A soft departure from jamming: the compaction of deformable granular matter under high pressures.

The high-pressure compaction of three dimensional granular packings is simulated using a bonded particle model (BPM) to capture linear elastic deformation. In the model, grains are represented by a collection of point particles connected by bonds. A simple multibody interaction is introduced to control Poisson's ratio and the arrangement of particles on the surface of a grain is varied to model both high- and low-frictional grains. At low pressures, the growth in packing fraction and coordination number follow the expected behavior near jamming and exhibit friction dependence. As the pressure increases, deviations from the low-pressure power-law scaling emerge after the packing fraction grows by approximately 0.1 and results from simulations with different friction coefficients converge. These results are compared to predictions from traditional discrete element method simulations which, depending on the definition of packing fraction and coordination number, may only differ by a factor of two. As grains deform under compaction, the average volumetric strain and asphericity, a measure of the change in the shape of grains, are found to grow as power laws and depend heavily on the Poisson's ratio of the constituent solid. Larger Poisson's ratios are associated with less volumetric strain and more asphericity and the apparent power-law exponent of the asphericity may vary. The elastic properties of the packed grains are also calculated as a function of packing fraction. In particular, we find the Poisson's ratio near jamming is 1/2 but decreases to around 1/4 before rising again as systems densify.

Universal behavior in fragmenting brittle, isotropic solids across material properties.

A bonded particle model is used to explore how variations in the material properties of brittle, isotropic solids affect critical behavior in fragmentation. To control material properties, a model is proposed which includes breakable two- and three-body particle interactions to calibrate elastic moduli and mode I and mode II fracture toughnesses. In the quasistatic limit, fragmentation leads to a power-law distribution of grain sizes which is truncated at a maximum grain mass that grows as a nontrivial power of system size. In the high-rate limit, truncation occurs at a mass that decreases as a power of increasing rate. A scaling description is used to characterize this behavior by collapsing the mean-square grain mass across rates and system sizes. Consistent scaling persists across all material properties studied, although there are differences in the evolution of grain size distributions with strain as the initial number of grains at fracture and their subsequent rate of production depend on Poisson's ratio. This evolving granular structure is found to induce a unique rheology where the ratio of the shear stress to pressure, an internal friction coefficient, decays approximately as the logarithm of increasing strain rate. The stress ratio also decreases at all rates with increasing strain as fragmentation progresses and depends on elastic properties of the solid.

Large-scale frictionless jamming with power-law particle size distributions.

Due to significant computational expense, discrete element method simulations of jammed packings of size-dispersed spheres with size ratios greater than 1:10 have remained elusive, limiting the correspondence between simulations and real-world granular materials with large size dispersity. Invoking a recently developed neighbor binning algorithm, we generate mechanically stable jammed packings of frictionless spheres with power-law size distributions containing up to nearly 4 000 000 particles with size ratios up to 1:100. By systematically varying the width and exponent of the underlying power laws, we analyze the role of particle size distributions on the structure of jammed packings. The densest packings are obtained for size distributions that balance the relative abundance of large-large and small-small particle contacts. Although the proportion of rattler particles and mean coordination number strongly depend on the size distribution, the mean coordination of nonrattler particles attains the frictionless isostatic value of six in all cases. The size distribution of nonrattler particles that participate in the load-bearing network exhibits no dependence on the width of the total particle size distribution beyond a critical particle size for low-magnitude exponent power laws. This signifies that only particles with sizes greater than the critical particle size contribute to the mechanical stability. However, for high-magnitude exponent power laws, all particle sizes participate in the mechanical stability of the packing.

Critical Scaling of Solid Fragmentation at Quasistatic and Finite Strain Rates.

Using two-dimensional simulations of sheared, brittle solids, we characterize the resulting fragmentation and explore its underlying critical nature. Under quasistatic loading, a power-law distribution of fragment masses emerges after fracture which grows with increasing strain. With increasing strain rate, the maximum size of a grain decreases and a shallower distribution is produced. We propose a scaling theory for distributions based on a fractal scaling of the largest mass with system size in the quasistatic limit or with a correlation length that diverges as a power of rate in the finite-rate limit. Critical exponents are measured using finite-size scaling techniques.

Criticality in sheared, disordered solids. I. Rate effects in stress and diffusion.

