Rapid cancer cell perineural invasion utilizes amoeboid migration.

The invasion of nerves by cancer cells, or perineural invasion (PNI), is potentiated by the nerve microenvironment and is associated with adverse clinical outcomes. However, the cancer cell characteristics that enable PNI are poorly defined. Here, we generated cell lines enriched for a rapid neuroinvasive phenotype by serially passaging pancreatic cancer cells in a murine sciatic nerve model of PNI. Cancer cells isolated from the leading edge of nerve invasion showed a progressively increasing nerve invasion velocity with higher passage number. Transcriptome analysis revealed an upregulation of proteins involving the plasma membrane, cell leading edge, and cell movement in the leading neuroinvasive cells. Leading cells progressively became round and blebbed, lost focal adhesions and filipodia, and transitioned from a mesenchymal to amoeboid phenotype. Leading cells acquired an increased ability to migrate through microchannel constrictions and associated more with dorsal root ganglia than nonleading cells. ROCK inhibition reverted leading cells from an amoeboid to mesenchymal phenotype, reduced migration through microchannel constrictions, reduced neurite association, and reduced PNI in a murine sciatic nerve model. Cancer cells with rapid PNI exhibit an amoeboid phenotype, highlighting the plasticity of cancer migration mode in enabling rapid nerve invasion.

Evaluating human papillomavirus testing, prevalence, and association with prognosis in head and neck squamous cell carcinoma by subsite: A national cancer database study.

PURPOSE: To compare human papillomavirus (HPV) testing, prevalence, and association with prognosis between head and neck squamous cell carcinoma (HNSCC) subsites. MATERIALS AND METHODS: This study utilized the National Cancer Database (NCDB) to identify patients diagnosed with HNSCC between 2010 and 2017. Rates of HPV testing, HPV-positivity, and changes in these rates over time were measured by subsite. The impact of HPV-positivity on overall survival across six head and neck subsites was assessed using multivariable-adjusted Cox proportional hazards analysis. RESULTS: A total of 121,550 patients were included. Of this cohort, 87,575 (72.1%) were tested for HPV, with the oropharynx (55,049/64,158; 85.8%) displaying the highest rates of testing and the sinonasal tract (1519/2853; 53.2%) displaying the lowest testing rates. Of the 86,136 with a definitive result, 46,878 (54.4%) were HPV-positive, with the oropharynx (40,313/54,205; 74.4%) displaying the highest rates of HPV-positivity and the oral cavity (1818/11,505; 15.8%) displaying the lowest. HPV-positive malignancy was associated with significantly improved adjusted overall survival in the oropharynx (HR = 0.42 [95% CI: 0.43-0.47]), oral cavity (HR = 0.86 [95% CI: 0.79-0.95]), sinonasal tract (HR = 0.63 [95% CI: 0.48-0.83]), larynx (HR = 0.78 [95% CI: 0.71-0.87]), and hypopharynx (HR = 0.56 [95% CI: 0.48-0.66]), but not the nasopharynx (HR = 0.93 [95% CI: 0.77-1.14]). CONCLUSION: HPV testing rates were significantly lower in non-oropharyngeal subsites. This is relevant as HPV-associated disease displayed significantly improved overall survival in both the oropharynx and four of five non-oropharyngeal subsites. While validation with prospective studies is necessary, these findings may warrant HPV testing in all HNSCC subsites.

Cluster model incorporating heterogeneous dose distribution of partial parotid irradiation for radiotherapy induced xerostomia prediction with machine learning methods.

