Reappraisal of p16 for Determining HPV Status of Head and Neck Carcinomas Arising in HPV Hotspots

In an era of head and neck oncology where HPV status will soon dictate patient management, reliable HPV detection is critical. P16 immunohistochemistry (IHC) is currently recommended as the test of choice for oropharyngeal squamous cell carcinomas (OPSCCs). The purpose of this study was to determine the performance characteristics of p16 IHC based on a large clinical experience of squamous cell carcinomas (SCC) arising from HPV hot-spot regions of the head and neck. Consecutive OPSCCs, sinonasal SCCs, and metastatic SCCs of unknown primary sites were evaluated for the presence of HPV by p16 IHC and PCR-based HPV DNA testing as part of clinical care. For discrepant cases, high-risk HPV E6/E7 mRNA in situ hybridization (ISH) and, when possible, matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MassArray) genotyping were performed. 746 cancers underwent HPV testing by p16 IHC and DNA PCR genotyping. There was a 95.6% concordance between the 2 assays. Of the 33 discrepant cases, 32 cases (4.3%) were p16 positive but HPV DNA negative. In these cases, 68% were positive for mRNA ISH, invariably related to a non-16 HPV genotype. P16 IHC had an overall accuracy of 98.8%, a sensitivity of 99.8%, and a specificity of 92.1%. P16 IHC is a sensitive and specific assay for determining HPV status. HPV DNA PCR appears vulnerable to HPV genotype diversity and is prone to missing rare non-16 genotypes. HPV mRNA ISH is a practical and reliable direct measure of HPV that may help eliminate the small number of false-positive p16 cases and avoid potential patient harm related to erroneous HPV classification.

Recurrent Wnt Pathway and ARID1A Alterations in Sinonasal Olfactory Carcinoma

Sinonasal tumors with neuroepithelial differentiation, defined by neuroectodermal elements reminiscent of olfactory neuroblastoma (ONB) and epithelial features such as keratin expression or gland formation, are a diagnostically challenging group that has never been formally included in sinonasal tumor classifications. Recently, we documented that most of these neuroepithelial neoplasms have distinctive histologic and immunohistochemical findings and proposed the term "olfactory carcinoma" to describe these tumors. However, the molecular characteristics of olfactory carcinoma have not yet been evaluated. In this study, we performed targeted molecular profiling of 23 sinonasal olfactory carcinomas to further clarify their pathogenesis and classification. All tumors included in this study were composed of high-grade neuroectodermal cells that were positive for pankeratin and at least 1 specific neuroendocrine marker. A significant subset of cases also displayed rosettes and neurofibrillary matrix, intermixed glands with variable cilia, peripheral p63/p40 expression, and S100 protein-positive sustentacular cells. Recurrent oncogenic molecular alterations were identified in 20 tumors, including Wnt pathway alterations affecting CTNNB1 (n = 8) and PPP2R1A (n = 2), ARID1A inactivation (n = 5), RUNX1 mutations (n = 3), and IDH2 hotspot mutations (n = 2). Overall, these findings do demonstrate the presence of recurrent molecular alterations in olfactory carcinoma, although this group of tumors does not appear to be defined by any single mutation. Minimal overlap with alterations previously reported in ONB also adds to histologic and immunohistochemical separation between ONB and olfactory carcinoma. Conversely, these molecular findings enhance the overlap between olfactory carcinoma and sinonasal neuroendocrine carcinomas. A small subset of neuroepithelial tumors might better fit into the superseding molecular category of IDH2-mutant sinonasal carcinoma. At this point, sinonasal neuroendocrine and neuroepithelial tumors may best be regarded as a histologic and molecular spectrum that includes core groups of ONB, olfactory carcinoma, neuroendocrine carcinoma, and IDH2-mutant sinonasal carcinoma.

Circulating Tumor HPV DNA in Patients With Head and Neck Carcinoma: Correlation With HPV Genotyping

Circulating tumor human papillomavirus DNA (ctHPVDNA) testing using digital-droplet polymerase chain reaction (PCR) detects fragments of tumor-modified human papillomavirus (HPV) in the plasma of patients with HPV-associated head and neck squamous cell carcinomas (HNSCCs). Its impact on tumor surveillance and primary diagnosis is limited by unresolved issues relating to sensitivity and specificity. The study population consisted of patients with HNSCC who had undergone ctHPVDNA testing. HPV status was determined by p16 immunohistochemistry and PCR-HPV genotyping on the tumor samples. For discrepant cases (HPV-positive/ctHPVDNA-negative), HPV status was confirmed by RNA in situ hybridization and, when possible, targeted single-nucleotide polymorphisms genotyping. A total of 167 patients had ctHPVDNA testing, and 141 tumors were HPV positive by p16 immunohistochemistry and PCR genotyping. Genotypes included types 16 (91.5%), 33 (4.3%), 35 (2.1%), and 18 (2.1%). ctHPVDNA was detected in 133 (94.3%) of HPV-positive HNSCCs but in none of the HPV-negative HNSCCs. Four of the 5 p16-positive cases that were negative by PCR and ctHPVDNA were positive by RNA in situ hybridization, and in 2 of these cases, rare high-risk genotypes were identified. ctHPVDNA had a sensitivity of 91.7%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 63.6%. The likelihood that patients with HPV-positive HNSCC have detectable ctHPVDNA is high. Non-HPV16 genotypes contribute to discrepancies but only in a small subset of cases. This finding validates ongoing efforts to use ctHPVDNA as a surveillance tool, and even as a primary diagnostic assay in patients presenting with masses in the neck and/or oropharynx.

Pulse granuloma presenting as a lateral neck mass: An unusual presentation of a fourth branchial cleft fistula

BACKGROUND

The pulse granuloma (PG) is believed to represent a distinctive foreign body reaction to ingested particles of legumes. Its presentation in the neck is entirely unexpected.

METHODS

A woman presented with a mass of the lower neck that recurred following incision and drainage. The recurrent mass was found to be associated with an open sinus tract at the apex of the left pyriform sinus. The opening of the sinus tract was closed and the cyst was removed.

RESULTS

Histologic examination of the neck mass showed vegetable material with an associated granulomatous reaction known as PG.

CONCLUSIONS

The documentation of a PG arising in the neck would seemingly discredit the legume theory, but it only further supports it. Its association with a fourth branchial cleft cyst provides evidence for the existence of the complete fourth branchial cleft fistula with seeding of ingested material through sinus tract opening.

Multidimensional biomarker predicts disease control in response to immunotherapy in recurrent or metastatic head and neck squamous-cell carcinoma

PURPOSE

Anti-PD-1 therapy provides clinical benefit in 40-50% of patients with relapsed and/or metastatic head and neck squamous cell carcinoma (RM-HNSCC). Selection of anti- PD-1 therapy is typically based on patient PD-L1 immunohistochemistry (IHC) which has low specificity for predicting disease control. Therefore, there is a critical need for a clinical biomarker that will predict clinical benefit to anti-PD-1 treatment with high specificity.

METHODS

Clinical treatment and outcomes data for 103 RM-HNSCC patients were paired with RNA-sequencing data from formalin-fixed patient samples. Using logistic regression methods, we developed a novel biomarker classifier based on expression patterns in the tumor immune microenvironment to predict disease control with monotherapy PD-1 inhibitors (pembrolizumab and nivolumab). The performance of the biomarker was internally validated using out-of-bag methods.

RESULTS

The biomarker significantly predicted disease control (65% in predicted non-progressors vs. 17% in predicted progressors, p < 0.001) and was significantly correlated with overall survival (OS; p = 0.004). In addition, the biomarker outperformed PD-L1 IHC across numerous metrics including sensitivity (0.79 vs 0.64, respectively; p = 0.005) and specificity (0.70 vs 0.61, respectively; p = 0.009).

CONCLUSION

This novel assay uses tumor immune microenvironment expression data to predict disease control and OS with high sensitivity and specificity in patients with RM-HNSCC treated with anti-PD-1 monotherapy.

Performance of Liquid Biopsy for Diagnosis and Surveillance of Human Papillomavirus-Associated Oropharyngeal Cancer

Importance

There is growing interest in the use of circulating plasma tumor human papillomavirus (HPV) DNA for diagnosis and surveillance of patients with HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). Recent advances in the assays, combining the identification of circulating HPV tumor DNA and tumor DNA fragment analysis (tumor tissue-modified viral [TTMV]-HPV DNA), have been shown to be highly accurate. However, use of these newer techniques has been limited to small cohort studies and clinical trials.

Objective

To establish the clinical efficacy of plasma TTMV-HPV DNA testing in the diagnosis and surveillance of HPV-associated OPSCC in a contemporary clinical setting.

Design, Setting, and Participants

This retrospective observational cohort study included patients with OPSCC who underwent TTMV-HPV DNA testing between April 2020 and September 2022 during the course of routine clinical care. For the diagnosis cohort, patients with at least 1 TTMV-HPV DNA measurement prior to initiation of primary therapy were included. Patients were included in the surveillance cohort if they had at least 1 TTMV-HPV DNA test performed after completion of definitive or salvage therapy.

Main Outcomes and Measures

Per-test performance metrics, including sensitivity, specificity, positive predictive value, and negative predictive value, for TTMV-HPV DNA testing.

Results

Of 399 patients included in the analysis, 163 were in the diagnostic cohort (median [IQR] age, 63 [56-68.5] years; 142 [87.1%] male), and 290 were in the surveillance cohort (median [IQR] age, 63 [57-70] years; 237 [81.7%] male). Of the 163 patients in the diagnostic cohort, 152 (93.3%) had HPV-associated OPSCC while 11 (6.7%) had HPV-negative OPSCC. The TTMV-HPV DNA sensitivity in pretreatment diagnosis was 91.5% (95% CI, 85.8%-95.4% [139 of 152 tests]), and the specificity was 100% (95% CI, 71.5%-100% [11 of 11 tests]). In the surveillance cohort, 591 tests conducted in 290 patients were evaluated. A total of 23 patients had molecularly confirmed pathologic recurrences. The TTMV-HPV DNA test demonstrated sensitivity of 88.4% (95% CI, 74.9%-96.1% [38 of 43 tests]) and specificity of 100% (95% CI, 99.3%-100% [548 of 548 tests]) in detecting the recurrences. Positive predictive value was 100% (95% CI, 90.7%-100% [38 of 38 tests]), and negative predictive value was 99.1% (95% CI, 97.9%-99.7% [548 of 553 tests]). The median (range) lead time from positive TTMV-HPV DNA test to pathologic confirmation was 47 (0-507) days.

