Utility of a Multi-Marker Panel with Ultrasound for Enhanced Classification of Adnexal Mass.

Pre-surgical clinical assessment of an adnexal mass typically relies on transvaginal ultrasound for comprehensive morphological assessment, with further support provided by biomarker measurements and clinical evaluation. Whilst effective for masses that are obviously benign or malignant, a large proportion of masses remain sonographically indeterminate at surgical referral. As a consequence, post-surgical diagnoses of benign disease can outnumber malignancies up to 9-fold, while less than 50% of cancer cases receive a primary referral to a gynecological oncology specialist. We recently described a blood biomarker signature (multi-marker panel-MMP) that differentiated patients with benign from malignant ovarian disease with high accuracy. In this study, we have examined the use of the MMP, both individually and in combination with transvaginal ultrasound, as an alternative tool to CA-125 for enhanced decision making in the pre-surgical referral process.

ReClassification of Patients with Ambiguous CA125 for Optimised Pre-Surgical Triage.

Pre-surgical clinical assessment of an adnexal mass is a complex process, and ideally requires accurate and rapid identification of disease status. Gold standard biomarker CA125 is extensively used off-label for this purpose; however its performance is typically inadequate, particularly for the detection of early stage disease and discrimination between benign versus malignant status. We recently described a multi-marker panel (MMP) and associated risk index for the differentiation of benign from malignant ovarian disease. In this study we applied a net reclassification approach to assess the use of MMP index to rescue those cases where low CA125 incorrectly excludes cancer diagnoses, or where benign disease is incorrectly assessed as "high risk" due to elevated CA125. Reclassification of such patients is of significant value to assist in the timely and accurate referral for patients where CA125 titer is uninformative.

A Novel Predictive Multi-Marker Test for the Pre-Surgical Identification of Ovarian Cancer.

Ovarian cancer remains the most lethal of gynecological malignancies, with the 5-year survival below 50%. Currently there is no simple and effective pre-surgical diagnosis or triage for patients with malignancy, particularly those with early-stage or low-volume tumors. Recently we discovered that CXCL10 can be processed to an inactive form in ovarian cancers and that its measurement has diagnostic significance. In this study we evaluated the addition of processed CXCL10 to a biomarker panel for the discrimination of benign from malignant disease. Multiple biomarkers were measured in retrospectively collected plasma samples (n = 334) from patients diagnosed with benign or malignant disease, and a classifier model was developed using CA125, HE4, Il6 and CXCL10 (active and total). The model provided 95% sensitivity/95% specificity for discrimination of benign from malignant disease. Positive predictive performance exceeded that of "gold standard" scoring systems including CA125, RMI and ROMA% and was independent of menopausal status. In addition, 80% of stage I-II cancers in the cohort were correctly identified using the multi-marker scoring system. Our data suggest the multi-marker panel and associated scoring algorithm provides a useful measurement to assist in pre-surgical diagnosis and triage of patients with suspected ovarian cancer.

The molecular origin and taxonomy of mucinous ovarian carcinoma.

Mucinous ovarian carcinoma (MOC) is a unique subtype of ovarian cancer with an uncertain etiology, including whether it genuinely arises at the ovary or is metastatic disease from other organs. In addition, the molecular drivers of invasive progression, high-grade and metastatic disease are poorly defined. We perform genetic analysis of MOC across all histological grades, including benign and borderline mucinous ovarian tumors, and compare these to tumors from other potential extra-ovarian sites of origin. Here we show that MOC is distinct from tumors from other sites and supports a progressive model of evolution from borderline precursors to high-grade invasive MOC. Key drivers of progression identified are TP53 mutation and copy number aberrations, including a notable amplicon on 9p13. High copy number aberration burden is associated with worse prognosis in MOC. Our data conclusively demonstrate that MOC arise from benign and borderline precursors at the ovary and are not extra-ovarian metastases.

A patient derived xenograft model of cervical cancer and cervical dysplasia.

