Aims: We sought to describe the clinical course of patients with carcinoma of unknown primary (CUP) presenting to Macarthur, Liverpool and Bowral Cancer Centres.
Methods: We searched the electronic medical record for patients diagnosed with CUP between July 2003 and June 2011. Demographics, investigations and treatment details were recorded. Predictors of overall survival were assessed with a Cox proportional hazards regression.
Results: Characteristics of the 126 patients were: male (54%); median age 67.5yrs; and ECOG-PS 0-1 (48%). The most common presentations were symptomatic bone metastases (23%), palpable lymphadenopathy (20%), abdominal pain (19%) and weight loss (10%). Adenocarcinoma was the most common histopathological subtype (40%), followed by poorly differentiated carcinoma (27%), squamous cell (15%), large cell (10%) and neuroendocrine carcinomas (3%). Investigations varied: CT chest/abdomen (93%), serum tumour-markers (68%), bone-scan (41%), ultrasound (35%), mammogram (34% of females), PET (25%), gastroscopy (25%) and colonoscopy (23%). 52% presented with >1 disease site, the most frequent sites being liver (40%), bone (35%), lung/pleura (33%), axial-nodes (25%) and cervical/supraclavicular nodes (16%). A minority received anti-cancer therapies: palliative radiotherapy (42%); first-line chemotherapy (31%); and second-line chemotherapy (6%). The most prescribed regimen was carboplatin/gemcitabine. 7 patients with cervical node SCC received surgery +/- radiotherapy. Median overall survival was 6.3 months (interquartile range 2.2–19.9 months). On univariable analysis chemotherapy did not impact survival while squamous histology and node-only disease were associated with better outcomes. Independent predictors of survival were ≥2 disease sites (HR 2.87; 95%CI 1.81-4.54; p<0.001) and ECOG-PS≥2 (HR 2.38; 95%CI 1.58-3.58; p<0.001).
Conclusions: Our experience with CUP confirms its heterogeneity, poor prognosis and lack of survival benefit with chemotherapy for most. Prognosis can be guided by performance status and extent of disease. Given the management of CUP is so variable, a team dedicated to standardise care may improve outcomes.