Ergonomic Assessment of Septorhinoplasty Maneuvers During Simulated Pregnancy.

Objective: Women represent an increasing proportion of the otolaryngology workforce. Work-related musculoskeletal disorders (WRMSD) are a little-studied yet important impediment to career completion. Scant attention has been directed to study the impact of pregnancy on surgeon posture and ergonomics. We piloted the use of a pregnancy simulation suit (Empathy Belly) to assess the risk of ergonomic compromise when performing open septorhinoplasty. Study Design: Surgical simulation. Setting: Single session, training simulation lab at academic medical center. Methods: Medical students and surgical residents performed the initial steps of a rhinoplasty procedure without and with a pregnancy simulation suit and were filmed with an artificial intelligence-based video analysis app from Kinetica Labs that calculates joint angles and categorizes the ergonomic risk factors. Still images from videos were taken and analyzed using validated posture-based analysis rubrics. Participants were asked to complete a qualitative questionnaire after the session. Results: Twelve medical students and surgical residents participated in the study. Posture-based analysis indicated increased ergonomics risk factors among trainees when performing a rhinoplasty while wearing the pregnancy suit. Video analysis indicated trends of worsening back angle and shoulder postures. Trainees reported experiencing pain in the neck, suprapubic area, and lower back. They acknowledged the importance of ergonomics in otolaryngology and desired further education about workplace injury risk mitigation. Conclusion: Pregnancy impacts the ergonomics of performing septorhinoplasty and further investigation is required into interventions to reduce risk of WRMSDs.

Prevalence of human papillomavirus in head and neck cancers at tertiary care centers in the United States over time.

BACKGROUND: Human papillomavirus (HPV) is responsible for a growing proportion of oropharyngeal squamous cell carcinomas (OPSCCs) among men and White individuals. Whether similar trends apply to women, non-Whites, and non-oropharyngeal squamous cell carcinomas (non-OPSCCs) is unknown. METHODS: This is a cross-sectional analysis combining 2 multi-institutional case series of incident head and neck squamous cell carcinoma (HNSCC) cases. Incident HNSCCs from 1995 to 2012 were enrolled retrospectively using banked tumor samples and medical record abstraction. Incident HNSCCs from 2013 to 2019 were enrolled prospectively. The prevalence of tumor HPV biomarkers was tested over 3 time periods (1995-2003, 2004-2012, and 2013-2019). Centralized testing was done for p16 immunohistochemistry (p16) and oncogenic HPV in situ hybridization (ISH). RESULTS: A total of 1209 incident cases of HNSCC were included. Prevalence of p16- and ISH-positive tumors increased significantly for oropharynx cancers over time. The majority were positive after 2013 for White patients (p16, 92%; P < .001; ISH 94%; P < .001), Black patients (p16, 72%; P = .021; ISH 67%; P = .011), and Hispanic patients (p16, 100%; P = .04; ISH 100%; P = .013). For women with OPSCC, the prevalence of p16- and ISH-positive tumors increased significantly to 82% (P < .001) and 78% (P = .004), respectively. For non-OPSCCs, there was increased p16 and ISH positivity overall with 24% p16 and 16% ISH positivity in the most recent time period (P < .001 for both). CONCLUSIONS: The majority of OPSCCs in US tertiary care centers are now p16 and ISH positive for all sex and race groups. In some populations in the United States, 91% of OPSCCs are now caused by HPV. Few non-OPSCCs are p16 and ISH positive.

Oral Human Papillomavirus Associated With Differences in Oral Microbiota Beta Diversity and Microbiota Abundance.

BACKGROUND: Although cervicovaginal microbiome has been associated with cervical human papillomavirus (HPV) infection, little is known regarding the association of oral microbiome with oral HPV, a cause of oropharyngeal cancer. METHODS: A cross-sectional analysis of 495 participants from the Men and Women Offering Understanding of Throat HPV study was conducted. 16S rRNA gene amplicon sequencing was performed on saliva samples. HPV DNA in oral rinse samples was tested. Associations of oral microbiome diversity, taxon abundance, and predicted functional pathways with oral HPV were assessed, adjusting for age, race/ethnicity, education, human immunodeficiency virus, current smoking, and sequencing batch. RESULTS: Participants with oral HPV (n = 68) compared with those without HPV had similar oral microbiome alpha-diversity yet different beta-diversity (Bray-Curtis distance for bacterial taxa, P = .009; functional pathways, P = .02). Participants with oral HPV had higher abundance of Actinomycetaceae, Prevotellaceae, Veillonellaceae, Campylobacteraceae, Bacteroidetes, and lower abundance of Gemellaceae (false discovery rate <0.10). We also found differential functional potential of oral microbiome by oral HPV status: xenobiotic biodegradation-related pathways were less abundant among participants with oral HPV, suggesting potential xenobiotic-induced toxic effects with implications for HPV susceptibility. CONCLUSIONS: Our findings suggest a shift in oral microbiome community structure, composition, and functional potential between individuals with and without oral HPV.