Conclusions and Relevance

This cohort study demonstrated that when evaluated in a clinical setting, the TTMV-HPV DNA assay demonstrated 100% specificity in both diagnosis and surveillance. However, the sensitivity was 91.5% for the diagnosis cohort and 88.4% for the surveillance cohort, signifying that nearly 1 in 10 negative tests among patients with HPV-associated OPSCC was a false negative. Additional research is required to validate the assay's performance and, if validated, then further research into the implementation of this assay into standard clinical practice guidelines will be required.

Intraoperative Use of Wide-Field Optical Coherence Tomography to Evaluate Tissue Microstructure in the Oral Cavity and Oropharynx

Importance

Involvement of deep margins represents a significant challenge in the treatment of oropharyngeal cancer, and given practical limitations of frozen-section analysis, a need exists for real-time, nondestructive intraoperative margin analysis. Wide-field optical coherence tomography (WF-OCT) has been evaluated as a tool for high-resolution adjunct specimen imaging in breast surgery, but its clinical application in head and neck surgery has not been explored.

Objective

To evaluate the utility of WF-OCT for visualizing microstructures at margins of excised oral and oropharyngeal tissue.

Design, Setting, and Participants

This nonrandomized, investigator-initiated qualitative study evaluated the feasibility of the Perimeter Medical Imaging AI Otis WF-OCT device at a single academic center. Included participants were adults undergoing primary ablative surgery of the oral cavity or oropharynx for squamous cell carcinoma in 2018 and 2019. Data were analyzed in October 2019.

Exposures

Patients were treated according to standard surgical care. Freshly resected specimens were imaged with high-resolution WF-OCT prior to routine pathology. Interdisciplinary interpretation was performed to interpret WF-OCT images and compare them with corresponding digitized pathology slides. No clinical decisions were made based on WF-OCT image data.

Main Outcomes and Measures

Visual comparisons were performed between WF-OCT images and hematoxylin and eosin slides.

Results

A total of 69 specimens were collected and scanned from 53 patients (mean [SD] age, 59.4 [15.2] years; 35 [72.9%] men among 48 patients with demographic data) undergoing oral cavity or oropharynx surgery for squamous cell carcinoma, including 42 tonsillar tissue, 17 base of the tongue, 4 buccal tissue, 3 mandibular, and 3 other specimens. There were 41 malignant specimens (59.4%) and 28 benign specimens (40.6%). In visual comparisons of WF-OCT images and hematoxylin and eosin slides, visual differentiation among mucosa, submucosa, muscle, dysplastic, and benign tissue was possible in real time using WF-OCT images. Microarchitectural features observed in WF-OCT images could be matched with corresponding features within the permanent histology with fidelity.

Conclusions and Relevance

This qualitative study found that WF-OCT imaging was feasible for visualizing tissue microarchitecture at the surface of resected tissues and was not associated with changes in specimen integrity or surgical and pathology workflow. These findings suggest that formal clinical studies investigating use of WF-OCT for intraoperative analysis of deep margins in head and neck surgery may be warranted.

Melanotic medullary thyroid carcinoma: A case report with review of the literature

Melanotic medullary thyroid carcinoma is morphologically defined by the presence of melanin deposits in the cytoplasm of tumor cells. It is an extremely rare variant with only 15 cases described in the literature to date and only one report of diagnosis by fine needle aspiration (FNA) biopsy. A 51-year-old woman presented with neck swelling. An ultrasound examination revealed a single solid nodule in the right thyroid lobe that measured 5.4 × 4.7 × 4.3 cm. Laboratory examination revealed elevated levels of serum calcitonin (8643.0 pg/ml), carcinoembryonic antigen (CEA) (86.2 ng/ml), and chromogranin A (123.2 ng/ml). An FNA biopsy of the thyroid nodule revealed predominantly single plasmacytoid cells with round to oval eccentric nuclei and dark brown intracytoplasmic granules. Immunohistochemical studies with Melan-A performed on a cell block slide confirmed that the granules contained melanin. The tumor cells were also positive for calcitonin, CEA, synaptophysin, AE1/AE3, CAM5.2, and HMB-45(focal); the tumor cells were negative for chromogranin, thyroglobulin, PAX8 and TTF-1. The diagnosis was reported as melanotic variant of medullary thyroid carcinoma. The patient underwent a total thyroidectomy which revealed tumor cell expression of insulinoma-associated protein 1 and confirmed neuroendocrine differentiation. Shortly after she presented with tumor recurrence in the thyroidectomy bed. The tumor cells were positive for only S100, SOX10, and Melan-A. Molecular analysis with the SEMA4 Solid Tumor Panel revealed mutations in the HRAS, PIK3CA, PIK3R1, MYC, and CCND3 genes. The final diagnosis was reported as melanocytic medullary thyroid carcinoma with high grade transformation and loss of epithelial and neuroendocrine expression.

High-risk HPV infection-associated hypermethylated genes in oropharyngeal squamous cell carcinomas

Background

HPV-positive oropharyngeal squamous cell carcinomas (OPSCCs) are sensitive to chemo-radiation therapy and have favorable survival outcomes compared with HPV-negative cancers. These tumors are usually not related to tobacco and alcohol exposure. Therefore, diagnosing HPV-positive OPSCCs for the appropriate disease management is crucial, and no suitable markers are available for detecting early malignancies in HPV-infected tissues. In this study, we attempt to find HPV-specific epigenetic biomarkers for OPSCCs.

Methods

A total of 127 surgical samples were analyzed for HPV positivity and promoter methylation of a panel of genes. HPV detection was performed by PCR detection of HPV E6 and E7 viral oncoproteins. In addition, promoter methylation of a total of 8 genes (DAPK, FHIT, RASSF1A, TIMP3, AGTR1, CSGALNACT2, GULP1 and VGF) was analyzed by quantitative-methylation specific PCR (QMSP), and their associations with HPV positivity or RB/p16 expressions were evaluated.

Results

AGTR1 and FHIT were frequently methylated in HPV-positive OPSCC samples with a good area under the curve (AUC over 0.70). In addition, these genes' promoter methylation was significantly associated with p16 positive and RB negative cases, which were the characteristics of OPSCC cases with favorable survival outcomes. Either AGTR1 or FHIT methylated cases were significantly associated with HPV-positive cancers with 92.0% sensitivity (P < 0.001). Also, they had significantly better overall survival (P = 0.047) than both unmethylated cases.

Conclusions

A combination of AGTR1 and FHIT methylation demonstrated a suitable detection marker of OPSCCs derived from the HPV-infected field, familiar with p16-positive and RB-negative phenotypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10227-w.

Sinonasal Tumors With Neuroepithelial Differentiation (Olfactory Carcinoma): Delineation of Their Pathologic and Clinical Features With Insights into Their Relationship to Olfactory Neuroblastoma and Sinonasal Carcinoma

Olfactory carcinoma is one of many names applied to sinonasal malignancies with histologic similarity to olfactory neuroblastoma (ONB) but cytokeratin expression or gland formation. It is unclear whether these neuroepithelial tumors represent a unified category and if they are separate from ONB and currently-recognized sinonasal carcinomas. This study aims to explore their clinicopathologic characteristics based on a large collective experience. A total of 53 sinonasal tumors with neuroepithelial differentiation were identified affecting 41 men and 12 women, median age 47 years (range: 12 to 82 y). The vast majority arose in the superior nasal cavity and presented at the high Kadish-Morita stage. Frequent histologic findings included (1) lobulated and solid growth, (2) rosettes and/or neurofibrillary stroma, (3) high-grade cytology, (4) complex, often ciliated glands, (5) nonfocal pancytokeratin expression, (6) neuroendocrine pos+itivity, and (7) variable S100-positive sustentacular cells. Twelve patients with available follow-up (48%) developed progressive disease at a median 8 months (range: 0 to 114 mo to progression), and 7 (28%) died of disease. Despite disparate historical terminology, neuroepithelial differentiation is a recurrent and recognizable histologic pattern that is associated with aggressive behavior in sinonasal tumors. While tumors with this phenotype may originate from olfactory mucosa, well-developed epithelial features warrant separation from conventional ONB and neural elements distinguish them from most sinonasal carcinomas. Although their full histogenesis remains uncertain and some heterogeneity may exist, we propose that this pattern is sufficiently distinctive to merit separate recognition as olfactory carcinoma. Use of consistent nomenclature may facilitate greater recognition of tumors with this phenotype and understanding of their pathogenesis and classification.

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.

This study evaluates the prevalence of p16 and in situ hybridization positivity in head and neck cancers over time. This study shows an increase in prevalence over time among women and non‐Whites, 2 groups that are understudied in the epidemiology of human papillomavirus.

Whole Slide Imaging for Teleconsultation: The Mount Sinai Hospital, Labcorp Dianon, and Philips Collaborative Experience

Background:

With the emergence of whole slide imaging (WSI) and widespread access to high-speed Internet, pathology labs are now poised to implement digital pathology as a way to access diagnostic pathology expertise. This paper describes a collaborative partnership between a high-volume reference diagnostic laboratory (Labcorp) and an academic pathology department (Mount Sinai Hospital) in the transition from a traditional glass slide service to a digital platform. Using the standard framework of implementation science, we evaluate the consistency and quality of the Philips IntelliSite Pathology Solution (PIPS) in delivering save and efficient diagnostic services.

Materials and Methods:

Digital and glass slide diagnoses of all consult cases were documented over a 12-month period. The Proctor guideline was used to quantitatively and qualitatively measure (e.g., focus group studies, field notes, and administrative data) implementation success. Lean techniques (e.g., value stream mapping) were applied to measure changes in efficiency with the transition to a digital platform.

