Improved characterization and translation of NK cells for canine immunotherapy

The field of cancer immunology has seen a meteoric rise in interest and application due to the discovery of immunotherapies that target immune cells, often leading to dramatic anti-tumor effects. However, successful cellular immunotherapy for solid tumors remains a challenge, and the application of immunotherapy to dogs with naturally occurring cancers has emerged as a high yield large animal model to bridge the bench-to-bedside challenges of immunotherapies, including those based on natural killer (NK) cells. Here, we review recent developments in the characterization and understanding of canine NK cells, a critical springboard for future translational NK immunotherapy research. The characterization of canine NK cells is exceptionally pertinent given the ongoing challenges in defining them and contextualizing their similarities and differences compared to human and murine NK cells compounded by the limited availability of validated canine specific reagents. Additionally, we summarize the current landscape of the clinical and translational literature employing strategies to capitalize on endogenous and exogenous NK cell immunotherapy in canine cancer patients. The insights regarding efficacy and immune correlates from these trials provide a solid foundation to design and test novel combinational therapies to enhance NK cell activity with the added benefit of motivating comparative work to translate these findings to human cancers with extensive similarities to their canine counterparts. The compilation of knowledge from basic canine NK phenotype and function to applications in first-in-dog clinical trials will support the canine cancer model and enhance translational work to improve cancer outcomes for both dogs and humans.

Missing a "Missing Self" Mechanism: Modeling and Detection of Ly49 Expression in Canine NK Cells

NK cells are a key focus in immuno-oncology, based on their ability to eliminate malignant cells without prior sensitization. Dogs are valuable models for translational immunotherapy studies, especially for NK cells, where critical species differences exist between mice and humans. Given that the mechanism for recognition of "self" by canine NK cells is currently unknown, we sought to evaluate expression of Ly49 in canine NK cells using in silico and high-throughput techniques. We interrogated the identified polymorphism/mutation in canine Ly49 and assessed the potential impact on structure using computational modeling of three-dimensional protein structure and protein-protein docking of canine Ly49 with MHC class I (MHC-I). Bulk and single-cell RNA-sequencing analysis was performed to detect gene expression of Ly49/KLRA1 in resting and activated NK cells. Tertiary protein structure demonstrated significant structural similarity to the known murine system. Molecular docking of canine Ly49 with MHC-I was favorable, converging at a single low-energy conformation. RNA sequencing revealed expression of Ly49/KLRA1 in both resting and activated NK cells and demonstrated almost exclusive expression of the gene in the NK cluster at the single-cell level. Despite prior reports of a mutated, nonfunctional canine Ly49, our data support that the protein product is predicted to bind to MHC-I in a comparable conformation to the murine system and is expressed in canine NK cells with upregulation following activation. Taken together, these data suggest that Ly49 is capable of recognizing MHC-I and therefore regulating NK cell function in dogs.

Intratumoral NKp46+ natural killer cells are spatially distanced from T and MHC-I+ cells with prognostic implications in soft tissue sarcoma

Introduction

Soft tissue sarcomas (STS) are rare, heterogenous malignancies with an unmet need for novel immunotherapies. Tumor infiltrating lymphocytes (TILs) have been linked with favorable outcomes in STS patients, though the contribution of natural killer (NK) cells and spatial relationships of TILs with MHC-I expressing cells lacks detailed characterization.

Experimental design

Using archived and prospectively collected specimens, we evaluated intratumoral NK cells by immunohistochemistry (IHC), flow cytometry, and immunofluorescence (IF). We assessed spatial localization of NK and T cells by multiplex IF, analyzing the effects of MHC-I expression status on NK and T cell clustering.

Results

Both intratumoral NKp46 and CD56dim expression were associated with significantly improved overall survival (P=0.05), while higher infiltrates of CD56bright NK cells predicted a worse prognosis (P=0.05). The presence of intratumoral NK cells was inversely proportional to CD3+ T cells. Spatial analyses showed NK cells preferentially clustering close to other NK cells with sparse CD3+ T and CD8+ T cells in range (P<0.0001). Additionally, CD3+ T and CD8+ T cells showed significantly greater co-localization with MHC-I+ cells, compared to NK cells (P<0.0001). After neoadjuvant radiotherapy, there was greater CD8 clustering, while after neoadjuvant chemotherapy, there was overall lower TIL clustering.

Conclusion

Intratumoral NK cells are prognostic in STS and localize closer to MHC-I- cells than T cells. Although both NK and T cells are associated with improved survival in STS, their differential distribution in the TME based on MHC-I expression status may serve as a biomarker for improved immunotherapy treatment selection.

The Landscape of Immunotherapy for Retroperitoneal Sarcoma

Significant multidisciplinary scientific effort has been undertaken to understand the heterogeneous family of neoplasms that comprise soft tissue sarcomas. Within this family of neoplasms, outcomes for retroperitoneal sarcomas (RPS) are currently limited given a lack of effective therapies. In this review, we focus on immunotherapy and its relationship with the common RPS histologic subtypes. Although initial outcomes for RPS patients with immune checkpoint inhibition alone have been somewhat disappointing, subsequent analyses on histologies, the tumor microenvironment, sarcoma immune class, tumor infiltrating lymphocytes and genetic analysis for tumor mutational burden have yielded insight into the interplay between sarcomas and immunotherapy. Such approaches have all provided critical insight into the environment and characterization of these tumors, with targets for potential immunotherapy in future clinical trials. With this insight, molecularly tailored combination treatments for improving response rates and oncologic outcomes for RPS are promising.

