGSCs. We found that most p53 signatures (80%) and incidental STICs without HGSC (77%) exhibited significant telomere shortening compared with adjacent normal-appearing fallopian tube epithelium (P<0.01). Interestingly, however, p53 signatures and incidental STICs without HGSC displayed longer telomeres and less cell-to-cell telomere length heterogeneity than STICs associated with HGSC (P<0.001). These findings indicate that telomere shortening occurs in p53 signatures, the earliest precancer lesion. Moreover, incidental STICs without concurrent HGSC are indeed similar to p53 signatures as they have less telomere shortening and less cell-to-cell telomere length heterogeneity than STICs associated with HGSC.

The Repertoire of Serous Ovarian Cancer Non-genetic Heterogeneity Revealed by Single-Cell Sequencing of Normal Fallopian Tube Epithelial Cells

The inter-differentiation between cell states promotes cancer cell survival under stress and fosters non-genetic heterogeneity (NGH). NGH is, therefore, a surrogate of tumor resilience but its quantification is confounded by genetic heterogeneity. Here we show that NGH in serous ovarian cancer (SOC) can be accurately measured when informed by the molecular signatures of the normal fallopian tube epithelium (FTE) cells, the cells of origin of SOC. Surveying the transcriptomes of ∼6,000 FTE cells, predominantly from non-ovarian cancer patients, identified 6 FTE subtypes. We used subtype signatures to deconvolute SOC expression data and found substantial intra-tumor NGH. Importantly, NGH-based stratification of ∼1,700 tumors robustly correlated with survival. Our findings lay the foundation for accurate prognostic and therapeutic stratification of SOC.

Characterization of Primary Cilia in Normal Fallopian Tube Epithelium and Serous Tubal Intraepithelial Carcinoma

Supplemental digital content is available in the text.

Objectives

The aim of this study was to investigate the distribution of primary cilia on secretory cells in normal fallopian tube (FT) and serous tubal intraepithelial carcinoma (STIC).

Methods

Fallopian tube tissue samples were obtained from 4 females undergoing prophylactic hysterectomies and 6 patients diagnosed with STIC. A mogp-TAg transgenic mouse STIC sample was also compared with a wild-type mouse FT sample. Serous tubal intraepithelial carcinoma was identified by hematoxylin and eosin staining and confirmed by positive Ki-67 and p53 immunohistochemical staining of tissue sections. We assessed the relative distribution of primary cilia on secretory cells and motile cilia on multiple ciliated cells by immunofluorescence and immunohistochemical staining. Ciliary function was assessed by immunofluorescence staining of specific ciliary marker proteins and responsiveness to Sonic Hedgehog signaling.

Results

Primary cilia are widespread on secretory cells in the ampulla, isthmus, and in particular, the fimbriae of human FT where they may appear to mediate ciliary-mediated Sonic Hedgehog signaling. A statistically significant reduction in the number of primary cilia on secretory cells was observed in human STIC samples compared with normal controls (P < 0.0002, Student t test), supported by similar findings in a mouse STIC sample. Immunohistochemical staining for dynein axonemal heavy chain 5 discriminated multiple motile cilia from primary cilia in human FT.

Conclusions

Primary cilia are widespread on secretory cells in the ampulla, isthmus, and in particular, the fimbriae of the human FT but are significantly reduced in both human and mouse STIC samples. Immunohistochemical staining for ciliary proteins may have clinical utility for early detection of STIC.

An Alternate Diagnostic Algorithm for the Diagnosis of Intraepithelial Fallopian Tube Lesions

