Dowdy, Sean C.

Abstract Blood lipids have been associated with the development of a range of cancers, including breast, lung and colorectal cancer. For endometrial cancer, observational studies have reported inconsistent associations between blood lipids and cancer risk. To reduce biases from unmeasured confounding, we performed a bidirectional, two‐sample Mendelian randomization analysis to investigate the relationship between levels of three blood lipids (low‐density lipoprotein [LDL] and high‐density lipoprotein [HDL] cholesterol, and triglycerides) and endometrial cancer risk. Genetic variants associated with each of these blood lipid levels ( P < 5 × 10 −8 ) were identified as instrumental variables, and assessed using genome‐wide association study data from the Endometrial Cancer Association Consortium (12 906 cases and 108 979 controls) and the Global Lipids Genetic Consortium (n = 188 578). Mendelian randomization analyses found genetically raised LDL cholesterol levels to be associated with lower risks of endometrial cancer of all histologies combined, and of endometrioid and non‐endometrioid subtypes. Conversely, higher genetically predicted HDL cholesterol levels were associated with increased risk of non‐endometrioid endometrial cancer. After accounting for the potential confounding role of obesity (as measured by genetic variants associated with body mass index), the association between genetically predicted increased LDL cholesterol levels and lower endometrial cancer risk remained significant, especially for non‐endometrioid endometrial cancer. There was no evidence to support a role for triglycerides in endometrial cancer development. Our study supports a role for LDL and HDL cholesterol in the development of non‐endometrioid endometrial cancer. Further studies are required to understand the mechanisms underlying these findings.

5593 Background: We conducted an international survey to evaluate the differences in the systemic, radiotherapeutic and operative management of endometrial cancer (EC) in different regions of the world. Methods: In 2009 avalidated 15-item-questionnaire regarding surgical and adjuvant procedures of EC was sent to all German gynaecological clinics and in 2010 the English adapted questionnaire was set online as well as sent per post in most major gynaecological cancer societies. Results: 316 German institutions and 302 Institutions from 24 countries participated. We combined the different countries into regional groups: Central Europe (CE), southern Europe (SE), Asia and USA/UK. In Asian countries and in CE a lymph node dissection (LND) was performed routinely in 72.8% and in 55.6% of the cases, whereas in the USA/UK and in SE a LND was done mainly in selected cases when specific risk factors such as high-grade or non-endometrioid-histology applied (62.8% and 72.5%) than routinely (p < 0.001). A systematic pelvic and paraaortic LND was performed most frequently in CE 91.0%, in SE 76.9%, in Asia 70.9% and in USA/UK 68.6% (p < 0.001). A systematic LND with the intention of both adequate staging and for therapeutic value was performed in countries of central Europe to 74.6% and in Asia to 67.2%. In USA/UK the LND was seen merely as a staging instrument by 53.5% (p < 0.001). The LND was performed up to renal veins in CE in 86.8%, in Asia in 80.8%, in USA/UK in 51.2% and in SE in 45.1 %. A significant difference war found in the treatment for FIGO stage I (high risk factors (high grade, L1,V1)) and stage II disease between the countries: chemotherapy was applied in 84.8% of the participated centers in Asia,42.3% in SE, 21.2% in CE and only 13.6% in USK/UK (p<0.001).Vaginal brachytherapy was indicated as follows: USA/UK 84.1%, CE 78.8%, SE 78.8%, Asia 5.6% (p < 0.001). Conclusions: There is a large variety in the operative therapy and the clinical management of EC in different regions of the world. Future international prospective trials, will be necessary to improve and harmonize the evidence based treatment guidelines for EC- disease.

