Risk of Alzheimer's Disease Following Influenza Vaccination: A Claims-Based Cohort Study Using Propensity Score Matching

Background:

Prior studies have found a reduced risk of dementia of any etiology following influenza vaccination in selected populations, including veterans and patients with serious chronic health conditions. However, the effect of influenza vaccination on Alzheimer’s disease (AD) risk in a general cohort of older US adults has not been characterized.

Objective:

To compare the risk of incident AD between patients with and without prior influenza vaccination in a large US claims database.

Methods:

Deidentified claims data spanning September 1, 2009 through August 31, 2019 were used. Eligible patients were free of dementia during the 6-year look-back period and≥65 years old by the start of follow-up. Propensity-score matching (PSM) was used to create flu-vaccinated and flu-unvaccinated cohorts with similar baseline demographics, medication usage, and comorbidities. Relative risk (RR) and absolute risk reduction (ARR) were estimated to assess the effect of influenza vaccination on AD risk during the 4-year follow-up.

Results:

From the unmatched sample of eligible patients (n = 2,356,479), PSM produced a sample of 935,887 flu–vaccinated-unvaccinated matched pairs. The matched sample was 73.7 (SD, 8.7) years of age and 56.9% female, with median follow-up of 46 (IQR, 29–48) months; 5.1% (n = 47,889) of the flu-vaccinated patients and 8.5% (n = 79,630) of the flu-unvaccinated patients developed AD during follow-up. The RR was 0.60 (95% CI, 0.59–0.61) and ARR was 0.034 (95% CI, 0.033–0.035), corresponding to a number needed to treat of 29.4.

Conclusion:

This study demonstrates that influenza vaccination is associated with reduced AD risk in a nationwide sample of US adults aged 65 and older.

Novel polymer-based system for intrauterine delivery of everolimus for anti-cancer applications

Non-surgical treatment options for low-grade endometrial cancer and precancerous lesions are a critical unmet need for women who wish to preserve fertility or are unable to undergo hysterectomy. The PI3K/AKT/mTOR pathway is frequently activated in endometrial cancers and has been associated with resistance to endocrine therapy, making it a compelling target for early stage disease. Oral everolimus, an inhibitor against mTORC1, has shown clinical benefit in advanced or recurrent disease but has severe adverse effects that may lead to treatment interruption or dose reduction. To overcome this, we developed a polymer-based intrauterine delivery system to achieve persistent, local delivery of everolimus without systemic exposure. In vivo studies, using a rat model, showed that a poly(propylene fumarate)-based rod loaded with everolimus achieved everolimus delivery to the endometrium with levels similar to oral administration, but with limited systemic exposure and up to 84 days of release. Biological activity of everolimus delivered with this system was confirmed, measured by reduced lumen epithelial cell height and PI3K pathway biomarkers. This study shows a promising new delivery approach for anti-cancer drugs for non-surgical treatment of low-grade endometrial cancer.

Abstract 3421: Identifying mechanisms of immune evasion in microsatellite instable endometrial cancers

Inherited or sporadic defects in mismatch repair genes (MLH1, MSH2, MSH6, and PSM2) can lead to microsatellite instable (MSI) tumors, most commonly colon, endometrial or gastric tumors. High mutation rates in MSI tumors have been associated with greater immunogenicity, but these tumors can evade immune response. Recently developed mouse models of MSI endometrial cancer (EC) were used to evaluate immune surveillance mechanisms.

Uterine-targeted MSH2 knockout (PR-Cre+MSH2flox/flox) mice were characterized and determined that 22% of mice develop spontaneous EC by 12-16 months of age. Microsatellite instability was evaluated by PCR. Immune infiltration was quantified by immunohistochemistry (IHC) using FoxP3 (Tregs), CD11b (myeloid cells) and CD8 (tumor infiltrating lymphocytes, TILs) antibodies. Tumors were divided into TILHigh and TILLow (<5 TIL/mm2). Comprehensive transcriptome analysis of tumor and normal controls was performed using the Affymetrix Clariom D assay. A subset of candidate gene changes were validated by RT-PCR and at the protein level by IHC. Cell lines were generated from spontaneous tumors and used for orthotopic syngeneic tumor studies of advanced EC. Immune infiltration in orthotopic tumors was characterized using flow cytometry.

