Demographic Factors Predict Risk of Lymph Node Involvement in Patients with Endometrial Adenocarcinoma.

The presence of lymph node positivity (LN+) guides adjuvant treatment for endometrial adenocarcinoma (EAC) patients, but recommendations regarding LN evaluation at the time of primary surgery remain variable. Sociodemographic factors in addition to pathologic tumor characteristics may more accurately predict risk of LN+ in EAC patients. Patients diagnosed between 2004 and 2016 with pathologic T1-T2 EAC who had at least one lymph node sampled at the time of surgery in the National Cancer Data Base were included. Pathologic primary tumor predictors of LN+ were identified using logistic regression. To predict overall, pelvic only, and paraaortic and/or pelvic LN+, nomograms were generated. Among the 35,170 EAC patients included, 2864 were node positive. Using multivariable analysis, younger patient age (OR 0.98, 95% CI 0.98-0.99, p < 0.001), black versus white race (OR 1.19, 95% CI 1.01-1.40, p = 0.04), increasing pathologic tumor stage and grade, increase in tumor size, and presence of lymphovascular invasion were predictive of regional LN+. Both black versus white (OR 1.64, 95% CI 1.27-2.09, p < 0.001) and other versus white race (OR 1.54, 95% CI 1.12-2.07, p = 0.006) strongly predicted paraaortic LN+ in the multivariable analysis. Independent subset analyses of black and white women revealed that tumor grade was a stronger predictor of LN+ among black women. In addition to standard pathologic tumor features, patient age and race were associated with a higher risk of regional LN+ generally and paraaortic LN+ specifically. This information may inform adjuvant treatment decisions and guide future studies.

Re-examining predictors of pathologic lymph node positivity in clinically node negative oral cavity cancer.

BACKGROUND: Elective lymph node dissection (ELND) is performed for many early-stage oral cavity squamous cell carcinomas (OCSCC) with clinically negative necks (cN0), often guided by depth of invasion (DOI). However, DOI is less validated in non-tongue OC sites, and often correlates with other adverse features. We sought to evaluate the utility of DOI versus other factors for independently predicting pathologic lymph node positivity (pN+) in patients with cN0 OCSCC. METHODS: Patients with cN0 OCSCC diagnosed from 2010 to 2015 undergoing primary surgery were identified in the National Cancer Data Base. RESULTS: 5060 cN0 OCSCC patients met inclusion criteria. The presence of lymphovascular invasion (LVI) was the strongest independent predictor of pN+ (odds ratio [OR] = 4.27, 95% confidence interval [CI] 3.36-5.42, P < 0.001). High histologic grade also strongly predicted pN+ (OR 3.33, 95% CI 2.20-4.60, P < 0.001). DOI had no association with the likelihood of pN+ among all OCSCC patients, but was predictive among patients within the oral tongue subset (OR 2.01, 95% CI 1.08-3.73, P = 0.03 for DOI > 20 mm vs. DOI: 2.0-3.99 mm). CONCLUSION: LVI and grade are the strongest independent predictors of pN+ in cN0 OCSCC. Contrary to prior studies, DOI was not found to be a predictor of pN+ among patients with cN0 OCSCC. However, DOI was a predictor of pN+ or the oral tongue subset, albeit still less strongly than LVI or grade. These findings could potentially be used to better identify a subset of cN0 OCSCC patients who could be considered for omission of ELND in future studies.

School-Based Interventions to Increase Student COVID-19 Vaccination Coverage in Public School Populations with Low Coverage - Seattle, Washington, December 2021-June 2022.

