The evolving landscape of salivary gland tumors.

Salivary gland cancers are a rare, histologically diverse group of tumors. They range from indolent to aggressive and can cause significant morbidity and mortality. Surgical resection remains the mainstay of treatment, but radiation and systemic therapy are also critical parts of the care paradigm. Given the rarity and heterogeneity of these cancers, they are best managed in a multidisciplinary program. In this review, the authors highlight standards of care as well as exciting new research for salivary gland cancers that will strive for better patient outcomes.

Rescue of NLRC5 expression restores antigen processing machinery in head and neck cancer cells lacking functional STAT1 and p53.

The antigen processing machinery (APM) components needed for a tumor cell to present an antigen to a T cell are expressed at low levels in solid tumors, constituting an important mechanism of immune escape. More than most other solid tumors, head and neck squamous cell carcinoma (HNSCC) cells tend to have low APM expression, rendering them insensitive to immune checkpoint blockade and most other forms of immunotherapy. In HNSCC, this APM deficiency is largely driven by high levels of EGFR and SHP2, leading to low expression and activation of STAT1; however, recent studies suggest that p53, which is often mutated in HNSCCs, may also play a role. In the current study, we aimed to investigate the extent to which STAT1 and p53 individually regulate APM component expression in HNSCC cells. We found that in cells lacking functional p53, APM expression could still be induced by interferon-gamma or DNA-damaging chemotherapy (cisplatin) as long as STAT1 expression remained intact; when both transcription factors were knocked down, APM component expression was abolished. When we bypassed these deficient pathways by rescuing the expression of NLRC5, APM expression was also restored. These results suggest that dual loss of functional STAT1 and p53 may render HNSCC cells incapable of processing and presenting antigens, but rescue of downstream NLRC5 expression may be an attractive strategy for restoring sensitivity to T cell-based immunotherapy.

Specimen-Based Resection Margins and Local Control during Transoral Robotic Surgery for Oropharyngeal HPV-Mediated Squamous Cell Carcinoma.

OBJECTIVES: The aim of the study was to investigate the association of surgical margin conditions, including positive specimen margins revised to negative relative to local recurrence, disease-free survival, and overall survival (OS) within a cohort of HPV-mediated oropharyngeal squamous cell carcinoma (OPSCC) who underwent en bloc resection via transoral robotic surgery (TORS). MATERIALS AND METHODS: Retrospective cohort of patients with untreated HPV-mediated OPSCC cT1 or T2 undergoing TORS resection between October 2014 and March 2020. The methodologic description of our interdisciplinary institutional approach, number of cut-through margins (CTMs) during intraoperative consultation, percentage of final positive margin cases, and disease-free survival and OS stratified by margin status and margin tumor-free distance is identified. RESULTS: 135 patients with primary cT1/T2 HPV-mediated OPSCC met inclusion criteria. Twenty-eight of 135 (20.7%) specimens revealed CTM and were revised during the same operative setting. Three of 135 (2.2%) surgical cases had positive final margin status. Local control rate was 97%. On univariate analysis, margin distance did not impact OS. CTM and final positive margins had lower OS than initially negative margins (p = 0.044). Pathologic N-stage significantly impacted OS (p < 0.001). CONCLUSIONS: High local control rate and low final positive margin status confound the study of specimen margin-based techniques in HPV-mediated OPSCC resected en bloc with TORS. Pathologic N-stage may impact OS more than margin status. Larger numbers are needed to confirm differences.

Team-Based Surgical Scheduling for Improved Patient Access in a High-Volume, Tertiary Head and Neck Cancer Center.

BACKGROUND: Delays in care can lead to inferior survival outcomes in head and neck cancer and other cancers. In the case of malignancies for which surgery is the preferred primary treatment modality, challenges in surgical scheduling can present a major hurdle to initiating definitive therapy in a timely fashion. It is critical to maintain efficient use of operating room resources. Traditionally, surgery is scheduled with the surgeon who initially saw the patient in consultation, and timing of surgery is tightly linked to the availability and operating room block time of the individual surgeon. METHODS: Scheduling of oncologic head and neck surgery was transitioned from a surgeon-specific method to a team-based approach wherein a patient in need of oncologic head and neck surgery is scheduled with the next-available surgeon with appropriate expertise. RESULTS: Despite substantial growth of our practice, transition to a team-based scheduling approach allowed us to maintain high utilization of operating room block time. Patient and surgeon satisfaction remain high with this new system. CONCLUSIONS: A team-based surgical scheduling approach can help optimize operating room utilization and minimize delays in cancer care, potentially leading to improved oncologic outcomes.

