Chemotherapy with irradiation in salivary gland carcinomas (SGC): A Rare Cancer Network study (RCN)

e17019 Background: To report the role of combined chemotherapy in SGT. Methods: 251 patients with SGC treated in 2001-2011 were included in a collaborative IRB-approved retrospective RCN study. Chemotherapy is empirically administered based on extrapolation from conventional head and neck squamous cell carcinoma (Ca) (SCC) and data on systemic treatment in localized SGC are lacking. Results: Median age was 60 yo with 2/5 females/males. Tumor sites were the parotid 74.9%, submandibular 16%, sublingual 2.8% or minor gland 4%. Histologic findings were adenoid cystic (ACC) 17.3%, mucoepidermoid (MEC) 19.8%, adenoCa 15.6%, salivary duct (SDC) 10.3%, acinic cell (Aci) 6.2%, ex-pleomorphic 7.8%, undifferentiated 4.9%, myoepithelial 3.3%, epithelial myoepithelial 1.6%, basal cell 1.2%, lymphoepithelial 1.2%, others 4.0%. Surgery was performed in 95.1% (complete resection 38.1%). T stages 1, 2, 3 and 4 were 17.2%, 41.2%, 18.1% and 23.5% respectively. N stages were N0 61%, N1 13%, N2 24%, N3 2%. Perineural, vascular or lymphatic emboli were present in 47%, 24%, 27% respectively. Irradiation was performed postoperatively 96% or exclusively 4% (unilateral 84%, performed w/ photons only 78%, IMRT 41%). Chemotherapy was administered in 18%, dependent on grade, N stage, and emboli (p ≤ .05). None of 17 ex-pleomorphic, 25% of undifferentiated, 36% of SDC, and 66.7% of lymphoepithelial Ca received chemotherapy (p NS). With a median follow-up of 42 months for living patients, crude local, regional, metastatic relapse rates were 112% (in field 85%), 10%, 25%, respectively. Crude death rate was 28% including 77% from SGC. 5-year survival (5y OS) was 63%. The only prognostic factor was nodal involvement (p .002). However, 5y OS differed by histology: ACC 79%, MEC 84%, Aci 67%, SCC 43%, adenoCa NOS 40%, SDC 37%. Chemotherapy did not improve survival whatever histology. Conclusions: Further prospective studies are warranted to define the role of chemotherapy by histology in the setting of localized SGT. Also molecular profile-driven systemic treatments should be investigated.