Abstract 2941: Functional proteomic aberrations post-chemotherapy with paclitaxel and carboplatin in patients with advanced ovarian cancer

Background: High-grade serous ovarian cancer (HGSOC) remains the leading cause of death from gynecologic malignancies. Here, we examined tumoral proteome changes following neoadjuvant chemotherapy (NACT) to identify potential predictive and prognostic biomarkers of response to primary chemotherapy.

Methods: A total of 65 tissue specimens from 10 patients with advanced-stage HGSOC were collected from matched pre- and post-NACT (3 cycles of dose-dense paclitaxel and carboplatin). Protein expression was assessed using reverse-phase protein arrays (RPPA). All relative protein levels using 297 antibodies were normalized by the expression level of pre-treatment samples, and then protein expression alterations and functional analyses were performed by Reactome pathway analysis followed by statistical analysis.

Results: The protein expression patterns of samples tended to cluster according to the time point (pre- and post-treatment) by a non-supervised clustering analysis using all the proteins assessed in the RPPA panel. Five differentially expressed proteins among 239 proteins (adj. p<0.1, log2FC≥1) were identified by RPPA. We identified XBP1, MYH11, and S100A4 as being upregulated and CCNB1 and TFRC were down-regulated post-treatment compared to pre-treatment. We also observed significant enrichment of specific functional and signaling pathways by pathway analysis; these included PI3K/AKT signaling, necrosis and programmed cell death (upregulated, p<0.05, FDR<1), and cell cycle and homology-directed repair (HDR) through homologous recombination repair and G2/M checkpoints (down-regulated, p<0.02, FDR<0.5) in post-treatment compared to pre-treatment. Interestingly, cell cycle, DNA damage, and G2 checkpoint pathways at post-treatment exhibited significantly lower pathway scores than pre-treatment.

Conclusion: Our findings identified significant proteomic alterations following NACT, and could provide insights into interval proteomic alterations following induction chemotherapy in advanced-stage ovarian cancer patients. These data present information to optimize future clinical trial designs for patients with ovarian cancer.

Citation Format: Sanghoon Lee, Li Zhao, Joseph Celestino, Kelly M. Rangel, Richard A. Hajek, Mark S. Kim, Sara E. Sharafi, Jinsong Liu, Nicole D. Fleming, Karen H. Lu, Jianhua Zhang, P. Andrew Futreal, Gordon B. Mills, Shannon N. Westin, Anil K. Sood, Amir A. Jazaeri, Robert L. Coleman. Functional proteomic aberrations post-chemotherapy with paclitaxel and carboplatin in patients with advanced ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2941.

PARP Inhibitors in the Management of Ovarian Cancer: ASCO Guideline

PURPOSE

To provide recommendations on the use of poly(ADP-ribose) polymerase inhibitors (PARPis) for management of epithelial ovarian, tubal, or primary peritoneal cancer (EOC).

METHODS

Randomized, controlled, and open-labeled trials published from 2011 through 2020 were identified in a literature search. Guideline recommendations were based on the review of the evidence, US Food and Drug Administration approvals, and consensus when evidence was lacking.

RESULTS

The systematic review identified 17 eligible trials.

RECOMMENDATIONS

The guideline pertains to patients who are PARPi naïve. All patients with newly diagnosed, stage III-IV EOC whose disease is in complete or partial response to first-line, platinum-based chemotherapy with high-grade serous or endometrioid EOC should be offered PARPi maintenance therapy with niraparib. For patients with germline or somatic pathogenic or likely pathogenic variants in BRCA1 (g/sBRCA1) or BRCA2 (g/sBRCA2) genes should be treated with olaparib. The addition of olaparib to bevacizumab may be offered to patients with stage III-IV EOC with g/sBRCA1/2 and/or genomic instability and a partial or complete response to chemotherapy plus bevacizumab combination. Maintenance therapy (second line or more) with single-agent PARPi may be offered for patients with EOC who have not received a PARPi and have responded to platinum-based therapy regardless of BRCA mutation status. Treatment with a PARPi should be offered to patients with recurrent EOC that has not recurred within 6 months of platinum-based therapy, who have not received a PARPi and have a g/sBRCA1/2, or whose tumor demonstrates genomic instability. PARPis are not recommended for use in combination with chemotherapy, other targeted agents, or immune-oncology agents in the recurrent setting outside the context of a clinical trial. Recommendations for managing specific adverse events are presented. Data to support reuse of PARPis in any setting are needed.Additional information is available at www.asco.org/gynecologic-cancer-guidelines.