Human soft tissue sarcomas harbor an intratumoral viral microbiome which is linked with natural killer cell infiltrate and prognosis

BACKGROUND

Groundbreaking studies have linked the gut microbiome with immune homeostasis and antitumor immune responses. Mounting evidence has also demonstrated an intratumoral microbiome, including in soft tissue sarcomas (STS), although detailed characterization of the STS intratumoral microbiome is limited. We sought to characterize the intratumoral microbiome in patients with STS undergoing preoperative radiotherapy and surgery, hypothesizing the presence of a distinct intratumoral microbiome with potentially clinically significant microbial signatures.

METHODS

We prospectively obtained tumor and stool samples from adult patients with non-metastatic STS using a strict sterile collection protocol to minimize contamination. Metagenomic classification was used to estimate abundance using genus and species taxonomic levels across all classified organisms, and data were analyzed with respect to clinicopathologic factors.

RESULTS

Fifteen patients were enrolled. Most tumors were located at an extremity (67%) and were histologic grade 3 (87%). 40% were well-differentiated/dedifferentiated liposarcoma histology. With a median follow-up of 24 months, 4 (27%) patients developed metastases, and 3 (20%) died. Despite overwhelming human DNA (>99%) intratumorally, we detected a small but consistent proportion of bacterial DNA (0.02-0.03%) in all tumors, including Proteobacteria, Bacteroidetes, and Firmicutes, as well as viral species. In the tumor microenvironment, we observed a strong positive correlation between viral relative abundance and natural killer (NK) infiltration, and higher NK infiltration was associated with superior metastasis-free and overall survival by immunohistochemical, flow cytometry, and multiplex immunofluorescence analyses.

CONCLUSIONS

We prospectively demonstrate the presence of a distinct and measurable intratumoral microbiome in patients with STS at multiple time points. Our data suggest that the STS tumor microbiome has prognostic significance with viral relative abundance associated with NK infiltration and oncologic outcome. Additional studies are warranted to further assess the clinical impact of these findings.

Inhaled recombinant human IL-15 in dogs with naturally occurring pulmonary metastases from osteosarcoma or melanoma: a phase 1 study of clinical activity and correlates of response

PURPOSE

Although recombinant human interleukin-15 (rhIL-15) has generated much excitement as an immunotherapeutic agent for cancer, activity in human clinical trials has been modest to date, in part due to the risks of toxicity with significant dose escalation. Since pulmonary metastases are a major site of distant failure in human and dog cancers, we sought to investigate inhaled rhIL-15 in dogs with naturally occurring lung metastases from osteosarcoma (OSA) or melanoma. We hypothesized a favorable benefit/risk profile given the concentrated delivery to the lungs with decreased systemic exposure.

EXPERIMENTAL DESIGN

We performed a phase I trial of inhaled rhIL-15 in dogs with gross pulmonary metastases using a traditional 3+3 cohort design. A starting dose of 10 µg twice daily × 14 days was used based on human, non-human primate, and murine studies. Safety, dose-limiting toxicities (DLT), and maximum tolerated dose (MTD) were the primary objectives, while response rates, progression-free and overall survival (OS), and pharmacokinetic and immune correlative analyses were secondary.

RESULTS

From October 2018 to December 2020, we enrolled 21 dogs with 18 dogs reaching the 28-day response assessment to be evaluable. At dose level 5 (70 μg), we observed two DLTs, thereby establishing 50 µg twice daily × 14 days as the MTD and recommended phase 2 dose. Among 18 evaluable dogs, we observed one complete response >1 year, one partial response with resolution of multiple target lesions, and five stable disease for an overall clinical benefit rate of 39%. Plasma rhIL-15 quantitation revealed detectable and sustained rhIL-15 concentrations between 1-hour and 6 hour postnebulization. Decreased pretreatment lymphocyte counts were significantly associated with clinical benefit. Cytotoxicity assays of banked peripheral blood mononuclear cells revealed significant increases in peak cytotoxicity against canine melanoma and OSA targets that correlated with OS.

CONCLUSIONS

In this first-in-dog clinical trial of inhaled rhIL-15 in dogs with advanced metastatic disease, we observed promising clinical activity when administered as a monotherapy for only 14 days. These data have significant clinical and biological implications for both dogs and humans with refractory lung metastases and support exploration of combinatorial therapies using inhaled rhIL-15.

Natural Killer and T Cell Infiltration in Canine Osteosarcoma: Clinical Implications and Translational Relevance

Metastatic osteosarcoma has a bleak prognosis in both humans and dogs, and there have been minimal therapeutic advances in recent decades to improve outcomes. Naturally occurring osteosarcoma in dogs is shown to be a highly suitable model for human osteosarcoma, and limited data suggest the similarities between species extend into immune responses to cancer. Studies show that immune infiltrates in canine osteosarcoma resemble those of human osteosarcoma, and the analysis of tumor immune constituents as predictors of therapeutic response is a promising direction for future research. Additionally, clinical studies in dogs have piloted the use of NK transfer to treat osteosarcoma and can serve as valuable precursors to clinical trials in humans. Cytotoxic lymphocytes in dogs and humans with osteosarcoma have increased activation and exhaustion markers within tumors compared with blood. Accordingly, NK and T cells have complex interactions among cancer cells and other immune cells, which can lead to changes in pathways that work both for and against the tumor. Studies focused on NK and T cell interactions within the tumor microenvironment can open the door to targeted therapies, such as checkpoint inhibitors. Specifically, PD-1/PD-L1 checkpoint expression is conserved across tumors in both species, but further characterization of PD-L1 in canine osteosarcoma is needed to assess its prognostic significance compared with humans. Ultimately, a comparative understanding of T and NK cells in the osteosarcoma tumor microenvironment in both dogs and humans can be a platform for translational studies that improve outcomes in both dogs and humans with this frequently aggressive disease.

