Faculty Bibliography

Immune checkpoint blockade (ICB) therapy has revolutionized head and neck squamous cell carcinoma (HNSCC) treatment, but <20% of patients achieve durable responses. Persistent activation of the PI3K/AKT/mTOR signaling circuitry represents a key oncogenic driver in HNSCC; however, the potential immunosuppressive effects of PI3K/AKT/mTOR inhibitors may limit the benefit of their combination with ICB. Here we employ an unbiased kinome-wide siRNA screen to reveal that HER3, is essential for the proliferation of most HNSCC cells that do not harbor PIK3CA mutations. Indeed, we find that persistent tyrosine phosphorylation of HER3 and PI3K recruitment underlies aberrant PI3K/AKT/mTOR signaling in PIK3CA wild type HNSCCs. Remarkably, antibody-mediated HER3 blockade exerts a potent anti-tumor effect by suppressing HER3-PI3K-AKT-mTOR oncogenic signaling and concomitantly reversing the immune suppressive tumor microenvironment. Ultimately, we show that HER3 inhibition and PD-1 blockade may provide a multimodal precision immunotherapeutic approach for PIK3CA wild type HNSCC, aimed at achieving durable cancer remission.

BACKGROUND:Transcervical arterial ligation has been studied as a useful procedure to prevent bleeding events after transoral robotic surgery (TORS). METHODS:A systematic review of English-language literature on arterial ligation in TORS from 2005 to 2019 was conducted using Cochrane, PubMed, Web of Science (WoS), and ScienceDirect databases. Studies evaluating ligation and rates of postoperative hemorrhage were included. Meta-analysis of included studies was performed to assess impact of ligation on postoperative hemorrhage. RESULTS:Five studies with 2008 patients were included. History of radiation (odds ratio [OR] = 2.26, P = .02) and advanced tumor stage (OR = 1.93, P = .02) were found to predispose patients to postoperative hemorrhage. Arterial ligation was protective against severe hemorrhage in the mixed primary surgical modality cohort (OR = 0.33, P = .03) and in the TORS-only subgroup (OR = 0.21, P = .02), but did not significantly impact overall odds of postoperative hemorrhage. CONCLUSION:Transcervical arterial ligation offers protection against major/severe postoperative hemorrhage in patients undergoing TORS. LEVEL OF EVIDENCE:II.

Despite the success of immune checkpoint blockade therapy, few strategies sufficiently overcome immunosuppression within the tumor microenvironment (TME). Targeting regulatory T cells (T_regs) is challenging, because perturbing intratumoral T_reg function must be specific enough to avoid systemic inflammatory side effects. Thus, no T_reg-targeted agents have proven both safe and efficacious in patients with cancer. Neuropilin-1 (NRP1) is recognized for its role in supporting intratumoral T_reg function while being dispensable for peripheral homeostasis. Nonetheless, little is known about the biology of human NRP1⁺ T_regs and the signals that regulate NRP1 expression. Here, we report that NRP1 is preferentially expressed on intratumoral T_regs across six distinct cancer types compared to healthy donor peripheral blood [peripheral blood lymphocyte (PBL)] and site-matched, noncancer tissue. Furthermore, NRP1⁺ T_reg prevalence is associated with reduced progression-free survival in head and neck cancer. Human NRP1⁺ T_regs have broad activation programs and elevated suppressive function. Unlike mouse T_regs, we demonstrate that NRP1 identifies a transient activation state of human T_regs driven by continuous T cell receptor (TCR) signaling through the mitogen-activated protein kinase pathway and interleukin-2 exposure. The prevalence of NRP1⁺ T_regs in patient PBL correlates with the intratumoral abundance of NRP1⁺ T_regs and may indicate higher disease burden. These findings support further clinical evaluation of NRP1 as a suitable therapeutic target to enhance antitumor immunity by inhibiting T_reg function in the TME.

The epidermal growth factor receptor (EGFR) inhibitor cetuximab is the only FDA-approved oncogene-targeting therapy for head and neck squamous cell carcinoma (HNSCC). Despite variable treatment response, no biomarkers exist to stratify patients for cetuximab therapy in HNSCC. Here, we applied unbiased hierarchical clustering to reverse-phase protein array molecular profiles from patient-derived xenograft (PDX) tumors and revealed 2 PDX clusters defined by protein networks associated with EGFR inhibitor resistance. In vivo validation revealed unbiased clustering to classify PDX tumors according to cetuximab response with 88% accuracy. Next, a support vector machine classifier algorithm identified a minimalist biomarker signature consisting of 8 proteins - caveolin-1, Sox-2, AXL, STING, Brd4, claudin-7, connexin-43, and fibronectin - with expression that strongly predicted cetuximab response in PDXs using either protein or mRNA. A combination of caveolin-1 and Sox-2 protein levels was sufficient to maintain high predictive accuracy, which we validated in tumor samples from patients with HNSCC with known clinical response to cetuximab. These results support further investigation into the combined use of caveolin-1 and Sox-2 as predictive biomarkers for cetuximab response in the clinic.

