Phase II Trial of Cisplatin, Gemcitabine, and Intensity-Modulated Radiation Therapy for Locally Advanced Vulvar Squamous Cell Carcinoma: NRG Oncology/GOG Study 279.

PURPOSE: To assess efficacy and toxicity of cisplatin (C) and gemcitabine (G) with intensity-modulated radiation therapy (IMRT) in patients with locally advanced vulvar cancer not amenable to surgery. METHODS: Patients enrolled in a single-arm phase II study. Pretreatment inguinal-femoral nodal assessment was performed. Sixty-four Gy IMRT was prescribed to the vulva, with 50-64 Gy delivered to the groins/low pelvis. Radiation therapy (RT) plans were quality-reviewed pretreatment. C 40 mg/m2 and G 50 mg/m2 were administered once per week throughout IMRT. Complete pathologic response (CPR) was the primary end point. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and adverse events were assessed with Common Terminology Criteria for Adverse Events v 4.0. RESULTS: Fifty-seven patients enrolled, of which 52 were evaluable. The median age was 58 years (range, 25-58), and 94% were White. Forty (77%) had stage II or III disease, and all had squamous histology. A median of six chemotherapy cycles (range, 1-8) were received. Eighty-five percent of RT plans were quality-reviewed with 100% compliance to protocol. Seven patients came off trial because of toxicity or patient withdrawal. Of 52 patients available for pathologic assessment, 38 (73% [90% CI, 61 to 83]) achieved CPR. No pelvic exenterations were performed. With a median follow-up of 51 months, the 12-month PFS was 74% (90% CI, 62.2 to 82.7) and the 24-month OS was 70% (90% CI, 57 to 79). The most common grade 3 or 4 adverse events were hematologic toxicity and radiation dermatitis. There was one grade 5 event unlikely related to treatment. CONCLUSION: Weekly C and G concurrent with IMRT sufficiently improved CPR in women with locally advanced vulvar squamous cell carcinoma not amenable to surgical resection.

Feasibility and Clinical Utility of Reporting Hereditary Cancer Predisposition Pathogenic Variants Identified in Research Germline Sequencing: A Prospective Interventional Study.

PURPOSE: Patients with cancer frequently undergo research-grade germline sequencing but clinically actionable results are not routinely disclosed. The objective of this study is to evaluate the feasibility of reporting clinically relevant secondary findings (SF) identified in germline research sequencing using the institutional molecular tumor board (MTB) and the treating oncology physician. METHODS: This prospective, interventional cohort study enrolled Total Cancer Care participants with any cancer diagnosis at a single institution. Patients underwent research-grade germline whole-exome sequencing, with bioinformatic analysis in a Clinical Laboratory Improvement Amendments-certified laboratory to verify pathogenic/likely pathogenic germline variants (PGVs) in any American College of Medical Genomics and Genetics SF v2.0 genes. After a protocol modification in consenting patients, the MTB reported PGVs to treating oncology physicians with recommendations for referral to a licensed genetic counselor and clinical confirmatory testing. RESULTS: Of the 781 enrolled participants, 32 (4.1%) harbored cancer predisposition PGVs, 24 (3.1%) were heterozygous carriers of an autosomal recessive cancer predisposition syndrome, and 14 (1.8%) had other hereditary disease PGVs. Guideline-directed testing would have missed 37.5% (12/32) of the inherited cancer predisposition PGVs, which included BRCA1, BRCA2, MSH6, SDHAF2, SDHB, and TP53 variants. Three hundred fifteen participants consented to reporting results; results for all living patients were reported to the clinical team with half referred to a licensed genetic counselor. There was concordance between all research variants identified in patients (n = 9) who underwent clinical confirmatory sequencing. CONCLUSION: MTB reporting of research-grade germline sequencing to the clinical oncology team is feasible. Over a third of PGVs identified using a universal testing strategy would have been missed by guideline-based approach, suggesting a role for expanding germline testing.

SYNE1 Mutation Is Associated with Increased Tumor Mutation Burden and Immune Cell Infiltration in Ovarian Cancer.

