Introduction: Despite being the 6th cause of cancer death in Australia, cancer of unknown primary (CUP) site remains poorly understood.

Aims: To describe practices relating to the diagnosis, investigation, classification, communication and management of CUP amongst medical oncologists.

Methods: We invited all members of the Medical Oncology Group of Australia to participate in a national, anonymous online survey about CUP. The survey collected data regarding diagnosis acceptance, diagnostic tests, treatment protocols and communication practices around the diagnosis of CUP.

Results: 302 oncologists were invited and 86 (28%) completed the survey. Eighty respondents (93%) were directly involved in the assessment of patients with CUP. Eighty-five (99%) respondents were prepared to make a diagnosis of CUP if, after appropriate diagnostic tests, the primary location could not be ascertained. 83% would assign a primary site to obtain Pharmaceutical Benefits Schedule (PBS) funding of medical therapy. 62% did not have a specific treatment protocol designed for CUP. The majority of oncologists used serum tumour markers and CT scans in the initial work-up, whilst 43% indicated they would use a PET scan in the majority of cases. The majority would arrange mammography in female patients. Thematic analysis of responses to openended questions about how CUP is described identified little consistency in the language being used.

Conclusion: The approach to diagnosis, investigation and management of CUP by medical oncologists in Australia is variable. Many preferred to estimate the primary site and treat accordingly. PBS restrictions may encourage the practice of ‘best guessing’.


Cancer of Unknown Primary, CUP, Survey, Diagnosis, Communication, Language



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