Intraepithelial fallopian tube neoplasia is thought to be a precursor lesion to high-grade serous carcinoma of the Müllerian adnexae, particularly in women with BRCA1 or BRCA2 mutations. This association has led to recommendations to assess fallopian tubes for intraepithelial atypia. However, the diagnostic reproducibility of a diagnosis of intraepithelial neoplasia is unclear. In this study, 2 gynecologic pathologists independently evaluated sections of fallopian tubes from a sample of women (N=198, 623 slides) undergoing salpingectomy. A total of 101 (54%) women were undergoing risk-reducing salpingo-oophorectomy. Pathologists were blinded to patient histories and prior diagnoses. Pathologists rendered one of three diagnoses for each slide: "negative for fallopian tube intraepithelial neoplasia (FTIN)," "indeterminate for FTIN," or "definite for FTIN." Cases that were considered by histology definite for FTIN or suspicious for FTIN were stained with p53 and Ki67. Pathologists agreed on the diagnosis of "definite for FTIN" 61.5% of the time. There was no agreement on any cases for the diagnosis of "indeterminate for FTIN." Fifteen "indeterminate for FTIN" and 12 "definite for FTIN" cases were stained with p53 and Ki67. Two of the "indeterminate" cases (13%) had p53-positive foci. Five of the "definite" cases had p53-positive foci. In 3 of the other 8 "definite" cases, there was obvious carcinoma present, but the carcinoma did not stain with p53, suggesting a possible null phenotype. We propose that immunostains should only be used to aid in the diagnosis of FTIN in cases with indeterminate histology. The use of p53 immunohistochemistry in cases that were considered "definite for FTIN" by histology was minimally helpful, and in fact often served to further confuse the diagnosis.

Genomic landscape and evolutionary trajectories of ovarian cancer precursor lesions

The clonal relationship between ovarian high-grade serous carcinoma (HGSC) and its presumed precursor lesion, serous tubal intraepithelial carcinoma (STIC), has been reported. However, when analyzing patients with concurrent ovarian carcinoma and tubal lesion, the extensive carcinoma tissues present at diagnosis may have effaced the natural habitat of precursor clone(s), obscuring tumor clonal evolutionary history, or may have disseminated to anatomically adjacent fimbriae ends, masquerading as precursor lesions. To circumvent these limitations, we analyzed the genomic landscape of incidental tubal precursor lesions including p53 signature, dormant STIC or serous tubal intraepithelial lesion (STIL) and proliferative STIC in women without ovarian carcinoma or any cancer diagnosis using whole-exome sequencing and amplicon sequencing. In three of the four cancer-free women with multiple discrete tubal lesions we observed non-identical TP53 mutations between precursor lesions from the same individual. In one of the four women with co-existing ovarian HGSC and tubal precursor lesion we found non-identical TP53 mutations and a lack of common mutations shared between her precursor lesion and carcinoma. Analyzing the evolutionary history of multiple tubal lesions in the same four patients with concurrent ovarian carcinoma indicated distinct evolution trajectories. Collectively, the results support diverse clonal origins of tubal precursor lesions at the very early stages of tumorigenesis. Mathematical modeling based on lesion-specific proliferation rates indicated that p53 signature and dormant STIC may take a prolonged time (two decades or more) to develop into STIC, whereas STIC may progress to carcinoma in a much shorter time (6 years). The above findings may have implications for future research aimed at prevention and early detection of ovarian cancer. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The prognostic value of Ki67 in ovarian high-grade serous carcinoma: an 11-year cohort study of Chinese patients

OBJECTIVE

This study sought to assess the prognostic role of Ki67 in primary ovarian high-grade serous carcinoma (HGSC) and to determine whether Ki67 expression can predict responsiveness to platinum and paclitaxel chemotherapy.

RESULTS

A total of 318 women were included in the analysis and the median follow-up time was 48 months (range, 3-150 months). Ki67 proliferation indices ranged from 3% to 95% with a median of 40%. Using 40% as the cut-off value for the Ki67 index, we classified 141 patients as having low Ki67 expression and 177 patients as having high Ki67 expression. Low Ki67 expression was a predictor of platinum resistance (hazard ratio (HR) 2.85, 95% CI 1.43-5.98, P < 0.001). In the Kaplan-Meier analysis, comparisons of patients with low versus high Ki67 expression demonstrated that low Ki67 expression was significantly associated with decreased progression-free survival (PFS) (22% vs. 34% for 5-year PFS, P < 0.001) and decreased overall survival (OS) (31% vs. 55%, P < 0.001). Multivariate analysis indicated that low Ki67 expression was associated with decreased PFS (HR 2.98, 95% CI 1.75-6.56, P < 0.001) and decreased OS (HR 1.74, 95% CI 1.38-5.01, P = 0.003).

MATERIALS AND METHODS

A retrospective study of patients with stage I-IV primary ovarian HGSC was conducted from January 1, 2002, to December 31, 2012. Ki67 levels were measured via immunohistochemistry (IHC) and analyzed with respect to clinicopathological factors, and a survival analysis was performed.