Survival, functional, and quality of life outcomes between total glossectomy with and without total laryngectomy: A narrative review.

BACKGROUND: A total glossectomy (TG) may be required for advanced tongue tumors. TG with total laryngectomy (TGL) may be indicated in some cases with tumor extension into the larynx or high risk of aspiration. Total glossectomy with laryngeal preservation (TGLP) may preserve phonation ability relative to TGL, yet TGLP may increase the risk of aspiration. METHODS: For this narrative review, we performed a comprehensive literature search of studies relevant to TG and TGL. Clinical studies investigating survival, functional outcomes, and quality of life in following TGLP or TGL were of particular interest. RESULTS: Few studies in the literature directly compare survival, functional, and quality of life (QOL) outcomes between TGLP and TGL. TGLP is associated with intelligible speech. However, studies investigating gastrostomy tube dependence following TGLP versus TGL have generated conflicting results. CONCLUSION: Further research on functional and QOL outcomes in patients undergoing TGL or TGLP is needed.

Chemoradiation-induced hearing loss remains a major concern for head and neck cancer patients.

OBJECTIVE: Review of the literature regarding hearing loss in patients with head and neck cancer treated with chemoradiation. DESIGN: Studies in the literature are reviewed that pertain to hearing loss sustained in head and neck cancer patients receiving cisplatin-based chemoradiation. Personal observations noted while treating these patients are also detailed. STUDY SAMPLE: PubMed was searched for pertinent articles regarding hearing loss in head and neck cancer patients receiving cisplatin chemotherapy and/or radiation. RESULTS: Studies on the incidence and severity of hearing loss in head and neck cancer patients are limited, but those studies suggest that the risk of hearing loss is greater with higher-dose regimens. CONCLUSIONS: Newer cisplatin chemotherapy regimens using lower, weekly doses may be associated with a lower incidence and severity of hearing loss; however, large prospective studies are needed. Such information will be paramount to effective pre-treatment counselling of head and neck cancer patients.

Human papillomavirus 16 E6 antibodies are sensitive for human papillomavirus-driven oropharyngeal cancer and are associated with recurrence.

BACKGROUND: Human papillomavirus 16 (HPV16) E6 antibodies may be an early marker of the diagnosis and recurrence of human papillomavirus-driven oropharyngeal cancer (HPV-OPC). METHODS: This study identified 161 incident oropharyngeal cancer (OPC) cases diagnosed at the University of Pittsburgh (2003-2013) with pretreatment serum. One hundred twelve had preexisting clinical HPV testing with p16 immunohistochemistry and HPV in situ hybridization (87 were dual-positive [HPV-OPC], and 25 were dual-negative [HPV-negative]); 62 had at least 1 posttreatment serum sample. Eighty-six of the 161 tumors were available for additional HPV16 DNA/RNA testing (45 were dual-positive [HPV16-OPC], and 19 were dual-negative [HPV16-negative). HPV16 E6 antibody testing was conducted with multiplex serology. The following were evaluated: 1) the sensitivity and specificity of HPV16 E6 serology for distinguishing HPV-OPC and HPV16-OPC from HPV-negative OPC, 2) HPV16 E6 antibody decay after treatment with linear models accommodating correlations in variance estimates, and 3) pre- and posttreatment HPV16 E6 levels and the risk of recurrence with Cox proportional hazards models. RESULTS: Seventy-eight of 87 HPV-OPCs were HPV16 E6-seropositive (sensitivity, 89.7%; 95% confidence interval [CI], 81.3%-95.2%), and 24 of 25 HPV-negative OPCs were HPV16 E6-seronegative (specificity, 96.0%; 95% CI, 79.6%-99.9%). Forty-two of 45 HPV16-OPCs were HPV16 E6-seropositive (sensitivity, 93.3%; 95% CI, 81.7%-98.6%), and 18 of 19 HPV16-negative OPCs were HPV16 E6-seronegative (specificity, 94.7%; 95% CI, 74.0%-99.9%). Posttreatment HPV16 E6 antibody levels did not decrease significantly from the baseline (P = .575; median follow-up, 307 days) and were not associated with the risk of recurrence. However, pretreatment HPV16 E6 seropositivity was associated with an 86% reduced risk of local/regional recurrence (hazard ratio, 0.14; 95% CI, 0.03-0.68; P = .015). CONCLUSIONS: HPV16 E6 antibodies may have potential clinical utility for the diagnosis and/or prognosis of HPV-OPC. Cancer 2017;123:4382-90. © 2017 American Cancer Society.