Results:

Our study supports the acceptability, high adoption, appropriateness, feasibility, fidelity, and sustainability of the digital pathology platform. The digital portal also improved the quality of patient care by increasing efficiency, effectiveness, safety, and timeliness. The intraobserver concordance rate was 100%. The digital transition resulted in a reduction in turnaround time from 86 h to an average 35 min and a 20-fold increase in efficiency of the consultation process.

Conclusion:

As the pathology community contemplates digital pathology as a transformational tool in providing broad access to diagnostic expertise across time and space, our study provides an implementation strategy along with evidence that the digital platform is safe, effective, and efficient.

Recurrent PTBP1-MAML2 fusions in composite hemangioendothelioma with neuroendocrine differentiation: A report of two cases involving neck lymph nodes

Composite hemangioendothelioma (CHE) displaying neuroendocrine differentiation is a rare histologic variant that is often mistaken for angiosarcoma, having a predilection for visceral locations and being associated with an aggressive clinical course. Their pathogenesis is still evolving, with only two cases to date from separate studies reporting a recurrent PTBP1-MAML2 fusion. Herein, we report two new cases of neuroendocrine CHE harboring PTBP1-MAML2 fusions occurring in two elderly patients (70-year-old male and 71-year-old female), both involving neck lymph nodes. The first case presented with multifocal cervical lymphadenopathy, while the second case occurred unifocally in an enlarged neck lymph node. Histologically, the tumors displayed heterogenous architectural patterns with areas reminiscent of benign cavernous hemangioma, retiform hemangioendothelioma, epithelioid hemangioendothelioma, and angiosarcoma. Cytologically, the cells were monotonous with round to ovoid nuclei, open to fine chromatin, scant to moderate cytoplasm, and frequent vacuolization. In addition, the first case showed focal solid areas of large epithelioid cells with severe nuclear atypia, enlarged nuclei and prominent nucleoli, resembling epithelioid angiosarcoma. Tumor cells were diffusely positive for vascular markers and focally positive for synaptophysin. In both cases, a next-generation sequencing fusion panel confirmed an in-frame fusion between PTBP1 exon 10 and MAML2 exon 2. One case with clinical follow-up showed stable recurrent disease and metastatic lung deposits following treatment. Both patients were alive at 3 months and 1 year following initial diagnosis. Our findings lend further support to classifying CHE with PTBP1-MAML2 fusions as a distinct variant of CHE with unique clinicopathologic features, including neuroendocrine features.

Microsecretory Adenocarcinoma of Salivary Glands: An Expanded Series of 24 Cases

Microsecretory adenocarcinoma (MSA) is a recently described salivary gland tumor with a characteristic histologic and immunophenotypic profile and recurrent MEF2C-SS18 fusions. Because only six cases of MSA have been published, its complete clinicopathologic spectrum is unclear, and its biologic behavior has not been documented. Here, we present an updated and expanded experience of 24 MSA cases. All cases of MSA were obtained from the authors' files. Immunohistochemistry for S100, SOX10, p63, p40, SMA, calponin, and mammaglobin was performed. Molecular analysis was performed by targeted RNA sequencing, SS18 break apart fluorescence in situ hybridization, and/or reverse transcriptase polymerase chain reaction for MEF2C-SS18 fusion. Clinical follow-up was obtained from medical records. A total of 24 MSA cases were collected, from 13 women and 11 men, ranging from 17 to 83 years (mean 49.5 years). The vast majority (23 of 24) arose in the oral cavity, with the palate (n = 14) and buccal mucosa (n = 6) as the most frequent subsites. Tumors showed consistent histologic features including: (1) microcystic tubules, (2) flattened intercalated duct-like cells, (3) monotonous oval hyperchromatic nuclei, (4) abundant basophilic luminal secretions, (5) fibromyxoid stroma, and (6) circumscribed borders with subtle infiltration. The tumors were very consistently positive for S100 (24 of 24), p63 (24 of 24), and SOX10 (14 of 14) and negative for p40 (0 of 21), calponin (0 of 12) and mammaglobin (0 of 16), while SMA (4 of 20) was variable. MEF2C-SS18 fusion was demonstrated in 21 of 24 cases; in the remaining 3 cases with insufficient RNA, SS18 break apart FISH was positive. Treatment information was available in 17 cases, all of which were managed with surgery only. In 14 cases with follow-up (1-216 months, mean 30), no cases recurred or metastasized. MSA is a distinct salivary gland neoplasm with remarkably consistent clinical, histologic, immunophenotypic, and genetic features that generally behaves in an indolent manner following surgery alone. These observations solidify MSA as a unique, low-grade salivary gland carcinoma that warrants inclusion in the next version of the WHO classification of head and neck tumors.

p16 Immunoreactivity Correlates With Morphologic Diagnosis of HPV-associated Anal Intraepithelial Neoplasia: A Study of 1000 Biopsies

p16 is the most useful diagnostic marker for human papillomavirus (HPV)-associated anogenital lesions. In the cervix, the pattern of p16 immunoreactivity generally correlates with lesion severity. p16 expression in anal intraepithelial neoplasia (AIN) is far less studied. Whether such correlation holds true has to be determined. We correlated the degree and pattern of p16 immunohistochemistry (IHC) results with morphologic diagnoses of 1000 anal squamous and transitional zone biopsy specimens. Using the Lower Anogenital Squamous Terminology criteria, p16 IHC results were classified as block staining, partial staining, or negative. Among 150 samples without morphologic evidence of AIN, p16 was negative in 85% and partial staining in 15%. AIN 1 (n=400) revealed diverse results: 28% negative, 35% partial, and 37% block staining. Among AIN 2 (n=298), 89% were block, 9% partial staining, and 2% negative. AIN 3 (n=152) revealed block (95%) or partial staining (5%). For the detection of AIN 2/3, p16 block staining yielded 91% sensitivity, 73% specificity, 80% positive predictive value, 91% negative predictive value, and a Youden Index of 0.64. Combining block staining and partial staining slightly increased sensitivity (99%) and negative predictive value (98%), but significantly decreased specificity (43%), positive predictive value (59%) and Youden Index (0.42, P<0.001). As with the cervix, p16 immunoreactivity correlates with morphologic diagnoses of AIN. Block staining offers the optimal diagnostic value for AIN 2/3. Caution is required since AIN 1 frequently exhibits block staining; the prognostic value of p16 warrants further investigation.

Tissue-based SARS-CoV-2 detection in fatal COVID-19 infections: Sustained direct viral-induced damage is not necessary to drive disease progression

Coronavirus disease 2019 (COVID-19) is an ongoing pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although viral infection is known to trigger inflammatory processes contributing to tissue injury and organ failure, it is unclear whether direct viral damage is needed to sustain cellular injury. An understanding of pathogenic mechanisms has been handicapped by the absence of optimized methods to visualize the presence and distribution of SARS-CoV-2 in damaged tissues. We first developed a positive control cell line (Vero E6) to validate SARS-CoV-2 detection assays. We then evaluated multiple organs (lungs, kidneys, heart, liver, brain, intestines, lymph nodes, and spleen) from fourteen COVID-19 autopsy cases using immunohistochemistry (IHC) for the spike and the nucleoprotein proteins, and RNA in situ hybridization (RNA ISH) for the spike protein mRNA. Tissue detection assays were compared with quantitative polymerase chain reaction (qPCR)-based detection. SARS-CoV-2 was histologically detected in the Vero E6 positive cell line control, 1 of 14 (7%) lungs, and none (0%) of the other 59 organs. There was perfect concordance between the IHC and RNA ISH results. qPCR confirmed high viral load in the SARS-CoV-2 ISH-positive lung tissue, and absent or low viral load in all ISH-negative tissues. In patients who die of COVID-19-related organ failure, SARS-CoV-2 is largely not detectable using tissue-based assays. Even in lungs showing widespread injury, SARS-CoV-2 viral RNA or proteins were detected in only a small minority of cases. This observation supports the concept that viral infection is primarily a trigger for multiple-organ pathogenic proinflammatory responses. Direct viral tissue damage is a transient phenomenon that is generally not sustained throughout disease progression.

Myeloid Cells Are Enriched in Tonsillar Crypts, Providing Insight into the Host Tropism of Human Papillomavirus

Viruses are the second leading cause of cancer worldwide, and human papillomavirus (HPV)-associated head and neck cancers are increasing in incidence in the United States. HPV preferentially infects the crypts of the tonsils rather than the surface epithelium. The present study sought to characterize the unique microenvironment within the crypts to better understand the host tropism of HPV to a lymphoid-rich organ. Laser-capture microdissection of distinct anatomic areas (crypts, surface epithelium, and germinal centers) of the tonsil, coupled with transcriptional analysis and multiparameter immunofluorescence staining, was performed and demonstrated that the tonsillar crypts are enriched with myeloid populations that co-express multiple canonical and noncanonical immune checkpoints, including PD-L1, CTLA-4, HAVCR2 (TIM-3), ADORA2A, IDO1, BTLA, LGALS3, CDH1, CEACAM1, PVR, and C10orf54 (VISTA). The resident monocytes may foster a permissive microenvironment that facilitates HPV infection and persistence. Furthermore, the myeloid populations within HPV-associated tonsil cancers co-express the same immune checkpoints, providing insight into potential novel immunotherapeutic targets for HPV-associated head and neck cancers.

De-Escalated Adjuvant Therapy After Transoral Robotic Surgery for Human Papillomavirus-Related Oropharyngeal Carcinoma: The Sinai Robotic Surgery (SIRS) Trial

BACKGROUND

Treatment of human papillomavirus-related oropharyngeal squamous cell carcinoma (HPVOPC) results in unprecedented high survival rates but possibly unnecessary toxicity. We hypothesized that upfront surgery and neck dissection followed by reduced-dose adjuvant therapy for early and intermediate HPVOPC would ultimately result in equivalent progression-free survival (PFS) and overall survival while reducing toxicity.

