Significance of the Extracapsular Spread of Metastatic Lymph Nodes in Papillary Thyroid Carcinoma

OBJECTIVES

The extracapsular spread (ECS) of metastatic lymph nodes is associated with aggressive tumor behavior, and is regarded as a major risk factor for local recurrence in patients with head and neck squamous cell carcinoma. However, the significance of ECS of metastatic lymph nodes has not been well established in well-differentiated thyroid carcinoma. The purpose of this study was to examine this question.

METHODS

A retrospective review was performed of 335 patients with papillary thyroid carcinoma who underwent total thyroidectomy with lymph node dissection from April 2001 to December 2009. We analyzed various clinical characteristics, pathologic factors, and the size, number, and ECS of foci in metastatic lymph nodes.

RESULTS

On pathologic review, 201 of the patients (56.6%) had lymph node metastasis. This was significantly related to age and tumor size. ECS was noted in 64 of these 201 patients (31.8%), and was significantly related to male gender, tumor size, presence of extrathyroidal extension, metastatic lymph node size, and focus size. Recurrence occurred in 13 patients (3.9%), and the presence of ECS was significantly related to recurrence.

CONCLUSION

ECS of metastatic lymph nodes is an important prognostic factor for loco-regional recurrence in papillary thyroid carcinoma.

High metastatic node number, not extracapsular spread or N-classification is a node-related prognosticator in transorally-resected, neck-dissected p16-positive oropharynx cancer

BACKGROUND

Due to unique biology and prognosis, precise identification of predictive parameters is critical for p16+ oropharyngeal squamous cell carcinoma (OPSCC). Prior studies showing absence of prognostication from extracapsular spread (ECS) and/or high N-classification in surgically-treated p16+ OPSCC necessitate new, evidence-based prognosticators.

METHODS

A prospectively assembled cohort of 220, transoral surgery+neck dissection±adjuvant therapy-treated, p16+ OPSCC patients was analyzed. Disease recurrence and disease-specific survival (DSS) were primary endpoints.

RESULTS

Median follow-up was 59 (12-189) months. Distribution of metastatic node numbers was: 0 in 9.5% (n=21), 1 in 33.6% (n=74), 2 in 17% (n=38), 3 in 14.5% (n=32), 4 in 8.2% (n=18), and ⩾5 in 17% (n=37). ECS was recorded in 80% (n=159), and N2c-N3 in 17% (n=38). Adjuvant radiotherapy and chemoradiotherapy was administered in 44% and 34%. Recurrence developed in 22 patients (10%); 4 local, 5 regional, 2 regional and distant, and 11 distant. The 3- and 5-year DSS estimates were 94.6% and 93%. Multivariable logistic regression identified ⩾5 nodes and T3-T4 classification as predictors for recurrence. In multivariable Cox analyses, ⩾5 nodes, T3-T4 classification and margins were prognostic for DSS. ECS, N2c-N3 classification and smoking were not prognostic.

CONCLUSIONS

Metastatic node number, not ECS or high N-classification is an independent nodal predictor of outcomes in surgically-treated p16+ OPSCC patients. Despite high DSS (~80%), closer surveillance for recurrence is recommended for patients with ⩾5 metastatic nodes.