The currently declining incidence of cancer of unknown primary

• Published in: Cancer epidemiology Vol. 61; pp. 139 - 141
• Main Authors: Rassy, Elie, Pavlidis, Nicholas
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.08.2019; Elsevier Limited; Elsevier
• Subjects: Age; Cancer; Cancer of unknown primary; CUP; Epidemiology; Female; Gene expression; Humans; Incidence; Life Sciences; Male; Medical diagnosis; Metastases; Metastasis; Neoplasms, Unknown Primary - epidemiology; Pathogenesis; Population; Registries; Risk Factors; Trends; Tumors; Scotland; Sweden; Netherlands; United Kingdom > UK; Norway; Switzerland; Cancer of unknown primary; Epidemiology; CUP; Incidence
• ISSN: 1877-7821; 1877-783X; 1877-783X
• DOI: 10.1016/j.canep.2019.06.006

•CUP accounts for 3–5% in the historical series.•The incidence-rate of CUP is currently decreasing and reaches 1–2%.•The reasons for the decline in the incidence-rate of CUP are speculative.•Multiple confounding factors should be taken into consideration in cancer-registry analysis. Cancer of unknown primary (CUP) is a heterogeneous group of metastatic cancers for which a primary tumor cannot be identified after a standardized work-up. The biology of CUP has not been fully elucidated and epidemiologic data may be helpful in this regard. The variations in the incidence-rate over time and between countries reflect changes in the risk factors for CUP, incidence trends of the primary tumors that potentially contribute to the burden of CUP and changes in the diagnostic technologies and practice. CUP accounted for 3–5% of cancers in the historical series but its incidence seems to decline in the recent publications. This paper reviews the published cancer-registry studies in order to identify and understand the variations in the incidence-rates of CUP.