Faculty Bibliography

OBJECTIVE:To determine the association between molecular classification and response in patients with endometrial intra-epithelial neoplasia or endometrial cancer treated with a levonorgestrel intra-uterine device. METHODS:Eligible patients were treated with a levonorgestrel intra-uterine device for endometrial intra-epithelial neoplasia or endometrial cancer for at least 6 months. Immunohistochemistry for MLH1, MSH2, MSH6, PMS2, and p53 was performed. Specimens were categorized using a modified Proactive Molecular Risk Classifier for Endometrial Cancer algorithm as deficient mismatch repair, p53 abnormal, or p53 wild-type. A subset underwent single-gene POLE sequencing. Best response was recorded as pathologic complete response, partial response, stable disease, or progressive disease. Kruskal-Wallis tests and Fisher exact tests were used for statistical analysis. RESULTS:There were 143 patients, including 83 with endometrial intra-epithelial neoplasia and 60 with endometrial cancer. Fertility preservation was desired in 35.7%, 53.8% had significant medical co-morbidities precluding hysterectomy, and 10.5% had levonorgestrel intra-uterine device placement for other indications, including patient preference, placement during the coronavirus disease 2019 pandemic, and logistical considerations for other cancer diagnoses. Molecular characterization showed 90.9% p53 wild-type, 7.0% deficient mismatch repair, and 2.1% p53 abnormal. Only 4.4% of specimens with sequencing had a POLE mutation (2 of 45). The overall response rate was 86.7% (endometrial cancer: complete response 38.3%, partial response 36.7%; endometrial intra-epithelial neoplasia: complete response 67.5%, partial response 27.7%). In patients with endometrial cancer, the response rate was 75% (45 of 60), varying by molecular sub-group: 50% in the p53 abnormal group (1 of 2) and 50% in the deficient mismatch repair group (5 of 10). Only 1 patient with endometrial intra-epithelial neoplasia had p53 abnormal expression; the remaining patients had intact MMR expression and p53 wild-type. CONCLUSIONS:The complete response to levonorgestrel intra-uterine device therapy was lower than expected for endometrial intra-epithelial neoplasia. Response rates varied by molecular classification, with worse outcomes observed in deficient mismatch repair and p53 abnormal sub-types. Although limited by sample size, these findings suggest that levonorgestrel intra-uterine device therapy may not be sufficient for all molecular sub-groups.

Endometrial cancer is the most common gynecologic malignancy in the United States, with rising incidence and high recurrence rates. Immune checkpoint inhibitors (ICIs) benefit patients with mismatch repair-deficient (dMMR) tumors, but options remain limited for those with mismatch repair-proficient (pMMR) disease. Homologous recombination deficiency (HRD), a genomic instability phenotype, has emerged as a therapeutic target. Poly(adenosine diphosphate-ribose) polymerase inhibitors (PARPis) are being investigated in endometrial cancer, with studies exploring whether HRD predicts response, particularly in combination with ICIs or chemotherapy. This review examines HRD in endometrial cancer, focusing on its molecular basis, clinical implications, and emerging therapeutic strategies. HRD occurs in a sub-set of endometrial cancers, particularly non-endometrioid sub-types, and is linked to genomic instability and platinum sensitivity. The Cancer Genome Atlas (TCGA) molecular classification has improved understanding of HRD prevalence across sub-types. HRD testing remains challenging due to a lack of standardization, with current methods including genomic-scar assays, next-generation sequencing, and functional assays. Clinical trials, such as DUO-E and RUBY-2, suggest that PARPi combined with ICIs or chemotherapy may improve outcomes in pMMR tumors, whereas PARPi monotherapy offers limited benefits. Resistance to PARPi is common, driven by the restoration of homologous recombination repair, replication fork stabilization, and drug efflux. HRD is a promising biomarker and therapeutic target in endometrial cancer. Evidence supports the integration of PARPi for select populations, although further research is needed to refine testing, optimize patient selection, and overcome resistance. Future trials should prioritize predictive biomarkers and novel combinations to maximize the benefits of PARPi in HRD endometrial cancer.

This Society of Gynecologic Oncology review synthesizes updated data from pivotal trials of poly-ADP-ribose polymerase inhibitors (PARPi) in ovarian cancer. Multiple phase III trials established PARPi as effective maintenance therapy, demonstrating substantial progression-free survival across biomarker-defined subgroups, particularly for patients with BRCA-mutated and homologous recombination-deficient (HRD) ovarian cancer. However, mature overall survival analyses and safety signals prompted the US Food and Drug Administration to narrow indications, while the broader indications were maintained by the European Medicines Agency. We review the current FDA approvals that now prioritize patients with BRCA-mutated and HRD ovarian cancers, underscoring the importance of biomarker stratification and careful patient selection. We discuss the evolving regulatory landscape and potential mechanisms of PARPi resistance.