Comparative Immunogenomics of Canine Natural Killer Cells as Immunotherapy Target

Natural killer (NK) cells are key effectors of the innate immune system, but major differences between human and murine NK cells have impeded translation. Outbred dogs offer an important link for studies of NK biology and immunotherapy. We analyzed gene expression of putative NK populations from healthy dogs and dogs with naturally-occurring cancers examining differential gene expression across multiple conditions, including steady-state, in vitro activation with cytokines and co-culture, and in vivo activation with inhaled IL-15 in dogs receiving IL-15 immunotherapy. We also compared dog, mouse and human CD3-NKp46+ NK cells using a novel orthologous transcriptome. Distinct transcriptional profiles between NK populations exist between conditions and in vitro versus in vivo treatments. In cross-species analysis, canine NK cells were globally more similar to human NK cells than mice. These data define canine NK cell gene expression under multiple conditions and across species, filling an important gap in translational NK studies.

Novel Targets in Melanoma: Intralesional and Combination Therapy to Manipulate the Immune Response

Clinical outcomes for metastatic melanoma have been dramatically altered by recent developments in immunotherapy and targeted strategies, but response to these therapies is not uniform, the majority of patients do not respond, and clinical response can be self-limited. Current directions in melanoma treatment aim to leverage a combination of therapies for tumors refractory to monoimmunotherapy, to include tumor-directed strategies, such as intralesional therapy and inhibitors designed for novel targets, which may augment current systemic agents when used in combination. Here, we summarize new classes of agents and emerging multimodal combination strategies that demonstrate significant promise in future melanoma management.

Chemotherapy After Diagnosis of Malignant Bowel Obstruction is Associated with Superior Survival for Medicare Patients with Advanced Malignancy

Background

Although malignant bowel obstruction (MBO) often is a terminal event, systemic therapies are advocated for select patients to extend survival. This study aimed to evaluate factors associated with receipt of chemotherapy after MBO and to determine whether chemotherapy after MBO is associated with survival.

Methods

This retrospective cohort study investigated patients 65 years of age or older with metastatic gastrointestinal, gynecologic, or genitourinary cancers who were hospitalized with MBO from 2008 to 2012 using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Fine and Gray models were used to identify factors associated with receipt of chemotherapy accounting for the competing risk of death. Cox models identified factors associated with overall survival.

Results

Of the 2983 MBO patients, 39% (n = 1169) were treated with chemotherapy after MBO. No differences in receipt of chemotherapy between the surgical and medical patients were found in the univariable analysis (subdistribution hazard ratio [SHR], 0.96; 95% confidence interval [CI], 0.86–1.07; p = 0.47) or multivariable analysis (SHR, 1.12; 95% CI, 1.00–1.26; p = 0.06). Older age, African American race, medical comorbidities, non-colorectal and non-ovarian cancer diagnoses, sepsis, ascites, and intensive care unit stays were inversely associated with receipt of chemotherapy after MBO (p < 0.05). Chemotherapy with surgery was associated with longer survival than surgery (adjusted hazard ratio [aHR], 2.97; 95% CI, 2.65–3.34; p < 0.01) or medical management without chemotherapy (aHR, 4.56; 95% CI, 4.04–5.14; p < 0.01). Subgroup analyses of biologically diverse cancers (colorectal, pancreatic, and ovarian) showed similar results, with greater survival related to chemotherapy (p < 0.05).

Conclusions

Chemotherapy plays an integral role in maximizing oncologic outcome for select patients with MBO. The data from this study are critical to optimizing multimodality care for these complex patients.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-09831-0.

Child-rearing During Postgraduate Medical Training and Its Relation to Stress and Burnout: Results From a Single-institution Multispecialty Survey

INTRODUCTION

Child-rearing is difficult for medical trainees, but much of the available evidence is limited to individual specialties or lacks an analysis of well-being. In light of this, we sought to examine current perspectives across a wide range of medical specialties, determine associations with stress and burnout, and identify potential supportive solutions.

METHODS

After Institutional Review Board approval, a voluntary and anonymous survey was sent to all residents and fellows at a large academic medical center with a U.S. Air Force joint training agreement in 2019. Frequency tables were generated for survey responses, using χ2 test for analysis between groups.

RESULTS

One hundred and eighty-four physician trainees completed the survey (21.6% response rate), of which 38.0% were parents. Overall, 90.8% of trainees want children but 68.5% plan to wait until after training to start or grow their families, mainly due to insufficient time or inadequate child care. Less than 2% cited lack of program support as the reason. Among trainee parents, 72.0% reported that child care was at least quite stressful. Child care contributes to burnout for 68.6% of trainee parents, and there was no difference between medical and surgical trainees or between military and nonmilitary trainees. Day care was the most common primary child care strategy, and 37.1% of trainee parents reported spending >25% of their household income on child care. Proposed helpful solutions include on-site day care and subsidies.

CONCLUSIONS

Most medical trainees in this sample want children, yet many are delaying growing their families due to time and financial constraints. For trainee parents, child care causes stress and family and financial strain and contributes to burnout. Physicians in training, including military members training at civilian medical centers, could benefit from child care assistance in order to relieve stress, reduce burnout, and improve well-being. Furthermore, by expanding existing resources and implementing new creative solutions to the challenges of child-rearing among medical professionals, the U.S. military has an opportunity to improve members' well-being and be a model to civilian graduate medical education programs nationwide.

