Hayashi H, et al. - As gene expression profiling is a promising diagnostic technique for ascertaining the tissue of origin for patients with cancer of unknown primary site (CUP), researchers investigated if site-specific therapy, directed by this approach, improves outcome vs empirical chemotherapy in previously untreated patients with CUP. They performed efficacy analysis for 50 and 51 patients in the site-specific therapy and empirical paclitaxel and carboplatin (PC) arms, respectively. Most commonly predicted cancer types included pancreatic (21%), gastric (21%), and lymphoma (20%). Outcomes revealed no significant improvement in 1-year survival with the reception of site-specific treatment that was based on microarray profiling vs empirical PC, although prediction of the original site seemed to be of prognostic value.