Abstract PR03: Single-cell proteomic analysis of the tumoral heterogeneity in response to PARP inhibitor

Although poly (ADP-ribose) polymerase (PARP) inhibitors have shown efficacy in the treatment and maintenance of ovarian cancer patients, development of PARP inhibitor resistance is frequent. Our group and others have demonstrated that the cancer cells’ adaptive responses to PARP inhibitor can be detected at the protein level and targeting these adaptive responses increases the depth and duration of treatment and might prevent the development of drug resistance. However, it is still unclear if these adaptive responses are conserved across cancer cells from the same tumor and across cells from different lesions. Having a better understanding of the heterogeneity of adaptive responses might help develop better approaches of PARP-based combination therapies. The objective of this study was to develop a single-cell proteomic approach to investigate the heterogeneity of adaptive responses in ovarian cancer tumors. We developed a cyclic-immunofluorescence antibody panel and measured the expression of more than 40 proteins at the single-cell level in several ovarian cancer tumors that have been treated with PARP inhibitors. We also performed reverse-phased protein array (RPPA) analysis on protein extracted from the tumors and measured the activity of several pathways know to be altered in response to PARP inhibitors. Overall, our results demonstrated that adaptive responses can be detected at the single-cell level through cyclic immunofluorescence. Furthermore, although RPPA assays capture the main pathway alterations in response to PARP inhibitors, cyclic immunofluorescence adds complementary information by allowing a spatial-oriented analysis of the different cell populations as well as their frequency. Overall, this approach might lead to a better understanding of how cancer cells try to survive therapeutic stress and improve the decision-making process in the treatment of ovarian cancer patients.

This abstract is also being presented as Poster A19.

Citation Format: Nicholas D. Kendsersky, Hongli Ma, Yong Fang, Lydia G. Campbell, Jenny Eng, Sanghoon Lee, Koei Chin, Shannon N. Westin, Gordon B. Mills, Marilyne Labrie. Single-cell proteomic analysis of the tumoral heterogeneity in response to PARP inhibitor [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr PR03.

Anti-cancer therapy and clinical trial considerations for gynecologic oncology patients during the COVID-19 pandemic crisis

OBJECTIVES

The COVID-19 pandemic has consumed considerable resources and has impacted the delivery of cancer care. Patients with cancer may have factors which place them at high risk for COVID 19 morbidity or mortality. Highly immunosuppressive chemotherapy regimens and possible exposure to COVID-19 during treatment may put patients at additional risk. The Society of Gynecologic Oncology convened an expert panel to address recommendations for best practices during this crisis to minimize risk to patients from deviations in cancer care and from COVID-19 morbidity.

METHODS

An expert panel convened to develop initial consensus guidelines regarding anti-neoplastic therapy during the COVID-19 pandemic with respect to gynecologic cancer care and clinical trials.

RESULTS

COVID-19 poses special risks to patients who are older, have medical co-morbidities, and cancer. In addition, this pandemic will likely strain resources, making delivery of cancer care or conduct of clinical trials unpredictable. Recommendations are to limit visits and contact with health care facilities by using telemedicine when appropriate, and choosing regimens which require less frequent visits and which are less immunosuppressive. Deviations will occur in clinical trials as a result of limited resources, and it is important to understand regulatory obligations to trial sponsors as well as to the IRB to ensure that clinical trial and patient safety oversight are maintained.

CONCLUSIONS

The ongoing crisis will strain resources needed to deliver cancer care. When alterations to the delivery of care are mandated, efforts should be taken to minimize risks and maximize safety while approximating standard practice.

Improving response to progestin treatment of low-grade endometrial cancer

OBJECTIVES

This review examines how response rates to progestin treatment of low-grade endometrial cancer can be improved. In addition to providing a brief overview of the pathogenesis of low-grade endometrial cancer, we discuss limitations in the current classification of endometrial cancer and how stratification may be refined using molecular markers to reproducibly identify 'low-risk' cancers which may represent the best candidates for progestin therapy. We also discuss constraints in current approaches to progestin treatment of low-grade endometrial cancer and perform a systematic review of predictive biomarkers.

METHODS

PubMed, ClinicalTrials.gov, and Cochrane Library were searched for studies reporting pre-treatment biomarkers associated with outcome in women with low-grade endometrial cancer or endometrial hyperplasia with an intact uterus who received progestin treatment. Studies of fewer than 50 women were excluded. The study protocol was registered in PROSPERO (ID 152374). A descriptive synthesis of pre-treatment predictive biomarkers reported in the included studies was conducted.

RESULTS

Of 1908 records reviewed, 19 studies were included. Clinical features such as age or body mass index cannot predict progestin response. Lesions defined as 'low-risk' by FIGO criteria (stage 1A, grade 1) can respond well; however, the reproducibility and prognostic ability of the current histopathological classification system is suboptimal. Molecular markers can be reproducibly assessed, have been validated as prognostic biomarkers, and may inform patient selection for progestin treatment. DNA polymerase epsilon (POLE)-ultramutated tumors and a subset of p53 wild-type or DNA mismatch repair (MMR)-deficient tumors with 'low-risk' features (eg, progesterone and estrogen receptor-positive) may have improved response rates, though this needs to be validated.

DISCUSSION

Molecular markers can identify cases which may be candidates for progestin treatment. More work is needed to validate these biomarkers and potentially identify new ones. Predictive biomarkers are anticipated to inform future research into progestin treatment of low-grade endometrial cancer and ultimately improve patient outcomes.