5510 Background: Transcriptional profiling of ovarian cancers has proven to be complex. As such it has been difficult to validate existing signatures across studies. Cancer Genome Atlas (TCGA) researchers have identified four molecular subtypes of high-grade serous ovarian cancer (HGSOC). However, survival duration did not differ significantly for the TCGA subtypes. Potential limitations of the TCGA data include short clinical follow-up (45% were alive at the time of last follow-up) and the need to unify gene expression measures from multiple platforms. Methods: Clinically annotated stage-II–IV HGSOC samples (n = 175) with >70% tumor cell content were profiled using the Agilent Whole Human Genome 4 x 44K chip. To identify subtypes non-negative matrix factorization (NMF) of mRNA expression was performed using ~2000 genes with the highest variability across patients. In parallel differentially expressed genes were identified using the Rosetta Similarity Search Tool as well as analysis of variance based on genes known to be involved in epithelial to mesenchymal transition. Results: Median follow-up time was 35 months (range, 0–202 months, 12% were alive at the time of last follow-up). NMF clustering confirmed four HGSOC subtypes (immunoreactive, differentiated, proliferative, and mesenchymal) on the basis of gene content in the clusters. Pathway signatures with therapeutic potential were identified for individual or multiple subtypes. Survival differed significantly between the four molecular subgroups in univariate (Hazard Ratio [HR] 2.4, 95% CI 1.5-4.1, p = 0.007) and multivariate (HR 2.3, 95% CI 1.3-4.0, p = 0.003) analyses when accounting for age, stage, grade, and postoperative residual tumor. Using the supervised clustering approach two distinct molecular subtypes of HGSOC based on epithelial and mesenchymal gene expression signatures were identified with significantly different survival outcomes. Conclusions: Here we independently validate and expand upon the molecular TCGA classification of HGSOC. The potential of these two prognostic classifiers may lie in their ability to recognize categories of patients that are more likely to respond to particular therapies.

5087 Background: Indication, technique and extent of lymph-node-dissection (LND) in endometrial cancer (EC) remains controversial and is strongly debated in cancer community. We conducted a national- and at a second step an international-survey evaluating the current status-quo of the surgical and medical management of EC. Methods: A validated 15-item-questionnaire regarding surgical and adjuvant procedures of EC was sent to all major gynaecological cancer societies and study groups worldwide. The questionnaire could also be answered online. Results: In a phase-I-national trial, the questionnaire was validated on basis of 316 German institutions. On the phase-II-international survey a total of 302 questionnaires were answered from 24 countries, mainly from Japan (38.7%), Spain (8.3%), Austria (7%), United-Kingdom (6.3%), Italy (6%), USA (4.3%) and Canada (4%). The vast majority of the participating clinics were academic (62.8%), while 75.2% of them belonged to gynaecology. Only 0.7% of the clinics internationally reported never performing LND in EC. 62.3% of the clinics perform both a pelvic and paraaortic lymph node dissection. 59.1% of the participants performed a systematic lymph node dissection with the intention of both adequate staging and for therapeutic value. 15.05% of the clinics perform LND up to the common-iliac-arteries, 9.03% up to the inferior-mesenteric-artery and 70.6% up to the renal-veins. The most common risk-factors to indicate LND were: high-grading (93%), non-endometrioid-histology (90.1%), lymphovascular-invasion (55.3%), blood-vessel invasion (45.4%) and tumor-diameter >2cm (38.4%). For advanced stage III&IV disease the vast majority (60% and 80%, respectively) of the physicians indicated systemic chemotherapy alone. Conclusions: This study presents the large variety in clinical management of EC worldwide, underlining so the high need of future prospective randomised trials which will establish standard and evidence based treatment guidelines for EC- disease.