All endometrial tumors from PR-Cre+MSH2flox/flox mice were MSI and included endometrioid, serous, and mixed histologies. Tumors showed varying degrees of immune infiltrate, irrespective of histology. Of 7 tumors, 4 (57%) were TILHigh and 3 (43%) were TILLow. Transcriptome analysis showed TILHigh tumors upregulated innate immunity related pathways including, pattern recognition-associated factors, Type I IFN signaling molecules and CXCL5. Activation of adaptive immunity was observed by an increase in T cell chemoattractants, CXCL9 and CCL21. TILHigh tumors displayed at least a 2-fold increase in MHC class I molecules and CD86 needed for T cell activation. IL1A, CSF1, and TGFB2 (cytokines involved in immunosuppressive cell recruitment and induction) were also highly expressed. IHC confirmed co-localization of TILs with myeloid cells and Tregs in TILHigh tumors. TILLow tumors had decreased expression of several members in the IFN family responsible for initiating innate responses. Primary cell lines from TILHigh and TILLow tumors used in an orthotopic syngeneic mouse model retained the immune profile of the original tumor.

Understanding mechanisms of immune evasion is critical for improving immunotherapy. This model of MSI EC reflects the spectrum of immunogenicity observed in clinical studies. TILHigh tumors express a wide range of factors involved in innate and adaptive anti-tumor responses, while TILLow tumors lack key mediators needed for immune activation. These new models for MSI EC will be essential to test the efficacy of immunotherapies and study mechanisms of resistance.

Citation Format: Brenda Melendez, Emily Hinchcliff, Nisha Gokul, Elizabeth Whitley, Russell R. Broaddus, Rosemarie E. Schmandt, Karen H. Lu, Melinda S. Yates. Identifying mechanisms of immune evasion in microsatellite instable endometrial cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3421.

Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) Promotes Uterine Serous Cancer Cell Proliferation and Cell Cycle Progression

Uterine serous carcinoma (USC) is the most aggressive form of endometrial cancer, with poor survival rates and high recurrence risk. Therefore, the purpose of this study was to identify therapeutic targets that could aid in the management of USC. By analyzing endometrial cancer samples from The Cancer Genome Atlas (TCGA), we found Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) to be highly expressed in USC and to correlate with poorer overall survival. UCHL1 silencing reduced cell proliferation in vitro and in vivo, cyclin B1 protein levels and cell cycle progression. Further studies showed that UCHL1 interacts with cyclin B1 and increases cyclin B1 protein stability by deubiquitination. Treatment of USC-bearing mice with the UCHL1-specific inhibitor reduced tumor growth and improved overall survival. Our findings suggest that cyclin B1 is a novel target of UCHL1 and targeting UCHL1 is a potential therapeutic strategy for USC.

Prospective Randomized Biomarker Study of Metformin and Lifestyle Intervention for Prevention in Obese Women at Increased Risk for Endometrial Cancer

Obesity increases risk of endometrial cancer through dysregulation of estrogen and insulin signaling. The primary aim of this study was to evaluate the impact of metformin or lifestyle intervention on endometrial proliferation in postmenopausal obese women. Secondary aims included evaluating obesity-related biomarkers and adverse events experienced. Obese, postmenopausal women with prediabetes were randomized into four groups for a 16-week intervention using a 2 (metformin 1700 mg/day vs. placebo) × 2 (lifestyle intervention vs. no lifestyle intervention) factorial design. Pre- and postintervention endometrial proliferation, anthropometrics, body composition, and serum biomarkers (sex hormones, sex hormone binding globulin, IGF-I, adiponectin, omentin, insulin, glucose, and others) were assessed. Data were analyzed with linear regression models and false-discovery rate correction. Of 576 women approached for the study, 52 attended initial screening, 29 were eligible and randomized, and 26 completed the study. Lifestyle intervention resulted in significant loss of weight (-4.23 kg, P = 0.006) and total fat mass (-3.23 kg, P < 0.001). Participants receiving metformin lost 3.43 kg of weight (P = 0.023), but this was not statistically significant after multiple comparisons adjustment controlling false-discovery rate to 10%. Endometrial proliferation was low at baseline (mean 7.1%) and remained unchanged by 16 weeks, but included substantial variability. Metformin and lifestyle intervention produced minor changes to serum biomarkers. Lifestyle intervention produced the most significant changes in weight and body composition. While it is known that obese postmenopausal women are at increased risk for endometrial cancer, improved biomarkers are needed to stratify risk and test prevention strategies, particularly at the endometrial tissue level. Cancer Prev Res; 11(8); 477-90. ©2018 AACR.