Molecular Analysis of Clinically Defined Subsets of High-Grade Serous Ovarian Cancer

The diversity and heterogeneity within high-grade serous ovarian cancer (HGSC), which is the most lethal gynecologic malignancy, is not well understood. Here, we perform comprehensive multi-platform omics analyses, including integrated analysis, and immune monitoring on primary and metastatic sites from highly clinically annotated HGSC samples based on a laparoscopic triage algorithm from patients who underwent complete gross resection (R0) or received neoadjuvant chemotherapy (NACT) with excellent or poor response. We identify significant distinct molecular abnormalities and cellular changes and immune cell repertoire alterations between the groups, including a higher rate of NF1 copy number loss, and reduced chromothripsis-like patterns, higher levels of strong-binding neoantigens, and a higher number of infiltrated T cells in the R0 versus the NACT groups.

Development of prediction models for lymph node metastasis in endometrioid endometrial carcinoma

BACKGROUND

In endometrioid endometrial cancer (EEC), current clinical algorithms do not accurately predict patients with lymph node metastasis (LNM), leading to both under- and over-treatment. We aimed to develop models that integrate protein data with clinical information to identify patients requiring more aggressive surgery, including lymphadenectomy.

METHODS

Protein expression profiles were generated for 399 patients using reverse-phase protein array. Three generalised linear models were built on proteins and clinical information (model 1), also with magnetic resonance imaging included (model 2), and on proteins only (model 3), using a training set, and tested in independent sets. Gene expression data from the tumours were used for confirmatory testing.

RESULTS

LNM was predicted with area under the curve 0.72-0.89 and cyclin D1; fibronectin and grade were identified as important markers. High levels of fibronectin and cyclin D1 were associated with poor survival (p = 0.018), and with markers of tumour aggressiveness. Upregulation of both FN1 and CCND1 messenger RNA was related to cancer invasion and mesenchymal phenotype.

CONCLUSIONS

We demonstrate that data-driven prediction models, adding protein markers to clinical information, have potential to significantly improve preoperative identification of patients with LNM in EEC.

Improvement in Patient-Reported Outcomes With Intensity-Modulated Radiotherapy (RT) Compared With Standard RT: A Report From the NRG Oncology RTOG 1203 Study

PURPOSE

In oncology trials, the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) is the standard tool for reporting adverse events (AEs), but it may underreport symptoms experienced by patients. This analysis of the NRG Oncology RTOG 1203 compared symptom reporting by patients and clinicians during radiotherapy (RT).

PATIENTS AND METHODS

Patients with cervical or endometrial cancer requiring postoperative RT were randomly assigned to standard 4-field RT or intensity-modulated RT (IMRT). Patients completed the 6-item patient-reported outcomes version of the CTCAE (PRO-CTCAE) for GI toxicity assessing abdominal pain, diarrhea, and fecal incontinence at various time points. Patients reported symptoms on a 5-point scale. Clinicians recorded these AEs as CTCAE grades 1 to 5. Clinician- and patient-reported AEs were compared using McNemar's test for rates > 0%.

RESULTS

Of 278 eligible patients, 234 consented and completed the PRO-CTCAE. Patients reported high-grade abdominal pain 19.1% (P < .0001), high-grade diarrhea 38.5% (P < .0001), and fecal incontinence 6.8% more frequently than clinicians. Similar effects were seen between grade ≥ 1 CTCAE toxicity and any-grade patient-reported toxicity. Between-arm comparison of patient-reported high-grade AEs revealed that at 5 weeks of RT, patients who received IMRT experienced fewer GI AEs than patients who received 4-field pelvic RT with regard to frequency of diarrhea (18.2% difference; P = .01), frequency of fecal incontinence (8.2% difference; P = .01), and interference of fecal incontinence (8.5% difference; P = .04).

CONCLUSION

Patient-reported AEs showed a reduction in symptoms with IMRT compared with standard RT, whereas clinician-reported AEs revealed no difference. Clinicians also underreported symptomatic GI AEs compared with patients. This suggests that patient-reported symptomatic AEs are important to assess in this disease setting.

Everolimus, Letrozole, and Metformin in Women with Advanced or Recurrent Endometrioid Endometrial Cancer: A Multi-Center, Single Arm, Phase II Study

PURPOSE

Treatment for patients with recurrent endometrioid endometrial cancer (EEC) are limited as paclitaxel is the only second-line chemotherapy with a response rate >13%. Targeting PIK3/mTOR in combination with hormonal therapy has shown promise. The addition of metformin may enhance this response. We conducted a phase II study evaluating everolimus, letrozole, and metformin in advanced/recurrent EEC.

PATIENTS AND METHODS

A Simon two-stage design was employed. Women with ≤2 prior chemotherapy regimens for recurrence were eligible. Pretreatment biopsy was required, followed by everolimus 10 mg orally, letrozole 2.5 mg orally, and metformin 500 mg orally twice a day on a 4-week cycle. The primary endpoint was clinical benefit (CB), defined as complete response (CR), partial response (PR), or stable disease (SD) confirmed at 16 weeks. Patients were treated until progression or toxicity.