SYNE1, a nuclear envelope protein critical for cellular structure and signaling, is downregulated in numerous malignancies. SYNE1 alterations are found in 10% of gynecologic malignancies and 5% of epithelial ovarian cancers. Previous studies demonstrated an association between SYNE1 mutation, increased tumor mutation burden (TMB), and immunotherapy response. This study evaluates the SYNE1 mutation frequency, association with TMB, and downstream effects of SYNE1 mutation in ovarian cancer. Genetic information, including whole-exome sequencing, RNA analysis, and somatic tumor testing, was obtained for consenting ovarian cancer patients at an academic medical center. Mutation frequencies were compared between the institutional cohort and The Cancer Genome Atlas (TCGA). Bioinformatics analyses were performed. In our cohort of 50 patients, 16 had a SYNE1 mutation, and 15 had recurrent disease. Median TMB for SYNE1 mutated patients was 25 compared to 7 for SYNE1 wild-type patients (p < 0.0001). Compared to the TCGA cohort, our cohort had higher SYNE1 mutation rates (32% vs. 6%, p < 0.001). Gene expression related to immune cell trafficking, inflammatory response, and immune response (z > 2.0) was significantly increased in SYNE1 mutated patients. SYNE1 mutation is associated with increased TMB and immune cell infiltration in ovarian cancer and may serve as an additional biomarker for immunotherapy response.

Hemoglobin level associates with survival in women from Appalachian Kentucky with uterine cervix cancer.

Introduction: The purpose of this retrospective study was to determine the relationship between pretherapy hemoglobin levels and progression-free survival among women with uterine cervix cancer undergoing concurrent weekly cisplatin and radiotherapy followed by brachytherapy. Methods: Patients with advanced-stage II-IVA uterine cervix cancer were grouped by hemoglobin level (Hgb ≥ 12.0, 11.9-10.0, or < 10.0 g/dL). Endpoints were progression-free survival, overall survival, and local control. Results: Between 01/2001 and 07/2022, 168 patients contributed demographic, tumor, pretherapy hemoglobin, and outcome data with a median follow-up of 31 months. Progression-free survival at three years was 73% (95% confidence interval: 58%-84%), 71% (95% confidence interval: 56%-82%), and 62% (95% confidence interval: 44%-75%) for the Hgb ≥ 12.0, 11.9-10.0, or < 10.0 g/dL groups, respectfully (P < 0.001). In addition, pretherapy hemoglobin levels were significant with treatment outcome when included in a multivariate analysis of prognostic variables. Discussion: In conclusion, the difference in pretherapy hemoglobin level was prognostic of progression-free survival.

Implementation of Nurse Navigation Improves Rate of Molecular Tumor Testing for Ovarian Cancer in a Gynecologic Oncology Practice.

PURPOSE: The purpose of this study was to assess the impact of implementing a Nurse Navigator (NN) to improve the rate and timeliness of molecular tumor testing. METHODS: This is an evaluation of the impact of education sessions, consensus building, and NN implementation for molecular tumor testing in patients with epithelial ovarian cancer. The NNs' responsibilities included attending tumor boards and ensuring Next Generation Sequencing (NGS) is ordered, reviewed, and coordinated for appropriate patients. RESULTS: NNs significantly improved NGS testing rates from 35.29% to 77.27%, p = 0.002. Ordering a targeted panel test (TPT) was the most common reason for not ordering NGS in the pre-NN cohort (13/22, 59%). The total turnaround time for testing was reduced after the introduction of NNs from 145.2 days to 42.8 days, p < 0.0001. The post-NN group had a significantly higher rate of actionable mutations identified for the recurrent setting [67.6% versus 20.8% (p = 0.0005)] and a trend towards a higher rate of actionable mutations identified in the frontline setting [41.2% versus 33.3% (p = 0.41)]. CONCLUSION: NNs significantly improved somatic tumor testing rates and timeliness for patients with ovarian cancer. Discontinuing TPT in favor of NGS revealed a higher rate of actionable tumor mutations that would have been missed with TPT alone.

Targeting receptor tyrosine kinases in ovarian cancer: Genomic dysregulation, clinical evaluation of inhibitors, and potential for combinatorial therapies.