PURPOSE: A cluster model incorporating heterogeneous dose distribution within the parotid gland was developed and validated retrospectively for radiotherapy (RT) induced xerostomia prediction with machine learning (ML) techniques. METHODS: Sixty clusters were obtained at 1 Gy step size with threshold doses ranging from 1 to 60 Gy, for each of the enrolled 155 patients with HNC from three institutions. Feature clusters were selected with the neighborhood component analysis (NCA) and subsequently fed into four supervised ML models for xerostomia prediction comparison: support vector machines (SVM), k-nearest neighbor (kNN), naïve Bayes (NB), and random forest (RF). The predictive performance of each model was evaluated using cross validation resampling with the area-under-the-curves (AUC) of the receiver-operating-characteristic (ROC). The xerostomia predicting capacity using testing data was assessed with accuracy, sensitivity, and specificity for these models and three cluster connectivity choices. Mean dose based logistic regression served as the benchmark for evaluation. RESULTS: Feature clusters identified by NCA fell in three threshold dose ranges: 5-15Gy, 25-35Gy, and 45-50Gy. Mean dose predictive power was 15% lower than that of the cluster model using the logistic regression classifier. Model validation demonstrated that kNN model outperformed slightly other three models but no substantial difference was observed. Applying the fine-tuned models to testing data yielded that the mean accuracy from SVM, kNN and NB models were between 0.68 and 0.7 while that of RF was ∼0.6. SVM model yielded the best sensitivity (0.76) and kNN model delivered consistent sensitivity and specificity. This is consistent with cross validation. Clusters calculated with three connectivity choices exhibited minimally different predictions. CONCLUSION: Compared to mean dose, the proposed cluster model has shown its improvement as the xerostomia predictor. When combining with ML techniques, it could provide a clinically useful tool for xerostomia prediction and facilitate decision making during radiotherapy planning for patients with HNC.

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.

Brain metastasis from squamous cell carcinoma of the head and neck: a review of the literature in the genomic era.

Squamous cell carcinoma of the head and neck (HNSCC) affects nearly 500,000 individuals globally each year. With the rise of human papillomavirus (HPV) in the general population, clinicians are seeing a concomitant rise in HPV-related HNSCC. Notably, a hallmark of HPV-related HNSCC is a predilection for unique biological and clinical features, which portend a tendency for hematogenous metastasis to distant locations, such as the brain. Despite the classic belief that HNSCC is restricted to local spread via passive lymphatic drainage, brain metastases (BMs) are a rare complication that occurs in less than 1% of all HNSCC cases. Time between initial diagnosis of HNSCC and BM development can vary considerably. Some patients experience more than a decade of disease-free survival, whereas others present with definitive neurological symptoms that precede primary tumor detection. The authors systematically review the current literature on HNSCC BMs and discuss the current understanding of the effect of HPV status on the risk of developing BMs in the modern genomic era.

GFRα1 released by nerves enhances cancer cell perineural invasion through GDNF-RET signaling.

The ability of cancer cells to invade along nerves is associated with aggressive disease and diminished patient survival rates. Perineural invasion (PNI) may be mediated by nerve secretion of glial cell line-derived neurotrophic factor (GDNF) attracting cancer cell migration through activation of cell surface Ret proto-oncogene (RET) receptors. GDNF family receptor (GFR)α1 acts as coreceptor with RET, with both required for response to GDNF. We demonstrate that GFRα1 released by nerves enhances PNI, even in the absence of cancer cell GFRα1 expression. Cancer cell migration toward GDNF, RET phosphorylation, and MAPK pathway activity are increased with exposure to soluble GFRα1 in a dose-dependent fashion. Dorsal root ganglia (DRG) release soluble GFRα1, which potentiates RET activation and cancer cell migration. In vitro DRG coculture assays of PNI show diminished PNI with DRG from GFRα1(+/-) mice compared with GFRα1(+/+) mice. An in vivo murine model of PNI demonstrates that cancer cells lacking GFRα1 maintain an ability to invade nerves and impair nerve function, whereas those lacking RET lose this ability. A tissue microarray of human pancreatic ductal adenocarcinomas demonstrates wide variance of cancer cell GFRα1 expression, suggesting an alternate source of GFRα1 in PNI. These findings collectively demonstrate that GFRα1 released by nerves enhances PNI through GDNF-RET signaling and that GFRα1 expression by cancer cells enhances but is not required for PNI. These results advance a mechanistic understanding of PNI and implicate the nerve itself as a key facilitator of this adverse cancer cell behavior.

Management algorithm for HIV-associated parotid lymphoepithelial cysts.