Analysis of tumor-infiltrating NK and T cells highlights IL-15 stimulation and TIGIT blockade as a combination immunotherapy strategy for soft tissue sarcomas

Purpose

Given the unmet need for novel immunotherapy in soft tissue sarcoma (STS), we sought to characterize the phenotype and function of intratumoral natural killer (NK) and T cells to identify novel strategies to augment tumor-infiltrating lymphocyte (TIL) function.

Experimental design

Using prospectively collected specimens from dogs and humans with sarcomas, archived specimens, and The Cancer Genome Atlas (TCGA) data, we evaluated blood and tumor NK and T cell phenotype and function and correlated those with outcome. We then assessed the effects of interleukin 15 (IL-15) stimulation on both NK and T cell activation and TIGIT upregulation. Finally, we evaluated cytotoxic effects of IL-15 combined with TIGIT blockade using a novel anti-TIGIT antibody.

Results

TILs were strongly associated with survival outcome in both archived tissue and TCGA, but higher TIL content was also associated with higher TIGIT expression. Compared with blood, intratumoral NK and T cells showed significantly higher expression of both activation and exhaustion markers, in particular TIGIT. Ex vivo stimulation of blood and tumor NK and T cells from patients with STS with IL-15 further increased both activation and exhaustion markers, including TIGIT. Dogs with metastatic osteosarcoma receiving inhaled IL-15 also exhibited upregulation of activation markers and TIGIT. Ex vivo, combined IL-15 and TIGIT blockade using STS blood and tumor specimens significantly increased cytotoxicity against STS targets.

Conclusion

Intratumoral NK and T cells are prognostic in STS, but their activation is marked by significant upregulation of TIGIT. Our data suggest that combined IL-15 and TIGIT blockade may be a promising clinical strategy in STS.

Disparities in the Occurrence of Late Effects following Treatment among Adolescent and Young Adult Melanoma Survivors

BACKGROUND

Melanoma is the third most common cancer in the adolescent and young adult (AYA) population; however, no studies have addressed the occurrence of adverse health conditions following melanoma treatment in these survivors.

METHODS

Data for patients ages 15 to 39 years diagnosed with cutaneous melanoma from 1996 to 2012 and surviving ≥2 years were obtained from the California Cancer Registry and linked to statewide hospitalization data. The influence of age at diagnosis, sex, race/ethnicity, neighborhood socioeconomic status (SES), health insurance, and surgery on the development of adverse health conditions was evaluated using Cox proportional hazards regression models.

RESULTS

Of 8,259 patients, 35.3% were male, 83.3% were non-Hispanic White, 82.4% had private health insurance, and 60.5% were considered high SES. In Cox regression models, males had an increased risk of developing adverse health conditions across all systems, including cardiac [HR, 1.73, 95% confidence interval (CI), 1.47-2.03], lymphedema (HR, 1.56; 95% CI, 1.37-1.77), hematologic disorders (HR, 1.17; 95% CI, 1.03-1.33), major infection/sepsis (HR, 1.59; 95% CI, 1.39-1.82), and second cancers (HR, 1.51; 95% CI, 1.31-1.74). Patients with public/no insurance (vs. private) had a greater risk of developing all studied adverse health conditions, including subsequent cancers (HR, 2.34; 95% CI, 1.94-2.82). AYA patients residing in low SES neighborhoods had similar increased risk of developing adverse health conditions.

CONCLUSIONS

Of AYA melanoma survivors, males, those with public/no health insurance, and those living in low SES neighborhoods had a greater likelihood of developing adverse health conditions.

IMPACT

Strategies to improve surveillance and secondary prevention of these adverse health conditions are needed among AYA melanoma survivors, specifically for the at-risk populations identified.

Abstract 1339: Transcriptomic profiles improve characterization natural killer cells and predict response to cytokine therapy in clinical trial for dogs with pulmonary metastases

Introduction: Natural killer (NK) cells are key effectors of the innate immune system, but major differences between human and murine NK cells have been a barrier to translation. Outbred dogs are an important link for NK-based cancer immunotherapy studies, so better characterization of canine NK cells is needed. We used RNAseq to compare gene expression profiles of ex vivo dog NK cells to in vivo NK signatures from dogs with pulmonary metastases receiving inhaled recombinant human (rh) IL-15 in a phase I clinical trial.

Methods: Eight dogs with spontaneous pulmonary metastases were enrolled on an IACUC and clinical trials review board-approved Phase I clinical trial of inhaled rhIL-15 using a 3+3 cohort design with escalating doses of inhaled rhIL-15. Blood was collected from study subjects immediately pre-treatment and on days 7, 14 and 21 after treatment initiation for isolation of NK cells (CD5dim) and RNAseq. We performed differential gene expression (DGE) comparing trial patients to healthy beagle CD5dim NK populations (resting) and ex vivo activated beagle NK cells using IL-15 and feeder line co-culture. We assessed global transcriptional profile, specific activating and inhibitory receptors of NK function, and principal component analysis (PCA) for variation between treatment groups (FDR &lt;0.05).