COVID-19 can lead to severe outcomes in children (1). Vaccination decreases risk for COVID-19 illness, severe disease, and death (2). On December 13, 2020, CDC recommended COVID-19 vaccination for persons aged ≥16 years, with expansion on May 12, 2021, to children and adolescents (children) aged 12-15 years, and on November 2, 2021, to children aged 5-11 years (3). As of March 8, 2023, COVID-19 vaccination coverage among school-aged children remained low nationwide, with 61.7% of children aged 12-17 years and approximately one third (32.7%) of those aged 5-11 years having completed the primary series (3). Intention to receive COVID-19 vaccine and vaccination coverage vary by demographic characteristics, including race and ethnicity and socioeconomic status (4-6). Seattle Public Schools (SPS) implemented a program to increase COVID-19 vaccination coverage during the 2021-22 school year, focusing on children aged 5-11 years during November 2021-June 2022, with an added focus on populations with low vaccine coverage during January 2022-June 2022.† The program included strategic messaging, school-located vaccination clinics, and school-led community engagement. Vaccination data from the Washington State Immunization Information System (WAIIS) were analyzed to examine disparities in COVID-19 vaccination by demographic and school characteristics and trends over time. In December 2021, 56.5% of all SPS students, 33.7% of children aged 5-11 years, and 81.3% of children aged 12-18 years had completed a COVID-19 primary vaccination series. By June 2022, overall series completion had increased to 80.3% and was 74.0% and 86.6% among children aged 5-11 years and 12-18 years, respectively. School-led vaccination programs can leverage community partnerships and relationships with families to improve COVID-19 vaccine access and coverage.

Predicting Pathologic Lymph Node Positivity in cN0 Pharynx and Larynx Cancers.

BACKGROUND: Elective neck dissection is a standard of care for pharynx and most larynx cancer patients undergoing surgery, based largely on historical series. It is unclear if this is necessary for all patients in the modern era. METHODS: Patients with cN0 oropharynx, larynx, and hypopharynx cancers diagnosed from 2010-2015 undergoing primary surgery were identified in the National Cancer Data Base. RESULTS: Inclusion criteria were met by 4117 cN0 patients. The presence of lymphovascular invasion (LVI) was the strongest independent predictor of pN+ (odds ratio [OR] = 4.19, 95% confidence interval [CI] 3.56-4.93, p < 0.001). Histologic grade strongly predicted pN+ (OR 2.58, 95% CI 1.88-3.59, p < 0.001). A nomogram predicted less than 10% of cN0 patients had pN+ risk <15%. CONCLUSION: LVI and grade are the strongest predictors of pN+ among patients with cN0 pharynx and larynx cancer. Even in the modern era, pN+ rates warrant neck dissection for cN0 patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1660-1666, 2023.

Lifestyle and sociodemographic factors associated with treatment choice of clinically localized prostate cancer in an equal access healthcare system.

Sociodemographic and lifestyle factors may play a role in determining whether patients with clinically localized prostate cancer (PC) are managed with active surveillance (AS), radical prostatectomy (RP), or radiation therapy (RT); however, these relationships have not been well examined. In a cross-sectional study conducted within an equal access healthcare system, multivariable adjusted regression analysis revealed that living with a spouse or partner was associated with a 65% lower chance of being managed by RT (P = 0.001) and 57% lower risk of being managed by AS (P = 0.042) compared with RP. No other sociodemographic or lifestyle factors were independently associated with treatment modality.

Nodal Metastasis Count and Oncologic Outcomes in Head and Neck Cancer: A Secondary Analysis of NRG/RTOG 9501, NRG/RTOG 0234, and EORTC 22931.