CONCLUSIONS

HGSC appears to be a heterogeneous disease with different clinical outcomes. Low Ki67 expression (< 40%) in HGSC is significantly associated with platinum resistance and decreased survival.

Diagnostic immunohistochemistry in gynaecological neoplasia: a brief survey of the most common scenarios

Immunohistochemistry is a valuable adjunct in routine gynaecological pathology. The molecular revolution has redesigned knowledge of gynaecological cancers and refined histological classification. The direct consequence has been the progressive introduction of new immunostainings for diagnostic and classification purposes. Hence, we review the routine diagnostic use of immunohistochemistry in the field of gynaecological neoplasia. We reviewed the immunomarkers useful in gynaecological pathology according to literature revision, our personal experience and research findings. We discuss the application of immunohistochemistry to reach the most accurate diagnosis in morphologically equivocal cases of gynaecological pathology and present the appropriate panel of immunomarkers in the most common scenarios of gynaecological pathology. This short review provides an updated overview of the essential immunohistochemical markers currently used in the diagnostics of gynaecological malignancies along with their molecular rationale.

Regeneration of the Fallopian Tube Mucosa Using Bone Marrow Mesenchymal Stem Cell Transplantation After Induced Chemical Injury in a Rat Model

In this study, we describe a novel insight about the use of bone marrow-derived mesenchymal stem cells (BM-MSCs) for fallopian tube (FT) regeneration. Seventy rats' tubes were involved in this study and divided into 4 groups: control (15), ethanol injured (20), mesenchymal stem cell (MSC)-recipient without injury (15), and MSC recipient after injury (20). The BM-MSCs were isolated from male rats, and their incorporation into the tissues was confirmed by the detection of Sry gene in MSC-recipient rats using RT-PCR. Histological and immunohistological sections of the 4 groups were comparably evaluated. We found that direct injection of ethanol into FT caused structural impairment, which was restored largely after receiving MSCs. We have revealed for the first time that prominin 1 (Prom1, stem cell marker) was expressed in the fimbriated distal tubal end. The MSC transplantation caused (1) significant increase in the tissue level and immunoexpresstion of Prom1 ( P < .001 and P = .017, respectively) and vascular endothelial growth factor (VEGF; vasculogenic marker; P < .001 and P = .004, respectively), (2) significant increase in the immunoexpresstion of proliferating cell nuclear antigen (PCNA; proliferation marker; P < .001), and (3) significant decrease in the immunoexpresstion of caspase 3 (CASP-3; apoptotic marker; P < .001) compared to the injured tissues. In conclusion, MSCs could exhibit its restorative effect on FT through their ability to (1) activate the resident stem cells in the distal tubal end, (2) mediate the expression of VEGF and PCNA, and (3) influence tissue apoptosis. This study laid the foundation for assessing the contribution of stem cells in the distal tubal end in direct repair of the tube when required to assist reproduction.

Steroid hormone synthesis by the ovarian stroma surrounding epithelial ovarian tumors: a potential mechanism in ovarian tumorigenesis

Epithelial ovarian tumors are responsive to steroid hormone stimulation and the ovarian stroma may have a direct role in this process. We evaluated immunohistochemical markers of sex-steroid differentiation and steroidogenesis (calretinin, inhibin, steroidogenic factor 1), steroid enzymes involved in hormone biosynthesis (CYP17, CYP19, HSD17β1, AKR1C3), and hormone receptors (estrogen receptor, progesterone receptor, and androgen receptor) in 101 epithelial ovarian tumors and in normal structures implicated in ovarian carcinogenesis (ovarian surface epithelium and cortical inclusion cysts) in an attempt to elucidate this process. We hypothesized that ovarian stroma immediately adjacent to tumors express markers of sex-steroid differentiation and steroidogenesis and steroid enzymes whereas the epithelium contains corresponding hormone receptors. As the findings in seromucinous, endometrioid, and clear cell neoplasms, tumors closely associated with endometriosis, were very similar, these were combined into a group designated 'endometriosis-related tumors.' Significantly increased expression of markers of sex-steroid differentiation and steroidogenesis was found in stroma immediately adjacent to endometriosis-related tumors (P=0.003) and mucinous tumors (primary and metastatic mucinous tumors were combined because of similar findings) (P<0.0001) compared with more remote ovarian stroma. In addition, sex-steroid enzymes were increased in stroma adjacent to endometriosis-related tumors (P=0.02) and mucinous tumors (P=0.02) compared with more distant stroma. Steroid hormone receptors showed greater expression in epithelium compared with stroma in the endometriosis-related tumors (P=0.0009), low-grade serous tumors (P<0.0001), and high-grade serous carcinoma (P=0.0036). In contrast, there was greater expression in stroma compared with epithelium (P<0.0001) in mucinous tumors, which may be due to the fact that they are not derived from müllerian epithelium. In conclusion, our findings strongly support the view that the stroma surrounding epithelial tumors in the ovary is activated to elaborate steroid hormones which may stimulate further neoplastic growth. The precise mechanisms by which this process might occur are complex and require further investigation.

