1160P - Evaluation of the prognostic benefit of postulating primary site in patients with cancer of unknown primary (CUP)

Date 27 September 2014
Event ESMO 2014
Session Poster Display session
Topics Carcinoma of Unknown Primary Site (CUP)
Presenter Joyutpal Das
Citation Annals of Oncology (2014) 25 (suppl_4): iv394-iv405. 10.1093/annonc/mdu345
Authors J. Das, S.N. Gilani
  • Cancer Centre, University Hospital of North Staffordshire, ST4 6QG - Stoke-on-Trent/GB



Previous studies have identified several prognostically unfavourable factors associated with CUP, such as: liver and lung/pleural involvements. Immunohistochemistry profile (IHC) is readily used in CUP cases to identified probable primary site. In our study we assessed whether there is a prognostic benefit of identifying primary sites in CUP patients.


In our retrospective study we reviewed the case notes of all 84 patients who presented with suspected CUP to UHNS hospital in Stoke-on-Trent, UK from 2011-12. Standard statistical tests were applied to analyse the data.


In our study 40/84 patients were unable to undergo all necessary investigations to identify primary site due to poor performance status. Therefore, 44/84 of those cases were categorised as confirmed CUP. The suspected CUP patients who were unable to undergo all investigations, had more frequent liver (28/40 vs 18/44) and lung/pleural (26/40 vs 19/44) involvements than confirmed CUP patients. IHC was able postulate the primary site in 59% (26/44) of those confirmed CUP cases. We have noticed that CUP cases in which the primary site was postulated from IHC, had higher frequencies of liver (11/26 vs 7/18) and lung/pleura (12/26 vs 7/18) metastasis than those with no probable site. Also the median survival in CUP cases with postulated primary site was shorter than those with no primary site (1.7 vs 2.8 months).


The identification of primary site using IHC can lead to a tailored approach in CUP treatment. However, only half of our suspected CUP patients were able to undergo necessary investigations and in 59% of those cases, the primary site was postulated from IHC. In addition, our data suggest that CUP patients, who have their primary sites identified from IHC, are likely to have prognostically unfavourable diseases with shorter median survival. From our data it is unclear whether waiting for the results of IHC has any detrimental effect on the outcome. We suggest that the treatment of CUP patients should be commenced at an earliest possible opportunity rather then waiting for investigation results such as IHC to maximise their survival. We had a small cohort. Therefore, future studies with larger cohorts are required to further verify our findings.


All authors have declared no conflicts of interest.