PURPOSE: A better understanding of the relationship between the spread of head and neck squamous cell carcinoma (HNSCC) to regional lymph nodes (LNs) and the frequency and manner of treatment failure should help design better treatment intensification strategies. In this study, we evaluated the relationship between recurrence patterns, mortality, and number of pathologically positive (+) LNs in HNSCC in 3 prospective randomized controlled trials. METHODS AND MATERIALS: We performed a secondary analysis of 947 patients with HNSCC enrolled in RTOG 9501 (n = 410), RTOG 0234 (n = 203), and EORTC 22931 (n = 334) undergoing surgery and postoperative radiation ± systemic therapy. Multivariable models were constructed for overall survival (OS), disease-free survival (DFS), locoregional relapse (LRR), and distant metastases (DM). Restricted cubic splines were used to model the nonlinear relationship between +LN number and outcomes. RESULTS: In multivariable analysis, OS and DFS decreased with each +LN without plateau, most pronounced up to 5 +LNs (OS: hazard ratio [HR], 1.21 per +LN; 95% confidence interval [CI], 1.10-1.34; P < .001; DFS: HR per +LN, 1.19; 95% CI, 1.08-1.30; P < .001) and more gradually beyond this (OS: HR per +LN, 1.02; 95% CI, 1.01-1.06; P < .001; DFS: HR per +LN, 1.04; 95% CI, 1.02-1.06; P < .001). In contrast to LRR risk, which increased sharply up to 5 +LNs (HR per +LN, 1.28; 95% CI, 1.10-1.50; P < .001) but plateaued beyond this (HR per +LN, 1.00; 95% CI, 0.96-1.04; P = .98), DM risk increased continuously with increasing +LNs (≤5 +LNs: HR per +LN, 1.10; 95% CI, 1.01-1.20; P = .04; >5 +LNs: HR per +LN, 1.05; 95% CI, 1.02-1.08; P = .003). CONCLUSIONS: In high-risk resected HNSCC, increased mortality was associated with increased +LN count. LRR and DM risk both increased in parallel up to 5 +LNs, but only DM continued to increase for further +LN increases. These differing recurrence patterns can help inform design of future treatments.

Pathologic primary tumor factors associated with risk of lymph node involvement in patients with non-endometrioid endometrial cancer.

PURPOSE/OBJECTIVES: Lymph node (LN) involvement is an important factor in guiding adjuvant treatment for patients with endometrial cancer. Risk factors for LN involvement are fairly well-established for endometrial adenocarcinoma, but it is not as well defined whether these factors similarly predict LN positivity in less common histologies. MATERIALS/METHODS: Patients diagnosed with pathologic T1-T2 carcinosarcoma, clear cell, uterine papillary serous carcinoma (UPSC), and mixed histologic type endometrial cancer between 2004 and 2016 undergoing primary surgery with at least 1 lymph node sampled in the National Cancer Data Base were identified. Logistic regression was performed to identify primary pathologic tumor predictors of LN positivity. Nomograms were created to predict overall, pelvic only, and paraaortic with or without pelvic LN involvement. RESULTS: Among 11,390 patients included, 1950 (18%) were node positive. On multivariable analysis, increasing pathologic tumor stage (pT2 versus pT1a, odds ratio [OR] 3.63, 95% confidence interval [CI] 3.15-4.18, p < 0.001), increase in tumor size per centimeter (OR 1.08, 95% CI 1.06-1.10, p < 0.001), and the presence of lymphovascular invasion (LVI) (OR 4.97, 95% CI 4.43-5.57, p < 0.001) were predictive of overall LN positivity. Relative to carcinosarcoma, both clear cell (OR 1.54, 95% CI 1.22-1.95, p < 0.001) and UPSC (OR 1.73, 95% CI 1.48-2.02, p < 0.001) histology were significantly associated with a higher risk of LN positivity while mixed histology was not (OR 1.07, 95% CI 0.92-1.24, p = 0.42). CONCLUSION: Among patients with non-endometrioid endometrial cancer, predictors of LN positivity are similar to endometrial adenocarcinoma. The nomograms provided could be helpful in making adjuvant treatment decisions for these less common histologies.

Advances in Pancreatic Ductal Adenocarcinoma Treatment.

