K.C. Fuh

The treatment and outcomes of early-stage epithelial ovarian cancer : have we made any progress?

The objective of this study is to determine the progress and trends in the treatment and survival of women with early-stage (I–II) epithelial ovarian cancer. Data were obtained from the SEER database between 1988 and 2001. Kaplan–Meier and Cox regressions methods were employed for statistical analyses. Of the 8372 patients, the median age was 57 years (range: 12–99 years). A total of 6152 patients (73.4%) presented with stage I and 2220 (26.5%) with stage II disease. Over the periods 1988–1992, 1993–1997, and 1998–2001, 3-year disease-specific survivals increased from 86.1 to 87.2 to 88.8% (P=0.076). The number of patients that underwent lymphadenectomy has increased significantly from 26.2 to 38.7 to 54.2% over the study period (P<0.001). Of those patients who underwent staging procedures with lymphadenectomy, there was no improvement in survival over the three study periods (from 93.2 to 93.5 to 93.1%; P=0.978). On multivariate analysis, younger age, nonclear cell histology, earlier stage, lower grade, surgery, and lymphadenectomy were significant independent prognostic factors for improved survival. After adjusting for surgical staging with lymphadenectomy, the year of diagnosis was no longer an important prognostic factor. In conclusion, the use of lymphadenectomy during surgery for early-stage ovarian cancer has doubled over the last 14 years. The marginal improvement in survival demonstrated over time is potentially attributed to the increased use of staging procedures with lymphadenectomy.

Concomitant chemotherapy and radiation for the treatment of advanced-stage endometrial cancer

INTRODUCTIONnCcombination chemotherapy and radiation therapy is used for adjuvant treatment of stage III-IV endometrial cancer. The goal of this study was to review the treatment duration, toxicity, and survival for patients treated with concomitant chemotherapy and radiation.nnnMETHODSnWomen with stage III-IV endometrial cancer treated with concurrent chemotherapy and radiation between 2006 and 2013 were included. Toxicities were classified per CTCAE v3.0 and RTOG/EORTC late radiation morbidity scoring. Descriptive statistics were used to quantify treatment and toxicities. Kaplan-Meier method was used to estimate survival.nnnRESULTSnFifty-one patients met our inclusion criteria. Median age was 60 (range 33-85). Thirty-six patients (70.6%) had endometrioid histology, 13 patients (25.5%) had serous, clear cell, or mixed histology, and 2 women (3.9%) had carcinosarcoma. Forty-eight patients had stage III disease and three patients were stage IVB. Mean treatment duration was 107 ± 19 days. Forty-two patients received all planned chemotherapy, and 16 patients required a dose reduction. Thirty-four patients (66.7%) experienced grade 3-4 toxicities, the majority of which were hematologic. There were no deaths related to therapy. Eighty-six percent of patients received leukocyte growth factors, and 25% of patients received a blood transfusion. Seven late grade 3-4 complications occurred: four gastrointestinal and two genitourinary, and one patient had ongoing neuropathy. Median progression-free survival was 42.8 months (range 4.4-81.5 months) and median overall survival was 44.9 months (range 5.1-82.6 months). Three-year overall survival was 80%.nnnCONCLUSIONnConcomitant chemotherapy and radiation is an adequately tolerated treatment modality that allows for shorter treatment duration.

The association between timing of initiation of adjuvant therapy and the survival of early stage ovarian cancer patients – An analysis of NRG Oncology/Gynecologic Oncology Group trials

OBJECTIVESnTo determine the association between timing of adjuvant therapy initiation and survival of early stage ovarian cancer patients.nnnMETHODSnData were obtained from women who underwent primary surgical staging followed by adjuvant therapy from two Gynecologic Oncology Group trials (protocols # 95 and 157). Kaplan-Meier estimates and Cox proportional hazards model adjusted for covariates were used for analyses.nnnRESULTSnOf 497 stage I-II epithelial ovarian cancer patients, the median time between surgery and initiation of adjuvant therapy was 23days (25th-75th%: 12-33days). The time interval from surgery to initiation of adjuvant therapy was categorized into three groups: <2weeks, 2-4weeks, and >4weeks. The corresponding 5-year recurrence-free survival rates were 72.8%, 73.9%, and 79.5% (p=0.62). The 5-year overall survival rates were 79.4%, 81.9%, and 82.8%, respectively (p=0.51; p=0.33 - global test). As compared to <2weeks, the hazard ratio for recurrence-free survival was 0.90 (95%CI=0.59-1.37) for 2-4weeks and 0.72 (95%CI=0.46-1.13) for >4weeks. Age, stage, grade, and cytology were important prognostic factors.nnnCONCLUSIONSnTiming of adjuvant therapy initiation was not associated with survival in early stage epithelial ovarian cancer patients.