Rate effects in sheared disordered solids are studied using molecular dynamics simulations of binary Lennard-Jones glasses in two and three dimensions. In the quasistatic (QS) regime, systems exhibit critical behavior: the magnitudes of avalanches are power-law distributed with a maximum cutoff that diverges with increasing system size L. With increasing rate, systems move away from the critical yielding point and the average flow stress rises as a power of the strain rate with exponent 1/ß, the Herschel-Bulkley exponent. Finite-size scaling collapses of the stress are used to measure ß as well as the exponent ν which characterizes the divergence of the correlation length. The stress and kinetic energy per particle experience fluctuations with strain that scale as L^{-d/2}. As the largest avalanche in a system scales as L^{α}, this implies α

Criticality in sheared, disordered solids. II. Correlations in avalanche dynamics.

Disordered solids respond to quasistatic shear with intermittent avalanches of plastic activity, an example of the crackling noise observed in many nonequilibrium critical systems. The temporal power spectrum of activity within disordered solids consists of three distinct domains: a novel power-law rise with frequency at low frequencies indicating anticorrelation, white-noise at intermediate frequencies, and a power-law decay at high frequencies. As the strain rate increases, the white-noise regime shrinks and ultimately disappears as the finite strain rate restricts the maximum size of an avalanche. A new strain-rate- and system-size-dependent theory is derived for power spectra in both the quasistatic and finite-strain-rate regimes. This theory is validated using data from overdamped two- and three-dimensional molecular dynamics simulations. We identify important exponents in the yielding transition including the dynamic exponent z which relates the size of an avalanche to its duration, the fractal dimension of avalanches, and the exponent characterizing the divergence in correlations with strain rate. Results are related to temporal correlations within a single avalanche and between multiple avalanches.

Shear Is Not Always Simple: Rate-Dependent Effects of Flow Type on Granular Rheology.

Despite there being an infinite variety of types of flow, most rheological studies focus on a single type such as simple shear. Using discrete element simulations, we explore bulk granular systems in a wide range of flow types at large strains and characterize invariants of the stress tensor for different inertial numbers and interparticle friction coefficients. We identify a strong dependence on the type of flow, which grows with increasing inertial number or friction. Standard models of yielding, repurposed to describe the dependence of the stress on flow type in steady-state flow and at finite rates, are compared with data.

Anisotropic avalanches and critical depinning of three-dimensional magnetic domain walls.

Simulations with more than 10^{12} spins are used to study the motion of a domain wall driven through a three-dimensional random-field Ising magnet (RFIM) by an external field H. The interface advances in a series of avalanches whose size diverges at a critical external field H_{c}. Finite-size scaling is applied to determine critical exponents and test scaling relations. Growth is intrinsically anisotropic with the height of an avalanche normal to the interface ℓ_{⊥} scaling as the width along the interface ℓ_{∥} to a power χ=0.85±0.01. The total interface roughness is consistent with self-affine scaling with a roughness exponent ζ≈χ that is much larger than values found previously for the RFIM and related models that explicitly break orientational symmetry by requiring the interface to be single-valued. Because the RFIM maintains orientational symmetry, the interface develops overhangs that may surround unfavorable regions to create uninvaded bubbles. Overhangs complicate measures of the roughness exponent but decrease in importance with increasing system size.

Factors associated with delivery of neoadjuvant chemotherapy in women with advanced stage ovarian cancer.

PURPOSE: To identify clinical and non-clinical factors associated with utilization of primary cytoreductive surgery (PCS) or neoadjuvant chemotherapy (NACT) in women with advanced stage epithelial ovarian cancer (EOC). METHODS: Using the National Cancer Database, we identified women with stage IIIC and IV EOC diagnosed from 2012 to 2014. The primary outcome was receipt of NACT, defined in the primary analysis as utilization of chemotherapy as the first cancer-directed therapy, irrespective of whether interval surgery was performed. Univariable and multivariable associations between clinical and non-clinical factors and receipt of NACT were investigated using mixed-effect logistic regression models. A secondary analysis excluded women who received primary chemotherapy but did not receive interval cytoreductive surgery. RESULTS: Among 17,302 eligible women, 10,948 (63.3%) underwent PCS and 6354 (36.7%) received NACT. Older age, stage IV disease, high-grade, and serous histology were associated with receipt of NACT in univariate (p<0.001) and multivariable analyses (p<0.001). Analysis of non-clinical factors revealed that residency in the Northeast region and receipt of treatment closer to home were associated with NACT in univariate (p<0.05) but not multivariable analysis (p>0.05). In multivariable analysis, African-American race/ethnicity (p=0.04), low-income level (p=0.02), treatment in high-volume centers (p<0.01), and insurance by Medicare or other government insurance (p<0.001) were associated with receipt of NACT. When women who received no surgery were excluded, all factors that were independent predictors of NACT in the main analysis remained significant, except for race/ethnicity. CONCLUSIONS: Non-clinical factors were associated with the use of NACT at a magnitude similar to that of clinically relevant factors.

