Zevallos, José P.

Abstract Recurrence after surgery remains a major cause of failure in head and neck squamous cell carcinoma (HNSCC), particularly for HPV-negative patients whose 2-year failure rate is > 50%. There is unmet need for an accurate diagnostic test that predicts risk of recurrence prior to adjuvant therapy selection. We evaluated ctDNA in lymphatic exudate (“lymph”) collected via surgical drains at 24 hours to detect molecular residual disease (MRD) and compared its performance to plasma and adverse pathology features. Lymph, plasma and blood were collected from 76 HPV- HNSCC patients 24 hours after surgery. Tumor tissue was collected at surgery. 73 patients passed QC. Samples were sequenced using a 699-gene custom panel to a median of 6322x (lymph and plasma cfDNA) or 533x (tumor and blood genomic DNA). Tumor variants were directly genotyped in lymph and plasma using a tumor-informed pipeline. MRD status was determined using a calibrated cutoff based on mean variant allele fraction. Wilcoxon signed-rank test was used for comparisons. Kaplan-Meier estimator with log-rank test and Cox proportional hazards model were used for survival analysis. We previously demonstrated that 24 hour postoperative lymph ctDNA detects recurrence in HPV(-) HNSCC across two independent multi-site cohorts and by orthogonal sequencing approaches (sensitivity (SN) = 72%, specificity (SP) = 65%, p = 0.003, hazard ratio (HR) = 3.1, n = 73). When compared to other data available at this early time point (pathology and 24 hour postoperative plasma), lymph ctDNA outperformed each for recurrence detection (extranodal extension (ENE, p = 0.30), lymphovascular invasion (p = 0.02), perineural invasion (p = 0.38), positive lymph nodes (p = 0.03), plasma (p = 0.8)). We next evaluated lymph ctDNA in a critical subpopulation: patients considered intermediate risk by pathology (negative for ENE or margins but with one or more other adverse pathologic feature). Current NCCN guidelines recommend radiotherapy and to “consider systemic therapy” for these patients. Lymph ctDNA accurately stratified recurrence in this group with high sensitivity (SN = 88%, SP = 69%; P = 0.013, HR = 9.1, n = 24). Within this cohort, 77% of patients who received RT alone and later recurred were positive for lymph ctDNA at 24 hours, suggesting an opportunity to use molecular data in concert with pathology to identify patients who may benefit from adjuvant treatment intensification. Postoperative lymph represents a novel proximal analyte for MRD detection in HPV- HNSCC designed specifically for use in the immediate post-surgical window when adjuvant therapy decisions must be made. Lymph ctDNA is significantly associated with recurrence and outperforms both time-matched plasma and pathology. Accurate MRD identification at this early timepoint has the potential to augment traditional pathology and personalize adjuvant treatment paradigms in HPV-negative HNSCC. Citation Format: Seka Lazare, Zhuosheng Gu, Noah Earland, Adam Harmon, Maciej Pacula, Megan Long, Ashley Tellis, Damion Whitfield, Adam Benson, Lucien Khalil, Robert L. Ferris, Marra Francis, Aadel A. Chaudhuri, Jose P. Zevallos, Wendy Winckler. Postoperative lymphatic exudate in HPV-negative head and neck cancer detects recurrence prior to adjuvant treatment decisions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1946.

ABSTRACT Background Head and neck squamous cell carcinoma remains challenging due to high recurrence rates and poor survival outcomes. Developing precise technologies for disease burden assessment, treatment response, and minimal residual disease (MRD) surveillance is crucial for improving prognosis. Methods This review explores the potential of liquid biopsy for MRD and recurrence detection. A novel liquid TNM (LiTNM) staging system is introduced, integrating biomarkers from saliva, surgical drain lymphatic fluid (SLF), and peripheral blood. Results Proximal liquid biopsies, particularly saliva and SLF, offer advantages due to their proximity to the tumor microenvironment. Saliva demonstrates high sensitivity in HPV‐associated oropharyngeal cancers, while SLF holds potential in identifying early postoperative recurrence. Despite these advancements, standardization and validation remain challenges. Conclusions Liquid biopsy approaches show promise for postoperative disease monitoring, yet their clinical implementation remains in the early stages. The proposed LiTNM staging system could complement TNM staging by providing a molecular framework for risk stratification. However, rigorous prospective studies are necessary to validate its clinical utility and facilitate adoption.