METHODS

This study was a nonrandomized phase II trial for early-stage HPVOPC treated with transoral robotic surgery (TORS) followed by reduced-dose radiotherapy. Patients with previously untreated p16-positive HPVOPC and <20 pack years' smoking history were enrolled. After robotic surgery, patients were assigned to group 1 (no poor risk features; surveillance), group 2 (intermediate pathologic risk factors [perineural invasion, lymphovascular invasion]; 50-Gy radiotherapy), or group 3 (poor prognostic pathologic factors [extranodal extension [ENE], more than three positive lymph nodes and positive margin]; concurrent 56-Gy chemoradiotherapy with weekly cisplatin).

RESULTS

Fifty-four patients were evaluable; there were 25 in group 1, 15 in group 2, and 14 in group 3. Median follow-up was 43.9 months (9.6-75.8). Disease-specific survival was 98.1%, and PFS was 90.7%. PFS probability via Kaplan-Meier was 91.3% for group 1, 86.7% for group 2, and 93.3% for group 3. There were five locoregional failures (LRFs), including one distant metastasis and one contralateral second primary. Average time to LRF was 18.9 months (9.6-59.0); four LRFs were successfully salvaged, and the patients remain disease free (11.0-42.7 months); one subject remains alive with disease.

CONCLUSION

The results indicate that upfront surgery with neck dissection with reduced-dose radiation for T1-2, N1 stage (by the eighth edition American Joint Committee on Cancer staging manual) HPVOPC results in favorable survival with excellent function in this population. These results support radiation dose reduction after TORS as a de-escalation strategy in HPVOPC.

IMPLICATIONS FOR PRACTICE

Transoral robotic surgery can provide a safe platform for de-escalation in carefully selected patients with early-stage human papillomavirus-related oropharyngeal cancer. In this clinical trial, disease-specific survival was 100%, over 90% of the cohort had a reduction of therapy from standard of care with excellent functional results, and the five patients with observed locoregional failures were successfully salvaged.

Redefining risk of contralateral cervical nodal disease in early stage oropharyngeal cancer in the human papillomavirus era

BACKGROUND

The optimal extent of surgery and/or radiation to the contralateral lymph node region is unknown in early-stage human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

To investigate the pathologic incidence of and risk factors for contralateral nodal disease (CND) in cT1-T2 HPV-related OPSCC treated with transoral robotic surgery (TORS) and bilateral neck dissection (BND), the records of 120 patients were reviewed.

RESULTS

Eleven patients displayed pathologic contralateral nodal disease (pCND), including 7.1% of tonsil and 10.9% of base of tongue (BOT) cases. Medial hemistructure involvement and cN2 disease were significantly associated with pCND. Zero cN0 patients had pCND, and on multivariate analysis only cN classification remained significantly associated with pCND. Four percent of BOT patients and 2% of tonsil patients with a well-lateralized primary and cN0/N1 neck demonstrated pCND.

CONCLUSIONS

HPV-related OPSCC that are cN0-N1 have exceedingly low rates of pCND. Well-lateralized HPV-related BOT primaries with limited clinical nodal disease may be candidates for ipsilateral only treatment.

Human papillomavirus genotype distribution in head and neck cancer: Informing developing strategies for cancer prevention, diagnosis, treatment and surveillance

Current clinical practice algorithms for HPV testing make no effort to discern the impact of genotypes for patients with head and neck squamous cell carcinoma (HNSC). Data was collected for all patients with HNSCs that had undergone HPV testing at an academic hospital as part of clinical care (2012-2019). Screening was performed using real-time PCR targeting L1 of low and high-risk HPV types, followed by genotyping of positive cases. Genotype status was correlated with age, site and histologic parameters. Of the 964 patients tested, 68% had HPV-positive cancers. Most arose from the oropharynx (OP) (89%) and sinonasal tract (5%). The most frequent genotype was 16 (84.4%) followed by 35 (5.6%), 33 (4.1%), 18 (2.7%), 45 (1.1%), 69 (0.8%) and others (1.3%). There was an association between genotype (16 vs non-16) and tumor origin (OP vs non-OP) (p < 0.0001). HPV18 was associated with transformation to an aggressive small cell phenotype, but HPV16 was not (22% vs 0%, p < 0.0001). Patients with HPV-non-16 OP carcinomas were older than patients with HPV16 OP carcinomas, but the difference was not significant. HPV genotypes are variable and unevenly distributed across anatomic sites of the head and neck. The association of HPV18 with small cell transformation suggests that variants can track with certain phenotypes in ways that may account for differences in clinical behavior. This study challenges the prevailing assumption of HPV equivalency across all high-risk genotypes in ways that may inform preventive, diagnostic, therapeutic and surveillance strategies.

Liquid phase human papillomavirus genotype analysis of aspirated metastatic head and neck squamous cell carcinoma: Fine needle aspiration supernatant is a rich source of tumor DNA that can increase the diagnostic yield

BACKGROUND

Most patients with human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSC) present with lymph node metastasis. In these patients, fine needle aspiration (FNA) is not only a diagnostic tool, but a means for determining HPV status. HPV status, in turn, is used to determine tumor origin, prognosis, and even guide therapy. Thus, the limited sampling afforded by FNA must be optimized to meet heavy clinical demands.

PURPOSE

The purpose of this study was to determine whether the residual supernatant portion of the FNA could serve as a resource for reliable determination of HPV status DESIGN/METHOD: 25 FNAs from 24 patients with metastatic HNSC underwent HPV genotyping of post-centrifuged supernatant fluid from FNA needle rinses. HPV genotyping was performed using two real time PCR-based assays, the two-step LightCycler and the one-step automated cobas HPV tests. HPV status of the supernatant was compared with the paired FNA cell blocks and/or surgical tissue samples.

RESULTS

The supernatant was adequate for HPV testing in 24 (96%) of 25 cases. Of these, 14 (56%) were HPV positive and 11 (44%) negative by the LightCycler assay. HPV16 was the most commonly detected genotype (n = 12). When results of supernatant and paired cell block testing were compared, HPV status was concordant in all cases. The LightCycler method was more sensitive than the cobas assay due to its ability to detect an expanded profile of HPV variant genotypes.

CONCLUSION

The current standard of practice for patients with HNSC who undergo FNA is to construct a cell block and then discard the supernatant. This supernatant is a rich source of tumor DNA that can be used to detect HPV status. It should not be wasted.

A new face of the HPV epidemic: Oropharyngeal cancer in the elderly

OBJECTIVES

As the human papillomavirus (HPV) epidemic continues to grow, the number of elderly patients with oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing. Despite this observation, this cohort remains understudied. We aimed to understand HPV prevalence and characteristics within this cohort as well as its impact on disease control in elderly patients.

METHODS AND MATERIALS

We identified patients aged ≥70 with newly diagnosed, non-metastatic, OPSCC treated with curative intent at our institution from 2007 to 2018. Logistic regression and survival analyses were used for outcome-specific endpoints.

RESULTS

In total, 88 patients were identified with a median age of 73 (interquartile range [IQR]: 71-78) and a median Charlson Comorbidity Index of 6 (IQR: 5-7). Eighty-two percent were ECOG 0 or 1 performance. Of note, 70% of the cohort had HPV+ tumors. Fifty-one percent of patients were AJCC 8th edition stage I/II and 49% were stage III/IV. Median follow-up time was 2.5 years (IQR: 0.9-4.7). Eight percent had surgery alone, 27% underwent adjuvant RT, and 64% received definitive RT. Sixty-four percent received concurrent chemotherapy. By both univariate and multivariable analyses, HPV+ status was significantly associated with improved locoregional control (LRC), overall survival (OS), and disease specific survival (DSS).

CONCLUSIONS

In our cohort of elderly patients with OPSCC, the majority was HPV+, which was associated with improved clinical outcomes. There are many challenges when managing elderly patients with OPSCC, but as the population ages and the HPV epidemic evolves, these patients should be considered for elderly specific clinical trials.

Dermal Filler Presenting as Parotid Mass: A Case Report

Dermal filler injections are common cosmetic procedures and are growing in popularity. While frequently performed, dermal filler injections carry a risk of adverse events including vascular compromise and foreign body granulomas. Here, we discuss an unusual case of a patient with a history of dermal filler injections presenting with a parotid mass and an eyebrow mass requiring surgical resection. This case demonstrates the risk of delayed granuloma formation many years after dermal filler injection and highlights the importance of awareness and management of these potential long-term complications.

HPV-positive Squamous Cell Carcinoma of the Larynx, Oral Cavity, and Hypopharynx: Clinicopathologic Characterization With Recognition of a Novel Warty Variant

Human papillomavirus (HPV) is a principal driver for most oropharyngeal squamous cell carcinomas (OPSCCs), where it is strongly associated with improved survival. HPV is much less frequently detected in squamous cell carcinomas arising in nonoropharyngeal sites (non-OPSCCs), and its pathogenic role and prognostic value in these tumors is unclear. We evaluated the clinicopathologic features of 52 non-OPSCCs considered HPV-positive based upon p16 immunohistochemistry and direct HPV detection using RNA in situ hybridization (ISH), DNA ISH, or real-time DNA polymerase chain reaction. The HPV-positive non-OPSCCs were from the larynx (n=27), oral cavity (n=21), and hypopharynx (n=4). While most cases (n=34, 65%) showed classic histologic features of HPV-positive OPSCC, including endophytic growth, minimal keratinization, and hyperchromatic nuclei without koilocytic changes, a subset (n=13, 25%) were characterized by exophytic growth, exuberant surface hyperkeratosis and parakeratosis, marked nuclear pleomorphism, and prominent koilocytic atypia. These antithetical features were highly reminiscent of the warty variant of HPV-positive squamous cell carcinoma described in anogenital sites. Compared with tumors without warty features, the warty tumors presented at lower stage and were not associated with lymph node metastasis, local recurrence, or distant spread (4 y disease-free survival of 100% vs. 66%, P=0.069). The presence of transcriptionally active HPV as detected by RNA ISH suggests a pathogenic role for HPV in these nonoropharyngeal sites. While most HPV-positive non-OPSCCs are morphologically similar to their tonsillar counterparts, this study highlights a previously unrecognized warty variant that may be associated with a highly favorable clinical outcome.