AIM: To develop a patient derived xenograft (PDX) model of cervical cancer and cervical dysplasia using the subrenal capsule. METHODS: Cervical cancer (12 Squamous Cell Carcinoma, 1 Adenocarcinoma, 1 Adenosquamous Carcinoma), 7 cervical dysplasia biopsy and normal cervical tissues were transplanted beneath the renal capsule of immunocompromised NOD/SCID/gamma mice. Resulting tumours were harvested and portions serially transplanted into new recipient mice for up to three in vivo passages. Parent and xenograft tumours were examined by immunohistochemistry for p16INK41, HPV, and CD-45. Single cell suspensions of mixed mouse and human, or human only cell populations were also transplanted. RESULTS: The overall engraftment rate for the primary cervical cancer PDX model was 71.4 ±12.5% (n = 14). Tumours maintained morphological, histoarchitecture and immunohistochemical features of the parent tumour, and demonstrated invasiveness into local tissues. Single cell suspensions did not produce tumour growth in this model. Mean length of time (32.4 +/- 3.5 weeks) for the transplanted tissue to generate a tumour in the animal was similar between successive transplantations. Three of four xenografted cervical dysplasia tissues generated microscopic cystic structures resembling dysplastic cervical tissue. Normal cervical tissue (4 of 5 xenografted) also developed microscopic cervical tissue grafts. CONCLUSION: The subrenal capsule can be used for a PDX model of human cervical cancer with a good engraftment rate and the ability to model in vivo characteristics of cervical cancer. For the first time we have demonstrated that cervical dysplasia and normal cervical tissue generated microscopic tissues in a PDX model.

Autoantibodies against HSF1 and CCDC155 as Biomarkers of Early-Stage, High-Grade Serous Ovarian Cancer.

Background: Tumor-directed circulating autoantibodies (AAb) are a well-established feature of many solid tumor types, and are often observed prior to clinical disease manifestation. As such, they may provide a good indicator of early disease development. We have conducted a pilot study to identify novel AAbs as markers of early-stage HGSOCs.Methods: A rare cohort of patients with early (FIGO stage Ia-c) HGSOCs for IgG, IgA, and IgM-mediated AAb reactivity using high-content protein arrays (containing 9,184 individual proteins). AAb reactivity against selected antigens was validated by ELISA in a second, independent cohort of individual patients.Results: A total of 184 antigens were differentially detected in early-stage HGSOC patients compared with all other patient groups assessed. Among the six most highly detected "early-stage" antigens, anti-IgA AAbs against HSF1 and anti-IgG AAbs CCDC155 (KASH5; nesprin 5) were significantly elevated in patients with early-stage malignancy. Receiver operating characteristic (ROC) analysis suggested that AAbs against HSF1 provided better detection of early-stage malignancy than CA125 alone. Combined measurement of anti-HSF1, anti-CCDC155, and CA125 also improved efficacy at higher sensitivity.Conclusions: The combined measurement of anti-HSF1, anti-CCDC155, and CA125 may be useful for early-stage HGSOC detection.Impact: This is the first study to specifically identify AAbs associated with early-stage HGSOC. The presence and high frequency of specific AAbs in early-stage cancer patients warrants a larger scale examination to define their value for early disease detection at primary diagnosis and/or recurrence. Cancer Epidemiol Biomarkers Prev; 27(2); 183-92. ©2017 AACR.

The significance of post-translational removal of α-DG-N in early stage endometrial cancer development.

Endometrial cancer is one of the most common gynecological malignancies affecting post-menopausal women, yet the underlying mechanisms are not well understood. Dystroglycan (DG) is a large glycoprotein, consisting of α- and ß-subunits that are non-covalently associated with each other. Modifications to α-DG have been linked to a variety of cancers, where the N-terminus of α-DG (α-DG-N) is post-translationally removed by a furin-like enzyme. However, the functional significance of α-DG-N removal is unknown. Our previous studies have established that the α-DG cleavage enzyme furin is significantly up-regulated in endometrial cancer. This study aimed to investigate the importance of α-DG-N removal in post-menopausal endometrial cancer. We demonstrated that α-DG-N removal predominantly occurred in early stage endometrial cancer tissues, and that the cleaved α-DG-N was significantly elevated in the uterine lavage of early grade endometrial cancer patients. Furthermore, α-DG-N removal significantly decreased the tight junction integrity and polarity of the endometrial epithelial cells, promoting the loss of polarity markers scribble and atypical protein kinase C (aPKC) and reducing the trans-epithelial electrical resistance. The removal of α-DG-N also sensitized the cells for estrogen-dependent proliferation. These results strongly suggest that α-DG-N removal plays an important role in early stage development of endometrial cancer, and that the elevated levels of α-DG-N in uterine fluid may provide a biomarker for early detection of endometrial cancer.

