[1311] Advantages of Three-Grade Histopronostic Classification in Therapeutic Management of Primary Epithelial Parotid Carcinoma

Vanessa Szablewski, Michel Wassef, Marie Christine Picot, Renaud Garrel, Valerie Costes. CHU de Montpellier, Montpellier, France; APHP, Paris, France

Background: The treatment of primary parotid carcinomas involves tumor staging and histological grading in two grades: low and high grade malignancy. We took recent publications in this area into account and assessed the benefits of a three-grade histological classification for identifying a group of tumors with an intermediate malignancy grade.
Design: A 20-year standardized single center treatment history, including total parotidectomy, neck dissection and radiotherapy, was assessed retrospectively. The histological review of 113 consecutively treated parotid malignancies identified 98 suitable cases for univariate and multivariate survival analysis.
Results: Treatment involved total parotidectomy in 91.6% of cases, partial or total facial nerve resection respectively in 16.7% and 13.5%, neck dissection in 83.3% and postoperative radiotherapy in 70.8%. Forty-one tumors (36.3%) were classified as low-grade carcinomas (13 acinic cell carcinomas, 10 low-grade mucoepidermoid carcinomas, 7 ex pleomorphic adenoma intracapsular or minimally invasive carcinomas, 4 basal cell adenocarcinomas, 2 low-grade adenocarcinomas NOS and 1 polymorphous low-grade adenocarcinoma), 28 cases (24.6%) as intermediate-grade (14 adenoid cystic carcinomas with a cribriform/tubular pattern, 5 intermediate-grade mucoepidermoid carcinomas, 4 acinic cell carcinomas with a KI-67 index of over 10%, 3 ex pleomorphic adenoma invasive carcinomas with an intermediate-grade component, 2 intermediate-grade adenocarcinomas NOS) and 44 cases (39%) as high-grade carcinomas (19 high-grade adenocarcinomas NOS, 11 high-grade mucoepidermoid carcinomas, 5 salivary duct carcinomas, 4 ex pleomorphic adenoma invasive carcinomas with a high grade histology, 3 solid adenoid cystic carcinomas and 2 dedifferentiated acinic cell carcinomas). The 5-year overall survival, disease specific and recurrence free survival rates were 79.4%, 83.5% and 70.8%, respectively. Univariate analysis confirmed the classical prognostic factors, while multivariate analysis identified the clinical stage and grade, especially when analyzing three groups, as the most important prognostic factors (p<0.005). In the Cox models studied, a one-grade elevation increased the risk of non-specific death by 2.6-fold and the risk of disease recurrence by 2.3-fold.
Conclusions: This study highlighted the possible prognostic significance of intermediate grade tumors. A three-grade histological classification could provide a more accurate risk stratification and management of patients with salivary gland carcinomas.
Category: Head & Neck

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 150, Tuesday Morning

 

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