Clinical and immunohistochemical analysis of patients with unknown primary tumour. A search for prognostic factors in UPT.

Background: The unknown primary tumour (UPT) is an intriguing clinical finding in approximately 5% of all newly diagnosed patients with cancer. To evaluate a correlation between the specific immunohistochemical alterations in UPT cells and the unique clinical features of UPT patients, to define the natural history of UPT and to verify prognostic factors, we undertook a detailed clinical and immunohistochemical analysis of patients with the diagnosis of adenocarcinoma of UPT.

Results: Patients with UPT present with a short history and have a poor prognosis. Univariate analysis was performed with clinical, biological and immunohistochemical variables. Patients with a higher age (>60 years), a poor performance score (2-3), liver metastases or more than two organ sites involved, or patients with elevated LDH-levels, were found to have worse prognosis. We confirm that the prognostic model published by Culine is a valuable model for the prediction of prognosis in patients with UPT. Immunohistochemical detection of proliferation (MIB-1), p53, vascular endothelial growth factor-A, CD34, CD44v6 and Her2neu indicated that these factors were of no prognostic value.

Conclusion: In conclusion, patients with UPT have a very poor median prognosis of 12 weeks. Prognostically favourable factors are young age, good performance status, no liver metastases and normal LDH level. We found no relationship with immunohistochemical factors.