Risk factors for human papillomavirus-positive nonoropharyngeal squamous cell carcinoma

BACKGROUND

Human papillomavirus (HPV)-positive oropharyngeal cancer (HPV-OPC) is distinct from HPV-unassociated head and neck cancer. However, whether risk factors for HPV-positive oropharyngeal and nonoropharyngeal squamous cell cancer are the same is unclear.

METHODS

Incident cases of HPV-positive head and neck cell cancer and matched non-cancer controls were enrolled in a multi-institutional, prospective study examining risk factors, biomarkers, and survival.

RESULTS

HPV-nonOPC (n = 20) were more likely to be ever smokers than controls (n = 80, OR 3.49, 95%CI 1.11-10.9) and HPV-OPC (n = 185, OR 3.28, 95%CI 1.10-10.2). Compared with HPV-OPC, HPV-nonOPC were less likely to have had over 3 oral sexual partners (OR 0.29, 95%CI 0.06-0.9), more likely to have multimorbidity (OR 3.30, 95%CI 1.04-10.5), and less likely to have antibodies to HPV16 E6 (90% vs 28%, OR 0.05, 95%CI 0.02-0.2). HPV-nonOPC had worse 4-year OS (77% vs 96%, P = .001) and RFS (69% vs 94%, P < .001) than HPV-OPC.

CONCLUSIONS

HPV-positive nonoropharyngeal are distinct from HPV-positive oropharyngeal cancers.

Adamantinoma-like Ewing Sarcoma of the Salivary Glands: A Newly Recognized Mimicker of Basaloid Salivary Carcinomas

Adamantinoma-like Ewing sarcoma (ALES) is a rare tumor that demonstrates the EWSR1-FLI1 translocation characteristic of Ewing sarcoma despite overt epithelial differentiation including diffuse expression of cytokeratins and p40. Most cases of ALES described to date have occurred in the head and neck where they can mimic a wide range of small round blue cell tumors. Because distinguishing ALES from basaloid salivary gland carcinomas can be particularly difficult, we analyzed a series of 10 ALESs that occurred in the salivary glands with the aim of identifying features that allow for better recognition of this entity. The salivary ALESs included 8 parotid gland and 2 submandibular gland tumors in patients ranging from 32 to 77 years (mean: 52 y). Nine were initially misclassified as various epithelial neoplasms. Although these tumors displayed the basaloid cytology, rosette formation, infiltrative growth, and nuclear monotony characteristic of ALES, peripheral palisading and overt keratinization were relatively rare in this site. Salivary ALESs not only displayed positivity for AE1/AE3, p40, and CD99, but also demonstrated a higher proportion of synaptophysin reactivity than has been reported for nonsalivary ALESs. These morphologic and immunohistochemical findings make ALES susceptible to misclassification as various other tumors including basal cell adenocarcinoma, adenoid cystic carcinoma, squamous cell carcinoma, NUT carcinoma, large cell neuroendocrine carcinoma and myoepithelial carcinoma. Nevertheless, monotonous cytology despite highly infiltrative growth and concomitant positivity for p40 and synaptophysin can provide important clues for consideration of ALES, and identification of the defining EWSR1-FLI1 translocations can confirm the diagnosis.

Mucoepidermoid carcinoma of the oropharynx: a tumor type with a propensity for regional metastasis unrelated to histologic grade

The designation "mucoepidermoid tumor" is a historic one used in reference to a form of mucoepidermoid carcinoma (MEC) that was believed to be benign. This bygone notion was based on the observation that the vast majority of MECs arising from the intraoral minor salivary glands behave in a benign fashion, particularly when they do not exhibit high grade features. There has been a recent move to partition the oral vault into the oral cavity proper and the oropharynx based on awareness that these compartments are distinct, and that similar tumor types arising from these compartments may behave in dramatically different ways (e.g, oral cavity squamous cell carcinoma vs oropharyngeal squamous cell carcinoma). The pathology databases from 3 large academic medical centers were searched for cases of MECs arising in the oropharynx. Relevant clinical and pathological information was collected from the medical records. Twenty-five cases were identified. They were from 18 females (72%) and 7 males (28%), ranging in age from 31 to 88 years (median, 61). Twenty-two (88%) were classified as low (n = 12) or intermediate (n = 10) grade, and 3 (12%) as high grade. Most arose from the base of tongue (n = 24), but one arose from the lateral pharyngeal wall. The median tumor size was 2.0 cm. Nineteen patients underwent neck node dissections. Of these, 13 (68%) had histologically documented lymph node metastases. MECs that lacked high grade features were almost as likely to metastasize as those with high grade features (50% vs 66%, Fisher exact = 1). Of 3 metastases tested, 2 harbored the MAML2 gene fusion. MECs arising from the base of tongue are associated with an alarmingly high rate of nodal metastases. This behavior cannot be predicted by histologic grading or MAML2 status. The propensity to metastasize may to some degree reflect the unique microenvironment of the oropharynx.

The Prevalence, Anatomic Distribution and Significance of HPV Genotypes in Head and Neck Squamous Papillomas as Detected by Real-Time PCR and Sanger Sequencing

Squamous papillomas (SPs) of the head and neck are generally regarded as a human papillomavirus (HPV)-driven process, but reported rates of HPV detection vary dramatically. Moreover, they are generally considered a benign condition, but the detection of high risk HPV types is commonly reported. This latter finding is particularly disturbing to clinicians and their patients given the alarming rise of HPV-associated head and neck cancer. The capriciousness of HPV detection reflects in large part differences in methodologies. The purpose of this study was to review an institutional experience using a state of the art detection method to determine the presence, type and anatomic distribution of HPV in head and neck SPs. The surgical pathology files of the Mount Sinai Hospital were reviewed for all SPs that had undergone HPV testing between 2012 and 2018. HPV screening was performed on tissue blocks with real-time PCR using primers designed to target the L1 region of low and high-risk HPV types. Genotyping was performed on HPV positive cases. HPV detection was repeated for cases that were originally reported to be positive for high risk HPV. 134 cases had undergone HPV analysis. Of the 131 with sufficient cellular material, 2 were excluded because the HPV testing yielded inconclusive results. The remaining 129 cases were the basis of this study. Thirty-eight cases (29%) were HPV positive and 91 (71%) were negative. The most common genotype was HPV 6 (n = 27, 71%), followed by HPV 11 (n = 10, 26%). One case (1%) was HPV positive but the genotype could not be determined. Of the HPV negative cases, 3 were originally reported as HPV 16 positive but found to be HPV negative on re-review and repeat testing. SPs arising in the larynx were more likely to harbor HPV than those arising in the oral cavity and oropharynx (64% vs. 10%, p < 0.00001). Similarly, recurrent respiratory papillomatosis (RRP) were much more likely to be HPV positive than solitary SPs (71% vs. 10%, p < 0.00001). Almost a third of head and neck SPs harbor HPV, but incidence is highly dependent on anatomic site. Those arising in the larynx are more prone to be HPV-driven than those arising in the oral cavity and oropharynx, particularly when occurring in the setting of RRP. High risk HPV could not be confirmed in any of the cases. Routine HPV testing as a strategy to unmask potentially malignant lesions harboring high risk HPV is not likely to be useful.

Abstract 1191: PD-L1 expression and the tumor immune microenvironment in NUT carcinoma

Nuclear protein in testis (NUT) carcinoma is a rare, highly aggressive malignancy that is defined by translocations of the NUTM1 gene and has a median survival of less than one year. Although immunotherapy is an attractive novel therapeutic option, the immune microenvironment has not yet been characterized in this tumor type. We performed immunohistochemistry for PD-L1, IDO1, CD8, CD68, FOXP3 and myeloperoxidase on whole-slide sections from 9 cases of NUT carcinoma, quantified immune cell subsets using Halo image analysis software, manually scored percentage of PD-L1 and IDO1 expression in tumor cells, and classified immune cell PD-L1 expression as focal (≤5%) or non-focal (&gt;5%). The 9 NUT carcinomas included 6 sinonasal, 2 mediastinal, and 1 soft tissue primaries. Median survival was 11 months (range 2-19); 7 patients (78%) died of disease while 2 (22%) had no evidence of disease at last follow up (12 and 19 months). All tumors demonstrated a dominant population of myeloperoxidase+ neutrophils, with a mean density of 954/mm2 (range 14-2311). There were also a mean 59/mm2 CD8+ cytotoxic T-cells (range 15-107), 75/mm2 FOXP3+ T-regulatory cells (range 9-349), and 54/mm2 CD68+ macrophages (range 0-417). Immune cell density did not correlate with survival. Four tumors (44%) expressed PD-L1, with mean 17% positivity (range 0-70%). PD-L1 expression was associated with improved survival (p=0.02), with higher mean PD-L1 levels in surviving patients (65% vs. 4%, p&lt;0.001). Two tumors (22%) expressed non-focal PD-L1 on tumor-infiltrating lymphocytes, which was also associated with survival (100% vs. 0%, p=0.03); whereas all tumors showed non-focal PD-L1 on neutrophils and macrophages. PD-L1+ tumors also had more CD8+ T-cells per mm2 (81 vs 41, p=0.07). Three tumors (33%) expressed IDO1, which was associated with improved survival (p=0.01). Overall, NUT carcinoma demonstrates an immunosuppressive microenvironment with a dominant population of tumor-infiltrating neutrophils that also show PD-L1 expression. However, evidence of PD-L1 and IDO1 expression on tumor cells with associated cytotoxic T-cell response and improved prognosis suggests that adaptive immunity plays an important role in NUT carcinoma outcomes, raising the possibility that immunotherapy might be harnessed to augment this response.

Note: This abstract was not presented at the meeting.

Citation Format: Lisa M. Rooper, Nyall R. London, Janis M. Taube, William H. Westra, Justin A. Bishop, Hyunseok Kang. PD-L1 expression and the tumor immune microenvironment in NUT carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1191.