Rationale for Developing a Specimen Bank to Study the Pathogenesis of High-Grade Serous Carcinoma: A Review of the Evidence

Women with clinically detected high-grade serous carcinomas (HGSC) generally present with advanced-stage disease, which portends a poor prognosis, despite extensive surgery and intensive chemotherapy. Historically, HGSCs were presumed to arise from the ovarian surface epithelium (OSE), but the inability to identify early-stage HGSCs and their putative precursors in the ovary dimmed prospects for advancing our knowledge of the pathogenesis of these tumors and translating these findings into effective prevention strategies. Over the last decade, increased BRCA1/2 mutation testing coupled with performance of risk-reducing surgeries has enabled studies that have provided strong evidence that many, but probably not all, HGSCs among BRCA1/2 mutation carriers appear to arise from the fallopian tubes, rather than from the ovaries. This shift in our understanding of the pathogenesis of HGSCs provides an important opportunity to achieve practice changing advances; however, the scarcity of clinically annotated tissues containing early lesions, particularly among women at average risk, poses challenges to progress. Accordingly, we review studies that have kindled our evolving understanding of the pathogenesis of HGSC and present the rationale for developing an epidemiologically annotated national specimen resource to support this research. Cancer Prev Res; 9(9); 713-20. ©2016 AACR.

Comparison of the Classical Method and SEE-FIM Protocol in Detecting Microscopic Lesions in Fallopian Tubes with Gynecological Lesions

Background

The objective of this study was to compare the classical method and Sectioning and Extensively Examining the Fimbriated End Protocol (SEE-FIM) in detecting microscopic lesions in fallopian tubes with gynecological lesions.

Methods

From a total of 1,118 cases, 582 with various parts of both fallopian tubes sampled in three-ring-shape sections and 536 sampled with the SEE-FIM protocol were included in this study. Pathological findings of cases with endometrial carcinoma, non-uterine pelvic malignant tumor, ovarian borderline tumors, premalignancy, and benign lesions were compared.

Results

We detected two tubal infiltrative carcinomas among 40 uterine endometrioid adenocarcinomas, 15 serous tubal intraepithelial carcinomas in 39 non-uterine pelvic serous high-grade carcinoma cases, seven papillary tubal hyperplasias in 13 serous borderline tumor cases, and 11 endometriotic foci and four adenomatoid tumors among all cases sampled with the SEE-FIM protocol. Using the classical method, we detected only one serous tubal intraepithelial carcinoma in 113 non-uterine pelvic serous high-grade carcinoma cases and two papillary tubal hyperplasia cases in 31 serous borderline tumors. We did not identify additional findings in 185 uterine endometrioid carcinoma cases, and neither endometriotic focus nor adenomatoid tumor was shown in other lesions by the classical method.

Conclusions

Benign, premalignant, and malignant lesions can possibly be missed using the classical method. The SEE-FIM protocol should be considered especially in cases of endometrial carcinoma, nonuterine pelvic serous cancers, or serous borderline ovarian tumors. For other lesions, at least a detailed examination of the fimbrial end should be undertaken.

Diagnostic implications of Ki-67 expression in adipocytes and lipoblasts: an immunohistochemical study

