title: The challenge of attributing causality in cancer of unknown primary.
authors: Claire M
authors: CM
authors: Vajdic
authors: Lucy
authors: L
authors: Wyld
authors: John N
authors: JN
authors: Symons
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary*; D005260:Female; D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis; D009382:Neoplasms, Unknown Primary / Q000401:mortality*