Background: Carcinoma of Unknown Primary (CUP) constitutes approximately 3% of all advanced cancer cases globally, posing a distinct and complex medical challenge due to its metastatic nature, with no identifiable primary tumour site despite comprehensive investigations. Aim: This study aimed to assess the quality of referrals to the Cancer of Unknown Primary Clinic at the Princess Margaret Cancer Centre (PMCC) by conducting a retrospective audit of initial referrals between January 2022 and March 2023. Methods: The adequacy of referrals was evaluated based on adherence to NICE guidelines, focusing on essential diagnostic investigations such as comprehensive history, physical examination, CT scans, and pathological assessment with immunohistochemistry. Our cohort consisted of 97 patients with a median age of 66 years. Results: The results indicated that only 55% of referrals met the criteria for adequacy, with significant deficiencies in computed tomography (CT) scans and immunohistochemistry (IHC). Notably, the adequacy of referrals varied by specialty, with the lowest rates in emergency medicine and family medicine, and the highest rates in medical oncology, gastroenterology, and neurosurgery. Conclusions: These findings underscore the need for improved standardization and education to enhance referral quality, ensuring that patients with CUP receive appropriate and timely care. This study marks the initial phase of the Knowledge-to-Action cycle, highlighting areas for quality improvement in the referral process to the CUP clinic.

Background/Objectives: Cancer of unknown primary (CUP) remains a significant challenge in the field of oncology. Despite advances elsewhere in the field, there have been few advances in the treatment of CUP and correspondingly no improvements in patient survival. Recent studies utilizing molecular profiling, including next-generation sequencing (NGS), and molecularly targeted treatment of CUP have shown some promising initial results, but have yet to be integrated into the standard of care in most jurisdictions. This study aimed to assess the use of molecular characterization and targeted treatment of patients with CUP treated at Princess Margaret Cancer Centre (PMCC). Methods: This study is a retrospective audit of patients with CUP treated between January 2019 and April 2024 to build understanding of the accessibility and use of these molecular tools. Results: We found that 82% of the 28 patients identified received NGS analysis, though all received the results late in their disease course and all accessed molecular profiling via either clinical trials, a charitable access programme, or a privately source outside of the hospital network. Only 13% of the patients who received molecular analysis received any modification of care as a result of this profiling, and only as third line of treatment. Conclusions: Our data highlights a lag between current understanding and current practice, and identifies a possible area for improvement of patient care by standardizing the use of molecular analysis in the early workup and targeted therapy in the treatment of CUP.