Lean Body Weight and Metformin Are Insufficient to Prevent Endometrial Hyperplasia in Mice Harboring Inactivating Mutations in PTEN

OBJECTIVES

Obesity is a major risk factor for endometrial cancer. We evaluated whether obesity exacerbates progression of endometrial hyperplasia (EH) using the PRCre/+ PTENflox/+ mouse model and examined if the type 2 diabetes drug, metformin, could prevent EH.

METHODS

Twenty obese (PRCre/+ PTENflox/+) mice were maintained on a high-fat diet, while 20 lean mice ate a matching low-fat diet. Ten mice from each group received metformin (1,000 mg/day) in drinking water. Mice were euthanized at 26 weeks. Uterine tissue was scored for degree of EH. Immunohistochemical staining for Ki67 was used to evaluate cellular proliferation. Markers of PI3K/AKT/mTOR activity were evaluated by immunohistochemistry using activation-specific antibodies. Serum adiponectin was quantified by ELISA.

RESULTS

Obesity had no effect on the extent of EH in (PRCre/+ PTENflox/+) mice. While metformin significantly altered circulating adiponectin levels in obese and lean animals, it had no effect on EH. There were no differences in endometrial proliferation as measured by Ki67 staining. Neither obesity nor metformin altered PI3K/AKT/mTOR activity in these animals.

CONCLUSIONS

Weight and metformin did not affect the severity of EH resulting from PTEN inactivation. Alternative mouse models of early endometrial cancer are required for preclinical cancer prevention studies.

Addressing the Role of Obesity in Endometrial Cancer Risk, Prevention, and Treatment

In sharp contrast to many other cancer types, the incidence and mortality of endometrial cancer continue to grow. This unfortunate trend is, in no small part, a result of the worldwide obesity epidemic. More than half of endometrial cancers are currently attributable to obesity, which is recognized as an independent risk factor for this disease. In this review, we identify the molecular mechanisms by which obesity and adipose tissue contribute to the pathogenesis of endometrial cancer. We further discuss the impact of obesity on the clinical management of the disease and examine the development of rational behavioral and pharmaceutical interventions aimed at reducing endometrial cancer risk, improving cancer outcomes, and preserving fertility in an increasingly younger population of patients with endometrial cancer.

Abstract 1263: UCHL1 modulates uterine papillary serous cancer progression through interaction with cyclin B1

Introduction:

Uterine papillary serous carcinoma (UPSC) comprises less than 10% of all endometrial cancers but is the most aggressive subtype of endometrial carcinoma. Few prospective studies focus solely on this rare subtype, making it difficult to determine optimal treatment strategies. The purpose of this study was to identify novel therapeutic targets that could aid in the management of UPSC.

Methods:

Clinical and RNA sequencing data from The Cancer Genome Atlas (TCGA) was used to identify differentially expressed genes between the more benign endometrioid endometrial carcinoma (EEC) and UPSC that also correlated with overall patient survival. Ubiquitin C-terminal hydrolase 1 (UCHL1) upregulation and survival correlation was validated by immunohistochemical staining of an independent cohort of paraffin samples. UCHL1 silencing by siRNA in UPSC cell lines ARK1, ARK2 and HEC50 was performed to measure changes in cell proliferation, migration, and apoptosis. Luciferase-expressing ARK1 cells transduced with lentiviral doxycycline-inducible control shRNA or anti-UCHL1 shRNA were injected intraperitoneally into nude mice and monitored by in vivo bioluminescent imaging over time. The effect of UCHL1 silencing on cyclin B1 RNA and protein levels was measured, and the effect on cell cycle progression was analyzed by flow cytometry. ARK1 and ARK2 cells were treated with a drug combination of the UCHL1 inhibitor LDN-57444 and paclitaxel; synergistic effect was evaluated using CompuSyn.