RESULTS

Sixty-two patients were enrolled. Median age was 62 years (40-77) with 401 cycles completed, median of 6 cycles (1-31). Fifty-four patients were evaluable for response with a CB rate of 50% (27/54). Best overall response (OR) was PR 28% (15/54) and SD 22% (12/54). Thirteen patients received >12 cycles. Median follow-up was 17.9 months (2-47). Median progression-free survival was 5.7 [95% confidence interval (CI), 3.0-8.1] and OS was 19.6 months (95% CI, 14.2-26.3). Positive progesterone receptor expression was associated with CB (89.5% vs. 27.3%, P = 0.001).

CONCLUSIONS

Everolimus, letrozole, and metformin resulted in 50% CB and 28% OR in women with recurrent EEC. Progesterone receptor-positive tumors may have better response; validation studies are needed.See related commentary by Madariaga et al., p. 523.

Implementation of a sentinel lymph node mapping algorithm for endometrial cancer: surgical outcomes and hospital charges

INTRODUCTION

The purpose of this study was to compare operative times, surgical outcomes, resource utilization, and hospital charges before and after the implementation of a sentinel lymph node (SLN) mapping algorithm in endometrial cancer.

METHODS

All patients with clinical stage I endometrial cancer were identified pre- (2012) and post- (2017) implementation of the SLN algorithm. Clinical data were summarized and compared between groups. Total hospital charges incurred on the day of surgery were extracted from the hospital financial system for each patient and all charges were adjusted to 2017 US dollars.

RESULTS

A total of 203 patients were included: 71 patients in 2012 and 130 patients in 2017. There was no difference in median age, body mass index, or stage. In 2012, 35/71 patients (49.3%) underwent a lymphadenectomy. In 2017, SLN mapping was attempted in 120/130 patients (92.3%) and at least one SLN was identified in 110/120 (91.7%). Median estimated blood loss was similar between groups (100 mL vs 75 mL, p=0.081). There was a significant decrease in both median operative time (210 vs 171 min, p=0.007) and utilization of intraoperative frozen section (63.4% vs 14.6%, p<0.0001). No significant differences were noted in intraoperative (p=1.00) or 30 day postoperative complication rates (p=0.30). The median total hospital charges decreased by 2.73% in 2017 as compared with 2012 (p=0.96).

DISCUSSION

Implementation of an SLN mapping algorithm for high- and low-risk endometrial cancer resulted in a decrease in both operative time and intraoperative frozen section utilization with no change in surgical morbidity. While hospital charges did not significantly change, further studies are warranted to assess the true cost of SLN mapping.

Phase I study of the PARP inhibitor talazoparib with radiation therapy for locally recurrent gynecologic cancers

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PARP inhibitors combined with radiotherapy may be promising for solid tumors.

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PARP inhibitors radiosensitize ovarian cancer cells both in vitro and in vivo.

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Talazoparib is a novel PARP-inhibitor with confirmed response in ovarian cancer.

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We propose a phase I study of talazoparib and concurrent radiation therapy.

PARP inhibitors have been shown to radiosensitize tumor cells in both in vitro and in vivo studies. This is a phase I study that aims to determine the safety, tolerability, and maximally tolerated dose of talazoparib, a PARP inhibitor, when delivered concurrently with radiotherapy in women with recurrent gynecologic cancers.

Phase II, 2-stage, 2-arm, PIK3CA mutation stratified trial of MK-2206 in recurrent endometrial cancer

Endometrial cancers have high rates of phosphoinositide 3-kinase (PI3K) pathway alterations. MK-2206 is an allosteric inhibitor of AKT, an effector kinase of PI3K signals. We hypothesized patients with tumors harboring PIK3CA mutations would be more likely to benefit from MK-2206 than those without PIK3CA mutation. A Phase II study was performed in patients with recurrent endometrial cancer; all histologies except carcinosarcoma were eligible. Up to two prior chemotherapy lines were permitted, excluding prior treatment with PI3K pathway inhibitors. The first 18 patients were treated with MK-2206 200 mg weekly. Due to unacceptable toxicity, dose was reduced to 135 mg. Co-primary endpoints were objective response rate (ORR) and progression-free survival at 6 months (6moPFS). Thirty-seven patients were enrolled (one ineligible). By somatic PIK3CA mutation analysis, nine patients were mutant (MT) [one with partial response (PR)/6moPFS, two with 6moPFS]. Twenty-seven patients were wild-type (WT) (one PR and four 6moPFS). Most common toxicities were rash (44%), fatigue (41%), nausea (42%) and hyperglycemia (31%). Grade 3 and 4 toxicities occurred in 25 and 17% of patients, respectively. Exploratory analysis found serous histology had greater 6moPFS as compared to all other histologies (5/8 vs. 2/28, p = 0.003). PTEN expression was associated with median time to progression (p = 0.04). No other significant associations with PI3K pathway alterations were identified. There is limited single agent activity of MK-2206 in PIK3CA MT and PIK3CA WT endometrial cancer populations. Activity was detected in patients with serous histology and due to their poor outcomes warrants further study (NCT01307631).