OBJECTIVE:To examine the association between malignant peritoneal cytology and survival outcomes in endometrial cancer. METHODS:This was an ancillary analysis of prospectively collected surgical-pathological data in the NRG Oncology / Gynecologic Oncology Group study on GOG-210 protocol. The study population included 2383 patients with stage I-III endometrial cancer from 2003 to 2011. Exposure was peritoneal cytology status: malignant peritoneal cytology (n = 215) or negative peritoneal cytology (n = 2168). Main outcome measures were recurrence-free survival and overall survival. Propensity score inverse probability treatment weighting was performed to balance the baseline clinico-pathological characteristics, followed by adjustment for adjuvant therapy. RESULTS:Malignant peritoneal cytology was associated with a 32% increased risk of recurrence (5-year rates, 72% versus 77%, hazard ratio 1.32, 95% confidence interval 1.03 to 1.69, P = 0.028) and 37% increased risk of all-cause mortality (78% versus 83%, hazard ratio 1.37, 95% confidence interval 1.06 to 1.78, P = 0.018) compared to negative peritoneal cytology. When controlling for adjuvant therapy, the association between malignant peritoneal cytology and survival was attenuated for both recurrence-free survival (adjusted-hazard ratio 1.16, 95% confidence interval 0.90 to 1.50, P = 0.24) and overall survival (adjusted-hazard ratio 1.22, 95% confidence interval 0.93 to 1.60, P = 0.16) without statistical significance. Peritoneal cytology status and adjuvant therapy type had a possible interaction on overall survival, and malignant peritoneal cytology was associated with decreased overall survival when radiotherapy was received as adjuvant therapy but not when chemotherapy was utilized (P-interaction = 0.059). CONCLUSION/CONCLUSIONS:The results of this prospective assessment suggest that malignant peritoneal cytology is a prognostic factor, if any, associated with a modest decrease in survival for endometrial cancer.

What is the purpose of this PLS-P? The purpose of this plain language summary of publication is to help you understand recent findings from Part 1 of the RUBY study (full name ENGOT-EN6/GOG3031/RUBY trial). • Researchers sometimes study new combinations of already approved individual treatments to see if the combinations work well together and if they are safe to prescribe to patients. • In Part 1 of the RUBY study, the combination of dostarlimab with carboplatin-paclitaxel was investigated to see how well it worked for patients with primary advanced or recurrent endometrial cancer when compared with patients who were given placebo plus carboplatin-paclitaxel. • Patients in the RUBY study were divided into subgroups according to their biomarker status. This allowed researchers to see if biomarker status could help determine how well patients with specific biomarkers would respond to the combination of dostarlimab with carboplatin-paclitaxel. • This summary reports the results of the second data cut (the second time investigators looked at all of the data since the start of the study) of the RUBY study. At this time, researchers were looking specifically at how long patients lived and how safe the treatment was in patients who received dostarlimab with carboplatin-paclitaxel compared with those patients who received placebo plus carboplatin-paclitaxel.

PURPOSE/OBJECTIVE:Tumor next generation sequencing (NGS) may identify potential germline DNA mutations associated with cancer susceptibility. We describe the frequency of tumor NGS results in patients meeting ESMO 2019 recommendations for germline genetic testing (GT) and reasons for not undergoing germline GT. METHODS:A retrospective study (Sept. 2019-Feb. 2022) in a large, urban healthcare system identified patients meeting ESMO guidelines for potentially actionable germline mutations on NGS. RESULTS:Of 3470 patients who underwent tumor NGS, 326 (9.4 %) had at least one potential actionable germline mutation. Of eligible patients, 189 (58.0 %) did not receive germline GT. Reasons for not undergoing GT include: 127 (67.2 %), not referred for GT; 30 (15.9 %), referred but did not attend genetic counseling; 32 (16.9 %), declined, died before GT, had insufficient samples, lacked insurance or lost to follow-up. Among 127 patients not referred for germline GT (39.0 % of the total eligible cohort), the most common cancer types were lung (33.0 %), colorectal (9.4 %), and cancer of unknown primary (9.4 %). Overall, 64 (50.4 %) patients not referred for germline GT had mutations in BRCA1/2 and/or Lynch syndrome genes. Of 137 patients who underwent germline GT, 86 (62.8 %) had positive GT. CONCLUSIONS:In this cohort, 60 % of the eligible population by ESMO criteria did not receive GT, most commonly due to lack of referral (over 2/3 of patients). Further, 50 % of patients not referred for GT had mutations in commonly known genes (i.e., BRCA1/2). Education on germline eligibility and reflex clinical protocols are needed to ensure patients receive germline GT.