Results:

RNA and protein expression of UCHL1 was significantly higher in UPSC than EEC. Kaplan-Meier analysis and cox regression of TCGA samples and an independent cohort of patient samples confirmed that UCHL1 expression correlated significantly with poorer overall survival in UPSC. siRNA-mediated silencing did not affect cell migration or apoptosis, but reduced cell proliferation in vitro. Following intraperitoneal injection of ARK1 cells in nude mice, control shRNA tumours exhibited significantly higher bioluminescence by week 10 than UCHL1-knockdown tumours. UCHL1 RNA expression correlated positively with cyclin B1 protein levels in the TCGA data set. UCHL1 silencing reduced cyclin B1 protein levels in ARK1, ARK2 and HEC50; this change was not due to reduced RNA expression. Cell cycle analysis after UCHL1 silencing showed a reduction in the percentage of cells in the S and G2/M phases, and inhibition by LDN-57444 delayed the entry of synchronized cells into G2/M. Combination treatment in vitro with LDN-57444 and paclitaxel was synergistic across a range of dose levels.

Conclusions:

These findings indicate that UCHL1 contributes to the aggressiveness of UPSC by stabilizing cyclin B1 and increasing tumor cell proliferation. Inhibition of UCHL1 alone or in combination with paclitaxel may be useful in the management of UPSC.

Citation Format: Suet Ying Kwan, Samuel C. Mok, Rosemarie E. Schmandt, Kwong-Kwok Wong, Karen H. Lu. UCHL1 modulates uterine papillary serous cancer progression through interaction with cyclin B1. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1263.

Abstract 3559: Ubiquitin C-terminal hydrolase L1 (UCHL1) modulates uterine papillary serous cancer progression through interaction with cyclin B1

Background:

Uterine papillary serous carcinoma (UPSC) comprises less than 10% of all endometrial cancers but accounts for a disproportionately high number of deaths. Few prospective studies focus solely on this aggressive subtype, making it difficult to determine optimal treatment strategies. The purpose of this study was therefore to identify novel therapeutic targets that could aid in the management of UPSC.

Methods:

Clinical and RNA sequencing data from The Cancer Genome Atlas (TCGA) was used to identify genes that were differentially expressed between endometrioid endometrial carcinoma (EEC) and UPSC, which also showed a significant association with overall patient survival duration in UPSC patients. Ubiquitin C-terminal hydrolase L1 (UCHL1) upregulation and correlation with survival was validated by immunohistochemical staining of an independent cohort of paraffin samples. UCHL1 was silenced by siRNA transfection and lentiviral shRNA transduction in UPSC cell lines ARK1, ARK2 and HEC50 to evaluate the role of UCHL1 on cell proliferation, migration and cell cycle progression. RPPA data from TCGA was used to identify proteins whose expression correlated with UCHL1 expression. Interaction between UCHL1 and cyclin B1 was determined by co-immunoprecipitation. The effect of UCHL1 silencing on cyclin B1 levels was evaluated by Western blot analysis, and the effect on cell cycle progression was determined by flow cytometry.

Results:

UCHL1 mRNA and protein expression levels were significantly higher in in UPSC compared to EEC. Kaplan-Meier analysis and cox regression of the TCGA data set and an independent cohort of patient samples revealed that UCHL1 expression correlated significantly with poorer overall survival in UPSC, especially in late-stage patients. siRNA-mediated silencing did not affect cell migration, but reduced the proliferation rates of ARK1, ARK2 and HEC50 in vitro. UCHL1 RNA expression was positively correlated with cyclin B1 protein levels in the TCGA data set. Accordingly, UCHL1 silencing reduced cyclin B1 protein but not mRNA expression levels in ARK1, ARK2 and HEC50. Cell cycle analysis of ARK1, ARK2 and HEC50 after UCHL1 silencing showed a reduction in the percentage of cells in the S and G2/M phases, with or without cell synchronization.