Disparities in receipt of care for high-grade endometrial cancer: A National Cancer Data Base analysis.

PURPOSE: To examine patterns of care and survival for Hispanic women compared to white and African American women with high-grade endometrial cancer. METHODS: We utilized the National Cancer Data Base (NCDB) to identify women diagnosed with uterine grade 3 endometrioid adenocarcinoma, carcinosarcoma, clear cell carcinoma and papillary serous carcinoma between 2003 and 2011. The effect of treatment on survival was analyzed using the Kaplan-Meier method. Factors predictive of outcome were compared using the Cox proportional hazards model. RESULTS: 43,950 women were eligible. African American and Hispanic women had higher rates of stage III and IV disease compared to white women (36.5% vs. 36% vs. 33.5%, p<0.001). African American women were less likely to undergo surgical treatment for their cancer (85.2% vs. 89.8% vs. 87.5%, p<0.001) and were more likely to receive chemotherapy (36.8% vs. 32.4% vs. 32%, p<0.001) compared to white and Hispanic women. Over the entire study period, after adjusting for age, time period of diagnosis, region of the country, urban or rural setting, treating facility type, socioeconomic status, education, insurance, comorbidity index, pathologic stage, histology, lymphadenectomy and adjuvant treatment, African American women had lower overall survival compared to white women (Hazard Ratio 1.21, 95% CI 1.16-1.26). Conversely, Hispanic women had improved overall survival compared to white women after controlling for the aforementioned factors (HR 0.87, 95% CI 0.80-0.93). CONCLUSIONS: Among women with high-grade endometrial cancer, African American women have lower all-cause survival while Hispanic women have higher all-cause survival compared to white women after controlling for treatment, sociodemographic, comorbidity and histopathologic variables.

Outcomes of Women With High-Grade and Low-Grade Advanced-Stage Serous Epithelial Ovarian Cancer.

OBJECTIVE: To compare outcomes of women with advanced-stage low-grade serous ovarian cancer and high-grade serous ovarian cancer and identify factors associated with survival among patients with advanced-stage low-grade serous ovarian cancer. METHODS: A retrospective study of patients diagnosed with grade 1 or 3, advanced-stage (stage IIIC and IV) serous ovarian cancer between 2003 and 2011 was undertaken using the National Cancer Database, a large administrative database. The effect of grade on survival was analyzed using the Kaplan-Meier method. Factors predictive of outcome were compared using the Cox proportional hazards model. Among women with low-grade serous ovarian cancer, propensity score matching was used to compare all-cause mortality among similar women who underwent chemotherapy and lymph node dissection and those who did not. RESULTS: A total of 16,854 (95.7%) patients with high-grade serous ovarian cancer and 755 (4.3%) patients with low-grade serous ovarian cancer were identified. Median overall survival was 40.7 months among high-grade patients and 90.8 months among women with low-grade tumors (P<.001). Among patients with low-grade serous ovarian cancer in the propensity score-matched cohort, the median overall survival was 88.2 months among the 140 patients who received chemotherapy and 95.9 months among the 140 who did not receive chemotherapy (P=.7). Conversely, in the lymph node dissection propensity-matched cohort, median overall survival was 106.5 months among the 202 patients who underwent lymph node dissection and 58 months among the 202 who did not (P<.001). CONCLUSION: When compared with high-grade serous ovarian cancer, low-grade serous ovarian cancer is associated with improved survival. In patients with advanced-stage low-grade serous ovarian cancer, lymphadenectomy but not adjuvant chemotherapy was associated with improved survival.

Minimally Invasive Staging Surgery in Women with Early-Stage Endometrial Cancer: Analysis of the National Cancer Data Base.

