Adenocarcinoma of unknown primary site

Adenocarcinoma of unknown primary site is a common clinical entity, comprising 2% to 4% of all incident cancers worldwide.

Untreated, prognosis is poor, with a median survival between 3 and 4 months.

A key goal in the diagnostic work-up is to identify subsets of patients with a more favourable clinico-pathological subtype and likely better outcome.

Systemic chemotherapy is the mainstay of treatment for the overwhelming majority of patients.

Rare subgroups may be candidates for targeted or immune therapies based on results of next-generation sequencing or other biomarkers predictive of response.

Supportive therapies control pain and other symptoms.

Adenocarcinoma of unknown primary site (ACUP) is the major subgroup in the common clinical entity of cancer of unknown primary site (CUP). It is defined as metastatic adenocarcinoma for which the primary site is undetectable at presentation, despite thorough physical examination and laboratory and radiographic investigation.[1]Varadhachary GR, Abbruzzese JL, Lenzi R. Diagnostic strategies for unknown primary cancer. Cancer. 2004 May 1;100(9):1776-85. https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.20202 http://www.ncbi.nlm.nih.gov/pubmed/15112256?tool=bestpractice.com