The Number of Radiographically Positive Lymph Nodes Further Stratifies Patient Survival Among Clinical N1 Patients With Human Papillomavirus-Associated Oropharyngeal Cancer.

Purpose: Human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV[+]OPSCC) requires further study to optimize the existing clinical staging system and guide treatment selection. We hypothesize that incorporation of the number of radiographically positive lymph nodes will further stratify patients with clinical N1 (cN1) HPV(+)OPSCC. Methods and Materials: A post hoc analysis from 2 prospective clinical trials at a high-volume referral center was conducted. Patients underwent primary tumor resection and lymphadenectomy, followed by either standard-of-care radiation therapy (60 Gy in 30 fractions) with or without cisplatin (40 mg/m2 weekly) or de-escalated radiation therapy (30 Gy in 20 twice-daily fractions) with concomitant 15 mg/m2 docetaxel once weekly. Imaging studies were independently reviewed by a blinded neuroradiologist classifying radiographic extranodal extension (rENE) and the number and maximal size of involved lymph nodes. Patients without pathologic data available for assessment were excluded. Results: A total of 260 patients were included. Of these, 216 (83%) were cN1. Patients had a median of 2 radiographically positive lymph nodes (range, 0-12), and 107 (41%) had rENE. For cN1 patients, stratifying by radiographically positive lymph nodes (1-2 vs 3-4 vs >4) was predictive of progression-free survival (PFS) (P = .017), with 2-year PFS rates of 96%, 88%, and 81%, respectively. More than 2 radiographically positive lymph nodes was identified as a significant threshold for PFS (P = .0055) and overall survival (P = .029). Radiographic ENE and lymph node size were not predictive of PFS among cN1 patients. Conclusions: The number of radiographically positive lymph nodes is predictive of PFS and overall survival and could be used to meaningfully subcategorize cN1 patients with HPV(+)OPSCC. We recommend further validation of our proposal that cN1 patients with 1 to 2 radiologically positive lymph nodes be categorized as cN1a, patients with 3 to 4 radiologically positive lymph nodes categorized as cN1b, and patients with >4 radiographically positive lymph nodes categorized as cN1c.

Second Primary Tumors in Patients Presenting With Unilateral HPV-Associated Tonsillar Squamous Cell Carcinoma.

OBJECTIVE: To describe and compare rates of metachronous and synchronous second primaries of the contralateral tonsil in patients with primary HPV(+) tonsillar squamous cell carcinoma (SCC). STUDY DESIGN: Retrospective cohort study. MATERIALS AND METHODS: This is a single tertiary care center retrospective case series, from 2006 to 2019, of HPV(+) tonsillar SCC patients who underwent primary surgical resection with unilateral wide-field tonsillectomy or bilateral tonsillectomy for diagnostic or therapeutic purposes. A metachronous second primary is one diagnosed >6 months after completion of surgical treatment. A synchronous second primary is one diagnosed during bilateral tonsillectomy for unilateral HPV(+) tonsillar SCC. Rates of second primary and patient characteristics were compared using chi-square tests. RESULTS: About 303 patients underwent unilateral surgical resection +/- adjuvant therapy for HPV(+) tonsillar SCC. One (0.3%) developed a metachronous second primary in the contralateral tonsil 11.9 years following treatment. Fifty-seven patients with HPV(+) tonsillar SCC underwent bilateral tonsillectomy, and 37/57 (65%) had no clinical signs for contralateral disease. Of these, only 1/37 (2.7%) was incidentally found to have a synchronous second primary. Twenty patients underwent bilateral tonsillectomy due to clinical concern for contralateral disease. Of these, 3/20 (15%) were found to have a synchronous HPV(+) SCC in the contralateral tonsil. CONCLUSIONS: The prevalence of metachronous second primary after appropriate treatment of HPV(+) tonsillar SCC is very low (0.3%) and so is the chance of incidentally discovering a synchronous second primary during bilateral tonsillectomy (2.7%). We do not recommend bilateral tonsillectomy as a part of the routine algorithm in the surgical management of these patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:332-338, 2022.

Correlation between radiographic and pathologic lymph node involvement and extranodal extension via CT and PET in HPV-associated oropharyngeal cancer.

PURPOSE/OBJECTIVES: Extranodal extension (ENE) and more than 4 pathologically involved lymph nodes (pN2) are critical prognostic factors in HPV-associated oropharyngeal cancer (HPV(+) OPSCC). We analyze a patient cohort with HPV(+) OPSCC to determine the sensitivity and specificity of CT and PET/CT in identifying involvement of more than 4 lymph nodes (rN2) compared to pN2 and radiographic ENE (rENE) compared to pathologic ENE (pENE). MATERIALS/METHODS: The dataset consisted of 261 patients enrolled in two prospective clinical trials. All imaging studies were independently reviewed by a blinded neuroradiologist, classifying the presence or absence of rENE and rN2. Secondary analyses included correlations of imaging accuracy and pathologic size of the primary tumor. RESULTS: CT demonstrated sensitivity of 59%, specificity of 92%, positive predictive value (PPV) of 53%, negative predictive value (NPV) of 94%, and accuracy of 88% for pN2. PET/CT showed similar results. Patients with up to 4 involved lymph nodes (rN0-1) had a 93-94% chance of remaining pN0-1. CT and PET/CT identified an equal number of involved nodes in 81% of patients. CT demonstrated sensitivity of 54%, specificity of 71%, PPV of 72%, NPV of 53%, and accuracy of 62% for pENE. PET/CT showed similar outcomes. Notably, when multiple radiographic criteria were used to identify rENE, PPV increased for both CT (84%) and PET/CT (79%). CONCLUSION: Patients with rN0-1 had a 93-94% chance of remaining pN0-1, suggesting rN0-1 could effectively stratify patients for clinical trials and treatment de-escalation. While CT and PET/CT were highly correlated, both showed low sensitivity for identifying pENE.