Results: Of 8 dogs, 2 demonstrated &gt; 100-day survival with 1 stable disease and 1 partial response based on RECIST criteria. DGE revealed distinct transcriptional profiles between the ex vivo resting, IL-15 and co-cultured canine NK cells. Among treated patients, hierarchical clustering revealed that in vivo NK cell transcriptional signatures grouped by individual dog, and not amount of time exposed to treatment. PCA showed in vivo profiles of the long term survivors were distinctly separate from the non-responding patients (PC1 38%, PC2 12%). This suggests response to therapy could be determined by baseline NK cell characteristics rather than changes over time following treatment. Patient in vivo NK cell transcription profiles most closely resembled those of ex vivo resting NK cells and not IL-15 or co-culture activated (PC1 43%, PC2 19%), likely reflecting key differences in activation ex vivo vs in vivo. Key genes induced in vivo (&gt;20X) post inhalation of rhIL-15 include DLA-DRA, B2M, and thymosin beta 4, while key genes induced ex vivo post rhIL-15 exposure include CD96, KLRB1, and SPP1/OPN.

Conclusion: In this first transcriptomic sequencing of dog NK cells, we demonstrate distinct gene profiles of ex vivo activated NK cells from healthy donors compared to circulating NK cells from dogs receiving inhaled rhIL-15 on clinical trial. Baseline NK cell profiles appear to predict response more than changes over time. These data highlight the strength of the outbred dog model in speeding novel immunotherapy and biomarker studies.

Citation Format: Alicia A. Gingrich, Taylor Reiter, Sean Judge, Daniel York, Mio Yanagisawa, Ian Sturgill, Rachel Brady, Kevin Stoffel, Arta Monjazeb, C. Titus Brown, Robert Rebhun, Robert J. Canter. Transcriptomic profiles improve characterization natural killer cells and predict response to cytokine therapy in clinical trial for dogs with pulmonary metastases [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 1339.

Radiotherapy is Associated With Improved Survival in Patients With Synovial Sarcoma Undergoing Surgery: A National Cancer Database Analysis

BACKGROUND

Previous studies have demonstrated an association of perioperative radiotherapy (RT) with improved survival in patients with synovial sarcoma (SS) undergoing surgery, but the mechanism for this is unknown. In this study, we sought to further analyze this association using a hospital-based data set where data on chemotherapy administration and surgical margin status are available.

METHODS

Using the National Cancer Database, we identified 1216 patients with SS (aged ≥18 y) from 2004-2012 undergoing surgery. Cox proportional hazards analysis was used to study the effect of clinicopathologic variables on overall survival (OS).

RESULTS

Mean age at diagnosis was 41.5 y (range 18-90), and 71.3% of tumors were high grade; 22.9% underwent surgery alone, 59.6% received RT with surgery, 44.2% received chemotherapy with surgery, and 26.3% received trimodality therapy. Age, sex, grade, Charlson-Deyo score, and RT (hazard ratio, 0.676; 95% confidence interval, 0.519-0.880; P = 0.004) were associated with improved OS, whereas chemotherapy (hazard ratio, 1.20; 95% confidence interval, 0.899-1.60; P = 0.217) and surgical margin status were not. Trimodality therapy with surgery, RT, and chemotherapy was associated with improved OS when compared with therapy with surgery and chemotherapy alone.

CONCLUSIONS

In patients with SS undergoing surgery, we observed a significant improved association of OS with the addition of RT when adjusting for comorbidity score, margin status, and receipt of chemotherapy. These data further support routine implementation of RT in the treatment of patients with SS, including those receiving aggressive multimodality and trimodality care.

Elderly Age Is Associated With More Conservative Treatment of Invasive Melanoma

BACKGROUND/AIM

Competing mortality risks complicate treatment of elderly melanoma patients potentially leading to conservative management, including no sentinel lymph node biopsy. As systemic immunotherapy offers justification for nodal evaluation, we examined treatment trends among elderly melanoma patients.

PATIENTS AND METHODS

We performed a National Cancer Database analysis of melanoma patients from 2004-2015. Patients were categorized by age (elderly ≥80-years-old). Multivariable logistic regression analyses were performed comparing characteristics and treatment by age.

RESULTS

Of 187,814 patients, 2.7% were 1-25, 11.6% were 26-40, 46.6% were 41-64, 28.8% were 65-79, and 10.3% were ≥80-years-old with clinicopathologic and treatment differences between age cohorts. Nodal surgery was least common among elderly patients (43.1% vs. 60.7-69.8%, p<0.0001). For stage III, immunotherapy was least common among the elderly (p<0.0001), but associated with greater survival (HR=0.52, 95%CI=0.32-0.84, p=0.008).

CONCLUSION

Elderly melanoma patients were often treated conservatively, including no nodal evaluation, concerning for the potential undertreatment of this population.

Cross-species gene expression analysis of human, canine and murine natural killer cells suggests convergence of activated dog and human transcriptomic profiles

