Abel, Kathryn M. Van

Background: The role of fine-needle aspiration (FNA) in diagnosing parotid tumors remains debated due to varying accuracy. This study evaluates FNA’s accuracy in diagnosing Warthin’s tumor (WT) and its safety in guiding observational management. Study design: Retrospective cohort study. Setting: Single institution, Tertiary referral center. Methods: Data from 2010 to 2022 including demographics, cytology, pathology, and surgical outcomes were extracted. Accuracy was assessed using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: Among 808 patients with parotid tumors, 234 were WTs. Seventy-eight patients underwent surgery with pathology while 156 underwent observation. FNA sensitivity, specificity, PPV, and NPV for WTs were 98.2%, 98.1%, 91.8%, and 99.6% respectively. No observational patients developed clinical signs of malignancy, and the median change in tumor size was 0 cm (range −3.1 to 2.1). Conclusions: FNA is highly specific for WT but limited by nondiagnostic results. Observation is a safe approach with minimal risk of growth, malignancy, or infection.

6057 Background: The incidence rate of human papillomavirus associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC) has persistently increased over the past decade and is anticipated to rise further over the next decade. Cost effective, accurate, and less invasive screening options for HPV(+)OPSCC have remained stagnant leading to the interrogation of circulating tumor DNA in liquid biopsies such as plasma. We hypothesized that candidate methylated DNA markers (MDMs), previously described by our group, would be present in the plasma of patients with HPV(+)OPSCC and absent in controls. Methods: HPV(+)OPSCC cases were enrolled from a high-volume referral practice. Cancer-free control patients were identified from the surrounding 7-county catchment area and frequency matched to cases by age and alcohol use. cfDNA was extracted from 4 mL of plasma and bisulfite converted prior to Target Enrichment Long-probe Quantitative Amplified Signal assays for 15 MDMs. Strand counts for individual MDMs were normalized to a methylated genomic reference marker. An MDM score was derived via random forest modeling of the 15 MDMs. Area under the receiver operator characteristic curve (AUC) for discriminating cases from controls was evaluated for individual markers and for the MDM score. The sensitivity of the MDM score at 95% specificity was also evaluated. Results: The study consisted of 96 HPV(+)OPSCC and 100 cancer-free controls. The study population was predominately white (95%) with a median age of 61 yrs (IQR: 52-69 yrs). Eighty-nine percent of the cases were male with cancers affecting either the tonsil in 50 (52%) or base of the tongue in 46 (48%) patients; by design 50% of controls were male. Stage I:II:III:IV disease was present in 66%:22%:9%:3% of the cases. The median (IQR) AUC across the 15 MDMs was 0.83 (0.82-0.85) overall: 0.78 (0.77-0.83) for stage I disease and 0.92 (0.91-0.93) for stage II-IV disease. The MDM score for the combined panel of 15 MDMs achieved a cross-validated AUC of 0.93 (CI: 0.89-0.97) overall: 0.90 (CI: 0.84-0.96) for stage I disease and 0.98 (CI: 0.97-1.00) for stage II-IV disease. At 95% specificity, the cross-validated sensitivity of the MDM score for HPV(+)OPSCC was 80% (CI: 71-87%) overall: 73% (CI: 60-83%) for stage I disease and 94% (CI: 78-99%) for stage II-IV disease. Conclusions: We validated a set of previously discovered MDM markers in HPV(+)OPSCC in a robust case control cohort using plasma. The MDMs were detected in both early and late-stage disease. Additional prospective studies in larger intended use cohorts are needed to validate our results for clinical use.