Tumor core biopsies adequately represent immune microenvironment of high-grade serous carcinoma

The prognostic and therapeutic value of the tumor microenvironment (TME) in various cancer types is of major interest. Characterization of the TME often relies on a small representative tissue sample. However, the adequacy of such a sample for assessing components of the TME is not yet known. Here, we used immunohistochemical (IHC) staining and 7-color multiplex staining to evaluate CD8 (cluster of differentiation 8), CD68, PD-L1 (programmed death-ligand 1), CD34, FAP (fibroblast activation protein), and cytokeratin in 220 tissue cores from 26 high-grade serous ovarian cancer samples. Comparisons were drawn between a larger tumor specimen and smaller core biopsies based on number and location (central tumor vs. peripheral tumor) of biopsies. Our analysis found that the correlation between marker-specific cell subsets in larger tumor versus smaller core was stronger with two core biopsies and was not further strengthened with additional biopsies. Moreover, this correlation was consistently strong regardless of whether the biopsy was taken at the center or at the periphery of the original tumor sample. These findings could have a substantial impact on longitudinal assessment for detection of biomarkers in clinical trials.

Abstract NT-098: WINDOW OF OPPORTUNITY TRIAL: ASSESSING THE ADAPTIVE RESPONSE OF HGSOC TO PARPI FOR INFORMED COMBINATION THERAPIES

At least 50% of high grade serous ovarian cancer (HGSOC) patients display defects in the components of the homologous recombination (HR) DNA repair pathway, which is the only high fidelity DNA repair mechanism for double strand breaks (DSB). This provides an exciting opportunity for targeted therapies using drugs such as poly (ADP-ribose) polymerase inhibitors (PARPi). PARP is an important component of the base excision repair and alternative non-homologous recombination DNA repair pathways. Therefore, inhibition of PARP enzymatic activity induces DNA damage and leads to synthetic lethality in HR defective tumors. Several clinical trials with PARPi have shown an improvement of progression-free survival in patients but have only shown a limited effect on overall survival. As for many other targeted therapies, the cancer cells rapidly adapt to the stress induced by the drug and develop resistance. Resistance can either be genomic or adaptive. In adaptive resistance the cellular networks are rewired in the absence of genomic changes to mediate resistance. To overcome this resistance, several groups, including ours, suggested the use of PARPi-based combination therapies. Several clinical trials are currently testing PARPi combinations with drugs targeting the immune checkpoint, the DNA damage checkpoint, the PI3K pathway, and the MAPK pathway. Although several of these combinations are promising, the main challenge remains in finding the right drug combination for the right patient since each tumor has the potential to adapt differently to PARPi. We thus implemented a window of opportunity trial to determine whether it is possible to identify different adaptive responses to PARPi by comparing pre and post-treatment tumor samples from multiple sites in the peritoneal cavity. We used reversed phase protein array (RPPA) analysis to measure the expression of over 300 proteins in each tumor samples and compared pathways activity in pre and post treatment samples from individual patients. We also compared the adaptive response detected in cancer patients with the one observed in cell lines. Base on pathway scores, we developed an approach to predict which combination with PARPi would be most likely to benefit a specific patient. Overall, our results indicate that the adaptive response to PARPi treatment can be detected early during treatment and that individual patients utilize different pathways to adapt to the stress induced by the drug. This study reinforces the need and opportunity for informed combination therapies to improve outcomes in this devastating disease.

Citation Format: Marilyne Labrie, Tae-Beom Kim, Zhenlin Ju, Sanghoon Lee, Yiling Lu, Ken Chen, Gordon B. Mills and Shannon N. Westin. WINDOW OF OPPORTUNITY TRIAL: ASSESSING THE ADAPTIVE RESPONSE OF HGSOC TO PARPI FOR INFORMED COMBINATION THERAPIES [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr NT-098.

Real-world adverse events with niraparib 200 mg/day maintenance therapy in ovarian cancer: a retrospective study

Aim: To assess real-world occurrence of common clinical trial-reported adverse events (AE) among patients with recurrent ovarian cancer initiating niraparib 200 mg/day. Materials & methods: This retrospective observational study used physician-extracted anonymized medical record data of eligible patients initiating niraparib 200 mg/day after platinum-based chemotherapy. Results: Of 153 patients, 57 (37%) experienced ≥1 of the three most common all-grade AEs within 3 months after niraparib initiation: nausea (16%; grade 3/4: 2%), thrombocytopenia (14%; grade 3/4: 3%) and fatigue (24%; grade 3/4: 3%). In the ENGOT-OV16/NOVA trial, these respective AEs occurred in 74, 61 and 59% of patients. Conclusion: Incidence of common clinical trial-reported AEs was lower among patients initiating niraparib 200 mg/day in real-world practice versus patients initiating niraparib 300 mg/day in ENGOT-OV16/NOVA.

National patterns of care and fertility outcomes for reproductive-aged women with endometrial cancer or atypical hyperplasia

BACKGROUND

Although it is uncommon, the incidence of endometrial cancer and atypical hyperplasia among reproductive-aged women is increasing. The fertility outcomes in this population are not well described.