Ki-67 expression is an important tool for distinguishing between malignant and benign tumors. It usually shows the nuclear staining. However, the cell membrane staining of MIB-1, which is one of the clones of Ki-67, in the hyalinizing trabecular adenoma of the thyroid gland and other tumors had also been reported. In our practice, we found that the 7B11 antibody could be immunoreactived with the adipose tissues inside or around tumors in the membrane. Thus, in this study, we determined if Ki-67 expression would be useful in recognizing the lipoblasts and adipocytes. The five clones of the Ki-67 antibody, namely, 7B11, K-2, SP5, MIB-1, and SP6 were selected. The adipocytes showed strong 7B11 staining in the cell membrane. The brown fat cells were strongly immunoreactive with 7B11 in the arachnoid layer of the cytoplasm. The adipocytes and brown fat cells showed positive, albeit weaker K-2 staining in the cell membrane and cytoplasm, respectively, compared to 7B11. The adipose tissues and brown fat cells were non-reactive to clones SP5, MIB-1, and SP6. All adipocytes in the lipomas, angiolipomas, uterine lipoleiomyomas, and angioleiomyolipomas showed diffusedly positive 7B11 and K-2 staining in the cell membrane, with stronger immunoreactivity to 7B11 compared with K-2. All hibernomas showed diffusedly cytoplasmic arachnoid staining of 7B11, but only focal to K-2. The lipoblasts in adipocytic tumors also showed positive 7B11 and K-2 staining; however, nearly all of the vacuolated lipoblasts showed strong 7B11 staining, only focal vacuolated lipoblasts in the adipocytic tumors were immunoreactive to K-2 positivity. All other components of the adipocytic tumors were non-reactive to 7B11, K-2, SP5, MIB-1, and SP6 in the cell membrane and cytoplasm. Our results showed that the 7B11 could well help to identify the lipoblasts, which would be useful to diagnose the malignant adipocytic tumors.

The association of serous tubal intraepithelial carcinoma with gynecologic pathologies and its role in pelvic serous cancer

OBJECTIVES

Possible primary sites of pelvic serous cancers are, fallopian tubes, ovaries or peritoneum. Recent studies have revealed that a portion of these tumors originates from serous tubal intraepithelial carcinoma (STIC) at the distal end of fallopian tubes. In this study, the association of STIC with pelvic serous carcinomas and the pathologic parameters that indicate the tubes as the primary site were assessed.

METHODS

In total, 495 pairs of fallopian tubes obtained via total abdominal hysterectomy and bilateral salpingo-oophorectomy between 2011 and 2013 were examined according to SEE-FIM protocol. Hematoxylin and eosin-stained slides were examined by pathologists. Suspicious areas were immunostained with p53 and Ki-67 to diagnose STIC precisely.

RESULTS

Of the 495 cases, 110 cases were malignant. Among 34 cases of non-uterine serous carcinomas, 13 were diagnosed with STIC. STIC was located at the fimbrial end of the fallopian tubes in 12 cases. No STIC was identified in the gynecologic malignancies other than non-uterine serous pelvic carcinomas and benign gynecologic pathologies. Comparison of the ovarian and tubal cancer cases with and without STIC did not reveal a factor that helps to define the primary site. STIC was an important factor associated in a higher portion of the cases with bilateral ovarian cancer.

CONCLUSION

The role of STIC in carcinogenesis continues to be discussed as it is unknown whether STIC is the precursor lesion or just associates with the malignancies. Discovering the accurate precursor lesions and tumor carcinogenesis is essential to prevent these malignancies and to develop early diagnostic methods.