5577 Background: Perioperative red blood cell transfusion (PRBCT) may be a negative prognostic marker in surgical oncology. We assessed PRBCT as an independent risk factor for recurrence and death from epithelial ovarian cancer (EOC) in the largest cohort to date. Methods: Patient characteristics and process-of-care variables (NSQIP-defined, >130 variables) were retrospectively abstracted from 587 women who underwent primary staging and cytoreduction for EOC (1/1/03-12/29/08). Evaluated using propensity scoring with univariate logistic regression and odds ratios (OR) and Cox proportional hazards regression and hazard ratios (HR). Factors with p<0.1 used in multivariate models. Results: Rate of PRBCT was 77.0% (452/587). In univariable analysis, PRBCT was associated with older age (OR 1.25[95% CI 1.06, 1.48]/10yr increase), stage≥IIIa (4.66[3.04, 7.13]), splenectomy (26.63[3.67, 193.17]), higher surgical complexity (1.86[1.17, 2.95] score 2; 21.48 [7.37, 62.59] 3; referent 1), serous histology (2.36[1.57, 3.55]vs non-serous), longer operating time (1.58[1.36, 1.83]/hr increase), and residual disease (3.26[1.97, 5.41]≤1cm; 1.97[1.09, 3.56]>1cm), and lower preop hemoglobin (Hb) (1.89[1.59, 2.27]per 1g/dL decrease). In univariable analysis, PRBCT was associated with a higher risk of recurrence (HR 1.96[95% CI 1.43, 2.68]) and death (1.71[1.28, 2.28]). However, in multivariable analysis, stage≥IIIa (4.03[2.05, 6.49]), splenectomy (1.41[1.02, 1.95]), residual disease (1.86[1.41, 2.46]≤1cm; 2.91[2.02, 4.18]>1cm), and lower preop Hb (1.09[1.01, 1.19]) were associated with higher risk of recurrence. Older age (1.24[1.12, 1.37]), stage≥IIIa (3.07[1.93, 4.90]), albumin ≤3 g/dL (2.06[1.28, 3.31]), residual disease (1.63[1.22, 2.19]≤1cm; 3.03[2.19, 4.18]>1cm), and low Hb (1.08[1.00, 1.19]) were associated with higher risk of death. Serous histology (0.70[0.52, 0.95]) associated with lower risk of death. Conclusions: PRBCT does not appear to be directly associated with disease-free and overall survival in EOC. Lower preoperative Hb was associated with a higher risk of both recurrence and death. The need for PRBCT appears to be a stronger prognostic indicator than the receipt of PRBCT.

5004 Background: Since 1999, patients with low-risk endometrial cancer (EC) as defined by the Mayo criteria have preferably not undergone lymphadenectomy (LND) at our institution. We assess survival, sites of recurrence, morbidity, and cost per up-staged case in this low-risk cohort. Methods: Consecutive patients with Mayo-defined low-risk EC managed without (non-LND) and with LND were compared. Cause-specific survival (CSS) was estimated using the Kaplan-Meier method and compared using the log-rank test. 30-day cost analyses were equated to 2010 Medicare dollars. Results: Among 1,393 consecutive surgically managed EC cases, 385 (27.6%) met the Mayo low-risk criteria, accounting for 34.1% of type I EC. The 5-year CSS of the low-risk cases was 98.6 %. There were 80 LND cases (median # nodes, 29) and 305 non-LND cases. Complications within 30 days occurred in 37.5% and 19.3% of LND and non-LND cases, respectively (P<0.001). Nodal metastasis was identified in a single LND case (1.3%). There were 11 recurrences, 6 of which were vaginal. Not a single recurrence was detected in the pelvic or paraaortic nodal areas in these 385 patients, with a median follow-up of 5.4 years. The estimated prevalence (combining surgery and surveillance) of lymph node metastasis was 0.3%. The 5-year CSS in LND and non-LND cases was 97.3% and 99.0%, respectively (P=0.32). Patients were more than seven times as likely to die of co-morbidities than from EC. The 30-day median cost of care was $15,678 for LND cases compared to $11,028 for non-LND cases (P<0.001). The estimated cost per up-staged low-risk case was $439,990 if performed via endoscopy and $327,866 via laparotomy. If the 305 non-LND cases had been subjected to LND, an estimated additional $1,418,189 would have been expended. Conclusions: For patients with low-risk EC as defined by the Mayo criteria, lymphadenectomy dramatically increases morbidity and 30-day cost of care without discernible short- or long-term benefits: CSS was 99% with a 0.3% rate of nodal metastasis. In these low-risk patients, hysterectomy with salpingo-oophorectomy alone is appropriate surgical management and should be standard of care.