JAK3 Variant, Immune Signatures, DNA Methylation, and Social Determinants Linked to Survival Racial Disparities in Head and Neck Cancer Patients

To inform novel personalized medicine approaches for race and socioeconomic disparities in head and neck cancer, we examined germline and somatic mutations, immune signatures, and epigenetic alterations linked to neighborhood determinants of health in Black and non-Latino White (NLW) patients with head and neck cancer. Cox proportional hazards revealed that Black patients with squamous cell carcinoma of head and neck (HNSCC) with PAX5 (P = 0.06) and PAX1 (P = 0.017) promoter methylation had worse survival than NLW patients, after controlling for education, zipcode, and tumor-node-metastasis stage (n = 118). We also found that promoter methylation of PAX1 and PAX5 (n = 78), was correlated with neighborhood characteristics at the zip-code level (P < 0.05). Analyses also showed differences in the frequency of TP53 mutations (n = 32) and tumor-infiltrating lymphocyte (TIL) counts (n = 24), and the presence of a specific C → A germline mutation in JAK3, chr19:17954215 (protein P132T), in Black patients with HNSCC (n = 73; P < 0.05), when compared with NLW (n = 37) patients. TIL counts are associated (P = 0.035) with long-term (>5 years), when compared with short-term survival (<2 years). We show bio-social determinants of health associated with survival in Black patients with HNSCC, which together with racial differences shown in germline mutations, somatic mutations, and TIL counts, suggests that contextual factors may significantly inform precision oncology services for diverse populations.

Functional characterization of alternatively spliced GSN in head and neck squamous cell carcinoma

We have recently performed the characterization of alternative splicing events (ASEs) in head and neck squamous cell carcinoma, which allows dysregulation of protein expression common for cancer cells. Such analysis demonstrated a high ASE prevalence among tumor samples, including tumor-specific alternative splicing in the GSN gene.In vitro studies confirmed that overall expression of either ASE-GSN or wild-type GSN (WT-GSN) isoform inversely correlated with cell proliferation, whereas the high ratio of ASE-GSN to WT-GSN correlated with increased cellular invasion. Additionally, a change in expression of either isoform caused compensatory changes in expression of the other isoform. Our results suggest that the overall expression and the balance between GSN isoforms are mediating factors in proliferation, while increased overall expression of ASE-GSN is specific to cancer tissues. As a result, we propose ASE-GSN can serve not only as a biomarker of disease and disease progression, but also as a neoantigen for head and neck squamous cell carcinoma treatment, for which only a limited number of disease-specific targeted therapies currently exist.

SOX10 Immunoexpression in Basaloid Squamous Cell Carcinomas: A Diagnostic Pitfall for Ruling out Salivary Differentiation

SOX10 immunoexpression is increasingly recognized in salivary gland tumors, including but not limited to those with myoepithelial, serous acinar, and intercalated duct differentiation. However, SOX10 expression has not been extensively evaluated in other epithelial tumors that can mimic salivary origin. Basaloid squamous cell carcinoma (SCC) is a unique variant of SCC that shows morphologic overlap with several salivary tumors, including adenoid cystic carcinoma, basal cell adenocarcinoma, and myoepithelial carcinoma. We performed SOX10 immunohistochemistry on 22 basaloid SCCs and 280 non-basaloid SCCs. If tissue was available, we also performed immunohistochemistry for S100 and p16, and in-situ hybridization for high-risk HPV RNA. SOX10 was positive in 13/22 basaloid SCCs (59%), including 5/6 (83%) that were HPV-positive and 6/12 (50%) that were HPV-negative. Only 2/12 basaloid SCC (17%) demonstrated focal S100 expression. All non-basaloid SCCs were SOX10 negative. Frequent positivity for SOX10 in basaloid SCC presents a significant diagnostic pitfall for distinguishing these tumors from various basaloid salivary carcinomas. The preponderance of SOX10 expression in the basaloid variant of HPV-positive SCC also presents a diagnostic challenge in separating it from HPV-related multiphenotypic sinonasal carcinoma. SOX10 may be more broadly considered a marker of basal differentiation and should not be assumed to be specific for salivary origin in epithelial head and neck tumors.

Human Papillomavirus Testing in Head and Neck Carcinomas: Guideline From the College of American Pathologists

Context Human papillomavirus (HPV) is a major cause of oropharyngeal squamous cell carcinomas, and HPV (and/or surrogate marker p16) status has emerged as a prognostic marker that significantly impacts clinical management. There is no current consensus on when to test oropharyngeal squamous cell carcinomas for HPV/p16 or on which tests to choose. Objective To develop evidence-based recommendations for the testing, application, interpretation, and reporting of HPV and surrogate marker tests in head and neck carcinomas. Design The College of American Pathologists convened a panel of experts in head and neck and molecular pathology, as well as surgical, medical, and radiation oncology, to develop recommendations. A systematic review of the literature was conducted to address 6 key questions. Final recommendations were derived from strength of evidence, open comment period feedback, and expert panel consensus. Results The major recommendations include (1) testing newly diagnosed oropharyngeal squamous cell carcinoma patients for high-risk HPV, either from the primary tumor or from cervical nodal metastases, using p16 immunohistochemistry with a 70% nuclear and cytoplasmic staining cutoff, and (2) not routinely testing nonsquamous oropharyngeal carcinomas or nonoropharyngeal carcinomas for HPV. Pathologists are to report tumors as HPV positive or p16 positive. Guidelines are provided for testing cytologic samples and handling of locoregional and distant recurrence specimens. Conclusions Based on the systematic review and on expert panel consensus, high-risk HPV testing is recommended for all new oropharyngeal squamous cell carcinoma patients, but not routinely recommended for other head and neck carcinomas.

Increasing prevalence of human papillomavirus-positive oropharyngeal cancers among older adults

BACKGROUND

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing among older adults. It is unknown whether these trends can be explained by human papillomavirus (HPV) and whether HPV-related tumors remain associated with an improved prognosis among older patients.

METHODS

In a retrospective study of OPSCCs diagnosed from 1995 to 2013 at 2 National Comprehensive Cancer Network-designated cancer centers, p16 immunohistochemistry and in situ hybridization (ISH) for HPV-16, high-risk DNA, and/or E6/E7 RNA were performed. The median age at diagnosis was compared by p16 and ISH tumor status. Trends in age were analyzed with nonparametric trends. Survival was analyzed with the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

Among 239 patients, 144 (60%) were p16-positive. During 1998-2013, the median age increased among p16-positive patients (P_trend = .01) but not among p16-negative patients (P_trend = .71). The median age of p16-positive patients increased from 53 years (interquartile range [IQR] in 1995-2000, 45-65 years) to 58 years (IQR for 2001-2013, 53-64 years). Among patients ≥ 65 years old, the proportion of OPSCCs that were p16-positive increased from 41% during 1995-2000 to 75% during 2007-2013 (P_trend = .04). Among all age groups, including older patients, a p16-positive tumor status conferred improved overall survival in comparison with a p16-negative status.

CONCLUSIONS

The median age at diagnosis for HPV-related OPSCC is increasing as the proportion of OPSCCs caused by HPV rises among older adults. The favorable survival conferred by an HPV-positive tumor status persists in older adults. Cancer 2018;124:2993-9. © 2018 American Cancer Society.

Prognostic factors for human papillomavirus-positive and negative oropharyngeal carcinomas

OBJECTIVES/HYPOTHESIS

Human papillomavirus (HPV)-positive and HPV-negative oropharyngeal squamous cell carcinoma (OPSCC) are distinct disease entities. Prognostic factors specific to each entity have not been adequately explored. Goals for this study were: 1) to determine whether HPV-positive and HPV-negative OPSCCs have distinct prognostic factors, and 2) to explore the prognostic significance of sex and race in OPSCC after HPV stratification STUDY DESIGN: Retrospective case series.

METHODS

A retrospective review of 239 incident OPSCC patients from 1995 to 2012, treated at Johns Hopkins and University of California-San Francisco was conducted. Women and nonwhite races were oversampled. All analyses were stratified by tumor HPV in situ hybridization status. The effects of sex and race on survival were considered in Kaplan-Meier and unadjusted and adjusted Cox regression models.

RESULTS

One hundred thirty-four (56.1%) OPSCC patients were HPV positive. On univariate analysis, women had better overall survival than men among HPV-positive (hazard ratio [HR]: 0.47, 95% confidence interval [CI]: 0.20-1.07; P = .06) but not HPV-negative (HR: 0.73, 95% CI: 0.43-1.24; P = .24) OPSCCs. On multivariate analysis, women with HPV-positive OPSCCs remained at lower risk of death (adjusted hazard ratio [aHR]: 0.34, 95% CI: 0.12-0.96; P = .04). Survival did not vary significantly by race among HPV-positive patients. Among HPV-negative patients, Hispanic patients had significantly better survival in unadjusted (HR: 0.27, 95% CI: 0.08-0.91; P = .04) but not adjusted (aHR: 0.93, 95% CI: 0.11-7.36; P = .94) analysis.

CONCLUSIONS

Women with HPV-positive OPSCC may have improved overall survival compared to men. Sex does not play a prognostic role in HPV-negative OPSCC. There are no differences in prognosis by race among HPV-positive or HPV-negative patients.

LEVEL OF EVIDENCE

4 Laryngoscope, E287-E295, 2018.

The impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features on the rate of malignancy for atypia of undetermined significance subcategories

BACKGROUND

The recent revision in terminology, with noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) replacing noninvasive follicular variant of papillary thyroid carcinoma, has reclassified the clinically indolent tumor as nonmalignant. The objective of this study was to evaluate the impact of this change on the rate of malignancy (ROM) for subcategories of an atypia of undetermined significance (AUS) diagnosis on fine-needle aspiration (FNA) cytology.

METHODS

Consecutive thyroid FNAs interpreted as AUS over a period of 4 years were retrospectively analyzed. The ROM for AUS subcategories, including atypia of undetermined significance with nuclear atypia (AUS-N), atypia of undetermined significance with a microfollicular pattern (AUS-F), atypia of undetermined significance with nuclear atypia and a microfollicular pattern (AUS-N/F), atypia of undetermined significance with Hürthle cells (AUS-H), and atypia of undetermined significance, not otherwise specified (AUS-NOS), were analyzed.