Epithelial ovarian cancer (EOC) remains one of the leading causes of cancer-related deaths among women worldwide. Receptor tyrosine kinases (RTKs) have long been sought as therapeutic targets for EOC, as they are frequently hyperactivated in primary tumors and drive disease relapse, progression, and metastasis. More recently, these oncogenic drivers have been implicated in EOC response to poly(ADP-ribose) polymerase (PARP) inhibitors and epigenome-interfering agents. This evidence revives RTKs as promising targets for therapeutic intervention of EOC. This review summarizes recent studies on the role of RTKs in EOC malignancy and the use of their inhibitors for clinical treatment. Our focus is on the ERBB family, c-Met, and VEGFR, as they are linked to drug resistance and targetable using commercially available drugs. The importance of these RTKs and their inhibitors is highlighted by their impact on signal transduction and intratumoral heterogeneity in EOC and successful use as maintenance therapy in the clinic through suppression of the VEGF/VEGFR axis. Finally, the therapeutic potential of RTK inhibitors is discussed in the context of combinatorial targeting via co-inhibiting proliferative and anti-apoptotic pathways, epigenomic/transcriptional programs, and harnessing the efficacy of PARP inhibitors and programmed cell death 1/ligand 1 immune checkpoint therapies.

Human epidermal growth factor receptor 2 expression in women with uterine cervix adenocarcinoma from Appalachian Kentucky.

Introduction: High-risk human epidermal growth factor receptor 2 (HER2)-positive adenocarcinomas associate with early recurrence and death, prompting consideration of novel radiotherapeutic options like a trastuzumab-linked thorium-227 alpha-particle emitting radionuclide. Methods: We conducted a retrospective pilot biomarker study of uterine cervix cancers among patients in Appalachian Kentucky, to characterize an exploitable triage biomarker like HER2 expression before starting a prospective phase 0 trial. Results: Most (60%) adenocarcinomas showed HER2 cell-surface overexpression, whereas squamous cell carcinomas (4%) did not do so. Discussion: Further validation tests of HER2 expression as a triage biomarker for radiopharmaceutical selection are warranted.

Phase III Randomized Trial of Maintenance Taxanes Versus Surveillance in Women With Advanced Ovarian/Tubal/Peritoneal Cancer: A Gynecologic Oncology Group 0212:NRG Oncology Study.

PURPOSE: To compare taxane maintenance chemotherapy, paclitaxel (P) and paclitaxel poliglumex (PP), with surveillance (S) in women with ovarian, peritoneal, or fallopian tube (O/PC/FT) cancer who attained clinical complete response after first-line platinum-taxane therapy. METHODS: Women diagnosed with O/PC/FT cancer who attained clinical complete response after first-line platinum-taxane-based chemotherapy were randomly allocated 1:1:1 to S or maintenance, P 135 mg/m2 once every 28 days for 12 cycles, or PP at the same dose and schedule. Overall survival (OS) was the primary efficacy end point. RESULTS: Between March 2005 and January 2014, 1,157 individuals were enrolled. Grade 2 or worse GI adverse events were more frequent among those treated with taxane (PP: 20%, P: 27% v S: 11%). Grade 2 or worse neurologic adverse events occurred more often with taxane treatment (PP: 46%, P: 36% v S: 14%). At the fourth scheduled interim analysis, both taxane regimens passed the OS futility boundary and the Data Monitoring Committee approved an early release of results. With a median follow-up of 8.1 years, 653 deaths were reported; none were attributed to the study treatment. Median survival durations were 58.3, 56.8, and 60.0 months for S, P, and PP, respectively. Relative to S, the hazard of death for P was 1.091 (95% CI, 0.911 to 1.31; P = .343) and for PP, it was 1.033 (95% CI, 0.862 to 1.24; P = .725). The median times to first progression or death (PFS) were 13.4, 18.9, and 16.3 months for S, P, and PP, respectively. Hazard ratio = 0.801; 95% CI, 0.684 to 0.938; P = .006 for P and hazard ratio = 0.854; 95% CI, 0.729 to 1.00; P = .055 for PP. CONCLUSION: Maintenance therapy with P and PP did not improve OS among patients with newly diagnosed O/tubal/peritoneal cancer, but may modestly increase PFS. GI and neurologic toxicities were more frequent in the taxane treatment arms.

Significance of Pelvic Fluid Observed during Ovarian Cancer Screening with Transvaginal Sonogram.