Pancreatic Ductal Adenocarcinoma (PDAC) is one of the deadliest malignancies among all cancers. Despite curative intent, surgery and the use of standard cytotoxic chemotherapy and radiation therapy, PDAC remains treatment-resistant. In recent years, more contemporary treatment modalities such as immunotherapy via checkpoint inhibition have shown some promise in many other malignancies, yet PDAC still eludes an effective curative treatment. In investigating these phenomena, research has suggested that the significant desmoplastic and adaptive tumor microenvironment (TME) of PDAC promote the proliferation of immunosuppressive cells and act as major obstacles to treatment efficacy. In this review, we explore challenges associated with the treatment of PDAC, including its unique immunosuppressive TME. This review examines the role of surgery in PDAC, recent advances in surgical approaches and surgical optimization. We further focus on advances in immunotherapeutic approaches, including checkpoint inhibition, CD40 agonists, and discuss promising immune-based future strategies, such as therapeutic neoantigen cancer vaccines as means of overcoming the resistance mechanisms which underly the dense stroma and immune milieu of PDAC. We also explore unique signaling, TME and stromal targeting via novel small molecule inhibitors, which target KRAS, FAK, CCR2/CCR5, CXCR4, PARP and cancer-associated fibroblasts. This review also explores the most promising strategy for advancement in treatment of pancreatic cancer by reviewing contemporary combinatorial approaches in efforts to overcome the treatment refractory nature of PDAC.

High-dose-rate fractionated brachytherapy monotherapy for localized prostate cancer: a systematic review and meta-analysis.

PURPOSE: High-dose-rate (HDR) brachytherapy as primary therapy (monotherapy) is a standard National Comprehensive Cancer Network (NCCN) endorsed treatment option for patients with localized prostate cancer. Thus far, most data are limited to single-institution experiences. Accordingly, we sought to systematically review rates of biochemical recurrence-free survival (bRFS) and toxicity associated with fractionated HDR monotherapy. MATERIAL AND METHODS: A systematic review was performed using PubMed and Embase databases for relevant articles published between January 1999 and December 2019, according to preferred reporting items for systematic review and meta-analyses (PRISMA) guidelines. Included studies were limited to fractionated HDR monotherapy publications in full manuscript form with at least 5-year median follow-up, at least 80 patients included, and adequate reporting of bRFS and toxicity data. Meta-analyses were performed with random-effect modeling. Extent of heterogeneity between studies was determined using I 2 and Cochran's Q tests. RESULTS: Seven unique studies were identified, including 2,123 patients. NCCN low-, intermediate-, and high-risk patients comprised 40%, 40%, and 20% of patients, respectively. Median follow-up at the study group level was 74 months (range, 60-131 months). The 5-year bRFS rate was 95% (95% confidence interval [CI]: 93-96%), and after adjusting to control for publication bias, it was 96% (95% CI: 94-99%). Estimated adjusted late grade ≥ 3 genitourinary and gastrointestinal toxicity rates were 2% (95% CI: 1-4%) and 0.3% (95% CI: 0-1.1%), respectively. CONCLUSIONS: Fractionated HDR monotherapy is associated with high rates of disease control and low rates of toxicity. Future studies are needed to better define the value of this treatment modality relative to other options.

Detecting silent stressors: Trace element effects on nutritional status of declining scoter ducks of Puget Sound, USA.