Total PC Activity Is Increased in Uterine Lavage of Post-Menopausal Endometrial but Not Ovarian Cancer Patients.

Endometrial and ovarian cancers are two most common cancers affecting women in their post-menopausal years. To date, there are no simple biochemical tests to detect these cancers at early stages. Our previous study has demonstrated that the activity of total proprotein convertases (PCs) is significantly increased in uterine lavage at all stages of endometrial cancer, suggesting uterine lavage which can be obtained relatively non-invasively may provide a simple tool for the detection of endometrial cancer. However, uterine lavage may also contain ovarian-derived factors, and PCs are also reported to be up-regulated in ovarian cancer. In this study we determined whether increases in uterine lavage PC activity are specific to endometrial cancer or are also associated with ovarian cancer. PC activity was detected in all uterine lavages examined but no difference was found between women with and without ovarian cancer. On the other hand, the PC activity was significantly higher in post-menopausal endometrial cancer patients, consistent with our previous report. These results suggest that measuring total PC activity in uterine lavage is a useful tool to detect endometrial cancer specifically.

Measuring PC activity in endocervical swab may provide a simple and non-invasive method to detect endometrial cancer in post-menopausal women.

Endometrial cancer is one of the most common gynecological malignancies in post-menopausal women. If detected at early stages, endometrial cancer can be effectively treated by abdominal hysterectomy. However, to date, there is no biochemical test available for early and easy detection of endometrial cancer. Our previous study has established that the total proprotein convertase (PC) activity is significantly increased in the uterine lavage of post-menopausal women with endometrial cancer. Uterine lavage can be obtained relatively non-invasively compared to uterine tissues, however, blood contamination and other factors limit the wide clinical use of uterine lavage. The aim of this study was to determine whether endocervical swab is a viable alternative to uterine lavage for the detection of endometrial cancer. We determined the correlation in PC activity between paired endocervical swabs and uterine lavages from individual post-menopausal women (control as well as endometrial cancer patients), and also compared the total PC activity in endocervical swabs between control and endometrial cancer patients. Our data demonstrated that the total PC activity in swab and lavage was highly correlative in post-menopausal women, and that the PC activity in endocervical swab was significantly increased in endometrial cancer patients compared to controls. These results strongly suggest that determining PC activity in endocervical swabs may provide a simple, non-invasive and novel method to detect endometrial cancer in post-menopausal women.

Transcriptomic analysis of stage 1 versus advanced adult granulosa cell tumors.

Ovarian granulosa cell tumors (GCT) are hormonally-active neoplasms characterized, in the adult-subtype, by a mutation in the FOXL2 gene (C134W). They exhibit an indolent course with an unexplained propensity for late recurrence; ~80% of patients with aggressive, advanced stage tumors die from their disease; aside from surgery, therapeutic options are limited. To identify the molecular basis of advanced stage disease we have used whole transcriptome analysis of FOXL2 C134W mutation positive adult (a)GCT to identify genes that are differentially expressed between early (stage 1) and advanced (stage 3) aGCT. Transcriptome profiles for early (n = 6) and stage 3 (n = 6) aGCT, and for the aGCT-derived KGN, cell line identified 24 genes whose expression significantly differs between the early and stage 3 aGCT. Of these, 16 were more abundantly expressed in the stage 3 aGCT and 8 were higher in the stage 1 tumors. These changes were further examined for the genes which showed the greatest fold change: the cytokine CXCL14, microfibrillar-associated protein 5, insulin-like 3 and desmin. Gene Set Enrichment Analysis identified overexpression of genes on chromosome 7p15 which includes the homeobox A gene locus. The analysis therefore identifies a small number of genes with clearly discriminate patterns of expression arguing that the clinicopathological-derived distinction of the tumor stage is robust, whilst confirming the relative homogeneity of expression for many genes across the cohort and hence of aGCT. The expression profiles do however identify several overexpressed genes in both stage 1 and/or stage 3 aGCT which warrant further study as possible therapeutic targets.

A Review of Current Animal Models for the Study of Cervical Dysplasia and Cervical Carcinoma.