PURPOSE: The aim of this study was to determine factors associated with the adoption of minimally invasive surgery (MIS) compared with laparotomy in the treatment of endometrial cancer and to compare surgical outcomes and survival between these two surgical modalities. METHODS: We utilized the National Cancer Data Base (NCDB) to identify women diagnosed with presumed early-stage endometrial cancer between 2010 and 2012. We also identified factors associated with the performance of MIS and utilized propensity score matching to create a matched cohort of women who underwent minimally invasive staging surgery or laparotomy for surgical staging. RESULTS: Overall, 20,346 women were eligible for inclusion in the study; 12,604 (61.9%) had MIS, while 7742 (38.1%) had a laparotomy. African American race (odds ratio [OR] 0.54, 95% confidence interval [CI] 0.49-0.60], Hispanic ethnicity (OR 0.70, 95% CI 0.61-0.80), Charlson score >2 (OR 0.79, 95% CI 0.69-0.91), high-grade histology (OR 0.63, 95% CI 0.59-0.68), presumed clinical stage II disease (OR 0.53, 95% CI 0.46-0.60), and surgery at a community cancer program (OR 0.46, 95% CI 0.39-0.55) or in the Midwest region (OR 0.70, 95% CI 0.64-0.76) were associated with a decreased likelihood of having MIS, while private insurance (OR 1.69, 95% CI 1.45-1.97) and highest quartile median household income (OR 1.13, 95% CI 1.03-1.24) were associated with an increased likelihood of having MIS. After propensity score matching, there was no association between minimally invasive staging surgery and 3-year overall survival (hazard ratio 1.03, 95% CI 0.92-1.16). CONCLUSION: There are notable racial, ethnic, socioeconomic, and geographic variations in the utilization of MIS for endometrial cancer staging in the US. After controlling for the aforementioned factors, MIS had a similar 3-year survival compared with laparotomy in women undergoing staging surgery for endometrial cancer.

Laparoscopic staging for apparent stage I epithelial ovarian cancer.

BACKGROUND: Whereas advances in minimally invasive surgery have made laparoscopic staging technically feasible in stage I epithelial ovarian cancer, the practice remains controversial because of an absence of randomized trials and lack of high-quality observational studies demonstrating equivalent outcomes. OBJECTIVE: This study seeks to evaluate the association of laparoscopic staging with survival among women with clinical stage I epithelial ovarian cancer. STUDY DESIGN: We used the National Cancer Data Base to identify all women who underwent surgical staging for clinical stage I epithelial ovarian cancer diagnosed from 2010 through 2012. The exposure of interest was planned surgical approach (laparoscopy vs laparotomy), and the primary outcome was overall survival. The primary analysis was based on an intention to treat: all women whose procedures were initiated laparoscopically were categorized as having had a planned laparoscopic procedure, regardless of subsequent conversion to laparotomy. We used propensity methods to match patients who underwent planned laparoscopic staging with similar patients who underwent planned laparotomy based on observed characteristics. We compared survival among the matched cohorts using the Kaplan-Meier method and Cox regression. We compared the extent of lymphadenectomy using the Wilcoxon rank-sum test. RESULTS: Among 4798 eligible patients, 1112 (23.2%) underwent procedures that were initiated laparoscopically, of which 190 (17%) were converted to laparotomy. Women who underwent planned laparoscopy were more frequently white, privately insured, from wealthier ZIP codes, received care in community cancer centers, and had smaller tumors that were more frequently of serous and less often of mucinous histology than those who underwent staging via planned laparotomy. After propensity score matching, time to death did not differ between patients undergoing planned laparoscopic vs open staging (hazard ratio, 0.77, 95% confidence interval, 0.54-1.09; P = .13). Planned laparoscopic staging was associated with a slightly higher median lymph node count (14 vs 12, P = .005). Planned laparoscopic staging was not associated with time to death after adjustment for receipt of adjuvant chemotherapy, histological type and grade, and pathological stage (hazard ratio, 0.82, 95% confidence interval, 0.57-1.16). CONCLUSION: Surgical staging via planned laparoscopy vs laparotomy was not associated with worse survival in women with apparent stage I epithelial ovarian cancer.

Overall Survival Following Neoadjuvant Chemotherapy vs Primary Cytoreductive Surgery in Women With Epithelial Ovarian Cancer: Analysis of the National Cancer Database.