6061 Background: PDS0101 is a T cell stimulating immunotherapy (therapeutic vaccine) targeting HPV16. The combination of PDS0101 + pembrolizumab (5 cycles) has shown durable clinical responses in HPV-positive recurrent/metastatic HNSCC. MC200710 is a window of opportunity study in patients with HPV-associated oropharyngeal squamous cell carcinoma (HPV+ OPSCC). This prospective phase II trial utilized 2 cycles of neoadjuvant PDS0101 aloneor in combination with pembrolizumab prior to surgical resection or chemoradiotherapy (CRT). Herein, we report the initial results, including primary endpoint of ctDNA response. Methods: Between June 2022 and September 2024, 20 patients (10 per Arm) with locally advanced HPV+ OPSCC were enrolled in a sequential alternating design. Arm A received 2 cycles of PDS0101 and Arm B received 2 cycles of PDS0101 and pembrolizumab with all patients undergoing subsequent surgery or CRT. Assessments were done at baseline, post cycle 1, and post cycle 2 (prior to surgery or CRT). The coprimary endpoint of ctDNA response was defined as a ≥50% decline in ctDNA post cycle 2 compared to baseline as quantified using NavDx (TTMV fragments/mL). Radiologic objective response rate (ORR) was assessed as per RECIST 1.1. Toxicity through the neoadjuvant period was assessed using CTCAE criteria and recurrence rates following surgery or CRT are reported. Results: Patients were similar between arms: male 90%, median age 61 years, cT1/T2 70%, cN1 65%, and no smoking history 65%. All patients completed both cycles of therapy with 13 (65%) undergoing primary operative management and 7 CRT (35%). The most common toxicity was injection site reaction 85% grade 1, 15% grade 2, 0% grade 3, consistent with prior studies. One patient experienced grade 2 pneumonitis during the neoadjuvant window (Arm B). There was one grade 3 toxicity (5%) possibly attributable to study intervention with one patient experiencing transient hepatitis requiring hospitalization (Arm A). Zero of 10 patients in Arm A had a ≥50% decline in ctDNA from baseline while 5 of 10 patients (50%) met this primary endpoint in ARM B (p=0.03). After Cycle 2, based on RECIST 1.1, no Arm A patients had a partial response (PR), with 7 having stable disease (SD); Arm B had 2 patients with PR and 8 with SD. With median follow up of 6 months, 2 patients in Arm A recurred and 0 patients in Arm B. Conclusions: The combination of PDS0101 and pembrolizumab met the trial’s primary endpoint of ctDNA response and shows promise for further evaluation. ctDNA can be used to assess early response and future studies could use ctDNA to adapt neoadjuvant therapy. Based on these findings, a neoadjuvant dose optimization study in HPV16+ oropharyngeal carcinoma is warranted and evaluation of PDS0101 and pembrolizumab in comparison to pembrolizumab alone. Clinical trial information: NCT05232851 .

ImportanceThe De-escalated Adjuvant Radiation Therapy (DART) phase 3 randomized clinical trial (RCT) showed that in patients with human papillomavirus (HPV)−associated oropharyngeal squamous cell carcinoma, postoperative minimal residual disease (MRD), detected through circulating tumor HPV DNA (ctHPVDNA), was associated with a higher risk of disease progression. When considered along with pathologic factors, postoperative ctHPVDNA assessment may improve patient selection for adjuvant treatment de-escalation; however, more data are needed to demonstrate how it may be used in personalizing treatment intensity.ObjectiveTo determine the association of postoperative MRD status with progression-free survival (PFS) after surgery for HPV-associated oropharyngeal squamous cell carcinoma.Design, Setting, and ParticipantsThis was a secondary analysis of the DART RCT, which was conducted from October 2016 to August 2020 in multiple sites in the US. Participants from the de-escalated adjuvant radiation therapy group and the standard of care group with available blood specimen data were included. Reports from 3-month posttreatment surveillance visits were used to assess associations and outcomes. Data analyses were performed from March 2023 to March of 2025.InterventionsThe DART group received 30 to 36 Gy of radiation therapy in 1.5 to 1.8 Gy twice daily, plus docetaxel, 15 mg/m2, on days 1 and 8. The standard of care group received 60 Gy with or without weekly cisplatin, 40 mg/m2.Main Outcome and MeasurePFS.ResultsThe analysis included 140 patients (mean [SD] age, 59.1 [8.4] years; 12 [8.6%] females and 128 [91.4%] males; 97 [69.3%] with no smoking history); characteristics were similar to the overall DART RCT population. Of these, 17 patients (12.1%) had postoperative MRD (13 of 96 [13.5%] receiving DART and 4 of 44 [9.1%] receiving standard of care). For all patients, postoperative MRD positivity was strongly associated with worsened PFS at 24 months (MRD positivity, 69.5%; MRD negativity, 95.9%; hazard ratio [HR], 0.19; 95% CI, 0.06-0.59). MRD positivity was associated with PFS when evaluating only those patients in the DART group, where 24-month PFS was 68.4% compared to 92.6% for MRD-negative patients (HR, 0.28; 95% CI, 0.08-0.93). Three months after completion of all treatment, 8 of 117 patients (6.8%) had detectable ctHPVDNA, whereas 109 of 117 (93.2%) did not, and detection was highly associated with PFS (HR, 20.48; 95% CI, 6.91-60.67).Conclusions and RelevanceThis secondary analysis of the DART RCT found that patients with detectable ctHPVDNA after surgery had a higher risk of disease progression. When added to the pathologic factors considered, ctHPVDNA assessment may improve selection of patients for treatment de-escalation. In addition, the 3-month posttreatment time point, early in surveillance, may identify a sizable portion of patients with progression and may guide intervention and surveillance after surgery for HPV-associated oropharyngeal squamous cell carcinoma.Trial RegistrationClinicalTrials.gov Identifier: NCT02908477