Key species differences exist between human and murine natural killer (NK) cells. Although outbred dogs are a link for translational NK studies, better characterization of dog NK cells is needed. We used RNAseq to profile resting and activated NK cells from mice, dogs and humans. Cells were isolated based on putative NK cell populations from healthy humans (CD56+CD3−), beagles (CD5dim) and C57BL/6J mice (NK1.1+CD3−) and sequenced from steady-state or following exposure to irradiated human feeder cells (K562 clone 9) with 100 IU/mL rhIL-2 × 14 days (human and dog) or 1000 IU/mL rhIL-2 × 7 days. Purity of expanded human and dog NK cells was ~ 90%, while for mouse it was ~ 70%. We performed differential gene expression (DGE) across species and conditions using ~7000 1:1 orthologous genes. DGE revealed distinct transcriptional profiles for each species (FDR &lt;0.05). Hierarchical clustering demonstrated mouse NK cells as an outgroup compared to dog and human. PCA showed within-species spatial clustering of resting NK cells. After activation, variance between dog and human NK cells decreased, variance between human and mouse NK cells increased (PC1 40%, PC2 28%). Species differed in expression of key genes after activation, including PRF1, GZMA, SPP1, IL2RB, CTSD and FCER1G, which showed greater increases in abundance counts in mice than dogs and humans. In this first transcriptomic sequencing of dog NK cells, we show distinct gene profiles of resting cells across the most commonly used mouse, dog, and human NK populations, with convergence of dog and human NK cells upon stimulation under these standard conditions. By defining the cross-species comparative transcriptional profiles of putative NK cells, these data fill a gap in translational NK studies.

Blood and tissue biomarker analysis in dogs with osteosarcoma treated with palliative radiation and intra-tumoral autologous natural killer cell transfer

We have previously reported radiation-induced sensitization of canine osteosarcoma (OSA) to natural killer (NK) therapy, including results from a first-in-dog clinical trial. Here, we report correlative analyses of blood and tissue specimens for signals of immune activation in trial subjects. Among 10 dogs treated with palliative radiotherapy (RT) and intra-tumoral adoptive NK transfer, we performed ELISA on serum cytokines, flow cytometry for immune phenotype of PBMCs, and PCR on tumor tissue for immune-related gene expression. We then queried The Cancer Genome Atlas (TCGA) to evaluate the association of cytotoxic/immune-related gene expression with human sarcoma survival. Updated survival analysis revealed five 6-month survivors, including one dog who lived 17.9 months. Using feeder line co-culture for NK expansion, we observed maximal activation of dog NK cells on day 17-19 post isolation with near 100% expression of granzyme B and NKp46 and high cytotoxic function in the injected NK product. Among dogs on trial, we observed a trend for higher baseline serum IL-6 to predict worse lung metastasis-free and overall survival (P = 0.08). PCR analysis revealed low absolute gene expression of CD3, CD8, and NKG2D in untreated OSA. Among treated dogs, there was marked heterogeneity in the expression of immune-related genes pre- and post-treatment, but increases in CD3 and CD8 gene expression were higher among dogs that lived > 6 months compared to those who did not. Analysis of the TCGA confirmed significant differences in survival among human sarcoma patients with high and low expression of genes associated with greater immune activation and cytotoxicity (CD3e, CD8a, IFN-γ, perforin, and CD122/IL-2 receptor beta). Updated results from a first-in-dog clinical trial of palliative RT and autologous NK cell immunotherapy for OSA illustrate the translational relevance of companion dogs for novel cancer therapies. Similar to human studies, analyses of immune markers from canine serum, PBMCs, and tumor tissue are feasible and provide insight into potential biomarkers of response and resistance.

Characterization and Potential Applications of Dog Natural Killer Cells in Cancer Immunotherapy

Natural killer (NK) cells of the innate immune system are a key focus of research within the field of immuno-oncology based on their ability to recognize and eliminate malignant cells without prior sensitization or priming. However, barriers have arisen in the effective translation of NK cells to the clinic, in part because of critical species differences between mice and humans. Companion animals, especially dogs, are valuable species for overcoming many of these barriers, as dogs develop spontaneous tumors in the setting of an intact immune system, and the genetic and epigenetic factors that underlie oncogenesis appear to be similar between dogs and humans. Here, we summarize the current state of knowledge for dog NK cells, including cell surface marker phenotype, key NK genes and genetic regulation, similarities and differences of dog NK cells to other mammals, especially human and mouse, expression of canonical inhibitory and activating receptors, ex vivo expansion techniques, and current and future clinical applications. While dog NK cells are not as well described as those in humans and mice, the knowledge of the field is increasing and clinical applications in dogs can potentially advance the field of human NK biology and therapy. Better characterization is needed to truly understand the similarities and differences of dog NK cells with mouse and human. This will allow for the canine model to speed clinical translation of NK immunotherapy studies and overcome key barriers in the optimization of NK cancer immunotherapy, including trafficking, longevity, and maximal in vivo support.

Defining Value for Pancreatic Surgery in Early-Stage Pancreatic Cancer

Importance

Value-based care is increasingly important, with rising health care costs and advances in cancer treatment leading to greater survival for patients with cancer. Regionalization of surgical care for pancreatic cancer has been extensively studied as a strategy to improve perioperative outcomes, but investigation of long-term outcomes relative to health care costs (ie, value) is lacking.

Objective

To identify patient and hospital characteristics associated with improved overall survival, decreased costs, and greater value among patients with pancreatic cancer undergoing curative resection.

Design, Setting, and Participants

This retrospective cohort study identified 2786 patients with stages I to II pancreatic cancer who underwent pancreatic resection at 157 hospitals from January 1, 2004, through December 31, 2012. The study used the California Cancer Registry, which collects data from all California residents newly diagnosed with cancer, linked to the Office of Statewide Health Planning and Development database, which collects administrative data from all California licensed hospitals. Data were analyzed from November 11, 2017, through September 4, 2018.

Exposures

Pancreatic resection at high-volume and/or National Cancer Institute (NCI)-designated cancer centers.

Main Outcomes and Measures

The primary outcomes were overall survival, surgical hospitalization costs, and value. High value was defined as the fourth quintile or higher for survival and the second quintile or less for costs. Costs were calculated from charges using cost-charge ratios and adjusted for geographic variation and inflation. Multivariable regression models were used to determine factors associated with overall survival, costs, and high value.