IMPORTANCE: Uncertainty remains about the relative benefits of primary cytoreductive surgery (PCS) vs neoadjuvant chemotherapy (NACT) for advanced-stage epithelial ovarian cancer (EOC). OBJECTIVE: To compare overall survival of PCS vs NACT in a large national population of women with advanced-stage EOC. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study of women with stage IIIC and IV EOC diagnosed between 2003 and 2011 treated at hospitals across the United States reporting to the National Cancer Data Base. We focused on patients 70 years or younger with a Charlson comorbidity index of 0 who were likely candidates for either treatment. EXPOSURES: Initial treatment approach of PCS vs NACT, examined using an intent-to-treat analysis. MAIN OUTCOMES AND MEASURES: Overall survival, defined as months from cancer diagnosis to death or date of the last contact. We used propensity score matching to compare similar women who underwent PCS and NACT. The association of treatment approach with overall survival was assessed using the Kaplan-Meier method and the log-rank test. We assessed whether the findings were influenced by differences in the prevalence of an unobserved confounder, such as limited performance status (Eastern Cooperative Oncology Group 1-2), preoperative disease burden, and BRCA status. RESULTS: Among 22 962 patients (mean [SD] age, 56.12 [9.38] years), 19 836 (86.4%) received PCS and 3126 (13.6%) underwent NACT. We matched 2935 patients treated with NACT with similar patients who received PCS. The median follow-up was 56.5 (95% CI, 54.5-59.2) months in the PCS group and 56.3 (95% CI, 54.5-59.8) months in the NACT group in the propensity-matched cohort. Among propensity score-matched groups, the median overall survival was 37.3 (95% CI, 35.2-38.7) months in the PCS group and 32.1 (95% CI, 30.8-34.1) months in the NACT group (P < .001). However, if the NACT group had a higher proportion of women with performance statuses of 1 to 2 compared with those who underwent PCS (60% vs 50%), the association of PCS and improved survival would not be statistically significant. CONCLUSIONS AND RELEVANCE: Primary cytoreductive surgery was associated with improved survival compared with NACT in otherwise healthy women with advanced-stage epithelial ovarian cancer aged 70 years or younger. The lower survival in women who received NACT could be explained by a higher prevalence of limited performance status in women undergoing NACT.

Trends in the use of neoadjuvant chemotherapy for advanced ovarian cancer in the United States.

OBJECTIVE: Neoadjuvant chemotherapy and interval debulking surgery for the treatment of advanced ovarian cancer has remained controversial, despite the publication of two randomized trials comparing this modality with primary cytoreductive surgery. This study describes temporal trends in the utilization of neoadjuvant chemotherapy and interval debulking surgery in clinical practice in the United States. METHODS: We completed a time trend analysis of the National Cancer Data Base. We identified women with stage IIIC and IV epithelial ovarian cancer diagnosed between 2004 and 2013. We categorized subjects as having undergone one of four treatment modalities: primary cytoreductive surgery followed by adjuvant chemotherapy, neoadjuvant chemotherapy followed by interval debulking surgery, surgery only, and chemotherapy only. Temporal trends in the frequency of treatment modalities were evaluated using Joinpoint regression, and χ2 tests. RESULTS: We identified 40,694 women meeting inclusion criteria, of whom 27,032 (66.4%) underwent primary cytoreductive surgery and adjuvant chemotherapy, 5429 (13.3%) received neoadjuvant chemotherapy and interval surgery, 5844 (15.4%) had surgery only, and 2389 (5.9%) received chemotherapy only. The proportion of women receiving neoadjuvant chemotherapy and surgery increased from 8.6% to 22.6% between 2004 and 2013 (p<0.001), and adoption of this treatment modality occurred primarily after 2007 (95%CI 2006-2009; p=0.001). During this period, the proportion of women who received primary cytoreductive surgery and chemotherapy declined from 68.1% to 60.8% (p<0.001), and the proportion who underwent surgery only declined from 17.8% to 9.9% (p<0.001). CONCLUSION: Between 2004 and 2013 the frequency of neoadjuvant chemotherapy and interval surgery increased significantly in the United States.

Patterns of care, predictors and outcomes of chemotherapy for ovarian carcinosarcoma: A National Cancer Database analysis.

