Poster 061: Recurrence of Minor Salivary Malignancies: An Analysis of the Mayo Clinic Experience

Abstract

Minor salivary gland tumors account for approximately 15% of all salivary gland neoplasms. Approximately 50% of all minor salivary gland tumors are malignant. Treatment of these tumors has generally been associated with a favorable outcome. However, in many cases patients succumb to late regional and distant recurrence. Identification of patients at high risk for recurrence may help the surgeon appropriately tailor effective treatment. Using the Mayo Clinic Tumor Registry, patients who presented from 1993-2004 with minor salivary gland malignancies were identified. A retrospective chart review was performed to identify patient variables predictive of recurrence. Data was statistically analyzed using a univariate model to identify features predictive of tumor recurrence. One hundred and eleven patients with minor salivary gland malignancies were identified from the institution’s tumor registry. Of these, seventy-eight met inclusion criteria. Histologically, the population included mucoepidermoid carcinoma (41.5%), adenoid cystic carcinoma (34.5%), adenocarcinoma (17.5%), polymorphous low grade adenocarcinoma (3.5%), and acinic cell carcinoma (2.5%). Seventeen (21.8%) patients suffered a recurrence. The mean time to recurrence was 753 days and 87% of recurrence occurred within the first 3 years. Three tumors recurred locally, 8 regionally, and 6 distantly. Gender (p=0.1657), primary tumor location (p=0.3397) and grade (p=0.3958) were not associated with recurrence. Histologic subtype was suggestive of recurrence (p=0.0776). Advancing T stage (p=0.0003) and tumors requiring multimodality treatment (p<.0001) were statistically significant predictors of recurrence. The overall recurrence for this study population was 21.8%. While histologic subtype was suggestive of recurrence, extent of local disease and the need for postoperative adjuvant therapy were predictors of recurrence. Tumors amenable to surgical extirpation were the least recurrent. Therefore surgery is an essential component in the initial treatment of minor salivary gland malignancies and offers the most durable chance of cure in tumors amenable to resection.