Risk stratification after recurrence of human papillomavirus (HPV)-related and non-HPV-related oropharyngeal cancer: Secondary analysis of NRG Oncology RTOG 0129 and 0522.

BACKGROUND: No risk-stratification strategies exist for patients with recurrent oropharyngeal cancer (OPC). METHODS: Retrospective analysis using data from prospective NRG Oncology clinical trials RTOG 0129 and 0522. Eligibility criteria included known p16 status and smoking history, and locoregional/distant recurrence. Overall survival (OS) was measured from date of recurrence. Recursive partitioning analysis was performed to produce mutually exclusive risk groups. RESULTS: Hundred and fifty-four patients were included with median follow-up after recurrence of 3.9 years (range 0.04-9.0). The most important factors influencing survival were p16 status and type of recurrence, followed by surgical salvage and smoking history (≤20 vs. >20 pack-years). Three significantly different risk groups were identified. Patients in the low-, intermediate-, and high-risk groups had 2-year OS after recurrence of 81.1% (95%CI 68.5-93.7), 50.2% (95%CI 36.0-64.5), and 20.8% (95%CI 10.5-31.1), respectively. CONCLUSION: Patient and tumor characteristics may be used to stratify patients into risk groups at the time of OPC recurrence.

Development of a web-based, patient-centered decision aid for oropharyngeal cancer treatment.

OBJECTIVES: Many patients diagnosed with oropharyngeal squamous cell carcinoma (OPSCC) have the option of radiation- or surgery-based therapy, and would benefit from a treatment decision aid (DA) to make decisions congruent with their personal values. Our objective was to develop a patient-centered DA for patients with OPSCC that is comprehensible, usable, acceptable, and well-designed. MATERIALS AND METHODS: Decisional needs from a pilot study of OPSCC survivors and treating physicians were used to inform a web-based prototype DA. A multidisciplinary steering group developed and iteratively revised the DA. Feasibility testing was conducted in two cycles to assess perspectives of stakeholders (medical, radiation and surgical oncologists, patient education experts, and OPSCC survivors). Survey data and open-ended responses were used to evaluate and refine the DA. RESULTS: 16 physicians, 4 patient education experts, and 6 survivors of OPSCC evaluated a web-based DA prototype in two cycles of testing. Participant feedback was used to revise the DA content and design between cycles. The majority of participants across both cycles indicated that the DA was comprehensible (97%), usable (86%), acceptable (78%), and well-designed (93%). Approximately three quarters of respondents indicated that they would use or share the DA in clinical practice. CONCLUSION: We developed the first patient-centered treatment decision aid (DA) designed for patients with OPSCC, to our knowledge. The DA was perceived favorably by stakeholders, with more than three quarters of respondents indicating they would use it in clinical practice. This tool may improve clinical practice as an adjunct to shared decision-making for OPSCC.

Biologic and behavioral associations of estrogen receptor alpha positivity in head and neck squamous cell carcinoma.