OBJECTIVE

We aim to describe the patterns of care and fertility outcomes of reproductive-aged women with endometrial cancer or atypical hyperplasia.

MATERIALS AND METHODS

A cohort of women aged ≤45 years with endometrial cancer or atypical hyperplasia diagnosed in 2000 to 2014 were identified in Truven Marketscan, an insurance claims database of commercially insured patients in the United States. Treatment information, including use of progestin therapy, hysterectomy, and assisted fertility services, was identified and collected using a combination of Common Procedural Terminology codes, International Statistical Classification of Diseases and Related Health Problems codes, and National Drug Codes. Pregnancy events were identified from claims data using a similar technique. Patients were categorized as receiving progestin therapy alone, progestin therapy followed by hysterectomy, or standard surgical management with hysterectomy alone. Multivariable logistic regression was performed to assess factors associated with receiving fertility-sparing treatment.

RESULTS

A total of 4007 reproductive-aged patients diagnosed with endometrial cancer or atypical hyperplasia were identified. The majority of these patients (n = 3189; 79.6%) received standard surgical management. Of the 818 patients treated initially with progestins, 397 (48.5%) subsequently underwent hysterectomy, whereas 421 (51.5%) did not. Patients treated with progestin therapy had a lower median age than those who received standard surgical management (median age, 36 vs 41 years; P < .001). The proportion of patients receiving progestin therapy increased significantly over the observation period, with 24.9% treated at least initially with progestin therapy in 2014 (P < .001). Multivariable analysis shows that younger age, a diagnosis of atypical hyperplasia diagnosis rather than endometrial cancer, and diagnosis later in the study period were all associated with a greater likelihood of receiving progestin therapy (P < .0001). Among the 421 patients who received progestin therapy alone, 92 patients (21.8%; 92/421) had 131 pregnancies, including 49 live births for a live birth rate of 11.6%. Among the 397 patients treated with progestin therapy followed by hysterectomy, 25 patients (6.3%; 25/397) had 34 pregnancies with 13 live births. The median age of patients who experienced a live birth following diagnosis during the study period was 36 years (interquartile range, 33-38). The use of some form of assisted fertility services was observed in 15.5% patients who were treated with progestin therapy. Among patients who experienced any pregnancy event following diagnosis, 54% of patients used some form of fertility treatment. For patients who experienced a live birth following diagnosis, 50% of patients received fertility treatment. Median time to live birth following diagnosis was 756 days (interquartile range, 525-1077). Patients treated with progestin therapy were more likely to experience a live birth if they had used assisted fertility services (odds ratio, 5.9; 95% confidence interval, 3.4-10.1; P < .0001).

CONCLUSION

The number of patients who received fertility-sparing treatment for endometrial cancer or atypical hyperplasia increased over time. However, the proportion of women who experience a live birth following these diagnoses is relatively small.

Safety lead-in of the MEK inhibitor trametinib in combination with GSK2141795, an AKT inhibitor, in patients with recurrent endometrial cancer: An NRG Oncology/GOG study

OBJECTIVE

We sought to determine safety and efficacy of the AKT inhibitor, GSK2141795, combined with the MEK inhibitor, trametinib, in endometrial cancer.

METHODS

Patients with measurable recurrent endometrial cancer were eligible. One to two prior cytotoxic regimens were allowed; prior use of a MEK or PI3K pathway inhibitor was excluded. Initial trial design consisted of a KRAS mutation stratified randomized phase II with a safety lead-in evaluating the combination. For the safety lead in, the previously recommended phase 2 dose (RP2D; trametinib 1.5 mg, GSK2141795 50 mg) was chosen for Dose Level 1 (DL1).

RESULTS

Of 26 enrolled patients, 14 were treated on DL1 and 12 were treated on DL-1 (trametinib 1.5 mg, GSK2141795 25 mg). Most common histologies were endometrioid (58%) and serous (27%). Four of 25 (16%) patients were KRAS mutant. Dose limiting toxicities (DLTs) were assessed during cycle 1. DL1 had 8 DLTs (hypertension (n = 2), mucositis (2), rash (2), dehydration, stroke/acute kidney injury). DL1 was deemed non-tolerable so DL-1 was explored. DL-1 had no DLTs. Sixty-five percent of patients had ≥ grade 3 toxicity. There were no responses in DL1 (0%, 90%CI 0-15%) and 1 response in DL-1 (8.3%, 90%CI 0.4-33.9%). Proportion PFS at 6 months for DL1 is 14%, and 25% for DL-1.

CONCLUSION

The combination of trametinib and GSK2141795 had high levels of toxicity in endometrial cancer at the previously RP2D but was tolerable at a reduced dose. Due to insufficient preliminary efficacy at a tolerable dose, the Phase II study was not initiated.

Three Lymphadenectomy Strategies in Low-Risk Endometrial Carcinoma: A Cost-Effectiveness Analysis

OBJECTIVE

To evaluate the cost-utility of three lymphadenectomy strategies in the management of low-risk endometrial carcinoma.

