Ovarian cancer is the most-deadly gynecologic malignancy, with greater than 14,000 women expected to succumb to the disease this year in the United States alone. In the front-line setting, patients are treated with a platinum and taxane doublet. Although 40–60% of patients achieve complete clinical response to first-line chemotherapy, 25% are inherently platinum-resistant or refractory with a median overall survival of about one year. More than 80% of women afflicted with ovarian cancer will recur. Many attempts have been made to understand the mechanism of platinum and taxane based chemotherapy resistance. However, despite decades of research, few predictive markers of chemotherapy resistance have been identified. Here, we review the current understanding of one of the most common genetic alterations in epithelial ovarian cancer, CCNE1 (cyclin E1) amplification, and its role as a potential predictive marker of cytotoxic chemotherapy resistance. CCNE1 amplification has been identified as a primary oncogenic driver in a subset of high grade serous ovarian cancer that have an unmet clinical need. Understanding the interplay between cyclin E1 amplification and other common ovarian cancer genetic alterations provides the basis for chemotherapeutic resistance in CCNE1 amplified disease. Exploration of the effect of cyclin E1 amplification on the cellular machinery that causes dysregulated proliferation in cancer cells has allowed investigators to explore promising targeted therapies that provide the basis for emerging clinical trials.

The development of patient-derived tumor organoids (TOs) from an epithelial ovarian cancer tumor obtained at the time of primary or interval debulking surgery has the potential to play an important role in precision medicine. Here, we utilized TOs to test front-line chemotherapy sensitivity and to investigate genomic drivers of carboplatin resistance. We developed six high-grade, serous epithelial ovarian cancer tumor organoid lines from tissue obtained during debulking surgery (two neoadjuvant-carboplatin-exposed and four chemo-naïve). Each organoid line was screened for sensitivity to carboplatin at four different doses (100, 10, 1, and 0.1 µM). Cell viability curves and resultant EC₅₀ values were determined. One organoid line, UK1254, was predicted to be resistant to carboplatin based on its EC₅₀ value (50.2 µM) being above clinically achievable Cmax. UK1254 had a significantly shorter PFS than the rest of the subjects (p = 0.0253) and was treated as a platinum-resistant recurrence. Subsequent gene expression analysis revealed extensively interconnected, differentially expressed pathways related to NF-kB, cellular differentiation (PRDM6 activation), and the linkage of B-cell receptor signaling to the PI3K–Akt signaling pathway (PI3KAP1 activation). This study demonstrates that patient-derived tumor organoids can be developed from patients at the time of primary or interval debulking surgery and may be used to predict clinical platinum sensitivity status or to investigate drivers of carboplatin resistance.

Conventional frontline treatment for ovarian cancer consists of successive chemotherapy cycles of paclitaxel and platinum. Despite the initial favorable responses for most patients, chemotherapy resistance frequently leads to recurrent or refractory disease. New treatment strategies that circumvent or prevent mechanisms of resistance are needed to improve ovarian cancer therapy. We established in vitro paclitaxel-resistant ovarian cancer cell line and organoid models. Gene expression differences in resistant and sensitive lines were analyzed by RNA sequencing. We manipulated candidate genes associated with paclitaxel resistance using siRNA or small molecule inhibitors, and then screened the cells for paclitaxel sensitivity using cell viability assays. We used the Bliss independence model to evaluate the anti-proliferative synergy for drug combinations. ABCB1 expression was upregulated in paclitaxel-resistant TOV-21G (q < 1x10^-300), OVCAR3 (q = 7.4x10^-156) and novel ovarian tumor organoid (p = 2.4x10^-4) models. Previous reports have shown some tyrosine kinase inhibitors can inhibit ABCB1 function. We tested a panel of tyrosine kinase inhibitors for the ability to sensitize resistant ABCB1-overexpressing ovarian cancer cell lines to paclitaxel. We observed synergy when we combined poziotinib or lapatinib with paclitaxel in resistant TOV-21G and OVCAR3 cells. Silencing ABCB1 expression in paclitaxel-resistant TOV-21G and OVCAR3 cells reduced paclitaxel IC₅₀ by 20.7 and 6.2-fold, respectively. Furthermore, we demonstrated direct inhibition of paclitaxel-induced ABCB1 transporter activity by both lapatinib and poziotinib. In conclusion, lapatinib and poziotinib combined with paclitaxel synergizes to inhibit the proliferation of ABCB1-overexpressing ovarian cancer cells in vitro. The addition of FDA-approved lapatinib to second-line paclitaxel therapy is a promising strategy for patients with recurrent ovarian cancer.

The primary objective of this study is to provide an updated analysis of the cost of screening for ovarian cancer in the United States. Here, we use updated information from the University of Kentucky Ovarian Cancer Screening Trial in conjunction with new modifying factors such as U.S. national estimates of the cost of care (Truven Health MarketScan Database), recently published estimates of earnings lost due to ovarian cancer death and estimates of federal income taxes paid on those earnings. In total, 326,998 screens were performed during the Kentucky trial from 1987 to 2019. At a cost of $56 per screen, we estimate that the total base cost to operate the program over the last 32 years is $18,311,888. When accounting for the surgical cost of 381 false-positive cases, the total cost of the screening program increases by $3,030,474. However, these costs are offset by the benefit of treating more early-stage ovarian cancer in the screened population, with a total cost advantage of $4,016,475 at our institution (Kentucky) or $1,525,050 ($725,700–$3,312,650) (U.S.) nationally. Additionally, program costs are offset by approximately $3,549,000 due to the potential earnings gained by the 26 women whose lives have been saved with screening. Furthermore, the cost of the program is offset by the federal tax dollars paid on the recovered earnings and amounts to $383,292. Ultimately, the net adjusted total cost of the Kentucky screening program is an estimated $13,393,595 at our institution or $15,885,020 ($13,978,068–$16,799,083) nationally. Thus, the adjusted cost per screen is an estimated $40.96 in Kentucky or $48.58 ($42.75–$51.37) nationally.

Ovarian anaplastic ependymoma is a rare gynecologic malignancy that poses diagnostic and treatment challenges. Treatment of sub-optimally debulked disease usually portends poor prognosis. Molecular testing of tumor specimen can identify more specific targets for additional therapy such as estrogen and progesterone receptors (ER/PR). A 29-year-old woman presented with incidental finding of large bilateral adnexal masses and elevated CA 125. Biopsy proved anaplastic ovarian ependymoma with high ER/PR expression. She underwent sub-optimal surgical debulking followed by adjuvant chemotherapy with bleomycin, etoposide and cisplatin (BEP) which resulted in a partial response. Due to extensive residual disease she has been maintained on anastrozole for over fifteen months without increased tumor burden. Targeted somatic mutation testing was negative for all high risk clinically useful variants. Aromatase inhibitors may be considered in patients with extra-axial anaplastic ependymoma and can produce prolonged stable disease.