OBJECTIVE:KEYNOTE-775 defined lenvatinib/pembrolizumab as the new standard-of-care for patients with proficient mismatch repair (pMMR) recurrent EC. However, the regimen required dose reductions in 66.5 % of participants and the generalizability of these results was uncertain. We conducted an observational study to determine the prescribing patterns, outcomes and side effects in a real-world setting. METHODS:A national multidisciplinary consortium was utilized to study treatment patterns of patients with advanced/recurrent EC treated with lenvatinib/pembrolizumab from 2019 through 2022. Treatment decisions were based on the physician's recommendation. RESULTS:188 patients across 14 institutions were included. Histologic subtypes were 33 % endometrioid, 41 % serous, 9.6 % mixed, 10.1 % carcinosarcoma, and 2.1 % clear cell. 85.6 % were pMMR and 5.3 % were dMMR. Lenvatinib starting dose was 20 mg in 19.7 %, 18 mg in 14.9 %, 14 mg in 47.3 %, and 10 mg in 18.1 %. Median dose intensity of lenvatinib was 14 mg. Pembrolizumab dosing was 200 mg Q3W in 94.1 %. Grade ≥ 3 adverse events (AE) rates related to lenvatinib were similar across starting doses: 20 mg (13.5 %), 18 mg (17.9 %), 14 mg (7.9 %), 10 mg (17.6 %) (p = 0.31). Response rates in relation to lenvatinib starting dose were 20 mg (27 %), 18 mg (35.7 %), 14 mg (39.3 %), 10 mg (44.1 %) (p = 0.50). In relation to lenvatinib starting dose, PFS, OS and duration of therapy were not statistically different. Response rates (p = 0.24), PFS (p = 0.66) & OS (p = 0.22) were similar in White and Black patients. CONCLUSIONS:In a real-world analysis, the predominant starting dose was 14 mg lenvatinib and 200 mg pembrolizumab. Starting at varying doses does not appear to compromise response rates or survival and no new severe adverse events emerged.

OBJECTIVE:Trastuzumab deruxtecan, a HER2 antibody drug conjugate (ADC), is active in HER2 expressing gynecologic cancers. This study aims to determine the proportion of endometrial cancers (EC) that are HER2 expressing and eligible for these ADCs. METHODS:This was a retrospective, single-institution study of patients who underwent surgery for EC over 18 months. Clinical HER2 testing consisted of HER2 IHC and reflex FISH for select 2+ IHC. The outcome of interest was the proportion of patients with HER2 expressing tumors by IHC (1+, 2+, 3+). Chi-square tests of independence were performed to examine relationships between categorical variables and HER2 expression. RESULTS:(2, N = 217) = 6.7, p = 0.035) than HER2 0 tumors. CONCLUSION/CONCLUSIONS:In this retrospective study, 60 % of newly diagnosed EC patients were HER2 expressing by IHC. One-third of unselected EC were HER2 2+ or 3+ and would potentially qualify for current NCCN listed HER2 directed ADCs. HER2 expression was distributed across all histologic and molecular EC subtype suggesting that all endometrial tumors should undergo HER2 IHC testing.

Antibody-drug conjugates (ADCs) have emerged as a promising therapeutic option for the treatment of gynecologic malignancies and have become a key component of treatment strategies for recurrent ovarian, endometrial, and cervical cancers. These agents offer targeted tumor cell specificity while delivering potent cytotoxic agents. Despite their selectivity, ADCs are associated with unique treatment-related adverse events. Oral mucositis (stomatitis) has become a notable on-target, off-tumor toxicity among gynecologic cancer patients receiving certain trophoblast cell surface antigen 2 targeting ADCs. Though often acute and self-limiting, oral mucositis can significantly impact patient quality of life, hinder nutritional intake, increase infection risk, and result in dose delays or discontinuation, ultimately affecting cancer treatment outcomes. This review focuses on prevention and management strategies for ADC-associated oral mucositis in the gynecologic oncology setting. We outline practical, evidence-based approaches including routine symptom monitoring, basic oral care, prophylactic interventions, and graded treatment strategies to address established mucositis. Integrating these strategies can reduce the incidence and severity of oral mucositis, thus preserving both treatment efficacy and quality of life for patients with gynecologic malignancies.