Superior laryngeal nerve monitoring using laryngeal surface electrodes and intraoperative neurophysiological monitoring during thyroidectomy.

The objective of this study is to establish normative waveform data for the external branch of the superior laryngeal nerve (SLN) utilizing laryngeal surface electrodes and intraoperative neurophysiological monitoring (IONM) in conjunction with a clinical neurophysiologist. A retrospective chart review of 91 consecutive at-risk SLN were identified in 51 patients in whom IONM using laryngeal surface electrodes was performed by a clinical neurophysiologist using Dragonfly (Neurovision Medical Products, Ventura, CA) recording electrodes and a Protektor (Natus Medical Inc., San Carlos, CA)16 channel- intraoperative nerve monitoring system. Inclusion criteria were met for 30 SLN. Data collected included preoperative diagnosis, surgical procedure, rates of nerve identification and stimulation, and waveform characteristics. Waveform analysis for 30 SLN yielded a peak latency of 4.0 ± 0.2 ms, onset latency 2.3 ± 0.1 ms, peak-to-peak amplitude of 220.4 ± 31.1 µV, onset-to-peak amplitude of 186.0 ± 25.0 µV, and stimulation current threshold of 0.55 ± 0.03 mA (data = mean ± SEM). Two patients had abnormal SLN function documented clinically on postoperative laryngoscopic examination. Laryngeal surface electrodes were successfully utilized to identify and monitor SLN function intraoperatively. IONM using laryngeal surface electrodes enables analysis of waveform morphology and latency in addition to threshold and amplitude data obtained with the traditional NIM system, potentially improving the performance of nerve monitoring during thyroid surgery.

Orthotopic injection of an established syngeneic mouse oral cancer cell line (MOC1) induces a robust draining lymph node response.

Background: Preclinical models are invaluable for studies on the pathogenesis and treatment of head and neck cancer. In recent years, there has been growing interest in the use of orthotopic syngeneic models, wherein head and neck cancer cell lines are injected into the oral cavity of immunocompetent mice. However, few such orthotopic models have been described in detail. In this brief report, we describe techniques for injection of mouse oral cancer 1 (MOC1) cells into the buccal mucosa and illustrate the tumor growth pattern, lymph node response, and changes in the tumor immune microenvironment over time. Methods: MOC1 cells were injected into the buccal mucosa of C57BL6 mice. Animals were sacrificed at 7, 14, 21, or 27 days. Tumors and lymph nodes were harvested and analyzed for immune cell subsets by flow cytometry. Results: All inoculated mice developed palpable buccal tumors by day 7 and required euthanasia for tumor burden and/or weight loss by day 27. Lymph node mapping showed that these tumors reliably drain to a submandibular lymph node, which enlarges considerably over time. As in MOC1 tumors in the flank, the proportion of intratumoral CD8+ T cells decreased over time, while neutrophilic myeloid cells increased dramatically. However, the pattern and time course of immune changes in the TME were slightly different in the orthotopic buccal model. Conclusions: When used orthotopically in the buccal mucosa, the MOC1 model induces a robust lymph node response and distinct pattern of immune cell infiltration, with peak immune infiltration by day 14.

Characterization of the tumor microenvironment in the mouse oral cancer (MOC1) model after orthotopic implantation in the buccal mucosa.

BACKGROUND: Preclinical models are invaluable for studies of head and neck cancer. There is growing interest in the use of orthotopic syngeneic models, wherein cell lines are injected into the oral cavity of immunocompetent mice. In this brief report, we describe injection of mouse oral cancer 1 (MOC1) cells into the buccal mucosa and illustrate the tumor growth pattern, lymph node response, and changes in the tumor immune microenvironment over time. METHODS: MOC1 cells were injected into the buccal mucosa of C57BL6 mice. Animals were sacrificed at 7, 14, 21, or 27 days. Tumors and lymph nodes were analyzed by flow cytometry. RESULTS: All mice developed tumors by day 7 and required euthanasia for tumor burden and/or weight loss by day 27. Lymph node mapping showed that these tumors reliably drain to a submandibular lymph node. The proportion of intratumoral CD8+ T cells decreased over time, while neutrophilic myeloid cells increased dramatically. Growth of orthotopic MOC2 and MOC22 also showed similar growth patterns versus published data in flank tumors. CONCLUSIONS: When used orthotopically in the buccal mucosa, the MOC1 model induces a robust lymph node response and distinct pattern of immune cell infiltration, with peak immune infiltration by day 14.