Conclusion:

These findings indicate that UCHL1 contributes to the aggressiveness of UPSC by stabilizing cyclin B1 and increasing cell proliferation, suggesting that it may be a therapeutic target for UPSC.

Citation Format: Suet Ying Kwan, Samuel C. Mok, Kwong-Kwok Wong, Rosemarie E. Schmandt, Karen H. Lu. Ubiquitin C-terminal hydrolase L1 (UCHL1) modulates uterine papillary serous cancer progression through interaction with cyclin B1. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3559. doi:10.1158/1538-7445.AM2015-3559

Abstract 4401: UCHL1 as a potential therapeutic target in uterine papillary serous carcinoma

Uterine papillary serous carcinoma (UPSC) comprises less than 10% of all endometrial cancers but accounts for a disproportionately high number of deaths. Due to its rarity, few prospective studies have been conducted which focus on this aggressive subtype, and it has been difficult to establish optimal treatment strategies. With poor survival rates and high recurrence rates, the identification of novel therapeutic targets would aid in the management of UPSCs. RNAseq data from The Cancer Genome Atlas (TCGA) was analyzed using Significant Analysis of Microarrays to identify genes that were differentially expressed between 81 cases of grade 2 endometrioid endometrial carcinoma (EEC) and 41 cases of UPSC. A gene of interest was then selected based on its subcellular location, correlation with survival and normal tissue specificity. The findings were validated by immunohistochemical staining of UPSC paraffin sections. All patient samples were obtained and stored in accordance with human subject research protocols approved by the Institutional Review Board. All paraffin sections were reviewed by a pathologist. By comparing the RNAseq profiles of UPSCs and EECs, we identified 242 genes that were differentially expressed (q&lt;0.005). Among these, ubiquitin C-terminal hydrolase 1 (UCHL1) showed higher expression in UPSCs compared to EECs, with an increase of over 6-fold. UCHL1 was chosen for further studies as Kaplan-Meier analysis of all endometrial cases in the TCGA database revealed that UCHL1 expression also correlated significantly with poorer disease-free survival (p&lt;0.05). Preliminary immunohistochemical studies also show higher expression of UCHL1 in UPSCs than in ECCs. Interestingly, contrast analysis of TCGA data for breast cancer indicates that basal-like breast tumors also show significantly higher UCHL1 expression compared to the other breast cancer subtypes (p&lt;0.005). Both basal-like breast cancer and UPSC have a high rate of p53 mutation (80% and 90%); this shared upregulation of UCHL1 suggests that a possible mechanism by which UCHL1 contributes to pathogenesis is through stabilization of mutant p53. In conclusion, our data identifies UCHL1 as a gene that is upregulated in UPSCs and is associated with poor disease-free survival. UCHL1 is a possible novel therapeutic target for the management of UPSCs. Further studies are needed to elucidate the underlying mechanisms in which it contributes to tumorigenesis.

Citation Format: Suet Ying Kwan, Kwong-Kwok Wong, Rosemarie E. Schmandt, Karen H. Lu. UCHL1 as a potential therapeutic target in uterine papillary serous carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4401. doi:10.1158/1538-7445.AM2013-4401

Significantly greater expression of ER, PR, and ECAD in advanced-stage low-grade ovarian serous carcinoma as revealed by immunohistochemical analysis

A 2-tier system that classifies ovarian serous carcinoma (OSC) as low grade or high grade is gaining acceptance. Women with low-grade OSC generally have higher 5-year survival rates than do women with high-grade OSC. We examined the expression of various markers to further understand the molecular differences between low-grade and high-grade OSCs: the potential therapeutic targets or prognostic markers Her-2/neu, estrogen receptor, and progesterone receptor (PR); the metastasis-associated markers cyclin D1 (BCL1), E-cadherin, matrix metalloproteinase (MMP) 2, and MMP-9; and the cell proliferation-associated markers BCL1, Ki-67 antigen (Ki-67), and p53. For this immunohistochemical analysis, we used paraffin-embedded specimens from 47 patients with advanced-stage low-grade OSC and from 49 patients with advanced-stage high-grade OSC. Our results showed that low-grade tumors expressed significantly higher levels of estrogen receptor, PR, and E-cadherin than did high-grade tumors, suggesting the involvement of gonadal steroid hormones, especially in the pathogenesis of low-grade OSC; the PR positivity was also observed in the stromal component of these low-grade tumors. On the other hand, high-grade tumors trended toward increased expression of MMP-9, BCL1, p53, and Ki-67, and robust MMP-9 positivity was observed in the stromal component of these high-grade tumors. These differences may lead to the development of different therapeutic strategies for women with either the low-grade or the high-grade form of OSC.