AbstractObjectiveLow‐grade parotid malignancies have high overall survival rates; however, controversy remains about the appropriate extent of surgery. We aim to explore the trends in the extent of parotidectomy performed over time in low‐grade parotid malignancies in the United States, with a hypothesis that there has been a trend towards less aggressive surgery.Study DesignRetrospective cohort study of all low‐grade (grade I) acinic cell carcinoma (ACC) and mucoepidermoid carcinoma (MEC) in the Surveillance, Epidemiology, and End Results (SEER) from 2004 to 2020.SettingGeographic areas served by SEER.MethodsTrends were assessed using Cochran‐Armitage tests and logistic regression; Kaplan‐Meier survival curves were used to analyze overall and cancer‐specific survival, and chi‐square tests were used to analyze patient characteristics.ResultsIn total, 1288 patients were identified (916 MEC; 372 ACC). Most patients (n = 772, 60%) were non‐Hispanic white, with an average age of 50.6 years and had a slight female predominance (1.58:1). Most of the cohort presented with tumor stage T1 or T2 (84%), N0 (90.1%), and M0 (96.9%). Treatment with total parotidectomy decreased significantly (34.6 vs 17.7%, P = .02) whereas sacrificing the facial nerve (FN) slightly decreased (20 vs 15.7%, P = .1). A significant increase in N0 patients (71%‐94%, P < .0001) was observed, whereas T staging remained stable (61%‐64%, P = .3). Overall, both ACC and MEC had excellent cancer‐specific survival.ConclusionOver the last 17 years, there has been a significant de‐escalation in the extent of parotidectomy for low‐grade parotid malignancy in the United States.

Background: Malignant mesenchymal tumors involving the parotid gland are uncommon, characteristically aggressive, and little is known with few reports documented. Study Design: Retrospective case series. Setting: Single institution tertiary care center, 2010 to 2022. Method: Patients were identified from an institutional parotid tumor database. Patient history, demographics, pathologic diagnosis, treatment, and follow up were documented. Results: Eight patients were identified, 3 were males. The average age was 61 years old, and the most common tumors identified were pleomorphic sarcomas (3 patients). Presenting symptoms included: preauricular/cheek mass in 7 patients, facial pain (4), otalgia (4), aural fullness (3), and numbness (1). All patients received a parotidectomy, and 4 patients received adjuvant therapy of either radiation or chemoradiation. Post-operatively, there were 3 cases of distant recurrence, 2 cases of regional recurrence, and 1 case of local recurrence. There were 2 reports of death. Conclusion: Malignant mesenchymal tumors of the parotid are rare, represent varied histologies. Due to their aggressive nature, surgical resection with radiation and close follow-up may be an appropriate treatment regimen in controlling the disease.

