title: Carcinoma of unknown primary: retrospective study of 437 patients treated at Salah Azaiez Institute.
abstract: BACKGROUND
  Carcinoma of unknown primary (CUP) origin is defined as histologically confirmed metastatic carcinoma in the absence of a detectable primary site at the time of making therapeutic decision.
  
  
  OBJECTIVE
  To report epidemiological, clinical, histopathological, therapeutic, and prognostic features of CUP's patients collected at the Salah Azaiez institute (SAI).
  
  
  METHODS
  We reviewed retrospectively the files of 437 CUP-patients in SAI between January 1994 and December 2006. We analyzed their epidemiological, clinical, histological and therapeutic features and classify patients in favourable and unfavourable subsets. Statistical analysis was performed with R software. Survival curves were made with the method of Kaplan-Meier.
  
  
  RESULTS
  We collected 437 patients with a median age of 60 years and a sex-ratio of 1.8. CUP are metastatic to lymph nodes (56.5%), bones (29.7%) and liver (28%). 33% of patients had a unique site of metastases. Adenocarcinoma represented 50.5% of cases while 10.5% are classified in the favourable subgroup. 141 out 437 patients received palliative chemotherapy, 83% of them by cisplatin-based regimens obtaining 13% (58 patients) of objective response. Median survival was 7 months. 24 out 58 patients (41%) relapsed. Poor prognostic factors for survival were: multiple metastases (p=0.00033), >3 sites (p=0.03), undifferentiated carcinoma and adenocarcinoma (p>0.0001), liver metastases (p=0.0137), bone (p=0.00653) and adrenal gland (p=0.0334) metastatic sites. Patients who underwent chemotherapy (p>0.001) and who received cisplatbased regimen had better survival (p=0.01).
  
  
  CONCLUSIONS
  Our retrospective study done in the context of a minimal and biological work-up confirmed the difficulty to find the primary in CUP.
authors.forename: Rania
authors.initials: R
authors.lastname: Fehri
authors.forename: Hela
authors.initials: H
authors.lastname: Rifi
authors.forename: Adel
authors.initials: A
authors.lastname: Alboueiri
authors.forename: Dhafer
authors.initials: D
authors.lastname: Malouche
authors.forename: Mouna
authors.initials: M
authors.lastname: Ayadi
authors.forename: Henda
authors.initials: H
authors.lastname: Rais
authors.forename: Amel
authors.initials: A
authors.lastname: Mezlini
mesh_terms: D002277:Carcinoma / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009382:Neoplasms, Unknown Primary / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D012189:Retrospective Studies; D014416:Tunisia