Study case flow diagram for WES of translational specimens from patients enrolled in GOG281. One hundred thirty-four samples underwent successful WES, of which 112 were also evaluable for pERK via IHC. Additionally, 36 samples were evaluable for pERK IHC that did not have matching WES.

The diagnosis and monitoring of ovarian cancer remain major clinical challenges due to nonspecific symptoms, late-stage detection, and high rates of recurrence. Increasing evidence suggests that circulating platelets reflect tumor presence and activity. Platelet-based molecular and functional signatures may, therefore, represent a promising new class of biomarkers for ovarian cancer.

Platelets are considered intravascular effectors of hemostasis, yet growing evidence indicates that they can migrate across the endothelium. Whether platelet exit from the vasculature is a regulated process analogous to leukocyte trafficking and how migration is coordinated with effector functions has remained unclear. Using genetic, pharmacologic, and imaging approaches, we define the molecular program governing platelet transendothelial migration into tumors in vivo. CXCL12-CXCR4 signaling contributed to platelet extravasation in vivo, with stromal rather than tumor-derived CXCL12 acting as the dominant cue; CXCR4 disruption reduced platelet infiltration and tumor growth. Efficient vascular exit required platelet focal adhesion kinase and platelet endothelial cell adhesion molecule 1, implicating cytoskeletal remodeling and junctional adhesion. Platelet trafficking was uncoupled from effector activity: Munc13-4-dependent dense granule secretion was dispensable for extravasation but required for growth promotion, whereas Munc18-2-regulated α-granule release preserved vascular integrity and restricted passage. Disruption of the CLEC-2/podoplanin axis destabilized vessels and increased leakage. Together, these findings establish regulated platelet extravasation.

Purpose: Low-grade serous ovarian carcinoma (LGSOC) is a distinct form of ovarian cancer characterized by younger patient age and relative chemoresistance. The GOG281/LOGS trial (NCT02101788) investigated the efficacy of the MEK inhibitor trametinib compared with physician's choice standard-of-care (SOC) in patients with LGSOC with persistent/recurrent disease. The study demonstrated significantly improved progression-free survival (PFS) in the trametinib-treated arm. Experimental Design: Two hundred and sixty patients with recurrent/persistent LGSOC were enrolled and randomly assigned in GOG281. We performed molecular analysis of 170 patients with available tumor specimens, comprising whole-exome sequencing and phospho-ERK (pERK) IHC, to identify biomarkers of clinical benefit from trametinib. The demographics of the translational cohort (n = 170) were comparable with those of the total trial cohort. Results: High tumor pERK expression (greater than the median histoscore of 140) was associated with significantly prolonged PFS with trametinib treatment versus SOC (median 20.1 vs. 5.6 months, log-rank P < 0.0001; test for interaction P = 0.023). Tumors harboring canonical RAS-RAF-MAPK mutations (KRAS/BRAF/NRAS: 44/134, 32.8% of cases) had a higher response rate to trametinib (50.0% vs. 8.3%; Barnard's P = 0.0004; test for interaction P = 0.054), but KRAS/BRAF/NRAS status was not predictive of prolonged PFS (test for interaction P = 0.719). KRAS amplification (n = 5 without KRAS/NRAS/BRAF mutation) and mutation of MAPK-associated genes (n = 25 without KRAS/NRAS/BRAF mutation or KRAS copy number gain) expanded the number of cases with identifiable MAPK defects to 55.2%, but consideration of these events did not improve the discrimination of trametinib responders. Chr1p loss (49% of cases) was associated with lower pERK expression (P = 0.021). Conclusions: This exploratory analysis suggests that pERK expression and mutation of KRAS/BRAF/NRAS are candidate biomarkers of improved PFS and response to trametinib, respectively.