Importance Circulating tumor human papillomavirus DNA (ctHPVDNA) is an important biomarker for the presence of HPV-associated oropharyngeal squamous cell carcinoma (OPSCC), but little is known about early postoperative kinetics of ctHPVDNA clearance. Objective To investigate early postoperative kinetics of ctHPVDNA in patients with HPV-associated OPSCC. Design, Setting, and Participants This prospective cohort study was conducted at a single tertiary care center from January 4, 2020, to January 26, 2023. Patients with newly diagnosed HPV-associated OPSCC undergoing surgical management were enrolled. HPV status was defined as positive if findings of p16 immunohistochemistry and/or HPV DNA in situ hybridization and/or E6/E7 RNA in situ hybridization were positive. Exclusion criteria included history of prior head and neck cancer and metastatic disease at presentation. Data were analyzed from September 1, 2024, to April 25, 2025. Exposures Transoral robotic surgery with concurrent neck dissection. Main Outcomes and Measures Blood was drawn prior to surgery (pretreatment), 1 to 2 days after surgery (postoperative days 1 to 2), and approximately 2 weeks after surgery (postoperative week 2; range, 8 to 20 days). ctHPVDNA was quantified by a tumor tissue–modified viral (TTMV) HPV DNA test. Correlations were tested between the pretreatment and postoperative day 1 to 2 TTMV HPV DNA levels using Gaussian regression. Concordance between detectability at postoperative day 1 to 2 and postoperative week 2 was explored using negative predictive value and positive predictive value. Results Of 57 included patients with detectable pretreatment TTMV HPV DNA, 51 (89%) were male, and the median (IQR) age was 59 (54-66) years. A total of 35 patients (61%) had blood draws at all 3 time points; 16 (28%) had detectable TTMV HPV DNA on postoperative day 1 to 2. Pretreatment and postoperative day 1 to 2 TTMV HPV DNA levels had a medium positive linear correlation ( r = 0.31; 95% CI, 0.04-0.54). Undetectable TTMV HPV DNA on postoperative day 1 to 2 blood draw had a negative predictive value of 0.95 (95% CI, 0.74-1.00) for an undetectable level on postoperative week 2 blood draw, but a detectable level on postoperative day 1 to 2 blood draw only had a positive predictive value of 0.19 (95% CI, 0.04-0.46). Of the 16 patients with detectable TTMV HPV DNA pretreatment and at postoperative day 1 to 2, only 3 (19%) continued to have detectable TTMV HPV DNA at postoperative week 2. One patient had undetectable levels at postoperative day 1 to 2 and detectable levels at postoperative week 2. Conclusions and Relevance In this study, ctHPVDNA detectability early after surgery did not predict detectability at 2 weeks after surgery. ctHPVDNA clearance early after surgery could predict a negative test at 2 weeks. A negative blood draw finding on postoperative day 1 may be used to omit a postoperative blood draw at 2 weeks for minimal residual disease detection in future clinical trials.

Importance A subset of Union for International Cancer Control ( UICC )/ American Joint Committee on Cancer ( AJCC ) eighth edition TNM stage I and II human papillomavirus–positive oropharyngeal carcinoma has undesirable outcomes, which might have contributed to a lack of success in phase III deintensification trials. Refining clinical stage groups, especially in the overabundant cN1/stage I group, has become important for treatment selection. Objective To assess the prognostic importance of pretreatment lymph node (LN) characteristics to optimize case distribution and outcome homogeneity within the N classification system. Design, Setting, and Participants This is an international multi-institutional retrospective prognostic cohort study. Analysis of human papillomavirus–positive oropharyngeal carcinoma treated curatively from 4 institutions (International Collaboration of Oropharyngeal Cancer Network for N-Classification [ICON-N] dataset) provided a refined clinical staging proposal; an independent dataset (Centre Hospitalier de l’Université de Montréal [CHUM] dataset) validated the proposal. Neuroradiologists reviewed pretreatment computed tomography and/or magnetic resonance imaging for nodal features, including presence or absence of abnormal LN(s), retropharyngeal LN, laterality, number of abnormal LN, and imaging-detected extranodal extension (iENE). Data were collected from February to May 2023, and data were analyzed from June to July 2023. Exposures Definitive chemoradiotherapy/radiotherapy or definitive surgery with or without postoperative chemoradiotherapy/radiotherapy. Main Outcomes and Measures The primary end point was overall survival. A Cox proportional hazards multivariable model was used to estimate adjusted hazard ratios (AHRs) and to derive an optimal clinical TNM stage classification (AHR-stage schema) incorporating the strongest prognostic nodal features within the UICC/AJCC eighth edition TNM framework after confirming the prognostication of iENE status. The performance (according to overall normalized scores and ranking) of the AHR-stage schema against the current UICC/AJCC eighth edition TNM staging system was evaluated for hazard consistency, hazard discrimination, prognostic importance, and sample size balance. Validation was performed in the CHUM dataset. Results The ICON-N dataset comprised 2053 patients, including 1898 (92.5%) with cN-positive disease and 155 (7.5%) with cN0 disease; a total of 298 (14.5%) were female, and the mean (SD) age was 60.6 (9.3) years. iENE-positive disease was identified in 710 of 1898 patients with cN-positive disease (37.4%). The median (range) follow-up was 5.1 (0.1-14.7) years. iENE was the strongest prognostic nodal feature in multivariable analysis; the AHR for iENE-positive vs iENE-positive disease was 2.43 (95% CI, 1.96-3.03) in the ICON-N dataset and 2.04 (95% CI, 1.28-3.23) in the CHUM dataset (n = 451). Reclassifying iENE-positive cases 1 stratum higher for N categorization without altering iENE-negative cases yielded an AHR-stage schema that outperformed the current TNM staging system in disease-free and overall survival with a lower (ie, better) overall normalized score (2 vs 3). Conclusions and Relevance In this study, reclassifying each N category 1 stratum higher for iENE-positive disease resulted in better disease-free and overall survival. The proposed new classification outperformed the currently TNM staging system in risk stratification and may facilitate future clinical trial design, outcomes research, and patient care.