Origin and molecular pathogenesis of ovarian high-grade serous carcinoma

A new paradigm for the pathogenesis of ovarian cancer has recently been proposed which helps to explain persistent problems in describing the development and diverse morphology of these neoplasms. The paradigm incorporates recent advances in our understanding of the molecular pathogenesis of epithelial 'ovarian' cancer with new insights into the origin of these tumors. Correlated clinicopathologic and molecular genetic studies led to the development of a dualistic model that divides all the various histologic types of epithelial ovarian carcinomas into two broad categories designated 'type I' and 'type II'. The prototypic type I tumor is low-grade serous carcinoma and the prototypic type II tumor is high-grade serous carcinomas (HGSCs). As the serous tumors comprise ∼70% of all epithelial ovarian tumors and account for the majority of deaths, the serous tumors will be the subject of this review. There are marked differences between the low-grade and high-grade serous tumors. Briefly, the former are indolent, present in stage I (tumor confined to the ovary) and develop from well-established precursors, so-called 'atypical proliferative (borderline) tumors,' which are characterized by specific mutations, including KRAS, BRAF and ERBB2; they are relatively genetically stable. In contrast, HGSCs are aggressive, present in the advanced stage, and develop from intraepithelial carcinomas in the fallopian tube. They harbor TP53 mutations in over 95% of cases, but rarely harbor the mutations detected in the low-grade serous tumors. At the time of diagnosis they demonstrate marked chromosomal aberrations but over the course of the disease these changes remain relatively stable. Along with the recent advances in understanding the molecular pathogenesis of these tumors, studies have demonstrated that the long sought for precursor of ovarian HGSC appears to develop from an occult intraepithelial carcinoma in the fimbrial region of the fallopian tube designated 'serous tubal intraepithelial carcinoma (STIC)' and involves the ovary secondarily. Another possible mechanism for the development of ''ovarian'' HGSC is implantation of normal fimbrial epithelium on the denuded ovarian surface at the site of rupture when ovulation occurs. We speculate that this tubal epithelium can result in the formation of a cortical inclusion cyst (CICs) that can then undergo malignant transformation. Thus, serous tumors may develop from inclusion cysts, as has been previously proposed, but by a process of implantation of tubal (müllerian-type) tissue rather than by a process of metaplasia from ovarian surface epithelium (OSE, mesothelial). The dualistic model serves as a framework for studying ovarian cancer and can assist investigators in organizing this complex group of neoplasms. In conjunction with the recognition that the majority of 'ovarian' carcinomas originate outside the ovary, this model also facilitates the development of new and novel approaches to prevention, screening and treatment of this devastating disease.

Reliable in vitro studies require appropriate ovarian cancer cell lines

Ovarian cancer is the fifth most common cause of cancer death in women and the leading cause of death from gynaecological malignancies. Of the 75% women diagnosed with locally advanced or disseminated disease, only 30% will survive five years following treatment. This poor prognosis is due to the following reasons: limited understanding of the tumor origin, unclear initiating events and early developmental stages of ovarian cancer, lack of reliable ovarian cancer-specific biomarkers, and drug resistance in advanced cases. In the past, in vitro studies using cell line models have been an invaluable tool for basic, discovery-driven cancer research. However, numerous issues including misidentification and cross-contamination of cell lines have hindered research efforts. In this study we examined all ovarian cancer cell lines available from cell banks. Hereby, we identified inconsistencies in the reporting, difficulties in the identification of cell origin or clinical data of the donor patients, restricted ethnic and histological type representation, and a lack of tubal and peritoneal cancer cell lines. We recommend that all cell lines should be distributed via official cell banks only with strict guidelines regarding the minimal available information required to improve the quality of ovarian cancer research in future.

The pathogenesis of atypical proliferative Brenner tumor: an immunohistochemical and molecular genetic analysis

Brenner tumors are ovarian tumors, usually benign, containing epithelium that resembles transitional epithelium. As with other epithelial tumors there exist frankly malignant tumors and tumors that display greater proliferation than the benign Brenner tumors but lack destructive infiltrative growth, and these have been designated 'atypical proliferative' (borderline) Brenner tumors. There have been no well-documented cases of atypical proliferative Brenner tumors that have exhibited malignant behavior. Based on shared morphologic features it is generally believed that atypical proliferative Brenner tumors develop from benign Brenner tumors. The aim of the present study was to confirm this impression by investigating the immunohistochemical and molecular genetic features of benign and atypical proliferative Brenner tumors. Immunohistochemical staining for p16, fluorescence in-situ hybridization (FISH) for CDKN2A (p16-encoding gene) and mutational analysis of the genes commonly mutated in ovarian tumors were performed. p16 immunostaining was positive in the epithelial component of 12 (92%) of 13 benign Brenner tumors, but completely negative in all 7 atypical proliferative Brenner tumors. FISH identified homozygous deletion of CDKN2A in the epithelial component of all atypical proliferative Brenner tumors, but CDKN2A was retained in all benign Brenner tumors. Two PIK3CA somatic mutations were detected in the stromal component in 1 (5%) of 20 Brenner tumors and 3 somatic mutations (1 in KRAS and 2 in PIK3CA) were identified in the atypical epithelial component of 2 (29%) of 7 atypical proliferative Brenner tumors. In summary, our findings suggest that loss of CDKN2A and, to a lesser extent, KRAS and PIK3CA somatic mutations have a role in the progression of a benign to an atypical proliferative Brenner tumor.

