Mucoepidermoidcarcinoma - Importance in molecular pathology

Mucoepidermoid carcinoma is the most common primary salivary gland malignancy and its tumor grading has an important prognostic significance. The 5 year overall survival rate is significantly higher for low grade mucoepidermoid carcinomas than for intermediate grade and high grade mucoepidermoid carcinomas. The translocation of t(11;19)(q21;p13) with the resulting CRTC1-MAML2 transfusion appears to be of prognostic relevance in patients with mucoepidermoid carcinoma. The translocation is detectable in 38-82 % of all mucoepidermoid carcinomas. Study results have shown a significantly better prognosis for patients with fusion-positive mucoepidermoid carcinomas than fusion-negative mucoepidermoid carcinomas. The t(11;19)(q21;p13) translocation can be found more often in low and intermediate grade mucoepidermoid carcinomas than in high grade tumors of the same entity. Moreover, fusion positive mucoepidermoid carcinoma were found more frequently in younger patients, smaller tumors, lower tumor stages and less frequently lymph node and distant metastases. Up to now, the translocation has not been of therapeutic importance. In selected cases, the lack of t(11; 19)(q21; p13) translocation might facilitate the decision towards further escalation of therapy. More studies will be necessary to evaluate the individual prognostic and therapeutic value of CRTC1-MAML2 transfusion.