Abstract Objective To (1) track the incidence of pleomorphic adenomas (PAs) and (2) compare demographic and treatment trends in PAs over the last five decades in a single county. Study Design Retrospective cohort of all patients with a pathologic diagnosis of nonrecurrent PA from January 1976 to December 2022. Setting Olmsted County, Minnesota. Methods Incidence was calculated per 100,000 persons/year and age and sex‐adjusted to the US 2020 census data. Incidence trends were identified using Poisson rate regression models. Changes in clinical features of diagnosis were evaluated using Spearman rank correlation coefficient tests, Wilcoxon rank sum tests, and Kruskal‐Wallis tests. Results In total, 251 patients with PA were identified. The median age at diagnosis was 50.0 years with a slight female predominance (1.24:1). The adjusted incidence during this period is 4.79/100,000 person‐years, increasing from 2.50 in 1976 to 1979 to 5.73/100,000 persons/year in 2020 to 2022. Less extensive surgery, including partial and superficial parotidectomies, increased significantly from 1976 to 2022, whereas total parotidectomies decreased ( P < .0001). The number of patients who presented with an incidental imaging finding increased during this time period ( P < .001), as did the age at diagnosis (45‐51 years, P = .05) Conclusion The average annual incidence of PAs in Olmsted County from 1976 to 2022 is higher than reported US estimates and has increased over the last five decades. The percentage of patients who presented with incidental imaging findings increased over this period, as did the age at diagnosis. These findings highlight modern imaging techniques and an aging population more willing to seek workup and treatment of a benign parotid mass.

Objective: To assess the impact of extent of parotidectomy on surgical and oncologic outcomes in low grade mucoepidermoid carcinoma (LGMEC). Methods: A retrospective chart review of all patients undergoing primary surgical treatment for LGMEC from 2000 to 2022 was conducted. Clinical features collected included demographics, facial nerve function, operative techniques, postoperative complications/facial nerve function, and recurrence. Results: 58 patients were included; 10 patients underwent partial parotidectomy (PP), 38 underwent superficial parotidectomy (SP), and 10 underwent near-total/total parotidectomy. PP and SP patients had smaller tumors and more superficial tumors compared to near-total/total parotidectomy group ( P = .03). PP and SP were more likely to have negative margins and less locoregional disease compared to near-total/total parotidectomy patients ( P < .01). Near-total/total parotidectomy were more likely to undergo facial nerve resection (20% vs 0% for PP & SP respectively) ( P = .05). Immediate postoperative facial nerve function was significantly better among PP patients (73% HB I) compared to SP (44% HB I) and near-total/total parotidectomy patients (0% HB I) ( P < .01). Most patients regained their facial nerve function although only 40% of the near-total/total parotidectomy patients had a HB I at the time of last follow up ( P < .01). Patients were followed for a median of 6.2 years, during which only 1 patient (total parotidectomy) had a recurrence. Conclusions: PP offers a safe and effective approach for small LGMEC tumors, ensuring better facial nerve function postoperatively with minimal complications compared to more extensive surgery.