Cancer research has long relied on animal models for the study of disease mechanisms and new therapeutics. Future cancer treatments are likely to rely heavily on patient-derived xenograft models to develop novel treatments and tailor regimens to individual patient needs. However, specific models for cervical cancer and cervical dysplasia are limited. Only 3 models have been described in the published literature. A transgenic model for cervical cancer has allowed for the study of the differential contributions of the human papillomavirus 16 proteins E6 and E7 during oncogenesis. This model has also shown dysplasia development, although this has received little attention. A patient-derived tumor xenograft model where cervical cancer tissue is transplanted to the subcutaneous and orthotopic sites has been described. Here we review the reported transgenic and xenograft models, their strengths and limitations, and highlight the potential for the development of improved models to study cervical neoplasia.

Carcinoma of the neovagina after male-to-female reassignment.

BACKGROUND: Carcinoma of the neovagina is extremely rare, and only one other case has been reported after sex-reassignment surgery. Malignancies seem to be dependent on the original tissue and are thought to be associated with HPV infection or chronic irritation. CASE REPORT: A 53-year-old male-to-female transsexual presented 21 years after initial surgery with vaginal discharge that was found to be due to a moderately differentiated squamous cell carcinoma. She was treated with chemoradiation with disease remission; however, she had significant stenosis and narrowing of the neovagina. COMMENT: The optimum treatment is unclear, although radiation seems to be the most common technique with surgery an alternative. All patients should have regular clinical follow-up provided by a primary treating unit, which includes pelvic examination and cytologic smears. As a minimum, follow-up should occur as per other vaginal malignancies for at least 10 years.

The utility of isotope-coded protein labeling for prioritization of proteins found in ovarian cancer patient urine.

Urine offers a number of attractive features as a sample type for biomarker discovery, including noninvasive sampling, quantity and availability, stability, and a narrow dynamic range. In this study we report the first application of isotope coded protein labeling (ICPL), coupled with in-solution isoelectric fractionation and LC-MALDI-TOF/TOF, to examine and prioritize urinary proteins from ovarian cancer patients. Following the definition of stringent exclusion criteria a total of 579 proteins were identified with 43% providing quantitation data. Protein abundance changes were validated for selected proteins by ESI-Qq-TOF MS, following which Western blot and immunohistochemical analysis by tissue microarray was used to explore the biological relevance of the proteins identified. Several established markers (e.g., HE4, osteopontin) were identified at increased levels in ovarian cancer patient urine, validating the approach used; we also identified a number of potential marker candidates (e.g., phosphatidylethanolamine binding protein 1, cell-adhesion molecule 1) previously unreported in the context of ovarian cancer. We conclude that the ICPL strategy for identification and relative quantitation of urine proteins is an appropriate tool for biomarker discovery studies, and can be applied for the selection of potential biomarker candidates for further characterization.

Proprotein convertases in post-menopausal endometrial cancer: distinctive regulation and non-invasive diagnosis.

Proprotein convertases (PCs) play critical roles in cleaving precursor proteins (growth factors, hormones, receptors and adhesion molecules) for activation. PCs are implicated in a number of cellular functions, including oncogenesis. Endometrial cancer is the most common gynecological cancer in the developed world, but the involvement of PCs is unclear. To characterize the role of PCs in endometrial cancer, we assessed expression of seven PCs (PC1/3, PC2, PACE4, PC4, furin, PC5/6 and PC7) by RT-PCR in six well characterized endometrial cancer cell lines. Expression was variable in all lines, with furin being most consistently expressed in all cell lines tested. We next determined the cellular localization and expression levels of four ubiquitously expressed PCs (furin, PACE4, PC5/6 and PC7) in post-menopausal endometrial biopsies from control (n=7) and endometrial cancer patients (n=30) by immunohistochemistry. Furin increased in tumors, whereas PC5/6, PACE4 and PC7 expression was reduced with increasing cancer grades. Uterine lavage is a non-invasive source material for evaluating the endometrium. We thus assessed whether total PC activity was altered in uterine lavage of endometrial cancer patients (n=36) compared to controls (n=10). PC activity was detected in all uterine lavage samples, and significantly elevated in all grades of endometrial cancer. This study demonstrates a complex association between individual PCs and endometrial cancer. Importantly, we show that monitoring the total PC activity in uterine lavage may provide a rapid and non-invasive method for the diagnosis of endometrial cancer in postmenopausal women.

