ALK expression is absent in pancreatic ductal adenocarcinoma

It has not yet been clearly defined whether anaplastic lymphoma kinase (ALK) expression can be detected in pancreatic ductal adenocarcinoma (PDAC). Within a retrospective study, archival PDAC surgical specimens were screened for ALK expression in tumor and normal tissue by immunohistochemistry (IHC) with the use of a specific ALK detection kit on a tissue microarray (TMA). PDAC tumor tissue was available from 99 resected cases: fifty-eight out of 99 patients (59 %) had nodal-positive disease, and 80 patients (81 %) had pT3 tumors. Forty-nine patients underwent R0 resection, and in 48 cases, resection status was classified R1. Regarding ALK expression, five cases showed faint immunoreactivity on TMA, which was negative on whole mount sections. All other 94 cases showed no ALK expression. In 99 PDAC cases, no ALK expression was detected by IHC; ALK thus may not serve as a relevant drug target in PDAC.