OBJECTIVE: The aim of this study is to determine if outcomes of patients with ovarian carcinosarcoma (OCS) differ from those of women with high-grade papillary serous ovarian carcinoma (HG-PSOC) when compared by stage and treatment modalities. METHODS: The National Cancer Database was queried to identify patients with OCS and HG-PSOC diagnosed between 2003 and 2011. Demographic and clinical data were compared, and the impact of tumor histology on survival was analyzed using the Kaplan-Meier method. Factors predictive of outcome were compared using the Cox proportional hazards model. RESULTS: The final study group consisted of 45,153 women. 2886 (6.39%) had OCS and 42,267 (93.61%) had HG-PSOC. The mean age at diagnosis was 65.43 (±12.21) years for women with OCS and 61.52 (±12.6) years for HG-PSOC (P<0.001). African-American women had higher rate of OCS relative to white non-hispanic women (7.84% vs. 6.37%; P=0.002). Overall, women with OCS had a worse five-year survival rate, 26.63% [95% Confidence Interval (CI)=24.86%-28.53%] vs. 43.61% (95% CI=43.07%-44.17%). This difference persisted for each FIGO disease stage I-IV, with five-year survival consistently worse for women with OCS compared to those with HG-PSOC. Over the entire study period and after adjusting for histology, age, period of diagnosis, SEER registry, marital status, stage, surgery, radiotherapy, and lymph node dissection, carcinosarcoma histology was associated with decreased survival. CONCLUSION: OCS is associated with a poor prognosis compared to HG-PSOC. This difference was noted across all FIGO stages.

Patterns of Care, Predictors, and Outcomes of Adjuvant Therapy for Early- and Advanced-Stage Uterine Clear Cell Carcinoma: A Population-Based Analysis.

OBJECTIVE: The aim of the study was to examine the patterns of care and the impact of chemotherapy and radiation on survival in women diagnosed with uterine clear cell carcinoma (UCCC). The primary outcomes of this analysis were receipt of treatment within 6 months of diagnosis and overall survival. METHODS AND MATERIALS: Women diagnosed with UCCC from 2003 to 2011 were identified through the National Cancer Data Base. Standard univariate and multivariable analyses with logistic regression were performed. Kaplan-Meier survival analysis was used to generate overall survival data. Factors predictive of outcome were evaluated using the log-rank test and Cox proportional hazards model. RESULTS: A total of 3212 patients were identified. Chemotherapy, radiation, and combination chemotherapy and radiation were administered in 23.3%, 19.7%, and 11.1% of women, respectively. After adjusting for age, race, socioeconomic status, facility type, stage, surgery, lymph node dissection, comorbidity index, period of diagnosis, and registry location, there was an association between combined chemotherapy and radiation (hazard ratio, 0.74; 95% confidence interval, 0.61-0.90) with improved survival. Adjuvant therapy was not associated with improved survival among patients with early-stage disease (stages I and II). Both chemotherapy and combined chemotherapy and radiation were associated with significantly improved survival among patients with advanced-stage disease (stages III and IV). CONCLUSIONS: In patients with early-stage UCCC, adjuvant therapy was not associated with significantly improved survival. Chemotherapy and combination of chemotherapy and radiation were associated with improved survival in patients with advanced-stage UCCC.

Racial disparities in survival in malignant germ cell tumors of the ovary.

OBJECTIVE: To investigate racial disparities with respect to adjuvant treatment and survival in patients presenting with malignant ovarian germ cell tumors (OGCT). METHODS: The National Cancer Database (NCDB) was used to identify women diagnosed with OGCT. Demographic data were abstracted, including stratification by race and histology. Standard univariate and multivariate analyses using logistic regression were performed to describe predictors of adjuvant treatment. Kaplan-Meier and Cox proportional hazards survival methods were used to evaluate racial differences in survival between African American (AA) and white (W) women. RESULTS: The study population included 2196 patients, with 1654 (75.3%) W and 328 (14.9%) AA women. Histologic distribution varied significantly by race (p<0.0001), but neither age nor stage at presentation showed racial differences (p=0.086 and p=0.209, respectively). AA received more chemotherapy than W (W: 54.6%, AA: 65.5%, p=0.008), but in multivariate analysis there was no statistically significant difference in any adjuvant treatment modality. Despite similar treatment, and independent of histology, survival varied significantly by race with 91% (CI 0.89-0.93) five year survival in W patients compared to 84% five year survival in AA (CI 0.8-0.89) (p=0.02). These disparities were most pronounced in advanced stage disease, with 5 year survival of 84% (CI 0.79-0.89) in W compared to 61% (CI 0.48-0.78) for AA in stage III (p=0.0002), and 54% (CI 0.42-0.68) compared to 14% (CI 0.03-0.71) for stage IV (p=0.05). CONCLUSIONS: AA with OGCT have significantly worse 5 year survival when compared to W patients despite similar rates and modalities of adjuvant treatment.