Abstract Background: High-grade serous ovarian cancer (HGSOC) is the deadliest gynecologic malignancy, with recurrence and chemoresistance driving poor survival outcomes. Beyond canonical resistance mechanisms, large portions of the genome encode non-canonical open reading frames (ncORFs) that produce short, intrinsically disordered proteins/peptides (ncPRs), largely undetectable by standard proteomics (“dark proteome”). Emerging evidence implicates ncPRs in tumor plasticity, stress adaptation, intercellular communication, and drug resistance. Their role in HGSOC chemoresistance and packaging into extracellular vesicles (EVs) remain unexplored. Methods: We analyzed RNA-seq datasets from primary tumors of 30 patients and matched EV RNA-seq from 28 patients. Cohorts included patients with complete gross resection (CGR, n = 10) and neoadjuvant chemotherapy (NACT) with excellent (NACT-ER, n = 9) or poor response (NACT-PR, n = 9). ncORF abundances were quantified using a non-canonical ORF database and associations with clinical outcomes were assessed. Results: Primary tumors and EVs showed distinct ncORF biotype distributions. exhibited a 17% decrease in coding and 10% decrease in intronic ncORFs (p < 0.0001), with 64% and 53% increases in pseudogene- and ncRNA-derived ncORFs and 3′UTR-derived ncORFs, respectively (p < 0.0001). Although fewer in number, pseudogene-derived ncORFs showed higher mean abundance than coding-derived ncORFs in EVs. Their abundance patterns trended toward discriminating CGR versus NACT patients (Fishers’ exact test p = 0.004) and NACT-ER vs NACT-PR (P = 0.08). Conclusions: ncORFs, particularly pseudogene and ncRNA-derived, are selectively enriched in EVs from HGSOC patients, suggesting roles in intercellular communication and therapy response. These findings highlight EV-associated ncORFs as potential biomarkers and therapeutic targets in ovarian cancer. Citation Format: Tatiana V. Karpinets, Xiaogang Wu, Sara Corvigno, Amma Asare, Joseph Celestino, Jeffry J. Cutrera, Pamela T. Soliman, Shannon N. Westin, Amir A. Jazaeri, P. Andrew Futreal, Anil K. Sood, Sanghoon Lee. Extracellular vesicle-associated noncanonical ORFs as biomarkers of surgical outcome and chemoresistance in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1041.

Background A recent meta-analysis reported that patients with ovarian cancer have a 3-fold increase in the risk of diagnosis of depression compared to the general population. However, the role of disease-related processes in depressive symptoms-particularly at diagnosis versus after treatment-remains unclear. This study aimed to examine the contribution of somatic symptoms to the assessment of depression severity in patients with ovarian cancer, both at diagnosis and 1 year later, compared to healthy controls.Methods A total of 428 patients with ovarian cancer completed psychosocial assessments at 1-2 weeks before surgical intervention or initiation of neoadjuvant chemotherapy and at a 1-year follow-up visit. A comparison sample from the Midlife in the United States study was included. Item factor analysis was used to examine the functioning of somatic items in a common depression symptom index in both samples.Results Somatic items demonstrated differential functioning between groups. Specifically, patients with ovarian cancer were more likely to endorse somatic symptoms at lower levels of depression as compared to healthy aging adults; they additionally required a lower level of depression to endorse somatic items as compared to nonsomatic items. These differences between patients with cancer and healthy aging adults were no longer present at 1 year postdiagnosis.Conclusions These findings support the conclusion that somatic symptoms may disproportionately inflate depression scores among patients with ovarian cancer at diagnosis, which may potentially lead to misclassification or overestimation of depression severity. This highlights the need for refined measurement approaches that account for the somatic burden of cancer in assessing depression during active disease.

BACKGROUND:Acute respiratory distress syndrome (ARDS) causes significant morbidity and mortality during viral pneumonia, including SARS-CoV-2 infections. Nevertheless, most patients with SARS-CoV-2 infections recover seamlessly without developing ARDS, suggesting the existence of endogenous pathways to protect the lungs. Since microRNAs (miRNAs) can regulate endogenous molecular pathways involved in lung protection, we hypothesized that alveolar miRNAs could function to dampen SARS-CoV-2-associated lung injury. METHODS:Screening studies in human alveolar epithelial cells and SARS-CoV-2-infected mice were performed to identify miRNAs induced during infection. Candidate miRNAs were confirmed via RT-qPCR. The role of hypoxia-inducible factor 1A (HIF1A) in regulating miRNA expression was examined in molecular studies. Loss- and gain-of-function approaches in a murine SARS-CoV-2 ARDS model were used to assess the physiological relevance of miRNA. Viral sequence analyses and site-directed mutagenesis were used to determine direct miRNA - viral RNA interactions. RESULTS:Screening studies identified miR-147b (hsa-miR-147b-3p or mmu-miR-147-3p) as the leading candidate during infection of human alveolar epithelia or mice with SARS-CoV-2. Functional and molecular studies implicate HIF1A in miR-147b induction during alveolar injury or SARS-CoV-2 infection. Studies in mice with induced deletion of miR-147b in alveolar epithelia (miR147fl/fl SPC-CreER mice) or nano-particle-mediated miR-147b overexpression revealed a protective role of alveolar-expressed miR-147b during murine SARS-CoV-2-associated ARDS. Moreover, we identified the ORF8 region within the SARS-CoV-2 template strand as a direct target of miR-147b, with an ORF8 silent mutation of the SARS-CoV-2 miR-147b-binding site abolishing the observed protection in vitro and in vivo. CONCLUSIONS:Alveolar epithelial cell-derived miR-147b serves as an endogenous lung protective miRNA against SARS-CoV-2-associated ARDS by directly targeting virus-encoded RNA, revealing a previously unrecognized antiviral and lung-protective mechanism.