Interleukin 11 is upregulated in uterine lavage and endometrial cancer cells in women with endometrial carcinoma.

BACKGROUND: Interleukin (IL) 11 is produced by human endometrium and endometrial cancer tissue. It has roles in endometrial epithelial cell adhesion and trophoblast cell invasion, two important processes in cancer progression. This study aimed to determine the levels of IL11 in uterine lavage fluid in women with endometrial cancer and postmenopausal women. It further aimed to determine the levels of IL11 protein and its signaling molecules in human endometrial cancer of varying grades, and endometrium from postmenopausal women and IL11 signalling mechanisms in endometrial cancer cell lines. METHODS: IL11 levels in uterine lavage were measured by ELISA. IL11, IL11 receptor(R) alpha, phosphorylated (p) STAT3 and SOCS3 were examined by immunohistochemistry in endometrial carcinomas and in control endometrium from postmenopausal women and normal cycling women. The effect of IL11 on pSTAT3/STAT3 and SOCS3 protein abundance in endometrial cancer cell lines and non-cancer endometrial epithelial cells was determined by Western blot. RESULTS: IL11 was present in uterine flushings and was significantly higher in women with Grade 1 carcinomas compared to postmenopausal women (p < 0.05). IL11 immunostaining was significantly elevated in the endometrial tumour epithelial cells from Grade 1 and 3 compared to endometrial epithelium from postmenopausal and cycling women. IL11R alpha immunostaining intensity was increased in cancer epithelium in the Grades 1 and 2 tumours compared to epithelium from postmenopausal women. Both IL11 and IL11R alpha localized to vascular endothelial and smooth muscle cells while IL11 also localized to subsets of leucocytes in the cancer tissues. pSTAT3 was found in both the tumour epithelial and stromal compartments but was maximal in the tumour epithelial cells, while SOCS3 was predominantly found in the tumour epithelial cells. pSTAT3 staining intensity was significantly higher in Grade 1 and 2 tumour epithelial cells compared to epithelial cells from cycling and postmenopausal women. SOCS3 staining intensity did not differ between between each tumour and postmenopausal endometrial epithelium but SOCS3 in cycling endometrium was significantly higher compared to postmenopausal and Tumour Grades 2 and 3. IL11 increased pSTAT3/STAT3 in all tumour cell lines, while SOCS3 abundance was increased only in one tumour cell line. CONCLUSIONS: The present study suggests that IL11 in uterine washings may be useful as a diagnostic marker for early stage endometrial cancer. It indicates that IL11, along with its specific receptor, IL11R alpha, and downstream signalling molecules, STAT3 and SOCS3, are likely to play a role in the progression of endometrial carcinoma. The precise role of IL11 in endometrial cancer remains to be elucidated.

Ovarian status in healthy postmenopausal women: follow-up 12 months after transvaginal ultrasound.

OBJECTIVE: We have previously reported on the point prevalence of ovarian lesions detected by transvaginal ultrasound (TVU) in 515 asymptomatic women at least 5 years postmenopause. The aims of this study were to report, in the same women, on the repeatability of visualization of the ovaries (TVU) and the natural history of ovarian lesions seen at baseline but not treated surgically and to assess whether any women developed new ovarian abnormalities 12 months later. METHODS: The study involved a cohort of 515 postmenopausal women recruited from the community, at least 5 years past their last period. They were assessed at baseline and again after 12 months with TVU and serum levels of inhibin and CA-125. RESULTS: The right and left ovaries were seen on both occasions in 80% and 68% of women, respectively. Of the 49 women who had an ovarian lesion at baseline, did not undergo surgery at that time, and had a follow-up TVU, the lesion was unchanged 12 months later in 30 women. Four women developed a new ovarian lesion within the 12 months. None of the 14 women who underwent surgery on the basis of the ovarian appearance at baseline, or the 2 who had surgery on the basis of the ovarian appearance at follow-up, had an ovarian malignancy. CONCLUSIONS: The use of TVU in women at least 5 years after menopause is problematic because the ovaries cannot be visualized in all women and because TVU has the potential to identify many benign lesions that would otherwise remain undetected. These are important considerations in weighing up the risks and benefits of using TVU as a screening tool.

Ovarian status in healthy postmenopausal women.

