Influence of histopathologic factors on pattern of metastasis in squamous cell carcinoma of the head and neck.

OBJECTIVES/HYPOTHESIS Knowledge of histopathological factors, such as perineural invasion (PNI), extracapsular spread (ECS), angiolymphatic vessel invasion, and conglomerate lymph nodes, in patients with head and neck squamous cell carcinoma is important for appropriate treatment decisions. Given the availability of aggressive therapeutic options with known side effects and burdens for the patient, choosing the correct treatment option is vital. STUDY DESIGN Retrospective patient database. METHODS Using a retrospective database of patients treated over a 10-year period, independent prognostic factors for disease-free survival and overall survival were assessed. Univariate analysis was used to identify significant variables, and multivariate Cox regression analysis was used to determine independent prognostic factors. RESULTS Between January 1, 1999 and December 31, 2009, 291 patients with head and neck squamous cell carcinoma were analyzed to identify influence of histopathological factors on pattern of metastasis. PNI tends to set metastasis locoregional, both in ipsilateral and contralateral lymph nodes. Lymphangiosis eases the way toward ipsilateral lymph node metastasis. ECS spread and hemangiosis demonstrated a significantly higher risk of distant metastasis. With the occurrence of conglomerate lymph nodes, patient data demonstrated a highly significant accumulation of distant metastasis. CONCLUSIONS Patients with PNI and lymph vessel invasion tend toward locoregional lymph node metastasis on the ipsilateral side of the neck. In cases of PNI, the patient is at risk for a contralateral neck recurrence of the tumor. In patients with ECS, blood vessel invasion, or conglomerate disease, disseminated spread of the disease to distant locations is more likely and has a high negative impact on survival of the patient.