Inhibition of the Receptor Tyrosine Kinase AXL Restores Paclitaxel Chemosensitivity in Uterine Serous Cancer

Uterine serous cancer (USC) is aggressive, and the majority of recurrent cases are chemoresistant. Because the receptor tyrosine kinase AXL promotes invasion and metastasis of USC and is implicated in chemoresistance in other cancers, we assessed the role of AXL in paclitaxel resistance in USC, determined the mechanism of action, and sought to restore chemosensitivity by inhibiting AXL in vitro and in vivo. We used short hairpin RNAs and BGB324 to knock down and inhibit AXL. We assessed sensitivity of USC cell lines to paclitaxel and measured paclitaxel intracellular accumulation in vitro in the presence or absence of AXL. We also examined the role of the epithelial–mesenchymal transition (EMT) in AXL-mediated paclitaxel resistance. Finally, we treated USC xenografts with paclitaxel, BGB324, or paclitaxel plus BGB324 and monitored tumor burden. AXL expression was higher in chemoresistant USC patient tumors and cell lines than in chemosensitive tumors and cell lines. Knockdown or inhibition of AXL increased sensitivity of USC cell lines to paclitaxel in vitro and increased cellular accumulation of paclitaxel. AXL promoted chemoresistance even in cells that underwent the EMT in vitro. Finally, in vivo studies of combination treatment with BGB324 and paclitaxel showed a greater than 51% decrease in tumor volume after 2 weeks of treatment when compared with no treatment or single-agent treatments (P < 0.001). Our results show that AXL expression mediates chemoresistance independent of EMT and prevents accumulation of paclitaxel. This study supports the continued investigation of AXL as a clinical target, particularly in chemoresistant USC. Mol Cancer Ther; 16(12); 2881–91. ©2017 AACR.

Recent Advances in Understanding, Diagnosing, and Treating Ovarian Cancer

Ovarian cancer, a term that encompasses ovarian, fallopian, and peritoneal cancers, is the leading cause of gynecologic cancer mortality. To improve patient outcomes, the field is currently focused on defining the mechanisms of cancer formation and spread, early diagnosis and prevention, and developing novel therapeutic options. This review summarizes recent advances in these areas.

TWIST1 induces expression of discoidin domain receptor 2 to promote ovarian cancer metastasis

The mesenchymal gene program has been shown to promote the metastatic progression of ovarian cancer; however, specific proteins induced by this program that lead to these metastatic behaviors have not been identified. Using patient derived tumor cells and established human ovarian tumor cell lines, we find that the Epithelial-to-Mesenchymal Transition inducing factor TWIST1 drives expression of discoidin domain receptor 2 (DDR2), a receptor tyrosine kinase (RTK) that recognizes fibrillar collagen as ligand. The expression and action of DDR2 was critical for mesothelial cell clearance, invasion and migration in ovarian tumor cells. It does so, in part, by upregulating expression and activity of matrix remodeling enzymes that lead to increased cleavage of fibronectin and spreading of tumor cells. Additionally, DDR2 stabilizes SNAIL1, allowing for sustained mesenchymal phenotype. In patient derived ovarian cancer specimens, DDR2 expression correlated with enhanced invasiveness. DDR2 expression was associated with advanced stage ovarian tumors and metastases. In vivo studies demonstrated that the presence of DDR2 is critical for ovarian cancer metastasis. These findings indicate that the collagen receptor DDR2 is critical for multiple steps of ovarian cancer progression to metastasis, and thus, identifies DDR2 as a potential new target for the treatment of metastatic ovarian cancer.

SQ1274, a novel microtubule inhibitor, inhibits ovarian and uterine cancer cell growth

OBJECTIVEnPaclitaxel, a microtubule inhibitor, is subject to tumor resistance while treating high-grade serous ovarian and uterine cancer. This study aims to directly compare the effects of SQ1274, a novel microtubule inhibitor that binds to the colchicine-binding site on tubulin, and paclitaxel in high-grade serous ovarian and uterine cancer cell lines both in vitro and in vivo.nnnMETHODSnWe assessed the sensitivity of ovarian (OVCAR8) and uterine (ARK1) cancer cell lines to SQ1274 and paclitaxel using XTT assays. We used western blot and quantitative real-time PCR to analyze changes in AXL RNA and protein expression by SQ1274 and paclitaxel. Differences in cell-cycle arrest and apoptosis were investigated using flow cytometry. Finally, we treated ovarian and uterine xenograft models with vehicle, paclitaxel, or SQ1274.nnnRESULTSnFirst, we demonstrate that SQ1274 has a much lower IC50 than paclitaxel in both ARK1 (1.26u202fnM vs. 15.34u202fnM, respectively) and OVCAR8 (1.34u202fnM vs. 10.29u202fnM, respectively) cancer cell lines. Second, we show SQ1274 decreases both RNA and protein expression of AXL. Third, we show that SQ1274 causes increased cell-cycle arrest and apoptosis compared to paclitaxel. Finally, we report that SQ1274 more effectively inhibits tumor growth in vivo compared to paclitaxel.nnnCONCLUSIONSnSQ1274 presents as a viable alternative to paclitaxel for treating ovarian and uterine cancer. This study supports the development of SQ1274 as a chemotherapeutic to treat ovarian and uterine cancer.