RESULTS

Of the 426 nodules interpreted as AUS, 244 were surgically excised. The incidence of NIFTP in each subcategory was as follows: 18% for AUS-N, 18% for AUS-F, 9% for AUS-N/F, 3% for AUS-H, and 0% for AUS-NOS. After the reclassification of NIFTP as nonmalignant, the ROM based on histologic follow-up significantly decreased from 43% to 26% for AUS-N (P < .001) and from 29% to 10% for AUS-F (P = .008). The ROM for AUS-N remained significantly higher than the ROM for AUS-F (P = .030).

CONCLUSIONS

A subset of resected AUS nodules can be reclassified as NIFTP, and that significantly decreases the ROM, especially for AUS-N and AUS-F. Nonetheless, AUS-N still harbors a substantially higher ROM than AUS-F. Cancer Cytopathol 2018;126:309-16. © 2018 American Cancer Society.

HLA class I antigen processing machinery (APM) component expression and PD-1:PD-L1 pathway activation in HIV-infected head and neck cancers

Human immunodeficiency virus (HIV)-infected individuals are at increased risk for developing several non-AIDS related malignancies and are often excluded from cancer immunotherapy regimens. To evaluate the immune competence of this cancer patient population, we evaluated HLA class I antigen presenting machinery (APM) component expression and PD-1:PD-L1 pathway upregulation in HIV(+) and HIV(-) head and neck cancers (HNCs). Sixty-two HIV(+) and 44 matched HIV(-) controls diagnosed with HNC between 1991 and 2011 from five tertiary care referral centers in the United States were identified. HLA class I APM component, PD-1, and PD-L1 expression were analyzed by immunohistochemical staining with monoclonal antibodies (mAbs). Clinical data was abstracted from the medical records. There was no significant difference between the cases and controls in LMP2, TAP1, HLA-A and HLA-B/C, as well as PD-1 and PD-L1 expression. Overall, 62% of all subjects had high PD-1 expression and 82% of the subjects expressed PD-L1 within the tumor microenvironment. LMP2, HLA-A and HLA-B/C expression were significantly associated with moderate to high PD-1 expression in the HIV(+) HNC cases (p = .004, p = .026, and p = .006, respectively) but not in the HIV(-) controls. In addition, HLA-A expression was significantly associated with PD-L1 expression in the HIV(+) HNC cases only (p = .029). HIV-infected individuals diagnosed with HNC do not have any detectable defects in HLA class I APM component expression and in PD-1:PD-L1 pathway activation. Given the current successes of HAART therapy in maintaining immune cell counts, HIV(+) patients diagnosed with cancer may benefit from the recently FDA-approved immune checkpoint blockade therapy.

Integrated Analysis of Whole-Genome ChIP-Seq and RNA-Seq Data of Primary Head and Neck Tumor Samples Associates HPV Integration Sites with Open Chromatin Marks

Chromatin alterations mediate mutations and gene expression changes in cancer. Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) has been utilized to study genome-wide chromatin structure in human cancer cell lines, yet numerous technical challenges limit comparable analyses in primary tumors. Here we have developed a new whole-genome analytic pipeline to optimize ChIP-Seq protocols on patient-derived xenografts from human papillomavirus-related (HPV⁺) head and neck squamous cell carcinoma (HNSCC) samples. We further associated chromatin aberrations with gene expression changes from a larger cohort of the tumor and normal samples with RNA-Seq data. We detect differential histone enrichment associated with tumor-specific gene expression variation, sites of HPV integration in the human genome, and HPV-associated histone enrichment sites upstream of cancer driver genes, which play central roles in cancer-associated pathways. These comprehensive analyses enable unprecedented characterization of the complex network of molecular changes resulting from chromatin alterations that drive HPV-related tumorigenesis. Cancer Res; 77(23); 6538-50. ©2017 AACR.

PD-1 Expression in Head and Neck Squamous Cell Carcinomas Derives Primarily from Functionally Anergic CD4+ TILs in the Presence of PD-L1+ TAMs

Oral tongue squamous cell carcinoma (OTSCC) is the most common oral cavity tumor. In this study, we examined the basis for the activity of programmed cell death protein (PD-1)-based immune checkpoint therapy that is being explored widely in head and neck cancers. Using multispectral imaging, we systematically investigated the OTSCC tumor microenvironment (TME) by evaluating the frequency of PD-1 expression in CD8⁺, CD4⁺, and FoxP3⁺ tumor-infiltrating lymphocytes (TIL). We also defined the cellular sources of PD-1 ligand (PD-L1) to evaluate the utility of PD-1:PD-L1 blocking antibody therapy in this patient population. PD-L1 was expressed in 79% of the OTSCC specimens examined within the TME. Expression of PD-L1 was associated with moderate to high levels of CD4⁺ and CD8⁺ TILs. We found that CD4⁺ TILs were present in equal or greater frequencies than CD8⁺ TILs in 94% of OTSCC and that CD4⁺FOXP3neg TILs were colocalized with PD-1/PD-L1/CD68 more frequently than CD8⁺ TILs. Both CD4⁺PD1⁺ and CD8⁺PD1⁺ TILs were anergic in the setting of PD-L1 expression. Overall, our results highlight the importance of CD4⁺ TILs as pivotal regulators of PD-L1 levels and in determining the responsiveness of OTSCC to PD1-based immune checkpoint therapy. Cancer Res; 77(22); 6365-74. ©2017 AACR.

Prognostic biomarkers in patients with human immunodeficiency virus-positive disease with head and neck squamous cell carcinoma

BACKGROUND

We examined the prognostic value of a panel of biomarkers in patients with squamous cell carcinoma of the head and neck (SCCHN) who were human immunodeficiency virus (HIV) positive (HIV-positive head and neck cancer) and HIV negative (HIV-negative head and neck cancer).

METHODS

Tissue microarrays (TMAs) were constructed using tumors from 41 disease site-matched and age-matched HIV-positive head and neck cancer cases and 44 HIV-negative head and neck cancer controls. Expression of tumor biomarkers was assessed by immunohistochemistry (IHC) and correlations examined with clinical variables.

RESULTS

Expression levels of the studied oncogenic and inflammatory tumor biomarkers were not differentially regulated by HIV status. Among patients with HIV-positive head and neck cancer, laryngeal disease site (P = .003) and Clavien-Dindo classification IV (CD4) counts <200 cells/μL (P = .01) were associated with poor prognosis. Multivariate analysis showed that p16 positivity was associated with improved overall survival (OS; P < .001) whereas increased expression of transforming growth factor-beta (TGF-β) was associated with poor clinical outcome (P = .001).

CONCLUSION

Disease site has significant effect on the expression of biomarkers. Expression of tumor TGF-β could be a valuable addition to the conventional risk stratification equation for improving head and neck cancer disease management strategies.

Patient with antiphospholipid syndrome presenting with testicular torsion-like symptoms

Testicular torsion, a urological emergency, occurs due to absence of testicular blood supply secondary to a mechanical twist of the spermatic cord. The authors describe a 28-year-old male who presented with torsion symptoms, first in the left testicle and four months later in the right testicle. Doppler ultrasound and surgical exploration revealed disruption of blood flow but no evidence of spermatic cord twisting. Additionally, physical examination findings at the time of presentation were inconsistent with testicular torsion. Hematologic workup revealed triple positive antiphospholipid syndrome as the cause of testicular ischemia. The patient was successfully treated with aspirin and therapeutic heparin.

Abstract 2424: The in-parallel whole-genome ChIP-Seq analysis of primary tissues, patient derived xenografts, and cancer cell lines from HPV-relative HNSCC samples

This project develops a novel experimental technique to perform ChIP-Seq (chromatin immunoprecipitation with massively parallel DNA sequencing) analysis of chromatin structure in primary tumor tissues from high risk HPV-related head and neck squamous cell carcinomas (HPV+ HNSCC). Recent data suggest that chromatin structure is the central regulator and predictor of cancer-specific expression and mutagenesis landscape of diseased cells. Genome-wide gene expression dysregulation in many tumors, including HPV+ HNSCC, are incompletely described by current knowledge. Methods for study of chromatin structure in primary tumor tissue are needed to better understand the role global epigenetic changes may play in these tumors. However, ChIP-Seq, which is the state-of-the-art method of elucidating chromatin structure, until now, has not been reliably performed on any HNSCC samples. Because chromatin structure is disrupted at room temperature, ChIP-Seq is especially complicated for primary patient tissues, which are primarily obtained as surgical waste after pathology review. Snap freezing of leftover waste surgical tissues and further tissue thawing for the analysis decreases chromatin structure integrity necessary for highly sensitive ChIP-Seq methodology, especially for tumor samples with chromatin structure deformed during carcinogenesis. To improve the chromatin structure integrity in tumor sample we added a xenografting step and minimized the exposure of cancer tissue to room temperature conditions after mouse surgery. We also minimized patient non-cancer tissue preservation at ambient temperature after patient surgery. We successfully performed ChIP-Seq for H3K4me3, H3K9me3, and H3K9ac on frozen uvulopalatopharyngoplasty (UPPP) primary tissues, frozen patient derived xenograft tissues, and freshly-cultured head and neck squamous cell carcinoma cell lines, revealing comparable success rates between tissue type and sample preservation techniques. ChIP-Seq techniques were performed and cross validated using tried and true qRT-PCR methods to demonstrate data reproducibility. The biological relevance of the ChIP-Seq data was confirmed through massive RNA-Seq analysis of 47 HPV+ HNSCC samples and 25 non-cancer controls. Analysis revealed that most H3K9ac and H3K9me3 enrichment is similar in primary tissues, regardless of disease status. Only small portion of them showed differential histone enrichment, which correlated with differential expression of corresponding genes. On the other hand, H3K4me3 showed strong tissue specificity and were found differentially enriched especially in tumor samples. The proposed experimental pipeline demonstrates high reproducibility between biological replicates, diversity of tissue models, and low dependence of ChIP-Seq analysis on tissue preservation techniques.