Effects of socioeconomic status on enrollment in clinical trials for cancer: A systematic review.

BACKGROUND: To achieve equitable access to cancer clinical trials (CCTs), patients must overcome structural, clinical, and attitudinal barriers to trial enrollment. The goal of this systematic review was to study the relationship between socioeconomic status (SES), assessed either by direct or proxy measures, and CCT enrollment. METHODS: The review team and medical librarian developed search strategies for each database to identify studies for this systematic review, which was conducted according to PRISMA guidelines. Inclusion criteria were as follows: studies published in relevant scientific journals between January 2000 and July 2022, primary sources, English literature, and studies conducted in the US. Sixteen studies fulfilled the inclusion criteria and were reviewed. The risk of bias assessment was conducted independently by two reviewers using the Newcastle Ottawa scale. RESULTS: The initial search yielded 4070 citations, and 16 studies were included in our review. Four of the studies included used patient reported annual income as a measure of SES, while the remaining 12 studies used patient zip code as a proxy measurement of SES. Consistent with our hypothesis, 13 studies showed a positive association between high SES (patient-reported or proxy measurement) and CCT enrollment. Two studies showed a negative association, and one study showed no relationship. CONCLUSIONS: The existing literature suggests that low SES is associated with lower participation in CCT. The small number of studies identified on this topic highlights the need for additional research on SES and other barriers to CCT participation.

Combined IL6 and CCR2 blockade potentiates antitumor activity of NK cells in HPV-negative head and neck cancer.

BACKGROUND: While T cell-activating immunotherapies against recurrent head and neck squamous cell carcinoma (HNSCC) have shown impressive results in clinical trials, they are often ineffective in the majority of patients. NK cells are potential targets for immunotherapeutic intervention; however, the setback in monalizumab-based therapy in HNSCC highlights the need for an alternative treatment to enhance their antitumor activity. METHODS: Single-cell RNA sequencing (scRNA-seq) and TCGA HNSCC datasets were used to identify key molecular alterations in NK cells. Representative HPV-positive ( +) and HPV-negative ( -) HNSCC cell lines and orthotopic mouse models were used to validate the bioinformatic findings. Changes in immune cells were examined by flow cytometry and immunofluorescence. RESULTS: Through integration of scRNA-seq data with TCGA data, we found that the impact of IL6/IL6R and CCL2/CCR2 signaling pathways on evasion of immune attack by NK cells is more pronounced in the HPV - HNSCC cohort compared to the HPV + HNSCC cohort. In orthotopic mouse models, blocking IL6 with a neutralizing antibody suppressed HPV - but not HPV + tumors, which was accompanied by increased tumor infiltration and proliferation of CD161+ NK cells. Notably, combining the CCR2 chemokine receptor antagonist RS504393 with IL6 blockade resulted in a more pronounced antitumor effect that was associated with more activated intratumoral NK cells in HPV - HNSCC compared to either agent alone. CONCLUSIONS: These findings demonstrate that dual blockade of IL6 and CCR2 pathways effectively enhances the antitumor activity of NK cells in HPV-negative HNSCC, providing a novel strategy for treating this type of cancer.

Submental Island Flaps for Lateral Reconstruction: Technical Refinements for Optimal Outcomes and Resource Efficiency.

Objective: To describe our modifications to the submental island flap (SMIF) in a case series that demonstrates improved reproducibility, shortened length of stay (LOS), and reduced utilization of hospital resources. Study Design: This retrospective case series with chart review included adult patients who underwent resection of malignant or benign tumors resulting in lateral facial, parotid, or temporal bone defects, which were reconstructed with SMIF. Setting: A tertiary-care academic referral center. Methods: Retrospective case series included all adult patients who underwent SMIF reconstruction between March 2020 and August 2021. Patient demographic and clinical data were collected. Primary outcomes were measures of hospital utilization including duration of surgery, LOS, and postoperative outcomes. Results: Twenty-eight patients were included with a mean age of 71.7 years. Eighty percent were male. All patients underwent parotidectomy, and the mean operative time was 347 minutes. The median LOS was 2.5 days (range 0-16 days). Seventy-five percent of the flaps drained into the internal jugular vein, and 25% drained into the external jugular vein. No patients required reoperation or readmission. All flaps survived. Conclusion: SMIFs are a safe and effective option for reconstruction of lateral facial, parotid, and temporal bone defects. Compared to free flap reconstruction, SMIFs offer reduced length of surgery, decreased use of health care resources, and lower rate of reoperation. As health care resource allocation is increasingly important, the SMIF offers an excellent alternative to free flap reconstruction of lateral defects.