White-winged scoters (Melanitta fusca; WWSC) and surf scoters (M. perspicillata; SUSC) have declined by over 60% in recent decades. Identifying contributing factors from within a mosaic of sublethal, multiple stressors is challenging. In urbanized Puget Sound, Washington, USA where scoters winter, changes in prey availability explained only a portion of local declines, suggesting that other "silent stressors" such as sublethal contaminants might play a role. Past studies of pollutant effects on scoters used Fisherian statistics that often revealed few correlates; however, novel statistical approaches could detect and provide more insights about sublethal impacts. Our objectives were to (1) relate pollutant accumulation to health of the birds, and (2) compare permutational multivariate statistics with traditional approaches in identifying sublethal health effects. We collected scoters from three locations in Puget Sound in December 2005 and March 2006, and measured cadmium (Cd), mercury (Hg), and selenium (Se) levels in livers and kidneys. To assess impacts of low contaminants levels in tissues on nutritional status (whole-body mass, lipid, and protein; and triglycerides, ß-hydroxybutyrate, and uric acid in blood), we compared statistical methods. Permutational multivariate methods use Monte Carlo techniques to assess how an integrated matrix of physiological responses in each animal respond to contaminants. Univariate regressions revealed very few and inconsistent relationships. In contrast, multivariate models showed that liver Hg and Se explained 25% of the variance in nutritional status of white-winged scoters; and in surf scoters, Cd, Hg, and Se in tissues explained 14 to 27% of nutritional status depending on site. The influence of these factors equals other aspects of habitat such as foraging conditions. Our study indicates that permutational multivariate statistics can be a powerful tool for identifying sublethal contaminant associations that, with non-contaminant stressors, can influence nutritional status and thus, contribute to population dynamics.

Variations in the association of grade with survival across the head and neck cancer landscape.

BACKGROUND: Although pathologic tumor grade is a well-established prognostic risk factor that impacts staging and treatment decisions across multiple cancer types, its role in head and neck squamous cell carcinoma (HNSCC) is less certain. METHODS: HNSCC patients diagnosed from 2010 to 2015 and undergoing primary surgery in the National Cancer Data Base were identified. Propensity score matching and multivariable Cox regression were performed. RESULTS: Among 27 041 HNSCC patients, 13 941 had oral cavity cancers (OCC). Intermediate-grade (hazard ratio [HR] 1.16, 95% CI 1.07-1.26, P < .001) and high-grade (HR 1.38, 95% CI 1.26-1.52, P < .001) tumors had worse survival than low-grade tumors. This magnitude was comparable to other well-established prognostic factors, including margin positivity, extranodal extension, and lymphovascular invasion. By contrast, there was no association between grade and survival in larynx/hypopharynx or HPV(-) oropharynx cancer. CONCLUSIONS: The prognostic impact of pathologic grade is highly variable across head and neck subsites and is the strongest among OCC patients.

Interstitial high-dose-rate brachytherapy in the treatment of keloids: Moving toward a volumetric approach.

PURPOSE: Brachytherapy (BT) after surgical resection of keloids reduces the risk of local recurrence, but standardization of dose/technique is lacking. Typical keloid BT treatment utilizes a single-channel source prescribed to 5-mm depth. We investigated the dosimetry of a volume-based target definition for interstitial high-dose-rate BT treatment of keloids. METHODS AND MATERIALS: We retrospectively identified consecutive 14 patients who had a total of 20 keloids treated with interstitial high-dose-rate BT for keloids at our institution between 2004 and 2014. Keloids were treated with a single 8 Gy fraction prescribed to 5 mm beneath the scar within 36 h of surgery. Retrospectively, a 3-mm skin high-risk clinical target volume (HR-CTV) was contoured under the scar for volume-based dose calculations. RESULTS: Mean (SD) HR-CTV was 3.91 cm3 (3.1) and mean (SD) HR-CTV dose was 11.3 Gy (3.6). Mean D90 (SD) was 62.9% (25.8) and mean V100 (SD) was 56.5% (26.4). The mean V150 (SD), V200 (SD), and V300 (SD) were as follows: 37.6% (19.9), 25.1% (14.4), and 11.3% (6.5), respectively. No local failures were reported at 9 months median followup. There were no Grade 2 or higher late toxicities. CONCLUSIONS: Using a volume-based target definition, a wide range of target coverage was observed. This is likely a consequence of the curvature of the skin and the challenges of keeping the catheter equidistant from the skin across the target. Additional data are needed to define the potential clinical impact on outcomes/toxicities of dosimetric correlates with single-catheter BT keloid treatment.

Adjuvant radiation followed by chemotherapy is associated with improved overall survival in endometrial cancer.