We report an evidence-based management algorithm for benign lymphoepithelial cysts (BLEC) of the parotid glands in HIV patients based on long-term outcomes after radiation therapy. From 1987 to 2013, 72 HIV-positive patients with BLEC of the parotid glands treated at our institutions were identified and their medical records were reviewed and analyzed. The primary endpoint of our study was to determine a dose response in HIV patients with BLEC. In group A (≤18 Gy), which received a median dose of 10 Gy (8-18), overall response (OvR), complete response (CR), partial response (PR), and local failure (LF) was experienced by 7, 7, 0, and 93 %, respectively. In group B (≥22.5 Gy), which received a median dose of 24 Gy (22.5-30), OvR, CR, PR, and LF was experienced by 88, 65, 23, and 12 %. Logistic regression revealed that higher dose (≥22.5 Gy) predicted for cosmetic control (p = 0.0003). Multiple regression analysis revealed higher dose predicted for cosmetic control (p = 0.0001) after adjusting for confounding variables (age, gender, race, HAART use, BLEC duration, and fractionation size). No patients in either group experienced RTOG grade ≥3 toxicities. A radiation dose of 24 Gy delivered in 12-16 fractions of 1.5-2 Gy per fraction provides long-term cosmetic control in HIV-positive patients with BLEC of the parotid glands.

A combination of modified transnasal endoscopic maxillectomy via transnasal prelacrimal recess approach with or without radiotherapy for selected sinonasal malignancies.

An external approach for resection of sinonasal tumors is associated with increased morbidity. Therefore, we employed a modified transnasal endoscopic maxillectomy combined with pre and/or postoperative radiotherapy for early stage maxillary carcinomas. It aims to evaluate our early experience with endoscopic resection of selected malignant sinonasal tumors. The medical and radiology records of patients who underwent endonasal endoscopic resection of malignant sinonasal tumors between 2008 and 2012 were retrospectively reviewed. Ten cases of selected malignant tumor were performed to resect by modified transnasal endoscopic maxillectomy. All the patients were without evidence of disease at a mean follow-up of 26.8 months. No major complications were recorded. The mean hospitalization stay was 6.6 days. In very carefully selected cases of malignant tumors, modified transnasal endoscopic maxillectomy is acceptable. The postoperative complication rate is low, cosmetic outcome is excellent and patients do not require a long hospitalization.

Tolerability, toxicity, and temporal implications of transoral robotic surgery (TORS) on adjuvant radiation therapy in carcinoma of the head and neck.

OBJECTIVES: Overall treatment package time (from surgery to radiotherapy [RT] completion) > 100 days can portend poor outcomes in head and neck cancer. Faster postoperative recovery seen with transoral robotic surgery may decrease treatment duration and toxicity for adjuvant RT and chemoradiation. METHODS: We retrospectively reviewed all patients treated with transoral robotic surgery (n = 124) and adjuvant RT and chemoradiation (n = 33) at our institution for head and neck cancer from April 2007 to December 2011 to determine treatment duration, acute toxicity, and long-term percutaneous gastric tube rates. RESULTS: The median overall treatment time was 86 days and from surgery to RT start was 41 days; median RT duration was 44 days. No wound breakdown or infection occurred during or after RT. Two-year actuarial locoregional control, distant metastasis-free survival, and overall survival rates were 93%, 96%, and 97%, respectively. CONCLUSIONS: Adjuvant RT after transoral robotic surgery for head and neck cancer can be completed safely and in a timely fashion. Longer follow-up and a larger cohort will be needed to determine if this regimen is more effective than traditional surgery followed by adjuvant RT.

Adjuvant Reirradiation With Proton Therapy in Head and Neck Squamous Cell Carcinoma.