CD28-CD57+ T cells from head and neck cancer patients produce high levels of cytotoxic granules and type II interferon but are not senescent.

T lymphocytes expressing CD57 and lacking costimulatory receptors CD27/CD28 have been reported to accumulate with aging, chronic infection, and cancer. These cells are described as senescent, with inability to proliferate but enhanced cytolytic and cytokine-producing capacity. However, robust functional studies on these cells taken directly from cancer patients are lacking. We isolated these T cells and their CD27/28+ counterparts from blood and tumor samples of 50 patients with previously untreated head and neck cancer. Functional studies confirmed that these cells have enhanced ability to degranulate and produce IFN-γ. They also retain the ability to proliferate, thus are not senescent. These data suggest that CD27/28-CD57+ CD8+ T cells are a subset of highly differentiated, CD45RA+ effector memory (TEMRA) cells with retained proliferative capacity. Patients with > 34% of these cells among CD8+ T cells in the blood had a higher rate of locoregional disease relapse, suggesting these cells may have prognostic significance.

Assessing survival outcomes of patients with oral tongue squamous cell carcinoma: Focus on age, sex, and stage.

BACKGROUND: The purpose of this study was to provide further insights into whether age and/or sex are associated with prognosis in oral tongue squamous cell carcinoma. METHODS: This was a retrospective cohort study utilizing hospital registry data from 2006 to 2016 obtained from the National Cancer Database. Identified patients were divided into various cohorts based on age, sex, and staging. A descriptive analysis was performed using chi-square tests and overall survival rates were estimated using Kaplan-Meier method. RESULTS: A total of 17 642 patients were included in the study. The 5-year overall survival rates were 82.0% (95% CI: 79.8%-84.0%) in younger patients versus 67.5% (95% CI: 66.7%-68.3%, p-value <0.0001) older patients. The median overall survival for females was 143.4 months (95% CI: 133.2-NA) versus 129.8 (95% CI: 125.4-138.7, p-value <0.0001) in males. CONCLUSIONS: Our analysis suggests that younger age and female sex are both predictors of improved survival in oral tongue squamous cell carcinoma.

Radiation and anti-PD-L1 synergize by stimulating a stem-like T cell population in the tumor-draining lymph node.

Radiotherapy (RT) and anti-PD-L1 synergize to enhance local and distant (abscopal) tumor control. However, clinical results in humans have been variable. With the goal of improving clinical outcomes, we investigated the underlying synergistic mechanism focusing on a CD8+ PD-1+ Tcf-1+ stem-like T cell subset in the tumor-draining lymph node (TdLN). Using murine melanoma models, we found that RT + anti-PD-L1 induces a novel differentiation program in the TdLN stem-like population which leads to their expansion and differentiation into effector cells within the tumor. Our data indicate that optimal synergy between RT + anti-PD-L1 is dependent on the TdLN stem-like T cell population as either blockade of TdLN egress or specific stem-like T cell depletion reduced tumor control. Together, these data demonstrate a multistep stimulation of stem-like T cells following combination therapy which is initiated in the TdLN and completed in the tumor.

Intensity-Modulated Reirradiation Therapy With Nivolumab in Recurrent or Second Primary Head and Neck Squamous Cell Carcinoma: A Nonrandomized Controlled Trial.