The role of the fallopian tube in the origin of ovarian cancer

Advanced cases of epithelial ovarian, primary peritoneal, and primary tubal malignancies have a relatively poor prognosis and collectively remain the most deadly of all gynecologic malignancies. Although traditionally thought of as one disease process, ongoing research suggests that there is not 1 single site or cell type from which these cancers arise. A majority of the serous tumors appear to originate from dysplastic lesions in the distal fallopian tube. Therefore, what we have traditionally considered "ovarian" cancer may in fact be tubal in origin. In this article, we will review epithelial ovarian cancer classification and genetics, theories regarding cells of origin with a focus on tubal intraepithelial carcinoma, and implications for prevention and screening.

Ovarian Brenner tumour: a morphologic and immunohistochemical analysis suggesting an origin from fallopian tube epithelium

BACKGROUND

Brenner tumours (BTs), like other epithelial ovarian tumours, are thought to develop from the ovarian surface epithelium.

AIM AND METHODS

We hypothesised that BTs arise from transitional metaplasia near the tuboperitoneal junction which, when embedded in the ovary as Walthard cell nests, may progress to BTs. The aim of this study was to validate this hypothesis by a morphologic and immunohistochemical (IHC) analysis.

RESULTS

The IHC analysis revealed that fallopian tube secretory cells, transitional metaplasia, Walthard cell nests and the epithelial component of BTs shared a similar IHC profile, consistently expressing AKR1C3 (an enzyme involved in androgen biosynthesis) and androgen receptor, but not calretinin. The tumour stromal cells that immediately surrounded the epithelial nests showed strong expression of calretinin, inhibin and steroidogenic factor 1 (markers of steroidogenic cells) in the majority of BTs. Using a highly sensitive immunofluorescent staining method, we detected small groups of cilia in transitional metaplasia and Walthard cell nests, multifocal stretches of cilia and/or ciliated vacuoles in benign BTs and well-developed cilia in atypical proliferative BTs.

CONCLUSIONS

Our findings suggest a tubal origin of BTs through transitional metaplasia and Walthard cell nests, based on their anatomic proximity, similar IHC profile and the presence of cilia. In addition, we hypothesise a role of androgenic stimulation in the pathogenesis of BT, based on the IHC staining pattern of calretinin, inhibin and steroidogenic factor 1 expressed in the luteinised stromal cells surrounding the epithelial nests of the tumours, and AKR1C3 and androgen receptor expressed in both the epithelial and stromal components.

Origin and pathogenesis of pelvic (ovarian, tubal, and primary peritoneal) serous carcinoma

A new paradigm for the pathogenesis of female pelvic cancer helps explain persistent problems in describing the development and diverse morphology of these neoplasms. This paradigm incorporates recent advances in the molecular pathogenesis of epithelial ovarian cancer (EOC) with new insights into the origin of these tumors. Correlated clinicopathologic and molecular genetic studies gave rise to a dualistic model that divides the various histologic types of EOCs into two broad categories designated type I and type II. Because serous carcinomas are the most common EOC and account for the vast majority of deaths, they form the subject of this review. Recent studies indicate that the precursor of ovarian high-grade serous carcinoma appears to develop from an occult intraepithelial carcinoma in the fimbria of the fallopian tube and involves the ovary secondarily. Another possible mechanism is implantation of normal fimbrial epithelium on the denuded ovarian surface at the site of rupture when ovulation occurs, causing the development of cortical inclusion cysts. The dualistic model serves as a framework for the study of ovarian cancer and can help investigators organize this complex group of neoplasms. It also facilitates the development of novel approaches to prevention, screening, and treatment of this devastating disease.

Clinicopathologic study of serous tubal intraepithelial carcinoma with invasive carcinoma: is serous tubal intraepithelial carcinoma a reliable feature for determining the organ of origin?

In the past several decades, the concept of serous ovarian carcinoma has been revised repeatedly. However, the exact pathogenesis remains controversial. The most popular current concept is origin from the epithelium of the fimbriated ends of the fallopian tubes. The objective of our study was to evaluate the characteristic clinical and morphologic features of serous tubal intraepithelial carcinoma (STIC) and associated invasive carcinomas. One hundred sixteen consecutive cases of STIC seen from 2007 to 2011 were included in this study. High-grade serous carcinoma (HGSC) with or without a mixed component was identified in 107 cases (92.2%), non-HGSC in 5 cases, and STICs without invasive carcinoma in 4 cases. Using conventional criteria, HGSCs were classified as fallopian tube in origin in 65 cases (60.7%), as ovarian in 30 (28.0%), as peritoneal in 9 (8.4%), and as endometrial in 3 (2.8%). Among the 107 cases with HGSCs, most STICs (86; 80%) were present unilaterally, whereas invasive tumors more commonly involved the ovaries bilaterally (79%; 84 cases). These findings support the hypothesis that STIC acts as a precursor lesion for most fallopian tube, ovarian, and peritoneal HGSCs, but not for endometrial HGSC.

