T. M. Connelly1, M. Alzamzami1, M. Foley2, M. S. Khan1, A. Mehmood1, G. T. O’Donoghue1 1University Hospital Waterford,General Surgery,Waterford, WATERFORD, Ireland 2Waterford Institute of Technology,School Of Health Sciences,Waterford, WATERFORD, Ireland
Introduction: Carcinoma of unknown primary (CUP) is an unpredictable and difficult diagnosis in up to 3% of cancer patients. We aimed to determine the incidence and clinical course of patients diagnosed with cancer CUP in the South East Ireland Regional Cancer Center.
Methods: Gastrointestinal multidisciplinary meeting (MDM) records of 4274 patients were used to identify those initially diagnosed with CUP between September 2008-December 2017. Patient demographics, radiology, endoscopy, pathology, hematology and biochemistry blood results were analyzed.
Results: 97 patients were initially diagnosed with CUP. In 50 (51.5%, Table 1), a primary was never determined by the study end. In this cohort (50% male, mean age=63.4 years), 94% underwent ≥one biopsy. The most common histological subtypes were adenocarcinoma (59.1%) and neuroendocrine tumors (18.2%). When comparing the CUP cohort to the cohort in whom a primary was determined (n=47, 48.5%), there was no difference in gender distribution, mean age, referral source or number of times discussed at MDM, biopsies or surgical interventions. CUP patients underwent twice as many radiological investigations (median 6 vs 12,p=0.003) and had a higher median CEA (5.8 vs 2.6,p=0.02). At the study endpoint, 72% of those with a primary diagnosed vs 82% of CUP patients were deceased (p=0.09).
Conclusion: In approximately half of patients initially diagnosed with CUP in an MDM setting, a primary is not determined. Mean survival is less than 8 months. These patients undergo more radiological investigations when compared to those in whom a primary is determined. However, no difference in mean age, number of biopsies or surgical interventions is found.