Importance: Intensity-modulated radiation therapy (IMRT) reirradiation of nonmetastatic recurrent or second primary head and neck squamous cell carcinoma (HNSCC) results in poor progression-free survival (PFS) and overall survival (OS). Objective: To investigate the tolerability, PFS, OS, and patient-reported outcomes with nivolumab (approved standard of care for patients with HNSCC) during and after IMRT reirradiation. Design, Setting, and Participants: In this multicenter nonrandomized phase 2 single-arm trial, the treatment outcomes of patients with recurrent or second primary HNSCC who satisfied recursive partitioning analysis class 1 and 2 definitions were evaluated. Between July 11, 2018, and August 12, 2021, 62 patients were consented and screened. Data were evaluated between June and December 2023. Intervention: Sixty- to 66-Gy IMRT in 30 to 33 daily fractions over 6 to 6.5 weeks with nivolumab, 240 mg, intravenously 2 weeks prior and every 2 weeks for 5 cycles during IMRT, then nivolumab, 480 mg, intravenously every 4 weeks for a total nivolumab duration of 52 weeks. Main Outcomes and Measures: The primary end point was PFS. Secondary end points included OS, incidence, and types of toxic effects, including long-term treatment-related toxic effects, patient-reported outcomes, and correlatives of tissue and blood biomarkers. Results: A total of 62 patients were screened, and 51 were evaluable (median [range] age was 62 [56-67] years; 42 [82%] were male; 6 [12%] had p16+ disease; 38 [75%] had salvage surgery; and 36 [71%.] had neck dissection). With a median follow-up of 24.5 months (95% CI, 19.0-25.0), the estimated 1-year PFS was 61.7% (95% CI, 49.2%-77.4%), rejecting the null hypothesis of 1-year PFS rate of less than 43.8% with 1-arm log-rank test P = .002 within a 1-year timeframe. The most common treatment-related grade 3 or higher adverse event (6 [12%]) was lymphopenia with 2 patients (4%) and 1 patient each (2%) exhibiting colitis, diarrhea, myositis, nausea, mucositis, and myasthenia gravis. Functional Assessment of Cancer Therapy-General and Functional Assessment of Cancer Therapy-Head and Neck Questionnaire quality of life scores remained stable and consistent across all time points. A hypothesis-generating trend favoring worsening PFS and OS in patients with an increase in blood PD1+, KI67+, and CD4+ T cells was observed. Conclusions and Relevance: This multicenter nonrandomized phase 2 trial of IMRT reirradiation therapy and nivolumab suggested a promising improvement in PFS over historical controls. The treatment was well tolerated and deserves further evaluation. Trial Registration: ClinicalTrials.gov Identifier: NCT03521570.

Laryngeal Anatomy, Molecular Biology, Cause, and Risk Factors for Laryngeal Cancer.

Laryngeal cancer is declining in incidence in many parts of the world, as smoking becomes a less common habit. However, challenging cases of laryngeal cancer still exist and require expertise from otolaryngologists. This article reviews the relevant anatomy and lymphatic drainage pathways of the larynx because they pertain to cancer spread. The molecular and immune landscapes of laryngeal cancer, which are tightly linked to smoking, are also discussed.

Role of HER2 in Prognosis of Salivary Duct Carcinoma: A Systematic Review and Meta-Analysis.

OBJECTIVES: Salivary duct carcinoma (SDC) is a rare, aggressive malignancy with a poor prognosis. These tumors frequently stain positive for HER2/ErbB2, but data on the prognostic significance of HER2 status in SDC are mixed. We sought to determine whether HER2 status affects survival outcomes in SDC. METHODS: PubMed, Embase, and Web of Science databases were searched from inception to October 2020. Eligibility was restricted to studies reporting HER2/ErbB2 overexpression in histologically confirmed de novo SDC or SDC ex pleomorphic adenoma, with corresponding overall (OS) and disease-free (DFS) survival measures. Separate multivariable and univariable meta-analyses were performed using random-effects models. Statistical heterogeneity was estimated by Cochran's Q and I2 tests. Funnel plots were generated and Egger's test was used to assess for publication bias. The risk of bias was assessed with the Newcastle-Ottawa Scale. RESULTS: Of 183 unique citations, 14 studies of 663 patients were included. Most included studies determined HER2 status according to ASCO/CAP guidelines. The univariable meta-analysis did not reveal an effect between HER2 status and OS (HR 1.09, 95% CI 0.84-1.42). In the multivariable analysis, HER2 positivity was associated with a HR of 1.49 for OS (95% CI 0.96-2.30). Fewer studies reported data for DFS than OS, with no relationship between HER2 status and DFS found on multivariable or univariable meta-analyses. CONCLUSION: In patients with salivary duct carcinoma, HER2 positivity was not found to be associated with worse overall survival. This information may be useful when counseling patients and considering treatment options. Laryngoscope, 133:476-484, 2023.