The diagnostic and biological implications of laminin expression in serous tubal intraepithelial carcinoma

There is compelling evidence to suggest that serous tubal intraepithelial carcinoma (STIC) is the likely primary site for the development of many pelvic high-grade serous carcinomas (HGSCs). Identifying molecules that are upregulated in STIC is important not only to provide biomarkers to assist in the diagnosis of STIC but also to elucidate our understanding of the pathogenesis of HGSC. In this study, we performed RNA sequencing to compare transcriptomes between HGSC and normal fallopian tube epithelium (FTE), and we identified LAMC1 encoding laminin γ1 as one of the preferentially upregulated genes associated with HGSC. Reverse transcription polymerase chain reaction further validated LAMC1 upregulation in HGSC as compared with normal FTE. Immunohistochemical analysis was performed on 32 cases of concurrent HGSC and STIC. The latter was diagnosed on the basis of morphology, TP53 mutations, and p53 and Ki-67 immunohistochemical patterns. Laminin γ1 immunostaining intensity was found to be significantly higher in STIC and HGSC compared with adjacent FTE in all cases (P<0.001). In normal FTE, laminin γ1 immunoreactivity was predominantly localized in the basement membrane or on the apical surface of ciliated cells, whereas in STIC and HGSC cells, laminin γ1 staining was diffuse and intense throughout the cytoplasm. More importantly, strong laminin γ1 staining was detected in all 13 STICs, which lacked p53 immunoreactivity because of null mutations. These findings suggest that the overexpression of laminin γ1 immunoreactivity and alteration of its staining pattern in STICs can serve as a useful tissue biomarker, especially for those STICs that are negative for p53 and have a low Ki-67 labeling index.

Proliferation in the normal FTE is a hallmark of the follicular phase, not BRCA mutation status

PURPOSE

Women who have inherited germline mutations of BRCA1/BRCA2 are at increased risk of developing high-grade serous carcinoma, and many of these cancers arise in the distal fimbriated end of the fallopian tube. We have previously shown that the fallopian tube epithelia of BRCA1 mutation carriers (FTE-BRCA) have altered signaling pathways compared to nonmutation carriers. In this study, we sought to determine whether these differences result in a proliferative advantage to the epithelia in this high-risk patient population and to investigate whether the postovulation environment of the FTE-BRCA compared to FTE from nonmutation carriers experiences a differential abundance of immune cells.

METHOD

Immunohistochemistry for Ki67, CD3, CD8, CD20, and CD68 was performed on histologically normal tubal epithelium (ampulla, n = 83), fimbria (n = 18) with known ovarian cycle status and germline mutation status and for Ki67 on fimbrial epithelium from women (n = 144) with and without BRCA1 or BRCA2 mutations who underwent risk-reducing salpingo-oophorectomy (RRSO). Serous tubal intraepithelial carcinomas (STIC) with concomitant cancer (n = 15) were also analyzed for presence of immune infiltrates. All slides were digitized and analyzed using automated image analysis software.

RESULTS

There was no significant difference in the proliferative index in histologically normal FTE between BRCA1/BRCA2 and non-BRCA, in 144 fimbriae and 83 ampullae. The FTE-BRCA1 epithelia did not exhibit a differential presence of lymphocytes or macrophages, however more macrophages were present in the luteal phase compared to the follicular phase epithelia. In STICs macrophages were more abundant than lymphocytes with an incremental increase noted with disease progression.

CONCLUSIONS

BRCA1/2 mutation carriers exhibited no significant increase in proliferation in the fallopian tube epithelial cells either in the ampulla or fimbriated ends of the tube. Rather, a significant proliferative increase was defined in the cases determined to be in the follicular, or proliferative, preovulatory phase of the ovarian cycle. Finally, we also show an incremental increase in leukocytes invading the STICs and HGSC, implicating a possible role of the leukocytes early in the progression or inhibition of tumor formation, which is independent of ovarian cycle status.