OBJECTIVES: Tumor HPV status is an established independent prognostic marker for oropharynx cancer (OPC). Recent studies have reported that tumor estrogen receptor alpha (ERα) positivity is also associated with prognosis independent of HPV. Little is known about the biologic and behavioral predictors of ERα positivity in head and neck squamous cell cancer (HNSCC). We therefore explored this in a multicenter prospective cohort study. MATERIALS AND METHODS: Participants with HNSCC completed a survey and provided a blood sample. Tumor samples were tested for ERα using immunohistochemistry. ERα positivity was defined as ≥1%, standardized by the American Society of Clinical Oncology/College of American Pathologists in breast cancer. Characteristics were compared with χ2 and Fisher's exact test. Odds ratios (OR) were calculated using logistic regression. RESULTS: Of 318 patients with HNSCC, one third had ERα positive tumors (36.2%, n = 115). Odds of ERα expression were significantly increased in those with HPV-positive tumors (OR = 27.5, 95% confidence interval[CI] 12.1-62), smaller tumors (≤T2, OR = 3.6, 95% CI 1.9-7.1), male sex (OR = 2.0, 95% CI 1.1-3.6), overweight/obesity (BMI ≥ 25, OR = 1.9, 95% CI 1.1-3.3), and those married/living with a partner (OR = 1.7, 95% CI 1.0-3.0). In a multivariate model, HPV-positivity (aOR = 27.5, 95% CI 11.4-66) and small tumor size (≤T2, aOR = 2.2, 95% CI 1.0-4.8) remained independently associated with ERα status. When restricted to OPC (n = 180), tumor HPV status (aOR = 17.1, 95% CI 2.1-137) and small tumor size (≤T2, aOR = 4.0 95% CI 1.4-11.3) remained independently associated with ERα expression. CONCLUSION: Tumor HPV status and small tumor size are independently associated with ERα expression in HNSCC.

RTOG-0129 risk groups are reproducible in a prospective multicenter heterogeneously treated cohort.

BACKGROUND: Recursive partitioning analysis (RPA) from the Radiation Therapy Oncology Group (RTOG)-0129 has identified a low-risk group of patients with oropharynx cancer (OPC) who might benefit from therapeutic de-intensification. These risk groups have not yet been reproduced in an independent cohort treated heterogeneously. Therefore, the objective of this analysis was to validate the RPA risk groups and examine the prognostic impact of novel factors. METHODS: Patients with OPC were enrolled in a prospective study at 3 academic medical centers from 2013 to 2018. Medical record abstraction was used to ascertain clinical variables including staging and survival according to the 7th edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual. Human papillomavirus-positive tumor status was determined by p16 immunohistochemistry and/or HPV RNA in situ hybridization. Kaplan-Meier and log-rank methods were used to compare survival. Cox proportional hazards were used to generate univariate and multivariable hazard ratios (HRs). RESULTS: Median follow-up time was 3.2 years. The low-, intermediate-, and high-risk groups had significant differences in 2-year overall survival (OS, 99.1%; 95% CI, 94.4%-99.9% vs OS, 93.0%; 95% CI, 74.7%-98.2% vs OS, 80.0%; 95% CI, 40.9%-94.6%; Poverall = .0001) and 2-year progression-free survival (PFS, 97.5%; 95% CI, 92.4%-99.2% vs PFS, 89.3%; 95% CI, 70.3%-96.4% vs PFS, 80.0%; 95% CI, 40.9%-94.6%; Poverall < .002). After adjustment for age, sex, and level of educational attainment, OS and PFS were significantly lower for the intermediate- (OS adjusted hazard ratio [aHR], 5.0; 95% CI, 1.0-23.0; PFS aHR, 3.4; 95% CI, 1.0-11.5), and high- (OS aHR, 7.3; 95% CI, 1.4-39; PFS aHR, 5.0; 95% CI, 1.2-21.6) risk groups compared with the low-risk group. Lower education was also independently significantly associated with worse OS (aHR, 8.9; 95% CI, 1.8-44.3) and PFS (aHR, 3.1; 95% CI, 1.0-9.6). CONCLUSIONS: In patients with OPC, the RTOG-0129 RPA model is associated with OS and PFS in a heterogeneously treated cohort.

Treatment decision-making among patients with oropharyngeal squamous cell cancer: A qualitative study.

Oropharyngeal squamous cell cancer (OPSCC) is now the most common site of head and neck squamous cell cancer. Despite the focus on treatment deintensification in clinical trials, little is known about the preferences, experiences and needs of patients with OPSCC when deciding between surgery and radiation therapy as primary treatment with curative intent. In this qualitative study, pre-treatment and post-treatment oropharyngeal cancer patients were recruited to take part in one-on-one interviews (n = 11 pre-treatment) and focus group discussions (n = 15 post-treatment) about treatment decision-making. Recordings were transcribed and assessed for emergent themes using framework analysis. From the one-on-one interviews and focus group discussions with OPSCC patients, fourteen themes were identified. Participants expressed alarm at diagnosis, decisional conflict, and a variety of roles in decision-making (physician-controlled, shared, and autonomous). Decisions were driven by the perceived recommendation of the treatment team, a desire for physical (surgical) tumor removal, fear of adverse effects of treatment, and patient-specific values. Although participants felt well-informed by their treating physicians, they identified a need for additional patient-centered information. Participants were critical of the poor quality of information available on the internet, and acknowledged the advantage of hearing the experiences of post-treatment patients. The experiences identified herein may be used to guide patient-centered communication during patient counseling and to inform interventions designed to support patients' needs at diagnosis, ultimately helping to implement high-quality, patient-centered care.