Results

Among the 2786 patients included (1394 [50.0%] male; mean [SD] age, 67.0 [10.7] years), postoperative chemotherapy (adjusted hazard ratio [aHR], 0.71; 95% CI, 0.64-0.79; P < .001) and high-volume centers (aHR, 0.78; 95% CI, 0.61-0.99; P = .04) were associated with greater overall survival. Higher Elixhauser comorbidity index scores (estimate, 0.006; 95% CI, 0.003-0.008), complications (estimate, 0.22; 95% CI, 0.17-0.27), readmissions (estimate, 0.34; 95% CI, 0.29-0.39), and longer lengths of stay (estimate, 0.03; 95% CI, 0.03-0.04) were associated with higher costs (P < .001), whereas postoperative chemotherapy was associated with lower costs (estimate, -0.06; 95% CI, -0.11 to -0.02; P = .006). National Cancer Institute-designated and high-volume centers were not associated with costs. Although grades III and IV tumors (odds ratio [OR], 0.65; 95% CI, 0.39-0.91; P = .001), T3 category disease (OR, 0.71; 95% CI, 0.46-0.95; P = .005), complications (OR, 0.68; 95% CI, 0.49-0.86; P < .001), readmissions (OR, 0.64; 95% CI, 0.44-0.84; P < .001), and length of stay (OR, 0.82; 95% CI, 0.78-0.85; P < .001) were inversely associated with high-value care, NCI designation (OR, 1.07; 95% CI, 0.66-1.49; P = .74) and high-volume centers (OR, 1.08; 95% CI, 0.54-1.61; P = .07) were not.

Conclusions and Relevance

In this study, high-value care was associated with important patient characteristics and postoperative outcomes. However, NCI-designated and high-volume centers were not associated with greater value. These data suggest that targeted measures to enhance value may be needed in these centers.

Clinical Outcomes and Costs Following Unplanned Excisions of Soft Tissue Sarcomas in the Elderly

BACKGROUND

Surgical guidelines for soft tissue sarcoma (STS) emphasize pretreatment evaluation and reports of the perils of unplanned excision exist. Given the paucity of population-based data on this topic, our objective was to analyze clinical outcomes and costs of planned versus unplanned STS excisions in the Medicare population.

METHODS

We analyzed 3913 surgical patients with STS ≥66 y old from 1992 to 2011 using the Surveillance, Epidemiology, and End Results-Medicare datafiles. Planned excisions were classified based on preoperative MRI and/or biopsy, whereas unplanned excisions were classified by excision as the first procedure. Inverse probability of treatment weighting with propensity scores was used to adjust for clinicopathologic differences. Re-excisions, complications, and Medicare payments were compared with multivariate models. Overall survival and disease-specific survival were analyzed using Cox proportional hazards and competing risk models.

RESULTS

Before the first excision, 24.3% had an MRI and biopsy, 27.3% had an MRI, 11.4% had a biopsy, and 36.9% were unplanned. Re-excision rates were highest for unplanned excisions: 46.3% compared to 18.1%, 36.4%, and 29.7% for other groups (P < 0.0001). There was no difference in disease-specific survival or overall survival between groups (P > 0.05). Planned excisions were associated with increased Medicare costs (P < 0.05), with the first resection contributing to the majority of costs. Subgroup analyses by histologic grade and tumor size revealed similar results.

CONCLUSIONS

Survival was comparable with greater health care costs in elderly patients undergoing planned STS excision. Although unplanned excisions remain a quality of care issue with high re-excision rates, these data have important implications for the surgical management of STS in the elderly.

Hospital utilization and disposition among patients with malignant bowel obstruction: a population-based comparison of surgical to medical management

BACKGROUND

Malignant bowel obstruction (MBO) is often a terminal event in end-stage cancer patients. The decision to intervene surgically is complex, given the risk of harm in patients with a limited lifespan. Therefore, we sought to compare clinically meaningful outcomes in MBO patients treated with surgical versus medical management using population-based data.

METHODS

We performed a retrospective analysis of hospitalized patients with MBO from 2006 to 2010 using the California Office of Statewide Health Planning and Development dataset. Hospital-free days (HFDs) at 30-, 90-, and 180-days were calculated accounting for all hospitalization, emergency department visit, and skilled nursing facility lengths of stay. Adjusted regression models were used to compare HFDs, disposition, complications, in-hospital death, and survival for surgical versus medical MBO cohorts, using inverse probability of treatment weighting with propensity scores.

RESULTS

Of 4576 MBO patients, 3421 (74.8%) were treated medically and 1155 (25.2%) were treated surgically. Surgical patients had higher rates of complications (44.0% vs. 21.3%, p < 0.0001) and in-hospital death (9.5% vs. 3.9%, p < 0.0001) with lower rates of disposition to home (76.3% vs. 89.8%, p < 0.0001). Surgical patients had fewer 30- and 90-day HFDs compared to medical patients (p < 0.01). However, at 180-days, there were no differences in HFDs between treatment groups. There was no difference in overall survival between surgical and medical patients (median 6.5 vs. 6.4 months).

CONCLUSION

In this population-based analysis, medical management was associated with less hospital utilization at 30- and 90-days, fewer in-hospital deaths, and more frequent discharges to home. These data underscore the potential benefits of medical management for MBO patients at the end-of-life.