Citation Format: Dylan Z. Kelley, Emily L. Flam, Hildegard A. Wulf, Theresa Guo, Evgeny Izumchenko, Dzov A. Singman, Ludmila V. Danilova, Elena D. Stavrovskaya, Michael Considine, Justin A. Bishop, William H. Westra, Zubair Khan, Wayne M. Koch, David Sidransky, Sarah Wheelan, Joseph A. Califano, Alexander V. Favorov, Elana J. Fertig, Daria A. Gaykalova. The in-parallel whole-genome ChIP-Seq analysis of primary tissues, patient derived xenografts, and cancer cell lines from HPV-relative HNSCC samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2424. doi:10.1158/1538-7445.AM2017-2424

Abstract 4667: mtDNA sequencing in HNSCC as a measurer of intratumoral heterogeneity and lymph node metastasis

Head and neck squamous cell carcinoma (HNSCC), accounts for 650,000 new cases worldwide. It is notorious for poor prognosis, which reflects its propensity to present as metastatic disease upon diagnosis. The prognosis and treatment regiments vary dramatically upon the manifestation of lymph node (LN) metastasis. Detection of regional LN metastasis is usually based on the clinical examination and imaging, followed by post-operational histological analysis. Unfortunately, current tools for detection of tumor cells in surgically resected LN may, in some cases, miss the presence of micrometastasis. Novel strategies for detection of micrometastasis based on the analysis of tumor-derived genetic aberrations by next generation sequencing (NGS) offer new hope for improved risk assessment and better selection of the treatment regimen. However, detection of mutations in minuscule metastatic lesions comprised of only few neoplastic cells may still fall below the detection threshold of these highly sensitive techniques. By virtue of their clonal nature, higher mutation rate and copy number, assessing tumor-specific mitochondrial DNA (mtDNA) mutations in histologically clean LN may provide a more sensitive diagnostic tool and eventually reduce the false negative rate in patients. Additionally, due to its circular configuration, mtDNA thought to be more stable than genomic DNA, and may also be suitable for sequencing formalin-fixed paraffin-embedded (FFPE) -derived genomic material, an invaluable resource for clinical research. However, current methods for library preparation are still imperfect for detection of low prevalence variants and heteroplasmy with high depth of coverage, especially in highly degraded samples. To this end, we aimed to set up a novel NGS assay for mtDNA analysis in primary and metastatic samples. Amplicon-based NGS library preparation approach, consisting of 148 primers pairs that cover the entire mitochondrial genome (with a dual coverage of 86.18%) was designed in collaboration with Fluidigm to be used on Access Array™ platform. To enhance the coverage of degraded material the amplicon size was limited to ~170 base pairs. Primers for three nuclear housekeeping genes were added to the panel to allow quantitative copy number analysis. To address mitochondrial mutational patterns, heteroplasmy and heterogeneity, we have used this novel high-throughput enrichment technology to sequence mtDNA from different areas of 16 primary HNSCC tumors (fresh frozen and FFPE), and multiple matched metastatic or histologically clean lymph-nodes. We obtained over 99% coverage with a median average depth of 3000X and no difference between fresh frozen and FFPE samples. This method allows obtaining a snapshot on the extent of mitochondrial heterogeneity of these lesions and may be used for detection of low frequency tumor-associated mtDNA mutations as a measurer of possible metastatic processes in histologically clean LN.

Citation Format: Adrian D. Schubert, Evgeny Izumchenko, William H. Westra, Aditi Chatterjee, Wayne M. Koch, Mohammad O. Hoque, David Sidransky. mtDNA sequencing in HNSCC as a measurer of intratumoral heterogeneity and lymph node metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4667. doi:10.1158/1538-7445.AM2017-4667

The impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features on the performance of the Afirma gene expression classifier

BACKGROUND

A recent revision in thyroid tumor nomenclature has resulted in a change from a malignant diagnosis (noninvasive follicular variant of papillary thyroid carcinoma) to one that is nonmalignant (noninvasive follicular thyroid neoplasm with papillary-like nuclear features [NIFTP]). The objective of the current study was to evaluate the impact of this change on the performance of the Afirma gene expression classifier (GEC).

METHODS

The authors retrospectively analyzed consecutive thyroid fine-needle aspiration specimens with indeterminate diagnoses on which GEC was performed. Surgical pathology material was reviewed with the reclassification of nodules into NIFTP.

RESULTS

GEC testing was performed on 384 fine-needle aspiration specimens diagnosed as atypia of undetermined significance (AUS) (304 cases) and suspicious for a follicular neoplasm (SFN) (80 cases) and yielded a suspicious result in 152 of the AUS cases (50%) and 50 of the SFN cases (63%). Thyroidectomy was performed on 177 patients. After reclassifying NIFTP, the positive predictive value of GEC decreased from 42% (95% confidence interval [95% CI], 39%-45%) to 24% (95% CI, 22%-26%) in the AUS group and from 23% (95% CI, 19%-27%) to 13% (95% CI, 9%-18%) in the SFN group. Total thyroidectomy was performed more frequently than a partial thyroidectomy in patients with AUS with a suspicious GEC result compared with pre-GEC controls (68% vs 49%; P = .037).

CONCLUSIONS

Reclassification of NIFTP significantly decreases the positive predictive value of GEC in indeterminate thyroid nodules. Nevertheless, the majority of patients with indeterminate thyroid nodules with a suspicious GEC result in the study institution have undergone total thyroidectomy. This finding raises concerns over reliance on a suspicious GEC result by clinicians to justify total thyroidectomy. Cancer Cytopathol 2017;125:683-91. © 2017 American Cancer Society.

IDO1 as a mechanism of adaptive immune resistance to anti-PD1 monotherapy in HNSCC

6053

Background: Patients with recurrent/metastatic human papillomavirus-associated head and neck squamous cell carcinoma (HPV-HNSCC) demonstrate improved response rates to anti-PD-1 blockade, which may be attributed to the inherent inflammation associated with the local expression of foreign, highly immunogenic viral antigens. However, these response rates are at best 25%, suggesting there may be immune resistance networks that are limiting clinical responses to anti-PD-1 therapy. To address this question, we investigated other potential immune checkpoint pathways that may be upregulated in PD-L1 expressing HPV-HNSCCs. Methods: Using a custom microarray of 59 immune-related genes, we compared the gene expression profile of laser-captured micro-dissected PD-L1 (+) and (-) immune fronts in HPV-HNSCCs. Gene expression was validated using quantitative PCR (qPCR) and protein expression geographically localized using quantitative multiplex biomarker imaging in a separate cohort of HPV-HNSCCs. Furthermore, we assayed pre- and post-treatment biopsies from anti-PD-1 treated patients and correlated gene expression with clinical responses. Results: Of the immune-related genes, IDO1 was increased 65-fold in 10 PD-L1(+) as compared to 5 PD-L1(-) HPV-HNSCCs (p = 0.004). qPCR confirmed upregulated expression of IDO1 and quantitative immunofluorescence demonstrated that PD-L1 and IDO1 geographically co-localized within the tumor microenvironment in a validation cohort of 25 HPV-HNSCC patients. In anti-PD1 treated patients, IDO1 expression increased up to two-fold and correlated with disease progression in HNSCC patients. Conclusions: IDO1 is an immune checkpoint molecule that modulates T cell activity through the depletion of L-tryptophan. We propose that IDO1 is an adaptive immune resistance pathway to anti-PD-1 monotherapy. The results provide rationale for combinatorial therapies targeting the IDO1 and PD-1:PD-L1 networks in HNSCC patients.

Intact APM and PD-1:PD-L1 pathway upregulation in HIV-infected head and neck cancer patients

6058

Background: HIV-infected individuals have a higher incidence of oral infection with human papillomavirus (HPV) and possibly a higher incidence of head and neck cancer (HNC). Whether this observation reflects defects in the ability of this Òimmune-compromisedÓ patient population to mount sufficient tumor specific immune responses and/or reflects activation of immune escape mechanisms is not known. To address this question, we investigated the expression of HLA class I antigen processing machinery (APM) components and PD-1:PD-L1 pathway activation in HIV(+) HNC patients. Methods: 62 HIV(+) HNC patients diagnosed between 1991-2011 from five tertiary care referral centers in the United States and matched HIV(-) HNC controls were identified. HLA class I APM component, PD-1, and PD-Ll expression were analyzed by immunohistochemical staining. Clinical data was abstracted from the medical records. Results: 44 of 62 (71%) HIV(+) HNC cases were matched based on gender, age ( < 10 years), and anatomic sub-site to HIV(-) HNC patients. There was no significant difference between the cases and controls in HLA-A, HLA-B/C, LMP2, and TAP1, as well as PD-1 and PD-L1 expression. Overall, 62% of all subjects had high PD-1 expression and 82% of the subjects expressed PD-L1. HLA-A, HLA-B/C, and LMP2 expression was significantly correlated with moderate to high PD-1 expression in the HIV(+) HNC cases (p = 0.004, p = 0.026, and p = 0.006, respectively) but not in the HIV(-) controls. Similarly, HLA-A expression was also significantly associated with PD-L1 expression only in the HIV(+) HNC cases (p = 0.029). Conclusions: No defects were detected in the expression of the HLA class I APM components tested. PD-1:PD-L1 pathway was found to be upregulated in both HIV(+) and HIV(-) HNC patients. Our data suggest that recently approved anti-PD-1 immunotherapy should not exclude HIV(+) patients.

Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Oropharynx

The changes for oropharyngeal lesions in the 2017 edition of the WHO/IARC Classification of Head and Neck Tumours reference book are dramatic and significant, largely due to the growing impact of high risk human papillomavirus (HPV). The upcoming edition divides tumours of the oral cavity and oropharynx into separate chapters, classifies squamous cell carcinomas (SCC) of the oropharynx on the basis of HPV status, abandons the practice of histologic grading for oropharyngeal SCCs that are HPV positive, recognizes small cell carcinoma of the oropharynx, and combines polymorphous low grade adenocarcinoma and cribriform adenocarcinoma of tongue and minor salivary glands under the single term "polymorphous adenocarcinoma." This review not only calls attention to these changes, but describes the rationale driving these changes and highlights their implications for routine clinical practice.