Purpose: For patients with head and neck squamous cell carcinoma (HNSCC), locoregional failure and second primary tumors are common indications for adjuvant reirradiation (re-RT). Given an absence of clear consensus on the role of adjuvant re-RT, we sought to assess histopathologic risk factors of patients with HNSCC and their resulting outcomes after adjuvant re-RT with proton therapy. Methods and Materials: We conducted a retrospective analysis of patients with HNSCC who underwent salvage surgery at our institution followed by adjuvant re-RT with proton therapy over 1.5 years. All included patients received prior radiation therapy. The Kaplan-Meier method was used to evaluate locoregional recurrence-free survival and overall survival. Results: The cohort included 22 patients, with disease subsites, including oropharynx, oral cavity, hypopharynx, larynx, and nasopharynx. Depending on adverse pathologic features, adjuvant re-RT to 66 Gy (32% of cohort) or 60 Gy (68%), with (59%) or without (41%) concurrent systemic therapy was administered. The majority (86%) completed re-RT with no reported treatment delay; 3 patients experienced grade ≥3 acute Common Terminology Criteria for Adverse Events toxicity and no patient required enteral feeding tube placement during re-RT. Median follow-up was 21.0 months (IQR, 11.7-25.2 months). Five patients had biopsy-proven disease recurrences a median of 5.9 months (IQR, 3.8-9.7 months) after re-RT. Locoregional recurrence-free survival was 95.2%, 70.2%, 64.8% at 6, 12, and 24 months, respectively. OS was 100%, 79.2%, and 79.2% at 6, 12, and 24 months, respectively. Four patients had osteoradionecrosis on imaging a median of 13.2 months (IQR, 8.7-17.4 months) after re-RT, with 2 requiring surgical intervention. Conclusions: Adjuvant re-RT for patients with HNSCC was well-tolerated and offered reasonable local control in this high-risk cohort but appears to be associated with a risk of osteoradionecrosis. Additional study and longer follow-up could help define optimal patient management in this patient population.

How I treat extramedullary acute myeloid leukemia.

Extramedullary (EM) manifestations of acute leukemia include a wide variety of clinically significant phenomena that often pose therapeutic dilemmas. Myeloid sarcoma (MS) and leukemia cutis (LC) represent 2 well-known EM manifestations with a range of clinical presentations. MS (also known as granulocytic sarcoma or chloroma) is a rare EM tumor of immature myeloid cells. LC specifically refers to the infiltration of the epidermis, dermis, or subcutis by neoplastic leukocytes (leukemia cells), resulting in clinically identifiable cutaneous lesions. The molecular mechanisms underlying EM involvement are not well defined, but recent immunophenotyping, cytogenetic, and molecular analysis are beginning to provide some understanding. Certain cytogenetic abnormalities are associated with increased risk of EM involvement, potentially through altering tissue-homing pathways. The prognostic significance of EM involvement is not fully understood. Therefore, it has been difficult to define the optimal treatment of patients with MS or LC. The timing of EM development at presentation versus relapse, involvement of the marrow, and AML risk classification help to determine our approach to treatment of EM disease.

Close Margins After Transoral Robotic Surgery for Human Papillomavirus-Positive Oropharyngeal Carcinoma: A Review of the Literature and Practical Recommendations.

The purpose of this article is to summarize the literature and practical recommendations from experienced centers for close margins after transoral robotic surgery for human papillomavirus-positive oropharyngeal carcinoma.

Clinical and Therapeutic Considerations for Older Adults with Head and Neck Cancer.

Approximately 30% of patients with head and neck squamous cell carcinoma (HNSCC) are at least 70 years of age, and this percentage is expected to increase as the population increases and lives longer. Elderly patients are underrepresented in head and neck oncology clinical trials, and there is minimal evidence on the management of HNSCC for this population. Subsequently, despite their best intentions, physicians may unknowingly recommend an ill-suited course of therapy, which may result in suboptimal oncological or functional outcomes or adverse events. Surgical approaches have the potential to carry a higher risk of morbidity and mortality in older adults, especially in patients with multiple comorbidities. Definitive radiation therapy treatment in patients with HNSCC frequently involves 7 weeks of daily radiation, sometimes with concurrent chemotherapy, and this demanding treatment can be difficult for older adult patients, which may lead to treatment interruptions, potential removal of concurrent systemic therapy, compromised outcomes, and diminished quality of life. There are clinical trials currently underway investigating altered fractionation regimens and novel, less toxic systemic treatments in this population. This review provides an overview of how best to approach an older adult with HNSCC, from initial work-up to treatment selection.