OBJECTIVE: Although multimodality therapy has been shown to improve outcomes for patients with high-risk endometrial carcinoma, optimal type and timing of adjuvant therapies is unknown. METHODS: Patients with stage I-IVA endometrial carcinoma diagnosed from 2004 to 2015, and treated with surgery, chemotherapy, and radiation were identified in the National Cancer Database. Adjuvant treatment was categorized as sequential radiation followed by chemotherapy (RT-CT), concurrent chemoradiation (CCRT, RT and CT started within 7 days), or sequential chemotherapy followed by radiation (CT-RT). Analysis for propensity score matched (PSM) cohorts comparing RT-CT to CCRT and CT-RT groups was additionally performed. RESULTS: A total of 17,070 patients were identified, including 12,402 (72.7%) treated with RT-CT, 2,153 (12.6%) with CCRT, and 2,515 (14.7%) with CT-RT. Median follow-up was 44.3 months. Five-year overall-survival (OS) by adjuvant treatment regimen was 77.3% (95% CI 76.4%-78.2%), 74.3% (95% CI 72.0%-76.3%), and 74.4% (95% CI 72.5%-76.3%), respectively (p < .001). When unmatched cohorts were stratified by stage, adjuvant RT-CT was associated with improved OS in stage I and III patients. A similar survival advantage associated with RT-CT was observed in PSM cohorts comparing RT-CT group to CCRT/CT-RT group (5-year OS 77.4% vs 74.2%, p = .001). However, the difference in OS was significant only among stage III patients (RT-CT 73.9% compared to CCRT/CT-RT 69.7%, p =.002). CONCLUSION: Our findings suggest survival benefit with adjuvant RT-CT compared to CT-RT or CCRT in patients undergoing trimodality therapy for endometrial cancer. This survival benefit may be limited to stage III patients.

Differences in S/G ratio in natural poplar variants do not predict catalytic depolymerization monomer yields.

The ratio of syringyl (S) and guaiacyl (G) units in lignin has been regarded as a major factor in determining the maximum monomer yield from lignin depolymerization. This limit arises from the notion that G units are prone to C-C bond formation during lignin biosynthesis, resulting in less ether linkages that generate monomers. This study uses reductive catalytic fractionation (RCF) in flow-through reactors as an analytical tool to depolymerize lignin in poplar with naturally varying S/G ratios, and directly challenges the common conception that the S/G ratio predicts monomer yields. Rather, this work suggests that the plant controls C-O and C-C bond content by regulating monomer transport during lignin biosynthesis. Overall, our results indicate that additional factors beyond the monomeric composition of native lignin are important in developing a fundamental understanding of lignin biosynthesis.

Factors Associated With Survival Following Radium-223 Treatment for Metastatic Castration-resistant Prostate Cancer.

BACKGROUND: Radium-223 (223Ra) improves survival in patients with metastatic castration-resistant prostate cancer (mCRPC). This retrospective analysis was performed to better understand its efficacy in routine clinical practice and identify factors associated with survival. MATERIALS AND METHODS: Sixty-four patients with mCRPC who received 223Ra between 2013 and 2015 were the basis of this retrospective study. Clinical outcomes and patient characteristics were obtained. Potential prognostic factors for survival were evaluated by univariate analysis using the log-rank test and multivariate analysis using the Cox proportional hazard method. RESULTS: The median survival was 12.9 months. Twenty-one patients (33%) developed a skeletal event, and the median time to the first skeletal event was 4.4 months. In univariate analysis, factors significantly associated with survival included: no prior chemotherapy, ≤ 5 bone metastases, baseline prostate-specific antigen (PSA) ≤ 36 ng/mL, baseline alkaline phosphatase (ALP) < 115 U/L, baseline hemoglobin > 12 g/dL, ALP response after 223Ra treatment, PSA decrease during 223Ra treatment, and absence of > 25% PSA increase during 223Ra treatment. In multivariate analysis, 4 factors remained significant: no prior chemotherapy, ≤ 5 bone metastases, baseline ALP < 115 U/L, and ALP response after 223Ra treatment. CONCLUSION: When 223Ra is administered in routine clinical practice, clinical outcomes can be more variable than those reported in the randomized study owing to patient heterogeneity. Four factors were identified to be significantly associated with survival after 223Ra treatment. These pretreatment factors may be used as stratification factors in future studies to investigate whether 223Ra would be more effective for patients with newly diagnosed metastatic disease that is sensitive to androgen deprivation therapy.