The primary objective was to examine the role of pelvic fluid observed during transvaginal ultrasonography (TVS) in identifying ovarian malignancy. A single-institution, observational study was conducted within the University of Kentucky Ovarian Cancer Screening trial from January 1987 to September 2019. We analyzed true-positive (TP), false-positive (FP), true-negative (TN), and false-negative (FN) groups for the presence of pelvic fluid during screening encounters. Measured outcomes were the presence and duration of fluid over successive screening encounters. Of the 48,925 women surveyed, 2001 (4.1%) had pelvic fluid present during a TVS exam. The odds ratio (OR) of detecting fluid in the comparison group (TN screen; OR = 1) significantly differed from that of the FP cases (benign pathology; OR: 13.4; 95% confidence interval (CI): 9.1-19.8), the TP cases with a low malignant potential (LMP; OR: 28; 95% CI: 26.5-29.5), TP ovarian cancer cases (OR: 50.4; 95% CI: 27.2-93.2), and FN ovarian cancer cases (OR: 59.3; 95% CI: 19.7-178.1). The mean duration that pelvic fluid was present for women with TN screens was 2.2 ± 0.05 encounters, lasting 38.7 ± 1.3 months. In an asymptomatic screening population, free fluid identified in TVS exams was more associated with ovarian malignancy than in the control group or benign ovarian tumors. While pelvic free fluid may not solely discriminate malignancy from non-malignancy, it appears to be clinically relevant and warrants thoughtful consideration.

Factors Predicting Participation in the Prospective Genomic Sequencing Study, Total Cancer Care (TCC), in Kentucky.

PURPOSE: Large-scale genomic sequencing studies are driving oncology drug development. However, rural populations, like those residing in Appalachian Kentucky, are underrepresented in these efforts. In this study, we determined the frequency of participation, reasons for nonparticipation, and factors predicting the decision to participate in the Total Cancer Care (TCC) prospective genomic cohort study. METHODS: A total of 1,188 patients were invited to enroll in the TCC prospective cohort from December 2018 to May 2019. Declining patients were queried for their rationale for nonparticipation and their patient data were obtained from the Kentucky Cancer Registry (KCR). Logistic regression was used to assess the association between characteristics and study participation. The association of study participation with survival was modeled with Cox proportional-hazards regression. RESULTS: 90.9% (1,081) patients consented to participate. In multivariate analysis, factors significantly associated with participation were age, gender, treatment status, and race. Though overall more women participated in the study, men were more likely to participate than women when invited (OR 1.57). Younger, Caucasian individuals who had received chemotherapy, but not surgery, were also more likely to participate. Patients in the Kentucky Appalachian cohort were primarily rural, had less educational attainment, and lower socioeconomic status. Kentucky Appalachian patients were no less likely to enroll in TCC than non-Appalachian patients. Consented individuals had higher overall survival compared to those who declined. CONCLUSION: Though minorities, those with low socioeconomic status, and rural populations are underrepresented in genomic studies, they were no less likely to participate when given the opportunity, and participation was associated with better clinical outcomes.

Characterization of Uterine Cervix Cancers in Women from Appalachian Kentucky.

Uterine cervix cancer (UCCx) is clinically and socioeconomically diverse among women in the United States (US), which obscures the discovery of effective radiochemotherapy approaches for this disease. UCCx afflicts 7.5 per 100,000 American women nationally but 11.7 per 100,000 women in Appalachian Kentucky (AppKY), when age-adjusted to the 2000 US standard population. Epidemiological chart review was performed on 212 women with UCCx treated at the University of Kentucky (UKY) between January 2001 and July 2021. Demographics, tumor characteristics, and relative radiochemotherapy dose and schedule intensity were compared among AppKY and non-AppKY cohorts as well as Surveillance, Epidemiology, and End Results (SEER) data. One hundred thirty-eight (65%) of 212 women seeking radiochemotherapy treatment for UCCx resided in AppKY. Most (80%) sought external-beam radiochemotherapy close to their AppKY residence. Brachytherapy was then most frequently (96%) conducted at UKY. Cancer stage at diagnosis was significantly more advanced in AppKY residents. Women residing in AppKY had a median 10-week radiochemotherapy course, longer than an 8-week guideline. Estimated survival in women residing in AppKY was 8% lower than US national averages. In summary, this study identified an increased percentage of advanced-stage UCCx cancer at diagnosis arising in AppKY residents, with a confounding population-specific delay in radiochemotherapy schedule intensity lowering survival.