Combining Radiotherapy and Immunotherapy in Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) is a leading cause of morbidity and mortality globally. Despite significant advances in well-established treatment techniques, prognosis for advanced-stage HNSCC remains poor. Recent, accumulating evidence supports a role for immunotherapy in HNSCC treatment. Radiation therapy (RT), a standard treatment option for HNSCC, has immunomodulatory and immunostimulatory effects that may enhance the efficacy of immunotherapy. In several cancer types, combining RT and immunotherapy has been shown to improve tumor response rates, increase survival, and reduce toxicity compared to traditional chemotherapy and radiation therapy. This review provides a timely overview of the current knowledge on the use of RT and immunotherapy for treating HNSCC. It highlights the potential advantages of combining these therapies, such as improved tumor response rates, increased survival, and reduced toxicity. The review also discusses the challenges that need to be addressed when redefining the standard of care in HNSCC, and proposes further research to optimize treatment combinations, minimize radiation-induced toxicity, and identify suitable patient populations for treatment.

Effect of treatment interruptions on overall survival in patients with triple-negative breast cancer.

INTRODUCTION: Currently, there are no data regarding the impact of treatment interruptions during radiotherapy for breast cancer. In this study, we examine the correlation between treatment interruptions during radiotherapy and outcomes in triple-negative breast cancer patients. METHODS: A total of 35 845 patients with triple-negative breast cancer treated between 2010 and 2014 were identified and analyzed from the National Cancer Database. The number of interrupted radiotherapy treatment days was calculated as the difference between the total elapsed days from the start to end of radiation treatment (both initial treatment and boost treatment, when boost was administered) and the total number of expected treatment days, defined as the number of expected treatment days with an addition of 2 weekend days for every multiple of 5 treatment days. Binomial multivariate regression analysis was used to detect correlates of treatment interruptions, and propensity-score matched multivariable Cox proportional hazard models were used to evaluate the association between treatment interruption and overall survival (OS). RESULTS: When modeled as a continuous variable, longer treatment duration was associated with poorer OS (hazard ratio [HR] = 1.023, 95% confidence interval [CI] = 1.015 to 1.031). In reference to 0-1 days of interruption, patients with 2-5 interrupted days (HR = 1.069, 95% CI = 1.002 to 1.140 interrupted days), 6-10 interrupted days (HR = 1.239, 95% CI = 1.140 to 1.348 interrupted days), and 11-15 interrupted days (HR = 1.265, 95% CI = 1.126 to 1.431 interrupted days) experienced increasing likelihood of mortality. CONCLUSION: In the first study of its kind, we report a correlation between treatment interruptions during adjuvant radiotherapy in triple-negative breast cancer and OS.

Proton Bragg Peak FLASH Enables Organ Sparing and Ultra-High Dose-Rate Delivery: Proof of Principle in Recurrent Head and Neck Cancer.

Proton pencil-beam scanning (PBS) Bragg peak FLASH combines ultra-high dose rate delivery and organ-at-risk (OAR) sparing. This proof-of-principle study compared dosimetry and dose rate coverage between PBS Bragg peak FLASH and PBS transmission FLASH in head and neck reirradiation. PBS Bragg peak FLASH plans were created via the highest beam single energy, range shifter, and range compensator, and were compared to PBS transmission FLASH plans for 6 GyE/fraction and 10 GyE/fraction in eight recurrent head and neck patients originally treated with quad shot reirradiation (14.8/3.7 CGE). The 6 GyE/fraction and 10 GyE/fraction plans were also created using conventional-rate intensity-modulated proton therapy techniques. PBS Bragg peak FLASH, PBS transmission FLASH, and conventional plans were compared for OAR sparing, FLASH dose rate coverage, and target coverage. All FLASH OAR V40 Gy/s dose rate coverage was 90-100% at 6 GyE and 10 GyE for both FLASH modalities. PBS Bragg peak FLASH generated dose volume histograms (DVHs) like those of conventional therapy and demonstrated improved OAR dose sparing over PBS transmission FLASH. All the modalities had similar CTV coverage. PBS Bragg peak FLASH can deliver conformal, ultra-high dose rate FLASH with a two-millisecond delivery of the minimum MU per spot. PBS Bragg peak FLASH demonstrated similar dose rate coverage to PBS transmission FLASH with improved OAR dose-sparing, which was more pronounced in the 10 GyE/fraction than in the 6 GyE/fraction. This feasibility study generates hypotheses for the benefits of FLASH in head and neck reirradiation and developing biological models.