Objective: Bevacizumab combined with oral cyclophosphamide has demonstrated activity in recurrent ovarian cancer, but data in heavily pre-treated high-grade disease are limited. We evaluated the safety and efficacy of this combination regimen in this setting. Methods: We conducted a retrospective review of patients with recurrent high-grade epithelial ovarian cancer treated with oral cyclophosphamide (50 mg daily) and bevacizumab (15 mg/kg every 3 weeks) at a single institution. Objective response rate was defined as complete or partial response. Progression-free survival was estimated using the Kaplan-Meier method, and adverse events were graded per Common Terminology Criteria for Adverse Events version 5.0. Results: Among 100 patients (median age 58 years; range; 38-80), 94% had highgrade serous histology and 96% had stage IIIC to IV disease. Fourteen (14%) were platinum-sensitive and 86 (86%) platinum-resistant, with a median of 3 prior treatment lines (range; 1-9). Patients received a median of 5 cycles (range; 2-34). The objective response rate was 40% (95% confidence interval 31 to 51), including 4% complete and 36% partial responses; 20% achieved stable disease. Response did not differ by prior bevacizumab exposure (36% vs 43%, p .59) or platinum sensitivity status. Median progression-free survival was 4.6 months (95% confidence interval 3.4 to 5.9). Twentyfour (24%) patients experienced adverse events. The most common grade 3 or 4 toxicities included hypertension (3%), thrombocytopenia (3%), and hemorrhagic cystitis (1%). Conclusions: Bevacizumab combined with oral cyclophosphamide demonstrated meaningful activity and manageable toxicity in heavily pre-treated high-grade ovarian cancer, supporting its use as a feasible treatment option.

Despite the advancement in therapies, ovarian cancer treatment is challenging due to poor prognosis and high relapse associated with acquired resistance. Targeting overexpression of FOLR1 in ovarian cancers has proven to be an attractive strategy. The recent FDA approval of FOLR1 targeted antibody drug conjugate has shown promising results albeit resistance with repeated use appears inevitable. Emerging targeted alpha-particle therapies, particularly Actinium-225 ( 225 Ac), for treating refractory cancers have opened avenues for improved therapeutic options. The success of alpha-particle therapy relies on tumor specific delivery of the alpha emitters. Herein we describe the first example of FOLR1-targeted 225 Ac alpha-particle therapy for treatment of ovarian cancer. Longitudinal PET imaging demonstrated high tumor-specific uptake of αFOLR1 in SKOV3 xenografts. FOLR1-targeted 225 Ac demonstrated high therapeutic efficacy achieving marked tumor regression, 80% survival and 40% complete response. The therapy resulted in tumor specific double stranded DNA damage, and no obvious toxicity was observed in normal tissues. Estimated human dosimetry showed high absorbed dose for tumor and minimal absorbed dose for healthy tissues establishing its safety. In totality, FOLR1-targeted 225 Ac alpha-particle therapy is an efficacious and safe treatment with high feasibility for clinical translation to fight against ovarian cancer.

Impact of pERK status and KRAS/BRAF/NRAS mutation status on GOG281 patient outcome. A, PFS of GOG281/LOGS patients with low-pERK tumors (pERK ≤ 140) in trametinib versus SOC arms. B, PFS of GOG281/LOGS patients with high-pERK tumors (pERK > 140) in trametinib versus SOC arms. C, PFS of GOG281/LOGS patients with KRAS/BRAF/NRAS WT tumors in trametinib versus SOC arms. D, PFS of GOG281/LOGS patients with KRAS/BRAF/NRAS-mutant tumors in trametinib versus SOC arms. Labeled HR refer to comparison of trametinib versus SOC arm.