Real-World Evaluation of Universal Germline Screening for Cancer Treatment-Relevant Pharmacogenes.

The purpose of this study was to determine the frequency of clinically actionable treatment-relevant germline pharmacogenomic variants in patients with cancer and assess the real-world clinical utility of universal screening using whole-exome sequencing in this population. Cancer patients underwent research-grade germline whole-exome sequencing as a component of sequencing for somatic variants. Analysis in a clinical bioinformatics pipeline identified clinically actionable pharmacogenomic variants. Clinical Pharmacogenetics Implementation Consortium guidelines defined clinical actionability. We assessed clinical utility by reviewing electronic health records to determine the frequency of patients receiving pharmacogenomically actionable anti-cancer agents and associated outcomes. This observational study evaluated 291 patients with cancer. More than 90% carried any clinically relevant pharmacogenetic variant. At least one disease-relevant variant impacting anti-cancer agents was identified in 26.5% (77/291). Nine patients with toxicity-associated pharmacogenomic variants were treated with a relevant medication: seven UGT1A1 intermediate metabolizers were treated with irinotecan, one intermediate DPYD metabolizer was treated with 5-fluorouracil, and one TPMT poor metabolizer was treated with mercaptopurine. These individuals were more likely to experience treatment-associated toxicities than their wild-type counterparts (p = 0.0567). One UGT1A1 heterozygote died after a single dose of irinotecan due to irinotecan-related adverse effects. Identifying germline pharmacogenomic variants was feasible using whole-exome sequencing. Actionable pharmacogenetic variants are common and relevant to patients undergoing cancer treatment. Universal pharmacogenomic screening can be performed using whole-exome sequencing data originally obtained for quality control purposes and could be considered for patients who are candidates for irinotecan, 5-fluorouracil, capecitabine, and mercaptopurine.

Lapatinib and poziotinib overcome ABCB1-mediated paclitaxel resistance in ovarian cancer.

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.

Utilizing Patient-Derived Epithelial Ovarian Cancer Tumor Organoids to Predict Carboplatin Resistance.

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.

Salvaging Detection of Early-Stage Ovarian Malignancies When CA125 Is Not Informative.

BACKGROUND: Ovarian cancer is the deadliest gynecologic cancer, with no recommended screening test to assist with early detection. Cancer antigen 125 (CA125) is a serum biomarker commonly used by clinicians to assess preoperative cancer risk, but it underperforms in premenopausal women, early-stage malignancies, and several histologic subtypes. OVA1 is a multivariate index assay that combines CA125 and four other serum proteins to assess the malignant risk of an adnexal mass. OBJECTIVE: To evaluate the performance of OVA1 in a cohort of patients with low-risk serum CA125 values. STUDY DESIGN: We analyzed patient data from previous collections (N = 2305, prevalence = 4.5%) where CA125 levels were at or below 67 units/milliliter (U/mL) for pre-menopausal women and 35 U/mL for post-menopausal women. We compare the performance of OVA1 to CA125 in classifying the risk of malignancy in this cohort, including sensitivity, specificity, positive and negative predictive values. RESULTS: The overall sensitivity of OVA1 in patients with a low-risk serum CA125 was 59% with a false-positive rate of 30%. OVA1 detected over 50% of ovarian malignancies in premenopausal women despite a low-risk serum CA125. OVA1 also correctly identified 63% of early-stage cancers missed by CA125. The most common epithelial ovarian cancer subtypes in the study population were mucinous (25%) and serous (23%) carcinomas. Despite a low-risk CA125, OVA1 successfully detected 83% of serous, 58% of mucinous, and 50% of clear cell ovarian cancers. CONCLUSIONS: As a standalone test, CA125 misses a significant number of ovarian malignancies that can be detected by OVA1. This is particularly important for premenopausal women and early-stage cancers, which have a much better long-term survival than late-stage malignancies. Using OVA1 in the setting of a normal serum CA125 can help identify at-risk ovarian tumors for referral to a gynecologic oncologist, potentially improving overall survival.