Abstract Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy globally, and the vast majority of cases are treated with primary surgical resection and adjuvant therapy. Our group has pioneered the use of HNSCC circulating tumor DNA (ctDNA) in surgical effluent collected postoperatively from surgical drains (surgical drain fluid, SDF) as a novel proximal bioanalyte for measuring minimal residual disease after surgery. We now profile the immune cell composition of SDF compared to paired peripheral blood mononuclear cells (PBMCs), and correlate SDF immune cell profiles with clinical variables and oncologic outcomes in HNSCC. Method: SDF and peripheral venous blood were collected 24 hours postoperatively from 58 HNSCC patients, including 11 HPV (+) and 47 HPV (-) patients undergoing standard of care surgical resection, lymph node dissection, and adjuvant therapy. Freshly collected SDF cells and PBMCs were cryopreserved until profiling by multicolor flow cytometry for respective leukocyte compositions. Analyses were used to define the following viable CD45+ leukocyte subsets: total T cells, CD4 T-cells CD8 T-cells, Treg cells, B-cells, non- classical monocytes, classical monocytes, natural killer (NK) cells, classical dendritic cells (cDC), plasmacytoid DC (pDC), macrophages, and monocytic myeloid-derived suppressive cells (MDSCs). Immune cell percentages were correlated with clinical characteristics and cancer recurrence. Results: CD45+ leukocytes comprised >99.5% of SDF cells, with very few EPCAM+ tumor cells (< 10^-4). HPV status did not significantly affect SDF immune cell composition, and no significant differences were noted by tumor site (larynx, oral cavity, oropharynx), or extracapsular lymph node extension. Among 13 HPV (-) HNSCC patients with paired peripheral blood drawn concurrently, SDF had a higher proportion of B-cells(16.8% vs. 9%, p=0.044), NK cells(56% vs. 12%, P<0.001), monocytes(14% vs. 1%, P<0.001), and macrophages(3.1% vs. 0.46%, P<0.001) compared to PBMCs, and a lower proportion of CD4+ T cells(1% vs. 24%, P<0.001), CD8+ T cells(0.6% vs. 18%, P<0.001), MDSCs(2.1% vs. 3.4%, P=0.029), and pDCs(0.1% vs. 0.2%, P=0.014). HPV (-) HNSCC patients that went on to recur (n=9) had a significantly higher proportions of SDF monocytes (total, classical, and non- classical) and CD56dimCD16+ NK cells (all P<0.001) compared to non-recurrent patients (n=38). Patients who went on to recur also had a significantly lower proportion of SDF B-cells (P<0.001), CD56bright NK cells(P=0.01), and macrophages (P=0.018) compared to non- recurrent cases. No significant differences were noted with respect to proportions of CD3+, CD4+, CD8+ T-cells, DC, and MDSC cells. Conclusion: SDF from HNSCC patients contains unique immune cell populations and may provide new insights into postoperative tumor immunity. Differences in SDF immune cell composition by oncologic outcome in patients that go on to recur, highlighting potential prognostic and predictive applications of SDF immune cell profiling for adjuvant therapy decision-making. Citation Format: Zhongping Xu, Noah Earland, Lucien Khalil, Lazar Vujanovic, Danny Azmi Elias, Riyue Bao, Jason J. Luke, Aadel A. Chaudhuri, Jose P. Zevallos. Immune cell composition in surgical drain fluid as a novel prognostic marker in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B031.

