Factors predictive of elective neck dissection (END) in patients with cN0 hard palate and upper gingival SCC and the impact of END on survival

Presentation: C008
Topic: Oral Cancer
Type: Poster
Date: Thursday, April 19, 2018
Session: 9:00 AM - 7:00 PM
Authors: A Obayemi, MD1, M Cohen, MD1, R Rahmati, MD2, J Migliacci1, J C Cracchiolo1, B Roman1
Institution(s): 1Memorial Sloan Kettering Cancer Center, 2Columbia University Medical Center

BACKGROUND: Recent literature notes that up to 40% of hard palate SCCs have regional metastasis and 11.9%-29.2% have occult disease. Consensus around elective neck dissection is lacking in this patient population. We sought to identify patient, tumor, and treatment factors predictive of elective neck dissection in clinically N0 patients with hard palate/upper gum SCC. We also used multivariable analysis to determine the effect of END on overall survival.

MATERIALS AND METHODS: Using the National Cancer Database (NCDB), cN0 patients diagnosed with squamous cell carcinoma of the head and neck with the sub-site hard palate and upper gum were identified. Chi-squared analysis was performed on a total of 1,837 patients to examine predictors of elective neck dissection based on tumor and demographic variables including stage, race, gender, age, hospital type, and insurance type. Multivariable logistic regression analysis was performed to determine predictors of END, and univariate logistic regression was used to determine predictors of occult disease. Cox proportional hazards regression analysis was performed to determine the effects of END on overall survival after controlling for patient, tumor, and treatment factors.

RESULTS: END was performed on 422 of 1,837 patients with cN0 tumors. There was a 14.0% rate of pathologically positive nodes. Higher tumor stage, hospital type (academic), and insurance status (private) were associated with higher likelihood of END both in univariate and multivariable analyses (p<0.05 ). No variables predicted occult metastases. Cox regression analysis showed that after controlling for tumor factors (such as T stage), patient factors, and treatment factors, patients who underwent END demonstrated improved overall survival (hazards ratio 0.75, p=0.002).

CONCLUSION: Tumor stage, hospital type and insurance status were associated with higher rate of elective neck dissection for patients with cN0 hard palate squamous cell carcinoma. When controlling for factors such as tumor stage and patient age, elective neck dissection was associated with better overall survival than patients that did not have an elective neck dissection. Further investigation should be pursued to determine the oncologic impact of elective neck dissection in this group of patients.