Serum C-reactive Protein and Neutrophil/Lymphocyte Ratio After Neoadjuvant Radiotherapy in Soft Tissue Sarcoma

BACKGROUND/AIM

The predictive value of serum C-reactive protein (CRP) and neutrophil/lymphocyte (N/L) ratio in soft tissue sarcoma (STS) patients receiving neoadjuvant radiotherapy (RT) has not been analyzed.

PATIENTS AND METHODS

From 2007 to 2015, we identified 98 STS patients from a prospective database. Using multivariate analysis, we analyzed CRP and N/L ratios as predictors of overall survival (OS).

RESULTS

Mean age of patients was 59 years, 46% were female, and 55% of tumors were located at the extremity. A total of 15 histologies were represented. Fifty percent received preoperative RT. Except for extremity location, characteristics were similar between the preoperative RT and upfront surgery cohorts, including baseline CRP levels and N/L ratios. Multivariate analysis of upfront surgery revealed histological grade, tumor size, and baseline N/L ratio to be predictors of OS, while for preoperative RT, baseline CRP and N/L ratio were not predictive.

CONCLUSION

Baseline CRP and N/L ratio did not predict poor clinical outcome in STS patients receiving neoadjuvant RT.

Neoadjuvant Radiotherapy is Associated with R0 Resection and Improved Survival for Patients with Extremity Soft Tissue Sarcoma Undergoing Surgery: A National Cancer Database Analysis

BACKGROUND

Neoadjuvant radiotherapy (RT) is increasingly advocated for the management of soft tissue sarcoma (STS). Therefore, this study sought to characterize the impact of neoadjuvant RT on rates of R0 resection and overall survival (OS) in extremity STS patients undergoing surgery.

METHODS

From January 2003 to December 2012, the study identified patients with a diagnosis of extremity STS from the National Cancer Database. After exclusion of patients younger than 18 years, not treated by surgery, who had metastases at diagnosis, intraoperative RT, and missing or unknown data, 27,969 patients were identified. Logistic regression and Cox-proportional hazard analysis were used to compare rates of R0 resection among preoperative, postoperative, and no-RT cohorts and to determine predictors of R0 resection and OS.

RESULTS

The mean age of the patients was 59.5 ± 17.1 years, and 45.9% were female. The median tumor size was 10.5 cm. The data showed that 51% of the patients did not receive RT, 11.8% received preoperative RT, and 37.2% received postoperative RT. The rates of R0 resection were 90.1% for the preoperative RT cohort, 74.9% for the postoperative RT cohort, and 79.9% for the no-RT cohort (P < 0.001). The independent predictors for achievement of R0 resection included academic facility type (odds ratio [OR] 1.36; 95% confidence interval [CI] 1.20-1.55), histologic subtype, tumor size (OR 0.99; 95% CI 0.99-0.99), Charlson score (OR 0.92; 95% CI 0.84-0.99), and preoperative RT (OR 1.83; 95% CI 1.61-2.07). Both R0 resection and RT (pre- or post-operative) were associated with increased OS.

CONCLUSIONS

Preoperative RT independently predicts higher rates of R0 resection for patients with extremity STS undergoing surgical resection. Negative surgical margins and pre- or postoperative RT are associated with improved OS.

Predictors of residual disease after unplanned excision of soft tissue sarcomas

BACKGROUND

Unplanned excision of soft tissue sarcomas (STS) is an important quality of care issue given the morbidity related to tumor bed excision. Since not all patients harbor residual disease at the time of reexcision, we sought to determine predictors of residual STS following unplanned excision.

METHODS

We identified 76 patients from a prospective database (January 1, 2008-September 30, 2014) who received a diagnosis of primary STS following unplanned excision on the trunk or extremities. We used univariable and multivariable analyses to evaluate predictors of residual STS as the primary endpoint. We calculated the sensitivity, specificity, and accuracy of interval magnetic resonance imaging (MRI) to predict residual sarcoma at reexcision.

RESULTS

Mean age was 52 y, and 63.2% were male. 50% had fragmented unplanned excision. Among patients undergoing reexcision, residual STS was identified in 70%. On univariable analysis, MRI showing gross disease and fragmented excision were significant predictors of residual STS (odds ratio, 10.59; 95% CI, 2.14-52.49; P = 0.004 and odds ratio, 3.61; 95% CI, 1.09-11.94; P = 0.035, respectively). On multivariable analysis, tumor size predicted distant recurrence and overall survival. When we combined equivocal and positive MRI, the sensitivity and specificity of MRI for predicting residual STS were 86.7% (95% CI, 73.2%-95.0%) and 57.9% (95% CI, 33.5%-79.8%), with an overall accuracy of 78.1% (95% CI, 66.0%-87.5%).

CONCLUSIONS

About 70% of patients undergoing repeat excision after unplanned excision of STS harbor residual sarcoma. Although interval MRI and fragmented excision appear to be the most significant predictors of residual STS, the accuracy of MRI remains modest, especially given the incidence of equivocal MRI.

Locally Advanced Spiroadenocarcinoma in the Regional Axilla of a Breast Cancer Patient: Hallmarks of Definitive Diagnosis and Management

Eccrine spiroadenocarcinoma is an extremely rare malignant eccrine gland tumor which may masquerade as other more common malignancies such as poorly differentiated squamous carcinoma or metastatic breast cancer. We report a case of an ulcerated axillary skin lesion with bulky adenopathy in a 77 year-old female with a prior history of ipsilateral triple negative breast carcinoma. The clear transition of benign spiradenoma to malignant carcinoma was essential to establishing a definitive diagnosis and treatment plan.