Extracapsular extension is a poor predictor of disease recurrence in surgically treated oropharyngeal squamous cell carcinoma

Abstract

Extracapsular extension in squamous cell carcinoma nodal metastases usually predicts worse outcome. However, there are no standard histologic grading criteria for extracapsular extension, and there have been few studies on oropharyngeal squamous cell carcinoma alone. We studied the extent of extracapsular extension utilizing a novel grading system and correlated grades with outcomes while controlling for p16 status. A cohort of surgically treated oropharyngeal squamous cell carcinoma cases were reviewed and metastases graded as 0 (within substance of node), 1 (filling subcapsular sinus with thickened capsule/pseudocapsule, but no irregular peripheral extension), 2 (≤1mm beyond capsule), 3 (>1mm beyond capsule), or 4 (no residual nodal tissue or architecture; ‘soft tissue metastasis’). There were 101 cases, for which p16 was positive in 90 (89%). Extracapsular extension grades did not correlate with nodal size (P = 0.28) or p16 status (P = 0.8). In follow up, 10 patients (10%) had disease recurrence with only 3 of 64 (5%) grade 0–3 cases and 7 of 37 (19%) with grade 4 recurring (P = 0.04). Grade 4 extracapsular extension was associated with poorer survival (P < 0.01). However, grade 4 extracapsular extension correlated with higher T-stage (P = 0.02), and in multivariate analysis, was not significantly associated with poorer overall (P = 0.14) disease-free (P = 0.2), or disease-specific survival (P = 0.09). The impact of extracapsular extension in nodal metastases is limited in oropharyngeal squamous cell carcinoma. Only extracapsular extension grade 4 associates with poorer outcomes, but not independently of T-stage and other variables.

Radiographic Imaging Does Not Reliably Predict Macroscopic Extranodal Extension in Human Papilloma Virus-Associated Oropharyngeal Cancer

“…To complicate matters, radiographic and pathologic definitions of ENE have been inconsistent, difficult to define, and somewhat subjective [9,12,13]. To address the lack of standardized diagnostic criteria and reporting of pENE, Lewis et al [9] proposed a novel grading system for the assessment of ENE and later simplified this scheme.…”

“…Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 43.7, 97.7, 82.6, and 87.3%, respectively [8]. Studies have demonstrated that ENE does not correlate with the size of nodal metastases, and ENE may be present in patients with smaller nodes and low burdens of disease [9]. Now that upfront neck dissections are part of the routine treatment of patients with early oropharyngeal squamous cell carcinoma (OPSCC), we have the opportunity to evaluate the accuracy of preoperative imaging with regards to pENE in this patient cohort.…”

Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: What Is New in the 2017 WHO Blue Book for Tumors and Tumor-Like Lesions of the Neck and Lymph Nodes

“…Several peculiar pathologic features can be seen. First, neck nodal metastases related to HPV-positive OPSCC are frequently large with pushing borders and expansion of the lymph nodes rather than extensive infiltration of the surrounding tissue [10]. In addition, they are very frequently cystic and/or necrotic [11].…”

Lymph Node Disease and Advanced Head and Neck Imaging: A Review of the 2013 Literature

“…In addition, there are no standard pathologic ECS grading criteria at this time [28]. In light of this it is not clear whether surgical pathology or pre-operative imaging should be the gold standard for the detection of ECS, or perhaps an alternative imaging feature such as central nodal necrosis should be used to predict overall survival in place of pathological ECS [26].…”