Mucinous Adenocarcinoma of the Endometrium Compared With Endometrioid Endometrial Cancer: A SEER Analysis.

OBJECTIVE: Mucinous endometrial cancer (MEC) is a rare histologic subtype of endometrial cancers. The purpose of this study is to compare the outcomes of patients with MEC with patients with endometrioid endometrial cancers (EEC), and to determine whether there are significant clinicopathologic differences between these tumors. METHODS: Surveillance, Epidemiology, and End Results (SEER) Program data for 1988 to 2009 was reviewed. Demographic and clinical data were compared. The impact of histology on survival was analyzed using the Kaplan-Meier method. Factors predictive of outcome were compared using the Cox proportional hazards model. RESULTS: The study group consisted of 104,659 women, 103,097 (98.5%) had EEC and 1562 (1.5%) MEC. The mean age at diagnosis for EEC and MEC was 62 and 63.4, respectively (P<0.001). MEC tumors were more frequently classified as grade 1 (51.3% vs. 44%; P<0.001). In patients with MEC, a higher rate of pelvic lymph node metastasis (16.3% vs. 10.4%; P<0.001) was noted, but not para-aortic lymph node metastasis (5.1% vs. 4%; P=0.1). After adjusting for race, period of diagnosis, SEER registry, marital status, stage, age, surgery, radiotherapy, grade, histology, and lymph node dissection, there was no difference in survival between MEC and EEC (hazard ratio 0.90; 95% confidence interval, 0.78-1.05). CONCLUSIONS: Mucinous histology does not significantly affect survival when compared with endometrioid histology in endometrial cancer. Patients with MEC were more likely to have positive pelvic lymph nodes at the time of surgery.

Management for Elderly Women With Advanced-Stage, High-Grade Endometrial Cancer.

OBJECTIVE: To examine the treatment and survival of elderly women diagnosed with advanced-stage, high-grade endometrial cancer. METHODS: We performed a retrospective cohort study of women diagnosed between 2003 and 2011 with advanced-stage, high-grade endometrial cancers (grade 3 adenocarcinoma, carcinosarcoma, clear-cell carcinoma, and uterine serous carcinoma) using the National Cancer Database. Women were stratified by age: younger than 55, 55-64, 65-74, 75-84, and 85 years old or older. Multivariate logistic regression models and Cox proportional hazards survival methods for all-cause mortality were used for analyses. RESULTS: Twenty thousand four hundred sixty-eight patients were included, 14.9% younger than 55 years, 30.9% 55-64 years, 31.1% 65-74 years, 18.8% 75-84 years, and 4.3% 85 years old or older. Patients younger than 55 years had surgery more frequently compared with patients 75-84 years (97.2% compared with 95.8%; P<.001) and 85 years or older (97.2% compared with 94.8%; P<.001) and a higher rate of lymph node dissection (78.7% compared with 70.5%; P<.001 and 78.7% compared with 59.5%; P<.001, respectively). Women younger than 55 years old were more likely to receive chemotherapy compared with those 75-84 years (63.9% compared with 42.2%; P<.001) and 85 years old or older (63.9% compared with 22%; P<.001). After adjusting for prognostic factors, women ages 75-84 and 85 years or older were less likely to have received chemotherapy compared with women younger than 55 years (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.29-0.38 and OR 0.12, 95% CI 0.10-0.14). The same was true with surgery (OR 0.63, 95% CI 0.45-0.88 and OR 0.46, 95% CI 0.30-0.70) and radiotherapy (OR 0.61, 95% CI 0.53-0.70 and OR 0.45, 95% CI 0.37-0.56). The Cox regression model showed that in women with stage III disease, women 75-84 years had a twofold higher risk of death (hazard ratio [HR] 2.38, 95% CI 2.14-2.65) and those 85 years or older had a threefold higher risk (HR 3.16, 95% CI 2.76-3.61) compared with patients younger than 55 years. Patients with stage IV and age 75-84 years had a 24% increased risk of death (HR 1.24, 95% CI 1.11-1.40) and those 85 years or older had a 52% increased risk (HR 1.52, 95% CI 1.29-1.79). CONCLUSION: Elderly women with high-grade endometrial cancer are less likely to be treated with surgery, chemotherapy, or radiation. LEVEL OF EVIDENCE: II.