Adenosquamous carcinoma of the head and neck: Molecular analysis using CRTC-MAML FISH and survival comparison with paired conventional squamous cell carcinoma.

Abstract

Adenosquamous carcinoma (ASC) is a rare variant of head-and-neck squamous cell carcinoma (HNSCC) generally thought to be uniformly aggressive with poor prognosis. However, it remains unknown how overall survival compare with conventional HNSCC. Here we report for the first time that ASC does not necessarily indicate a worse prognosis than conventional HNSCC. Case-control retrospective study. Forty-two primary tumors of the head and neck, treated with curative intent, were identified. Next, 2:1 matching of HNSCC was performed using the following matching criteria: gender, site, pathologic tumor stage, and pathologic node stage. Successful matching was performed for 32 of 42 tumors. Additionally, 20 samples were sent for break-apart FISH testing to evaluate for the presence of the CRTC1-MAML2 translocation. There was a 1.8:1 male to female ratio, with a mean age of 62 years (range 38-84). The layrnx was the most common site (26%), followed by oropharynx (24%), oral cavity (19%), and sinonasal (17%). Kaplan-Meier analysis of adenosquamous and matched HNSCC showed similar survival curves. Median survival times for ASC and HNSCC were 4 and 6 years, respectively. A random-effects Cox model with Gamma frailty revealed no statistical difference between the two groups (P=0.25). All cases of ASC were negative for the CRTC1-MAML2 translocation. This study directly compares primary ASC with HNSCC. No difference in overall survival was detected in contradistinction to the previously thought uniformly poor prognosis. We also highlight the importance of the CRTC1-MAML2 translocation in distinguishing ASC from mucoepidermoid carcinoma. 3b.