The current evidence for a biomarker-based approach in cancer of unknown primary.

Cancer of unknown primary (CUP) accounts for the seventh to eighth most frequently diagnosed cancer yet its prognosis remains poor with conventional chemotherapy. The spectrum of therapeutic management includes both locoregional and systemic therapy and should intend to offer optimal benefit to favorable CUP patients and palliative care to unfavorable cases. The recent molecular advances have revolutionized the armamentarium of cancer treatments though a biomarker-based approach. Unfortunately, solid data in CUP is lacking in the absence of a CUP-specific driver molecular signature. This prompted us to screen the medical literature for clinical data that evaluates the efficacy and safety of the biomarker-based approach in CUP patients. In this review, we will summarize the available evidence for the applicability of targeted therapies in CUP.