Abstract AP18: FUNCTIONAL GENOMIC SCREEN FOR ATTACHMENT AND INVASION IN METASTATIC OVARIAN CANCER

PURPOSE: To perform a biologically relevant functional genomic screen for genes involved in attachment and early invasion incorporating tumor microenvironment cells cultured from human omentum. METHODS: Primary fibroblasts cultured from the human omentum were plated as one component to recapitulate the tumor microenvironment. An arrayed small interfering RNA (siRNA) panel targeting 719 genes encoding kinases was used. Each well contained 2 oligos per gene. Three ovarian cancer cells with known metastatic capabilities (OVCAR8, ES2, and A2780) were selected and stably labeled with GFP. Following exposure to siRNA, ovarian cancer cells are overlaid upon a mixed submesothelial matrix (NOFs, collagen I, and fibronectin). After 72 hours of attachment/early invasion, a wash step was performed, and the functional readout of the intensity of fluorescence was performed. Cell death due to the siRNA was evaluated by staining with resazurin. Data was analyzed by expressing the effect of increased or decreased attachment using the median average deviation (MAD). RESULTS: MAD values were generated for each gene. A baseline MAD value of 0 was used and positive MAD values denoted genes that influenced an increase in adhesion when knocked down whereas negative values represented genes that had decreased adhesion when knocked down. Negative controls for adhesion/early invasion were used and found to have a MAD value of 0.52 for mock transfection reagent control and 2.45 for siNEG control. Positive controls for adhesion/early invasion had a MAD value of -6.13 for siB1- integrin and -8.91 for a known inhibitor of attachment – canthardin. The transfection efficiency control, siDEATH, had a MAD value of -8.8. Of the 719 genes encoding kinases, we found 17 genes with MAD values above +3 and 19 genes with MAD values below -3. Of these hits, JAK1 and Wee1 were identified. JAK1 has been found to contribute to ovarian cancer invasion, migration, and metastasis in preclinical models. Wee1 is involved in cell cycle progression, and a Wee1 inhibitor is currently in a Phase II trial in relapsed ovarian cancer. Both targets confirm that biologically-relevant genes can be identified through this screen by incorporating stromal cells cultured from human omentum. Additionally, across 3 cell lines, we identified kinases that overlapped in at least 2 cell lines with a MAD lower range of -1.85. There were 94 kinases identified: 9 with a role in adhesion, 7 in immune response, 17 in proliferation, 6 in apoptosis, 16 in metabolism, 33 in cell cycle, 2 in migration, 3 in ribosomal, 1 in autophagy, and 23 genes with overlapping functions. CONCLUSIONS: By incorporating the tumor microenvironment into a functional genomic screen, biologically relevant genes for ovarian cancer cell attachment and early invasion can be identified and will be validated as potential novel therapeutic targets. Citation Format: Katherine Fuh, Anne Gibson, Daniel Wilke, Maxene Ilagan, Andrea Hagemann, Carolyn McCourt, Premal Thaker, David Mutch, Matthew Powell, and Gregory Longmore. FUNCTIONAL GENOMIC SCREEN FOR ATTACHMENT AND INVASION IN METASTATIC OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP18.

Abstract LB-060: A novel target for genetic silencing of AXL mediates taxane resistance, invasion, and migration in uterine cancer

Objectives: We investigated the role of AXL expression in chemotherapy response in uterine papillary serous cancer, and sought to reverse chemoresistance through inactivation of AXL. Methods: In vitro cell viability (XTT) assays were performed to confirm response to chemotherapy in AN3CA (taxane sensitive) and ARK1 (taxane resistant) uterine cell lines. AXL knockdown by siRNA was performed with either a traditional transfection reagent (DharmaFECT) or with a novel serum-stable, cell-penetrating, endosomolytic amphipathic peptide delivery system (p5RHH). Following knockdown of AXL using siRNA and p5RHH, chemotherapy response was assessed by XTT assay and invasion and migration assays were performed. Cell viability assays were analyzed using multiple t-tests. P Citation Format: Marguerite Palisoul, Mai Nguyen, Hua Pan, Anne Lohrey, Samuel Wickline, Matthew Powell, David Mutch, Katherine Fuh. A novel target for genetic silencing of AXL mediates taxane resistance, invasion, and migration in uterine cancer. [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 LB-060.

Abstract AS19: The role of the receptor tyrosine kinase AXL in an immunocompetent mouse model of invasive endometrioid ovarian cancer

Objective: To evaluate the role of AXL in an immunocompetent model of ovarian cancer metastasis. Methods: Immunohistochemical staining of ovarian cancer tissue microarrays of advanced stage, high-grade epithelial ovarian cancer specimens for AXL expression was performed and correlated with overall survival. Metastatic endometrioid ovarian cancer was generated through intrabursal AdCre-infected LSL-K-rasG12D/+Ptenfl/fl mouse model. LSL-K-rasG12D/+Ptenfl/fl Axl+/+ and LSL-K-rasG12D/+Ptenfl/flAxl−/−were used to evaluate the role of AXL. Necropsy was performed to evaluate burden of the primary and metastatic tumors. Hematoxylin and eosin (HE Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS19.