Interrogating the immune-modulating roles of radiation therapy for a rational combination with immune-checkpoint inhibitors in treating pancreatic cancer.

BACKGROUND: Radiation therapy (RT) has the potential to enhance the efficacy of immunotherapy, such as checkpoint inhibitors, which has dramatically altered the landscape of treatments for many cancers, but not yet for pancreatic ductal adenocarcinoma (PDAC). Our prior studies demonstrated that PD ligand-1 and indoleamine 2,3-dioxygenase 1 (IDO1) were induced on tumor epithelia of PDACs following neoadjuvant therapy including RT, suggesting RT may prime PDAC for PD-1 blockade antibody (αPD-1) or IDO1 inhibitor (IDO1i) treatments. In this study, we investigated the antitumor efficacy of the combination therapies with radiation and PD-1 blockade or IDO1 inhibition or both. METHODS: We developed and used a mouse syngeneic orthotopic model of PDAC suitable for hypofractionated RT experiments. RESULTS: The combination therapy of αPD-1 and RT improved survival. The dual combination of RT/IDO1i and triple combination of RT/αPD-1/IDO1i did not improve survival compared with RT/αPD-1, although all of these combinations offer similar local tumor control. RT/αPD-1 appeared to result in the best systemic interferon-γ response compared with other treatment groups and the highest local expression of immune-activation genes, including Cd28 and Icos. CONCLUSION: Our RT model allows examining the immune-modulatory effects of RT alone and in combination with immune-checkpoint inhibitors in the pancreas/local microenvironment. This study highlights the importance of choosing the appropriate immune-modulatory agents to be combined with RT to tip the balance toward antitumor adaptive immune responses.

Deintensification of treatment for human papillomavirus-related oropharyngeal cancer: Current state and future directions.

Human papillomavirus (HPV)-related oropharyngeal squamous cell cancer (OPSCC) has emerged as a distinct clinical entity of head and neck cancer with expected high survival. This recognition has led to the investigation of whether a population of patients can be identified who can safely undergo treatment de-escalation, in an effort to minimize long-term treatment toxicity while maintaining excellent survival. The purpose of this review is to describe the rationale for treatment deintensification for HPV-related OPSCC, summarize available results from published clinical trials, explore the methods by which risk groups are assigned, and provide context for the multitude of clinical trials that are currently underway.

Burden of comorbidities is higher among elderly survivors of oropharyngeal cancer compared with controls.

BACKGROUND: The prevalence of survivors of oropharyngeal cancer (OPC) is increasing due to improved survival for individuals with human papillomavirus (HPV)-related disease. Although elderly survivors of OPC are known to have a high burden of comorbidities, to the authors' knowledge it is unknown how this compares with a similar cohort without a history of cancer. METHODS: The current retrospective, cross-sectional study included individuals with a first incident primary diagnosis of OPC from 2004 through 2011 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked databases and matched controls. The baseline prevalence and subsequent incidence of comorbid conditions were identified. The association between comorbidity and overall survival was evaluated. RESULTS: A total of 2497 eligible patients with OPC were matched to 4994 noncancer controls. Baseline comorbidity was higher in cases (Charlson Comorbidity Index >0 for 48.5% of cases vs 35.8% of controls). At 5 years, cases were more likely than controls to develop comorbidities. Survivors of OPC were at high risk (≥20% cumulative prevalence by 5 years) of developing several comorbidities, including cardiovascular diseases, cerebrovascular disease, chronic obstructive pulmonary disease, and tobacco abuse, and were at moderately high risk (10%-19% cumulative prevalence) of developing other conditions including carotid artery occlusive stroke, alcohol abuse, depression, and anxiety. In both cases and controls, the presence of the majority of comorbidities either at the time of diagnosis or during the follow-up period was associated with worse survival. CONCLUSIONS: Patients with OPC have a higher comorbidity burden compared with matched controls, both at baseline and during survivorship, the majority of which are associated with decreased survival. Oncologic surveillance of survivors of OPC should include screening for highly prevalent conditions.