Representativeness of Study Participants

Abstract Ovarian cancer remains the most lethal gynecologic malignancy, and current therapeutic options beyond surgery and chemotherapy provide only modest benefit. Although immune checkpoint inhibitors (ICIs) have transformed treatment for several cancer types, their efficacy in ovarian cancer is limited, partly due to downregulation of Major Histocompatibility Complex class I (MHC-I) that impairs antigen presentation and CD8+ T cell-mediated tumor control. Emerging evidence suggests that epidermal growth factor-like protein 6 (EGFL6), produced by cancer-associated fibroblasts and malignant epithelial cells, promotes tumor progression and immune evasion; however, its role in tumor immunogenicity remains unclear. To address this gap, we quantified surface MHC-I by flow cytometry following EGFL6 knockdown using lentiviral shRNA, with efficiency validated by western blotting. Protein abundance and signaling changes were assessed by SDS-PAGE and immunoblotting. Functional consequences were evaluated in co-culture assays with activated OT-I CD8+ T cells to measure cytotoxicity and cytokine production. We found that EGFL6 expression inversely correlates with immune infiltration in human ovarian tumors, with EGFL6-high tumors exhibiting a 30-50% reduction in CD8+ T-cell density. Therapeutic blockade of EGFL6 using a monoclonal antibody significantly enhanced antitumor immunity in ID8 and KPCA ovarian cancer models in C57BL/6 mice, increasing intratumoral CD8+ T-cell infiltration by ∼1.5-fold and elevating granzyme B+ and IFN-γ+ CD8+ T-cell frequencies. Mechanistically, EGFL6 promoted internalization and lysosomal degradation of surface MHC-I, reducing H-2Kb/H-2Db or HLA-A/B/C expression by 40-60% in mouse and human ovarian cancer cells. EGFL6 knockdown or antibody blockade restored MHC-I stability, resulting in a ∼2-fold increase in surface MHC-I and improved CD8+ T cell-mediated tumor recognition. These findings identify EGFL6 as a previously unrecognized regulator of tumor immunogenicity and provide strong preclinical rationale for combining EGFL6 inhibition with immunotherapeutic strategies in ovarian cancer. Citation Format: Weiche Wu, Zonghao Tang, Sujanitha Umamaheswaran, Zhiqiang An, Ningyan Zhang, Lingegowda S. Mangala, Anil K. Sood. Reprogramming tumor immunogenicity by targeting EGFL6 in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4303.

Abstract Adaptive drug resistance remains a major barrier in cancer therapy, driving poor patient outcomes. Bevacizumab (Bev) is a mainstay of ovarian cancer (OC) treatment, yet prolonged exposure frequently leads to resistance and diminished clinical benefit. Understanding the mechanisms underlying Bev response and tumor adaptation is therefore critical for improving therapeutic strategies. To investigate these mechanisms, we established a SKOV3 Bev-resistant tumor model. RNA-seq analysis revealed that two ferroptosis-inhibitory genes, SLC40A1 (fold change 4.01) and AKR1C2 (fold change 3.81) among the top five differentially expressed genes, implicating ferroptosis regulation as a potential determinant of Bev sensitivity. Consistently, public datasets indicate that OC cells with high SLC40A1 expression are resistant to ferroptosis, whereas low SLC40A1 correlates with ferroptosis susceptibility. In vitro experiments further demonstrated that OC cell lines with elevated SLC40A1 levels exhibit reduced labile iron pools and enhanced ferroptosis resistance. Likewise, Bev-resistant OVCAR5 and OVCAR8 cell lines derived from in vivo models showed significant upregulation of ferroportin (FPN), the protein encoded by SLC40A1, compared to parental controls. Pharmacologic inhibition of FPN increased labile iron across multiple OC cell lines, and the FPN inhibitor VIT-2763 markedly sensitized Bev-resistant cells to ferroptosis (P<0.01). Proteiomic profiling revealed that Bev-sensitive tumors accumulate higher levels of polyunsaturated fatty acids and lower glutathione (P<0.05) compared with both untreated controls and resistant tumors. Collectively, these findings indicate that Bev induces ferroptosis in OC models, while tumor-associated upregulation of FPN enables escape from this lethal stress. These data highlight FPN as a promising therapeutic target to overcome Bev resistance. Citation Format: Zonghao Tang, Amir A. Jazaeri, Weiche Wu, Mark Kim, Shannon N. Westin, Timothy A. Yap, Sanghoon Lee, Anil K. Sood. Ferroportin mediates bevacizumab resistance and ferroptosis evasion in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1799.