METHODS

A decision analysis model compared three lymphadenectomy strategies in women undergoing minimally invasive surgery for low-risk endometrial carcinoma: 1) routine lymphadenectomy in all patients, 2) selective lymphadenectomy based on intraoperative frozen section criteria, and 3) sentinel lymph node mapping. Costs and outcomes were obtained from published literature and Medicare reimbursement rates. Costs categories consisted of hospital, physician, operating room, pathology, and lymphedema treatment. Effectiveness was defined as 3-year disease-specific survival adjusted for the effect of lymphedema (utility=0.8) on quality of life. A cost-utility analysis was performed comparing the different strategies. Multiple deterministic sensitivity analyses were done.

RESULTS

In the base-case scenario, routine lymphadenectomy had a cost of $18,041 and an effectiveness of 2.79 quality-adjusted life-years (QALYs). Selective lymphadenectomy had a cost of $17,036 and an effectiveness of 2.81 QALYs, whereas sentinel lymph node mapping had a cost of $16,401 and an effectiveness of 2.87 QALYs. With a difference of $1,005 and 0.02 QALYs, selective lymphadenectomy was both less costly and more effective than routine lymphadenectomy, dominating it. However, with the lowest cost and highest effectiveness, sentinel lymph node mapping dominated the other modalities and was the most cost-effective strategy. These findings were robust to multiple sensitivity analyses varying the rates of lymphedema and lymphadenectomy, surgical approach (open or minimally invasive surgery), lymphedema utility, and costs. For the estimated 40,000 women undergoing surgery for low-risk endometrial carcinoma each year in the United States, the annual cost of routine lymphadenectomy, selective lymphadenectomy, and sentinel lymph node mapping would be $722 million, $681 million, and $656 million, respectively.

CONCLUSION

Compared with routine and selective lymphadenectomy, sentinel lymph node mapping had the lowest costs and highest quality-adjusted survival, making it the most cost-effective strategy in the management of low-risk endometrial carcinoma.

Prospective pilot trial with combination of propranolol with chemotherapy in patients with epithelial ovarian cancer and evaluation on circulating immune cell gene expression

OBJECTIVE

To determine the feasibility of pharmacologic beta-adrenergic blockade in women with newly diagnosed stage II-IV epithelial ovarian cancer (EOC) throughout primary treatment.

METHODS

Patients initiated propranolol prior to beginning chemotherapy or surgery. Feasibility was assessed as proportion able to complete 6 chemotherapy cycles while on adrenergic suppression. Descriptive statistics summarized surveys, and paired changes were analyzed using signed rank tests. Random-intercept Tobit models examined immune response.

RESULTS

Median age was 59.9; 88.5% were stage IIIC/IV; and 38.5% underwent primary debulking. Thirty-two patients were enrolled; 3 excluded because they never took propranolol; an additional 3 didn't meet inclusion criteria, leaving 26 evaluable. Eighteen of 26 (69%), 90% credible interval (CI) of 53-81%, completed 6 chemotherapy cycles plus propranolol (an 82% posterior probability that the true proportion of success is ≥60%). Among the 23 patients with baseline and six month follow up data, overall QOL, anxiety, and depression improved (P < 0.05) and leukocyte expression of pro-inflammatory genes declined (P = 0.03) after completion of therapy. Decrease from baseline of serum IL-6 and IL-8 preceded response to chemotherapy (P < 0.0014). Change from baseline IL-10 preceded complete response.

CONCLUSION

Use of propranolol during primary treatment of EOC is feasible and treatment resulted in decrease in markers of adrenergic stress response. In combination with chemotherapy, propranolol potentially results in improved QOL over baseline.

Abstract 2070: Exploration of markers of synergistic lethality of PARP and PI3K-Akt-mTOR inhibitors in women's cancers

Introduction: The objective was to identify molecular mechanisms and protein networks involved in synthetic lethality as well as mechanisms of adaptive changes to the combination of olaparib (O) combined with inhibitors of the PI3K-AKT axis.

Methods: 110 patients with recurrent ovarian, endometrial, and triple negative breast cancer were treated with a combination of O and vistusertib (V) or capivasertib (C) (mTORC1/2 and AKT inhibitors, respectively). We have previously reported durable clinical efficacy of these combinations, regardless of BRCA status. Tumor samples were collected pre-treatment and 30 days post-treatment and reverse-phase protein array (RPPA) was performed. Baseline expression was assessed and change in expression was calculated. Bioinformatics and statistical methods were developed to assess activity of signaling pathways. Pathway scores were determined based on the expression of sets of proteins known to be involved in a specific pathway, including PI3K, RAS/RAF, and DNA damage repair. Association between protein expression and treatment efficacy was determined.

