Carcinoma of unknown primary: 35 years of a single institution's experience

Aim: To assess the incidence and characteristics of carcinoma of unknown primary (CUP). Methods: We retrospectively collected the clinical data of CUP cases treated in our medical center between 1975 and 2010, the results of which were statistically analyzed. Further, a comprehensive literature search, using PubMed database, on CUP cases was performed, and the results were discussed. Results: A total of 1250 cases were identified, with male to female ratio of 1.2:1. Median age at diagnosis was 56 ± 16 years. Liver was the most common site of metastasis, followed by neck and peritoneum. Majority of cases (54.5%) received supportive treatment only, with the overall survival, over 1 year period, being 49%. Univariate analysis revealed pathology, gender, and site of disease as the significant predictors of survival, whereas pathology failed to reach significance on multivariate analysis, with “lymph nodes only” carrying the best prognosis. Conclusion: Our data confirm the heterogeneity of CUP cases and variable treatment courses. This highlights the importance of establishing a national registry for this subgroup of cancer patients. Moreover, there is a need to develop multidisciplinary specialist teams and protocols to manage this group of patients, and participation in clinical trials should be strongly encouraged.