OBJECTIVES/HYPOTHESIS:The incidence of human papillomavirus-positive (HPV+) oropharyngeal cancer is rising, but public knowledge about this diagnosis remains low. This study aimed to investigate the quality and readability of online information about HPV+ oropharyngeal cancer. STUDY DESIGN:Cross-sectional website analysis. METHODS:This study conducted a total of 12 web searches across Google, Yahoo, and Bing to identify websites related to HPV+ oropharyngeal cancer. The QUality Evaluation Scoring Tool (QUEST) was used to measure quality based on seven website criteria. The Flesch Reading Ease Score (FRES) and Flesch-Kincaid Grade Level (FKGL) were used to measure readability, with scores estimating the education level a reader would require to understand a piece of text. Readability improves as FRES increases and FKGL decreases. RESULTS:Twenty-seven unique web pages were evaluated. The mean USA reading grade level as measured by FKGL was 10.42 (standard deviation = 1.54). There was an inverse relationship between quality and readability, with a significant positive correlation between QUEST score and FKGL (r = 0.343, P = .040) and a significant negative correlation between QUEST score and FRES (r = -0.537, P = .002). CONCLUSIONS:With a mean USA reading grade level more than four grades above the American Medical Association's recommendation and results indicating that readability suffers as quality improves, these findings suggest that the currently available online information about HPV+ oropharyngeal cancer is insufficient. Improved patient education practices and resources about this diagnosis are needed. LEVEL OF EVIDENCE:NA Laryngoscope, 131:87-94, 2021.

Current immunotherapy paradigms aim to reinvigorate CD8⁺ T cells, but the contribution of humoral immunity to antitumor immunity remains understudied. Here, we demonstrate that in head and neck squamous cell carcinoma (HNSCC) caused by human papillomavirus infection (HPV⁺), patients have transcriptional signatures of germinal center (GC) tumor infiltrating B cells (TIL-Bs) and spatial organization of immune cells consistent with tertiary lymphoid structures (TLS) with GCs, both of which correlate with favorable outcome. GC TIL-Bs in HPV⁺ HNSCC are characterized by distinct waves of gene expression consistent with dark zone, light zone and a transitional state of GC B cells. Semaphorin 4a expression is enhanced on GC TIL-Bs present in TLS of HPV⁺ HNSCC and during the differentiation of TIL-Bs. Our study suggests that therapeutics to enhance TIL-B responses in HNSCC should be prioritized in future studies to determine if they can complement current T cell mediated immunotherapies.

OBJECTIVE:To analyze the role of transoral robotic base-of-tongue mucosectomy in a cohort of patients with human papilloma virus negative unknown primary carcinoma. STUDY DESIGN:Retrospective database analysis. METHODS:A retrospective database review from 2012 to 2018 was performed at two large tertiary centers to study patients with human papilloma virus (HPV)-negative unknown primary carcinoma who underwent transoral robotic base-of-tongue mucosectomy. P16 testing was used as a surrogate for HPV status. Patients were included that had squamous cell carcinoma metastatic to the lateral neck based on fine needle aspiration or open biopsy. Preoperatively, all patients were classified as having an unknown primary based on normal clinical and flexible endoscopic exam, normal operative endoscopy, nonlocalizing imaging, and tonsillectomy. All patients underwent robotic base-of-tongue mucosectomy. The primary outcome measure was the incidence of pathologic identification of a mucosal primary. RESULTS:Twenty-three patients with p16-negative unknown primary carcinoma were identified and studied. All patients underwent transoral robotic base-of-tongue mucosectomy. Median age was 60 years at the time of diagnosis, and 18 of 23 (78.2%) were male. Pathologic analysis of the base-of-tongue specimens showed a primary tumor in only three of 23 (13.0%) of patients. CONCLUSION:Despite prior evidence suggesting a high rate of primary site identification in HPV-related disease, robotic base-of-tongue mucosectomy may not be indicated for HPV-negative unknown primary carcinoma based on a low likelihood of finding the primary. LEVEL OF EVIDENCE:4 Laryngoscope, 131:78-81, 2021.