[1251] T(11;19) Translocation in Mucoepidermoid Carcinoma

R Seaberg, L Park, I Weinreb, D Goldstein, S Kamel-Reid, B Perez-Ordonez. University Health Network, Toronto, ON, Canada

Background: Mucoepidermoid carcinoma (MEC) is the most common malignancy of salivary glands. MEC is also seen in the sinonasal and lower respiratory tracts. The prognosis of MEC largely depends on tumor stage and grade. Recently the recurrent t(11;19) translocation with a CRTC1-MAML2 chimeric gene has been described in MEC. The presence of t(11;19) in MECs has ranged from 38-81% and has been has been associated with grade I-II tumors and a favorable outcome. Nevertheless, the presence of t(11;19) in grade III MEC remains controversial. The aim of this study is to investigate the presence of the t(11;19) translocation in a large series of surgically treated MUC.
Design: Seventy-three (73) MECs were retrieved from the pathology files of the University Health Network. The tumors were resected between 1992-2007. All the slides available were reviewed and the tumors were graded using the Healey's system. RNA was extracted from representative formalin-fixed, paraffin-embedded tissue from each case and the presence of the t(11;19) translocation was investigated by reverse transcriptase polymerase chain reaction (RT-PCR).
Results: Twenty-three cases (32%) were positive for the t(11;19) translocation with 22 containing the CRTC1-MAML2 chimeric gene and 1 the CRTC3-MAML2 gene indicating a likely t(11:15) translocation. The t(11;19) translocation was found in 8/23 (35%) grade I tumors, 11/35 (31%) grade II tumors, 3/12 (25%) grade III tumors, and 1/3 (33%) of oncocytic MECs. The tumor with the CRTC3-MAML2 gene was grade I. Clinical follow-up of fusion-positive MECs ranged from 2-331 months with a mean of 52. At last follow-up 18 patients were alive with no disease, 3 were alive with widely recurrent disease (22, 23, and 331 months), and 1 had died with disease (10 months). The patient that died had a T3N2Mx lesion of the base of tongue whereas those with recurrent disease had advanced sinonasal tumors at presentation.
Conclusions: The t(11;19) translocation was more common in grade I-II MECs but was also seen in 25% of grade III tumors. MECs arising in the sinonasal tract may have an adverse outcome despite the presence of t(11;19) underscoring the importance of primary tumor site and stage in the prognosis of MEC. Given the variable detection of t(11;19) using RT-PCR, there is a need to assess its incidence and clinical significance using fluorescence in-situ hybridization. Rare MECs have a variant CRTC3-MAML2 chimeric gene.
Category: Head & Neck

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 160, Wednesday Morning

 

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