PD-1/PD-L1 blockade together with vaccine therapy facilitates effector T-cell infiltration into pancreatic tumors.

Pancreatic ductal adenocarcinoma (PDA) has a poor prognosis due to late detection and resistance to conventional therapies. Published studies show that the PDA tumor microenvironment is predominantly infiltrated with immune suppressive cells and signals that if altered, would allow effective immunotherapy. However, single-agent checkpoint inhibitors including agents that alter immune suppressive signals in other human cancers such as cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed death 1 (PD-1), and its ligand PD-L1, have failed to demonstrate objective responses when given as single agents to PDA patients. We recently reported that inhibition of the CTLA-4 pathway when given together with a T cell inducing vaccine gives objective responses in metastatic PDA patients. In this study, we evaluated blockade of the PD-1/PD-L1 pathway. We found that PD-L1 is weakly expressed at a low frequency in untreated human and murine PDAs but treatment with a granulocyte macrophage colony-stimulating factor secreting PDA vaccine (GVAX) significantly upregulates PD-L1 membranous expression after treatment of tumor-bearing mice. In addition, combination therapy with vaccine and PD-1 antibody blockade improved murine survival compared with PD-1 antibody monotherapy or GVAX therapy alone. Furthermore, PD-1 blockade increased effector CD8 T lymphocytes and tumor-specific interferon-γ production of CD8 T cells in the tumor microenvironment. Immunosuppressive pathways, including regulatory T cells and CTLA-4 expression on T cells were overcome by the addition of vaccine and low-dose cyclophosphamide to PD-1 blockade. Collectively, our study supports combining PD-1 or PD-L1 antibody therapy with a T cell inducing agent for PDA treatment.

The prognostic value of stroma in pancreatic cancer in patients receiving adjuvant therapy.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDA) is comprised of a prominent desmoplastic stromal compartment and only 10-40% of the tumour consists of PDA cells. However, how stromal components should be assessed and how the characteristics of the stromal compartment determine clinical outcomes in PDA patients remain unknown. METHOD: A cohort of 66 consecutive patients who underwent pancreaticoduodenectomy and were primarily followed at Johns Hopkins Hospital between 1998 and 2004, and treated with adjuvant therapy, were included in a retrospective analysis. Resected PDA blocks with good tissue preservation were available for all patients. A new, computer-aided, quantitative method was developed to assess the density and activity of stroma in PDAs and the associations of these characteristics with clinical outcomes. RESULTS: High stromal density in resected PDA was found to be significantly associated with longer disease-free [adjusted hazard ratio (aHR) 0.39; P = 0.001] and overall (aHR 0.44; P = 0.004) survival after adjusting for the use of pancreatic cancer vaccine therapy, as well as gender and resection margin positivity. Stromal activity, representing activated pancreatic stellate cells in PDAs, was not significantly associated with the prognosis of resected PDAs. CONCLUSIONS: These results illustrate the complexity of the role of stroma in PDAs. Further exploration of the prognostic ability of the characteristics of stroma is warranted.

Immunotherapy converts nonimmunogenic pancreatic tumors into immunogenic foci of immune regulation.

Pancreatic ductal adenocarcinoma (PDAC) is considered a "nonimmunogenic" neoplasm. Single-agent immunotherapies have failed to demonstrate significant clinical activity in PDAC and other "nonimmunogenic" tumors, in part due to a complex tumor microenvironment (TME) that provides a formidable barrier to immune infiltration and function. We designed a neoadjuvant and adjuvant clinical trial comparing an irradiated, granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting, allogeneic PDAC vaccine (GVAX) given as a single agent or in combination with low-dose cyclophosphamide to deplete regulatory T cells (Treg) as a means to study how the TME is altered by immunotherapy. Examination of resected PDACs revealed the formation of vaccine-induced intratumoral tertiary lymphoid aggregates in 33 of 39 patients 2 weeks after vaccine treatment. Immunohistochemical analysis showed these aggregates to be regulatory structures of adaptive immunity. Microarray analysis of microdissected aggregates identified gene-expression signatures in five signaling pathways involved in regulating immune-cell activation and trafficking that were associated with improved postvaccination responses. A suppressed Treg pathway and an enhanced Th17 pathway within these aggregates were associated with improved survival, enhanced postvaccination mesothelin-specific T-cell responses, and increased intratumoral Teff:Treg ratios. This study provides the first example of immune-based therapy converting a "nonimmunogenic" neoplasm into an "immunogenic" neoplasm by inducing infiltration of T cells and development of tertiary lymphoid structures in the TME. Post-GVAX T-cell infiltration and aggregate formation resulted in the upregulation of immunosuppressive regulatory mechanisms, including the PD-1-PD-L1 pathway, suggesting that patients with vaccine-primed PDAC may be better candidates than vaccine-naïve patients for immune checkpoint and other immunomodulatory therapies.