In this phase II trial, patients with endometrial cancer (EC) were randomized to everolimus/letrozole with (experimental arm) or without ribociclib (control arm) (ClinicalTrials.gov Identifier: NCT03008408). The primary endpoint was progression-free survival (PFS). Secondary endpoints included toxicity, overall survival (OS), objective response rate (ORR), and clinical benefit rate (CBR). For all-comers, there was no difference in PFS (HR 0.78, 95% CI 0.4-1.4, p = 0.38), OS (HR 0.8, 95% CI 0.4-1.5, p = 0.46), ORR (44.1% vs 25.7%, p = 0.11), or toxicity-related treatment discontinuation (4 [8.6%] vs 3 [11.4%], p = 0.22). Among those with prior endocrine therapy, ORR was higher in the experimental arm (61.5% vs 0.0%, p < 0.001). Within the experimental arm, CTNNB1mut tumors were associated with improved PFS (HR 0.27, 95% CI 0.1-0.7, p = 0.006) and OS (HR 0.24, 95% CI 0.1-0.7, p = 0.004) compared to those with non-CTNNB1mut tumors. Despite no survival improvement in all-comers, addition of ribociclib to everolimus/letrozole may improve efficacy in patients with prior endocrine therapy and cases with CTNNB1mut tumors may have prolonged response. Therapeutic options for recurrent endometrial cancer (rEC) are limited. Here, the authors present a randomized phase 2 clinical trial comparing the combination of mTOR and aromatase inhibitors (everolimus and letrozole) with or without the CDK4/6 inhibitor, ribociclib, in patients with rEC.

Importance: Lifestyle and supportive care interventions may improve treatment tolerance, long-term health behaviors, and survivorship outcomes among breast cancer patients receiving radiotherapy. Few randomized trials have integrated nutrition, exercise, stress management, and psychosocial counseling concurrently with radiotherapy and extended across survivorship. Objective: To evaluate the effects of a comprehensive lifestyle intervention (CompLife) initiated during radiotherapy and maintained for 12 months on body composition, fitness, quality of life, symptoms, and nutrition. Design, Setting, and Participants: Randomized clinical trial at a single cancer center. Eligible women were aged ≥18 years with stage II/III breast cancer scheduled for radiotherapy, BMI ≥ 24.5, and ≥2 lifestyle risk factors. Participants were randomized to CompLife or standard of care (SOC). Assessments occurred at baseline, end of radiotherapy, and 3, 6, and 12 months. The primary outcome of recurrence is ongoing; this report examines prespecified secondary outcomes. Interventions: CompLife included 6 weeks of in-person counseling integrating nutrition, physical activity, mindfulness, stress management, and psychosocial support; twice-weekly exercise, diet, and mind-body sessions during radiotherapy; and telehealth counseling for 12 months. SOC participants received standard educational materials. Main Outcomes and Measures: Secondary outcomes included visceral adipose tissue (VAT), weight, waist circumference, fitness (VO2 max, strength), SF-36 Physical and Mental Component Summary scores, MD Anderson Symptom Inventory scores, mindfulness (FFMQ), and dietary fiber intake. Results: Ninety-five women were randomized (CompLife, n = 50; SOC, n = 45). CompLife participants had lower VAT at 3 and 6 months (e.g., 3 months: 118 vs. 141 cm2; p = 0.044) and greater improvements in VO2 max at 3 (23.4 vs. 18.8 mL/kg/min; p = 0.025) and 6 months. SF-36 Physical scores improved to within population norms for CompLife at all follow-ups but remained below norms in SOC. CompLife participants reported fewer symptoms at 12 months (MDASI: 1.3 vs. 2.5; p = 0.014). Fiber intake was consistently higher in CompLife participants (20.5 g vs. 14.0 g; p < 0.001). The results should be interpreted with caution due to the large number of comparisons among the secondary outcomes. Conclusions and Relevance: A multidisciplinary lifestyle intervention delivered during radiotherapy and extended across survivorship produced clinically meaningful improvements in body composition, fitness, diet, and patient-reported outcomes. The findings suggest potential value in integrating structured lifestyle and psychosocial counseling into oncology care and warrant confirmation in larger multicenter trials with mature recurrence endpoints.

Demographics of translational research population.