Dosimetric Comparison of Intensity-Modulated Radiation Therapy (IMRT) and Intensity-Modulated Proton Therapy (IMPT) for a Novel Oral Tongue Avoidance Concept in Low-Risk Squamous Cell Carcinoma of the Oral Tongue.

Purpose: After adequate surgical resection, early-stage oral tongue cancer patients can harbor a low risk of local recurrence but remain at risk of regional recurrence. Oral tongue avoidance during adjuvant radiation therapy is an attractive potential treatment strategy to mitigate treatment toxicity. We sought to quantify the dosimetric advantages of this approach and hypothesized that intensity-modulated proton therapy (IMPT) may further reduce organs at risk doses compared with intensity-modulated radiation therapy (IMRT). Materials and Methods: Five patients with oral tongue cancer treated with postoperative radiation therapy from August 2020 to September 2021 were retrospectively reviewed. Novel clinical target volume contours, excluding the oral tongue, were generated while maintaining coverage of bilateral at-risk lymph nodes. Comparison IMRT (X) and IMPT (PBT) plans were generated using standard treatment volumes (control) and avoidance volumes (study) (n = 4 plans/patient). Dosimetric variables for organs at risk were compared using the paired t test. Results: The prescribed dose was 60 Gy in 30 fractions. D95% clinical target volume coverage was similar between X and PBT plans for both control and study clinical target volumes. Comparing control with study plans, both X (58.9 Gy vs 38.3 Gy, P = .007) and PBT (60.2 Gy vs 26.1 Gy, P < .001) decreased the oral cavity dosemean. The pharyngeal constrictor dosemean was also reduced (P < .003). There was no difference between control and study plans for larynx (P = .19), parotid (P = .11), or mandible dose (P = .59). For study plans, PBT significantly reduced oral cavity dosemean (38.3 Gy vs 26.1 Gy, P = .007) and parotid dosemean (23.3 Gy vs 19.3 Gy, P = .03) compared with X. For control plans, there was no difference in oral cavity dosemean using PBT compared with X, but PBT did improve the parotid dosemean (26.6 Gy vs 19.7 Gy, P = .02). Conclusion: This study quantifies the feasibility and dosimetric advantages of oral tongue avoidance while still treating the at-risk lymph nodes for oral tongue cancer. The dosimetric difference between PBT and X was most prominent with an oral tongue-avoidance strategy.

High Failure Rates in Young Nonsmoker Nondrinkers With Squamous Cell Carcinoma of the Oral Tongue.

OBJECTIVE(S): There has been a disproportionate increase in the incidence of young patients with squamous cell carcinoma of the oral tongue (SCCOT). The purpose of this study was to compare young patients to older patients with SCCOT without prior drinking or smoking history as this population is poorly characterized in the literature. METHODS: A retrospective review of patients presenting to our institution with SCCOT was performed. The clinical and pathologic characteristics, as well as, outcomes were compared between younger patients (age ≤45) and older patients (age >45). Outcome analysis was performed using Kaplan Meier method. Multivariable Cox proportional hazard models were performed for age and stage. RESULTS: Eighty-two patients (38 young, 44 old) were included in this study. Median follow-up was 29.4 months. When compared to the older cohort (age >45), the younger cohort (age ≤45) demonstrated lower rates of 5-year locoregional control (LC) (79.6% vs. 52.5%, p = 0.043) and distant metastasis-free survival (88.1% vs. 61.8%, p = 0.006). Both cohorts demonstrated similar overall survival rates (55.5% vs. 58.1%) and disease-specific survival (66.2% vs. 58.1%). Of patients experiencing locoregional failure with available radiation therapy plans and PET scans in younger cohorts (n = 7), 100% demonstrated in-field failures. Multivariable Cox proportional hazards demonstrated age was an independent predictor of DMFS (p = 0.004) and the advanced stage was a predictor of DSS (p = 0.03). CONCLUSIONS: Young, nondrinker, nonsmokers with SCCOT demonstrate high rates of locoregional recurrence, distant metastasis, and in-field failures. Future studies are warranted to determine underlying mechanisms driving pathogenesis in this unique cohort. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1110-1121, 2023.

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.