Abstract BRCA1 plays a key role in homologous recombination (HR) DNA repair. Accordingly, changes that downregulate BRCA1, including BRCA1 mutations and reduced BRCA1 transcription, due to promoter hypermethylation or loss of the BRCA1 transcriptional regulator CDK12, disrupt HR in multiple cancers. In addition, BRCA1 has also been implicated in the regulation of metabolism. Here, we show that reducing BRCA1 expression, either by CDK12 or BRCA1 depletion, led to metabolic reprogramming of ovarian cancer cells, causing decreased mitochondrial respiration and reduced ATP levels. BRCA1 depletion drove this reprogramming by upregulating nicotinamide N-methyltransferase (NNMT). Notably, the metabolic alterations caused by BRCA1 depletion and NNMT upregulation sensitized ovarian cancer cells to agents that inhibit mitochondrial metabolism (VLX600 and tigecycline) and to agents that inhibit glucose import (WZB117). These observations suggest that inhibition of energy metabolism may be a potential strategy to selectively target BRCA1-deficient high-grade serous ovarian cancer, which is characterized by frequent BRCA1 loss and NNMT overexpression. Significance: Loss of BRCA1 reprograms metabolism, creating a therapeutically targetable vulnerability in ovarian cancer.

Abstract Purpose: Predicting surgical outcome could improve individualizing treatment strategies for patients with advanced ovarian cancer. It has been suggested earlier that gene expression signatures (GES) might harbor the potential to predict surgical outcome. Experimental Design: Data derived from high-grade serous tumor tissue of FIGO stage IIIC/IV patients of AGO-OVAR11 trial were used to generate a transcriptome profiling. Previously identified molecular signatures were tested. A theoretical model was implemented to evaluate the impact of medically associated factors for residual disease (RD) on the performance of GES that predicts RD status. Results: A total of 266 patients met inclusion criteria, of those, 39.1% underwent complete resection. Previously reported GES did not predict RD in this cohort. Similarly, The Cancer Genome Atlas molecular subtypes, an independent de novo signature and the total gene expression dataset using all 21,000 genes were not able to predict RD status. Medical reasons for RD were identified as potential limiting factors that impact the ability to use GES to predict RD. In a center with high complete resection rates, a GES which would perfectly predict tumor biological RD would have a performance of only AUC 0.83, due to reasons other than tumor biology. Conclusions: Previously identified GES cannot be generalized. Medically associated factors for RD may be the main obstacle to predict surgical outcome in an all-comer population of patients with advanced ovarian cancer. If biomarkers derived from tumor tissue are used to predict outcome of patients with cancer, selection bias should be focused on to prevent overestimation of the power of such a biomarker. See related commentary by Handley and Sood, p. 9

INTRODUCTION: To compare two published risk stratification criteria (Milwaukee Model vs. Mayo Criteria) to predict lymphatic dissemination (LD) in endometrioid endometrial cancer (EC). METHODS: Patients who underwent surgery for EC between 1/1/2004-9/30/2013 and had endometrioid histology without stage IV disease were included and classified as either low-risk or at-risk for LD using two independent risk stratification systems. LD was defined as positive nodes at time of surgery or lymph node recurrence within 2 years of surgery after negative lymph node assessment (LNA) or when LNA was not performed. False positive (FP) and false negative (FN) rates for each risk model were calculated. RESULTS: Among 1103 patients, 81 (7.3%) had LD (72 positive LN and 9 LN recurrences). Most patients (90.2%) had stage I disease. Integration of the Milwaukee Model was associated with a low at-risk rate for LD (38.1%) but a relatively high FN rate (13.6%, 95% CI 7.0-23.0). Conversely, the traditional Mayo Criteria using a tumor diameter (TD) cutoff of ≤2 cm (vs >2 cm) had a higher at-risk rate for LD (69.5%) but a FN rate of 0.0% (95% CI, 0-4.5). Modifying Mayo Criteria using a TD cutoff of ≤3 cm (vs >3 cm) identified fewer women at-risk than using ≤2 cm cutoff (56.8% vs. 69.5%), but had a higher FN rate of 3.7% (95% CI, 0.8-10.4). CONCLUSIONS: The Milwaukee Model had the lowest at-risk rate of LD but an unacceptable FN rate. Modifying the Mayo Criteria by increasing the TD cutoff from the traditional ≤2 cm to ≤3 cm would spare an estimated 12.7% of patients LNA, but the accompanying FN rate is unacceptably high. The traditional Mayo Criteria for low-risk EC remains the most accurate in determining which patients LNA can be omitted.