OBJECTIVE: There are currently no programs to assess ovarian health in postmenopausal women. The aim of this study was to describe the ovaries in healthy women at least 5 years after menopause by questionnaire, transvaginal ultrasonography, and blood ovarian cancer markers. DESIGN: A total of 515 women who were asymptomatic and at the Stages of Reproductive Aging Workshop +2 stage of menopause (>5 y postmenopause) were recruited by advertisement. Clinical history was obtained by questionnaire, and biophysical assessment by a transvaginal ultrasound investigation and biochemical assessment by serum CA-125 and inhibin were performed. Abnormal findings were confirmed and then reviewed. RESULTS: Both ovaries were identified by transvaginal ultrasonography in 71% of women. The right ovary was visualized in 86.3% of these volunteers, and the left ovary was visualized in 78%. The presence of small unilocular cysts and echogenic foci facilitated identification of the ovary in some women. Ovarian/paraovarian lesions were present in 12.6% of women. Abnormalities of the endometrium and uterus were also common, prompting surgery in 7.2% of the women. Total serum inhibin concentrations were normal for postmenopausal women, whereas serum CA-125 was elevated in two women. CONCLUSIONS: We find that the description and detection of postmenopausal ovaries by transvaginal ultrasonography allows the identification of both ovaries in most postmenopausal women. Ultrasonography-detected abnormalities of the ovary and/or the uterus/endometrium are common in women at this stage of life. The potential need for surgical intervention after the detection of such abnormalities needs to be carefully evaluated when considering transvaginal ultrasonography as a screening tool for ovarian cancer.

Inhibin as a diagnostic marker for ovarian cancer.

The inhibins are a family of growth factors comprised of several different species that are secreted in the female principally from the ovarian follicle. The inhibins perform best as markers of ovarian cancer when measured collectively (total inhibin) by immunoassays targeted to common epitopes. After menopause with the depletion of ovarian follicles, the circulating level of total inhibin becomes undetectable. In contrast, serum total inhibin levels are elevated in women with ovarian cancer, in particular those with granulosa cell tumours and those with the mucinous subtype of epithelial carcinoma. Investigations into the clinical utility of inhibin to detect ovarian cancer have shown that it complements CA125, an established marker of epithelial ovarian cancer, in that each performs best in detecting different subtypes of ovarian cancer. In some published studies, the two markers together have detected up to 95% of ovarian cancers with 95% specificity.

Serine proteases HTRA1 and HTRA3 are down-regulated with increasing grades of human endometrial cancer.

OBJECTIVE: The high temperature requirement factor A (HTRA) family consists of serine proteases with domains homologous to those of bacterial HTRA. Four human HTRA members have been described: HTRA1-4. HTRA1 and HTRA3 share a high degree of domain homologies and may therefore share a functional similarity. HTRA1 mRNA and protein is reported to be down-regulated in SV40-transformed cells, a malignant melanoma cell line, ovarian tumors, and ovarian cancer cell lines, suggesting a progressive loss of HTRA1 and the protein in cancer. This raises the possibility that HTRA3 may likewise be involved in cancer. This study examined the expression of mRNA and protein levels of HTRA1 and HTRA3 in human endometrial cancer (EC). METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis was performed in normal endometrium (n = 4) and in three grades of EC (n = 5 for each EC grade). Immunohistochemistry was used to determine the protein expression and the cellular localization of HTRA1 and HTRA3 in normal endometrium tissue (n = 6) and in three grades of EC (n = 8-10 for each EC grade). RESULTS: RT-PCR analysis showed a significant reduction of HTRA1 and HTRA3 mRNA in endometrial cancer compared to normal endometrium. HTRA1 and HTRA3 protein showed a similar pattern of expression in EC tissue. Positive immunostaining, scored semiquantitatively, revealed a significant decrease of HTRA1 and 3 protein expression with increasing grades of EC. CONCLUSION: These data suggest that HTRA1 and HTRA3 mRNA and protein levels decrease with increasing grades of EC.

Expression of aromatase, estrogen receptors, and their coactivators in patients with endometrial cancer.

Quantitative polymerase chain reaction analysis of a panel of normal and malignant endometrial tissues revealed significant expression of both aromatase and estrogen receptor alpha in low-grade tumors, suggesting that local estrogen synthesis and action might contribute to the proliferation of these tumors.