Results: We analyzed a total of 55 paired samples from patients treated with O/V (n=25) and O/C (n=30). These included 20 endometrial (37% PR, 31.5% SD, 31.5% PD), 21 ovarian (10% PR, 55% SD, 35% PD) and 14 triple negative breast (15% PR, 23% SD, 62% PD) tumors. Response to O/V was associated with low pre-treatment mTOR pathway activity and led to altered immune activity based on decreased CD4 and PD1 expression. Resistance to O/V was associated with high pre-treatment cell proliferation (high CCNB1, CDK1 and PLK1 protein expression). In contrast, response to O/C was associated with adaptive responses indicated by decreased mTOR activity and induction of the DNA damage checkpoint (high phospho-CHK1, -WEE1 and -CDC2). Resistance was associated with high pre-treatment RTK activity levels (high phospho-HER3, -EGFR, -IGFR, -MET) and AKT-independent activation of mTOR in the on-treatment samples.

Conclusion: Analysis of pre- and on-treatment samples from responders and non-responders to PARP and PI3K pathway combination therapy identified biomarkers of patients likely to benefit from therapy and helps to understand molecular mechanisms involved in response and resistance to these drug combinations.

Citation Format: Marilyne Labrie, Zhenlin Ju, Jennifer K. Litton, Tae-Beom Kim, Sanghoon Lee, Ken Chen, Pamela T. Soliman, Michael Frumovitz, Larissa A. Meyer, Stacy Moulder, Amir A. Jazaeri, Karen H. Lu, Anil K. Sood, Robert L. Coleman, Gordon B. Mills, Shannon N. Westin. Exploration of markers of synergistic lethality of PARP and PI3K-Akt-mTOR inhibitors in women's cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2070.

Abstract CT020: Phase I dose escalation of olaparib (PARP inhibitor) and selumetinib (MEK Inhibitor) combination in solid tumors with Ras pathway alterations

Background: Preclinical data from our team demonstrated that MEK inhibition increases antitumor efficacy of PARP inhibitors in tumors with Ras pathway alterations. We sought to identify dose limiting toxicities (DLTs) and maximum tolerated dose (MTD) of olaparib and selumetinib combination in solid tumors with Ras pathway alterations.

Methods: Olaparib and selumetinib were given orally twice daily. Dose escalation with three planned dose levels (DL) was performed using the modified toxicity probability interval 2 design with toxicity assessed by CTCAE v4.03. RECIST criteria (v1.1) were used to assess response. Clinical benefit was defined as partial (PR) or complete response, or stable disease for 4 months or longer.

Results: 14 patients are evaluable for toxicity in the dose escalation phase, and 12 patients are evaluable for response. Median age was 56.5 years, and 10/14 (71%) patients were female. Median number of prior treatments was 4 (1-9). Of the 14 patients enrolled, 11 had KRAS mutations, 1 amplified KRAS, 1 NRAS mutation and 1 amplified NRAS. The majority of patients had gynecologic cancers. 4 and 3 patients were treated at DL1 and DL2, respectively, and 7 patients at DL3. No DLTs were observed (Table 1). MTD was not reached. DL3 (olaparib 300mg; selumetinib 75mg) was confirmed as the recommended Phase II dose (RP2D). Of 12 evaluable patients, ORR was 17%, and CBR 33%. 2 patients had a PR: 1 patient with KRAS mutant primary peritoneal cancer, and 1 with NRAS mutant ovarian cancer. 2 patients remained on treatment for more than 15 months: 1 with KRAS mutant primary peritoneal cancer (on DL-1), and 1 with KRAS mutant non-small cell lung cancer (DL1). All patients with clinical benefit were BRCA wildtype.

Conclusions: The combination of olaparib and selumetinib is well-tolerated at the identified RP2D. This combination also shows promising preliminary anti-tumor activity in patients with mutant RAS. Enrollment to expansion cohorts is ongoing.

Table 1Grade 3/4 and Most Common Adverse Events. NOTE: No Grade 4 Events Occurred.Adverse EventGrade 3Any GradeAbdominal pain7%7%Acneiform Rash7%71%Anemia79%Anorexia29%Constipation29%Decreased ejection fraction7%14%Decreased white blood cell count7%36%Diarrhea50%Dizziness29%Dry mouth43%Dry skin29%Dysgeusia36%Edema29%Elevated aspartate aminotransferase7%50%Elevated bilirubin7%7%Elevated CPK7%36%Elevated creatinine29%Fatigue7%64%Hepatic pain7%7%Hypophosphatemia79%Nausea57%Neutropenia7%21%Oral mucositis50%Other skin effects36%Thromboembolic event7%7%

Citation Format: Katherine C. Kurnit, Funda Meric-Bernstam, Kenneth Hess, Robert L. Coleman, Priya Bhosale, Katerina Savelieva, Filip Janku, David Hong, Aung Naing, Shubham Pant, Jordi Rodon, Timothy A. Yap, Anil K. Sood, Pamela T. Soliman, David M. Gershenson, Gordon B. Mills, Shannon N. Westin. Phase I dose escalation of olaparib (PARP inhibitor) and selumetinib (MEK Inhibitor) combination in solid tumors with Ras pathway alterations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT020.

Microsatellite instability in endometrial cancer: New purpose for an old test

Historically, microsatellite instability testing has been used to identify endometrial cancer patients with Lynch Syndrome. Now, it is also being used to identify those who may be immunotherapy candidates.