The BRK tyrosine kinase is expressed in high-grade serous carcinoma of the ovary

BACKGROUND

We identified the BRK tyrosine kinase in a PCR-based screen of tyrosine kinases expressed by ovarian tumors. BRK expression is restricted to normal differentiating epithelial cells and its overexpression may play a role in processes related to tumor development and growth. Its expression in normal ovary and ovarian tumors has not previously been described, and is the focus of this study.

METHODS

BRK expression levels were determined in 14 normal ovaries and 138 high-grade, late stage serous carcinomas of the ovary by immunohistochemical analysis, and in 19 ovarian cancer cell lines and immortalized ovarian surface epithelium by Western blot analysis. Furthermore, BRK/PTK6 gene copy number was determined in seven primary serous carcinomas by fluorescence in situ hybridization.

RESULTS

Immunohistochemical studies indicate that BRK is highly expressed in 97/138 (70%) of high-grade, serous carcinomas of the ovary, but is absent in normal ovarian surface epithelia. BRK is also expressed by 9/19 of ovarian cancer cell lines, but is undetectable in immortalized ovarian surface epithelium. Interestingly, the BRK gene has been mapped to chromosome 20q13.3, a site frequently amplified in ovarian cancers, and associated with poor prognosis. We have determined by fluorescence in situ hybridization (FISH) that BRK is specifically amplified at low levels in 6/7 primary ovarian carcinomas.

CONCLUSIONS

The amplification of the BRK gene and overexpression of BRK protein in the majority of high-grade serous carcinomas and ovarian cancer cell lines suggest that BRK may play a role in the development and growth of ovarian tumors.

Expression of c-ABL, c-KIT, and platelet-derived growth factor receptor-beta in ovarian serous carcinoma and normal ovarian surface epithelium

BACKGROUND

Tyrosine kinases, such as c-KIT, c-ABL, and platelet-derived growth factor-beta (PDGFR-beta), are important regulators of cell growth. Highly potent and selective inhibitors of tyrosine kinases are being investigated as alternatives to standard chemotherapy. One such inhibitor, imatinib mesylate, is being used to treat gastrointestinal stromal tumors and chronic myelogenous leukemia. Ovarian carcinomas frequently develop resistance to conventional chemotherapeutic agents. Immunohistochemical expression of c-ABL, PDGFR-beta, and c-KIT was evaluated in ovarian carcinomas to determine whether treatment with imatinib mesylate might be feasible.

METHODS

The expression of c-ABL, c-KIT, and PDGFR-beta in tumors was evaluated by immunohistochemical analysis of 52 ovarian serous carcinomas, including 21 low-grade (well differentiated) and 31 high-grade (poorly differentiated) tumors. Fourteen normal ovaries were also evaluated.

RESULTS

In normal ovarian surface epithelium, c-ABL was expressed universally. PDGFR-beta was expressed in the majority (93%) of samples of normal ovarian epithelium, whereas the c-KIT protein was undetectable in normal ovarian surface epithelium. Overall, c-ABL was expressed in 71% of serous carcinomas. c-ABL was expressed more frequently in the low-grade serous carcinomas (81%) compared with the high-grade serous carcinomas (65%). PDGFR-beta expression was observed in 81% of serous carcinomas overall and was observed more frequently in higher-grade tumors. c-KIT immunohistochemical staining was absent in low-grade tumors but was present in 26% of high-grade serous carcinomas.

CONCLUSIONS

The majority of ovarian serous carcinomas express one or more of the kinases targeted by the tyrosine kinase inhibitor, imatinib mesylate, suggesting the potential usefulness of this drug in the treatment of ovarian carcinoma.