[Whole genome sequencing to find the primary tumour in cancer of unknown primary origin].

Cancer of unknown primary origin (CUP) remains a serious problem. The incidence in the Netherlands is stable, 1-2 percent of all new cancer cases. In general, patients undergo a long diagnostic trajectory and only a minority receive a tumour directed treatment. More than half of the patients die within two months after the diagnosis. A complete analysis of the DNA of a tumour specimen by means of whole genome sequencing may be helpful in finding the primary tumour. Dutch medical oncologists and pathologists set up a protocol for CUP patients, in which WGS may be implemented in the diagnostic procedure.