The Prognostic Significance of Pretreatment Hematologic Parameters in Patients Undergoing Resection for Colorectal Cancer.

OBJECTIVES: The prognostic value of several hematologic parameters, including platelet, lymphocyte, and neutrophil counts, has been studied in a variety of solid tumors. In this study, we examined the significance of inflammatory markers and their prognostic implications in patients with colorectal cancer (CRC). MATERIALS AND METHODS: Patients with stage I-III CRC who underwent surgical resection at the Stanford Cancer Institute between 2005 and 2009 were included. Patients were excluded if they did not have preoperative complete blood counts performed within 1 month of surgical resection, underwent preoperative chemotherapy or radiation, had metastatic disease at diagnosis, or had another previous malignancy. We included 129 eligible patients with available preoperative complete blood counts in the final analysis. RESULTS: A preoperative neutrophil-to-lymphocyte ratio of>3.3 was significantly associated with worse disease-free (DFS) and overall survival (OS) (P=0.009, 0.003), as was a preoperative lymphocyte-to-monocyte ratio of ≤2.6 (P=0.01, 0.002). Preoperative lymphopenia (P=0.002) was associated with worse OS but not DFS (P=0.09). In addition, preoperative thrombocytosis was associated with worse DFS (P=0.006) and OS (P=0.010). Preoperative leukocytosis was associated with worse OS (P=0.048) but not DFS (P=0.49). Preoperative hemoglobin was neither associated with OS (P=0.24) or DFS (P=0.15). CONCLUSIONS: Pretreatment lymphopenia, thrombocytosis, a decreased lymphocyte-to-monocyte ratio, and an elevated neutrophil-to-lymphocyte ratio independently predict for worse OS in patients with CRC.

Do the antipredator strategies of shared prey mediate intraguild predation and mesopredator suppression?

Understanding the conditions that facilitate top predator effects upon mesopredators and prey is critical for predicting where these effects will be significant. Intraguild predation (IGP) and the ecology of fear are hypotheses used to describe the effects of top predators upon mesopredators and prey species, but make different assumptions about organismal space use. The IGP hypothesis predicts that mesopredator resource acquisition and risk are positively correlated, creating a fitness deficit. But if shared prey also avoid a top predator, then mesopredators may not have to choose between risk and reward. Prey life history may be a critical predictor of how shared prey respond to predation and may mediate mesopredator suppression. We used hierarchical models of species distribution and abundance to test expectations of IGP using two separate triangular relationships between a large carnivore, smaller intraguild carnivore, and shared mammalian prey with different life histories. Following IGP, we expected that a larger carnivore would suppress a smaller carnivore if the shared prey species did not spatially avoid the large carnivore at broad scales. If prey were fearful over broad scales, we expected less evidence of mesopredator suppression. We tested these theoretical hypotheses using remote camera detections across a large spatial extent. Lagomorphs did not appear to avoid coyotes, and fox detection probability was lower as coyote abundance increased. In contrast, white-tailed deer appeared to avoid areas of increased wolf use, and coyote detection probability was not reduced at sites where wolves occurred. These findings suggest that mesopredator suppression by larger carnivores may depend upon the behavior of shared prey, specifically the spatial scale at which they perceive risk. We further discuss how extrinsic environmental factors may contribute to mesopredator suppression.