DACH1 mutation frequency in endometrial cancer is associated with high tumor mutation burden.

OBJECTIVE: DACH1 is a transcriptional repressor and tumor suppressor gene frequently mutated in melanoma, bladder, and prostate cancer. Loss of DACH1 expression is associated with poor prognostic features and reduced overall survival in uterine cancer. In this study, we utilized the Oncology Research Information Exchange Network (ORIEN) Avatar database to determine the frequency of DACH1 mutations in patients with endometrial cancer in our Kentucky population. METHODS: We obtained clinical and genomic data for 65 patients with endometrial cancer from the Markey Cancer Center (MCC). We examined the clinical attributes of the cancers by DACH1 status by comparing whole-exome sequencing (WES), RNA Sequencing (RNASeq), microsatellite instability (MSI), and tumor mutational burden (TMB). RESULTS: Kentucky women with endometrial cancer had an increased frequency of DACH1 mutations (12/65 patients, 18.5%) compared to The Cancer Genome Atlas (TCGA) endometrial cancer population (25/586 patients, 3.8%) with p-value = 1.04E-05. DACH1 mutations were associated with increased tumor mutation count in both TCGA (median 65 vs. 8972, p-value = 7.35E-09) and our Kentucky population (490 vs. 2160, p-value = 6.0E-04). DACH1 mutated patients have a higher tumor mutation burden compared to DACH1 wild-type (24 vs. 6.02, p-value = 4.29E-05). DACH1 mutations showed significant gene co-occurrence patterns with POLE, MLH1, and PMS2. DACH1 mutations were not associated with an increase in microsatellite instability at MCC (MSI-H) (p-value = 0.1342). CONCLUSIONS: DACH1 mutations are prevalent in Kentucky patients with endometrial cancer. These mutations are associated with high tumor mutational burden and co-occur with genome destabilizing gene mutations. These findings suggest DACH1 may be a candidate biomarker for future trials with immunotherapy, particularly in endometrial cancers.

CCNE1 Amplification as a Predictive Biomarker of Chemotherapy Resistance in Epithelial Ovarian Cancer.

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.

Olaparib Combined with an ATR or Chk1 Inhibitor as a Treatment Strategy for Acquired Olaparib-Resistant BRCA1 Mutant Ovarian Cells.

OBJECTIVE: Despite the promise of PARP inhibitors (PARPi) for treating BRCA1/2 mutated ovarian cancer (OC), drug resistance invariably develops. We hypothesized rationale drug combinations, targeting key molecules in DNA repair pathways and the cell cycle may be synergistic and overcome acquired PARPi resistance. METHODS: Drug sensitivity to PARPi alone and in combination with inhibitors of key DNA repair and cell cycle proteins, including ATR (VE-821), Chk1 (MK-8776), Wee1 (MK-1775), RAD51 (RI-1) was assessed in PARPi-sensitive (UWB1) and -resistant (UWB1-R) gBRCA1 mutant OC cell lines using a cell proliferation assay. The Bliss synergy model was used to estimate the two-drug combination effect and pharmacologic synergy (Bliss score ≥ 0) or antagonistic (Bliss score ≥ 0) response of the PARPi in combination with the inhibitors. RESULTS: IC50 for olaparib alone was 1.6 ± 0.9 µM compared to 3.4 ± 0.6 µM (p = 0.05) for UWB1 and UWB1-R cells, respectively. UWB1-R demonstrated increased sensitivity to ATRi (p = 0.04) compared to UWB1. Olaparib (0.3-1.25 µM) and ATRi (0.8-2.5 µM) were synergistic with Bliss scores of 17.2 ± 0.2, 11.9 ± 0.6 for UWB1 and UWB1-R cells, respectively. Olaparib (0.3-1.25 µM) and Chk1i(0.05-1.25 µM) were synergistic with Bliss scores of 8.3 ± 1.6, 5.7 ± 2.9 for UWB1 and UWB1-R cells, respectively. CONCLUSIONS: Combining an ATRi or Chk1i with olaparib is synergistic in both PARPi-sensitive and -resistant BRCA1 mutated OC cell models, and are rationale combinations for further clinical development.