Low total lymphocyte count is associated with poor survival in patients with resected pancreatic adenocarcinoma receiving a GM-CSF secreting pancreatic tumor vaccine.

BACKGROUND: Low total lymphocyte count (TLC) and lymphocyte-to-neutrophil ratio have been found to be poor prognostic indicators in several different tumor types at various stages. Although immune-based therapies are under rapid development, it is not known whether baseline complete blood counts, particularly lymphocytes, are associated with the clinical outcomes of patients receiving immunotherapies. METHODS: We performed a retrospective analysis of complete blood count for 59 patients enrolled onto a phase II trial evaluating the integration of an adjuvant immunotherapy-irradiated granulocyte-macrophage colony-stimulating factor (GM-CSF) secreting allogeneic pancreatic tumor vaccine (GVAX)-with standard chemoradiation. RESULTS: After adjusting for nodal status, individuals with a TLC of <1,500 cells/mm(3) (10 patients) had significantly higher risk, both in terms of overall survival (OS) [adjusted hazard ratio 2.63, 95 % confidence interval (CI) 1.22-5.67, p = 0.013] and progression-free survival (adjusted hazard ratio 3.07, 95 % CI 1.03-6.93, p = 0.003), compared to those with a TLC of ≤ 1,500 cells/mm(3) (49 patients). Adjuvant chemoradiation significantly reduced lymphocyte counts from baseline values. Patients with suppression of their lymphocytes to <500 cells/mm(3) after chemoradiation also had shorter disease-free and OS. CONCLUSIONS: Immunosuppressive conditions associated with surgical procedures and chemoradiation may affect the efficacy of immunotherapy.

Immunohistochemical staining of B7-H1 (PD-L1) on paraffin-embedded slides of pancreatic adenocarcinoma tissue.

B7-H1/PD-L1, a member of the B7 family of immune-regulatory cell-surface proteins, plays an important role in the negative regulation of cell-mediated immune responses through its interaction with its receptor, programmed death-1 (PD-1). Overexpression of B7-H1 by tumor cells has been noted in a number of human cancers, including melanoma, glioblastoma, and carcinomas of the lung, breast, colon, ovary, and renal cells, and has been shown to impair anti-tumor T-cell immunity. Recently, B7-H1 expression by pancreatic adenocarcinoma tissues has been identified as a potential prognostic marker. Additionally, blockade of B7-H1 in a mouse model of pancreatic cancer has been shown to produce an anti-tumor response. These data suggest the importance of B7-H1 as a potential therapeutic target. Anti-B7-H1 blockade antibodies are therefore being tested in clinical trials for multiple human solid tumors including melanoma and cancers of lung, colon, kidney, stomach and pancreas. In order to eventually be able to identify the patients who will benefit from B7-H1 targeting therapies, it is critical to investigate the correlation between expression and localization of B7-H1 and patient response to treatment with B7-H1 blockade antibodies. Examining the expression of B7-H1 in human pancreatic adenocarcinoma tissues through immunohistochemistry will give a better understanding of how this co-inhibitory signaling molecule contributes to the suppression of antitumor immunity in the tumor's microenvironment. The anti-B7-H1 monoclonal antibody (clone 5H1) developed by Chen and coworkers has been shown to produce reliable staining results in cryosections of multiple types of human neoplastic tissues, but staining on paraffin-embedded slides had been a challenge until recently. We have developed the B7-H1 staining protocol for paraffin-embedded slides of pancreatic adenocarcinoma tissues. The B7-H1 staining protocol described here produces consistent membranous and cytoplasmic staining of B7-H1 with little background.