Abstract Introduction: Recurrence after tumor resection is a major cause of failure in HPV-negative head and neck squamous cell carcinoma (HNSCC), with up to 50% of patients recurring within 2 years. There is unmet need for an accurate diagnostic test that can predict risk of recurrence prior to adjuvant therapy selection. We previously demonstrated that ctDNA in lymphatic exudate collected via surgical drains (“lymph”) accurately identifies molecular residual disease (MRD) and outperforms plasma in HNSCC patients using a targeted sequencing (TS) approach. While TS assays are robust and sensitive, they have key limitations, namely limited ctDNA features, higher cost, longer turnaround times, and lower throughput. Here we evaluate whole genome sequencing (WGS) for detection of MRD in both lymph and plasma sampled 24 hours after surgery. Methods: Lymph, plasma, and whole blood were collected 24 hours postoperatively from 30 HPV-negative HNSCC patients (stages I – IV) along with resected tumor. To detect ctDNA, we utilized WGS analyses of patient matched tumor, germline (blood), and cfDNA from lymph or plasma samples at approximately 150x, 30x, and 30x depth, respectively. Tumor- specific single nucleotide variants were identified from tumor and germline datasets, from which a candidate variant set was used to determine the presence of ctDNA within lymph or plasma DNA through a random forest machine learning model. ctDNA status was determined based on the level of signal compared to a reference population of noncancerous donor plasma samples (n=80). 5 tumors and 1 lymph sample failed QC; in total, 24 patients remained, yielding 10 patients with disease recurrence and 14 with no evidence of disease with >1 year of follow-up. The Kaplan-Meier (KM) estimator with log-rank test and Cox proportional-hazards model were used for survival analyses. Results: KM survival analyses indicated that WGS of lymph ctDNA accurately predicts recurrence (sensitivity (SN) = 50%, specificity (SP) = 93%; p = 0.003, Hazard ratio (HR) = 6.0), consistent with previously published results using a TS MRD approach in this cohort (SN = 80%, SP = 64%, p = 0.02, HR = 5.3). WGS of lymph ctDNA outperformed plasma at this timepoint (SN = 30%, SP = 93%, p = 0.03, HR = 4.2). WGS of lymph ctDNA also showed enhanced performance in locoregional relapse (n=21, SN = 57%, SP = 93%; p = 0.006, HR = 6.7). Finally, the ctDNA fraction of proximal lymph was higher than paired plasma in all locoregional recurrences (n=7), while peripheral plasma had a higher ctDNA fraction in 2 out of 3 distant recurrences. Conclusions: Tumor-informed WGS analysis of lymph ctDNA represents a robust MRD approach in HPV-negative HNSCC. Lymph outperforms time-matched plasma for prediction of recurrence, particularly in patients with locoregional relapse. Accurate MRD identification in the immediate post-surgical timeframe suggests that lymph analysis has potential to augment pathology and longitudinal plasma testing to provide more personalized adjuvant treatment decision-making in patients with HPV-negative HNSCC. Citation Format: Zhuosheng Gu, Seka Lazare, Noah Earland, Marra S Francis, Adam Harmon, Megan Long, Amy Greer, Ellen Verner, Andrew Georgiadis, Mark Sausen, Shakti Ramkissoon, Jose P Zevallos, Aadel A Chaudhuri, Taylor J Jensen, Wendy Winckler. Tumor-informed whole genome sequencing of ctDNA from lymph and plasma detects molecular residual disease in HPV-negative head and neck cancer patients [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A043.

PURPOSE The volume treated with postoperative radiation therapy (PORT) is a mediator of toxicity, and reduced volumes result in improved quality of life (QOL). In this phase II trial, treatment volumes were reduced by omitting PORT to the pathologically negative (PN0) neck in patients with primary head and neck squamous cell carcinoma. METHODS Patients with head and neck squamous cell carcinoma who underwent surgical resection and neck dissection with a PN0 neck and high-risk features mandating PORT to the primary and/or involved neck were eligible. The primary end point was greater than 90% disease control in the unirradiated neck. QOL was evaluated using the MD Anderson Dysphagia Inventory and the University of Michigan patient-reported xerostomia questionnaire. RESULTS Seventy-three patients were enrolled, and 72 were evaluable. Median age was 56 years (range, 31 to 81 years); 58 patients were male, and 47 (65%) had a smoking history. Sites included oral cavity (n = 14), oropharynx (n = 37), hypopharynx (n = 4), larynx (n = 16), and unknown primary tumor (n = 1). According to the American Joint Committee on Cancer Staging Manual (7 th edition), 67 patients (93%) had stage III/IV disease, and 71% of tumors involved or crossed midline. No patient had contralateral neck PORT. In 17 patients (24%), only the primary site was treated. At a median follow-up of 53 months, two patients experienced treatment failure of the PN0 unirradiated neck; they also experienced treatment failure locally. Unirradiated neck control was 97% (95% CI, 93.4% to 100.0%). Five-year rates of local control, regional control, progression-free survival, and overall survival were 84%, 93%, 60%, and 64%, respectively. QOL measures were not significantly different from baseline at 12 and 24 months post-PORT ( P > .05). CONCLUSION Eliminating PORT to the PN0 neck resulted in excellent control rates in the unirradiated neck without long-term adverse effects on global QOL.