Rapid Diagnostic Centres and early cancer diagnosis

TLDR: In the UK, only 39% of cancer diagnoses were made via 2WW pathways in 2017, while significant proportions of diagnoses are made via other outpatient clinics (32%) or emergency presentation (19%), representing potentially missed diagnostic opportunities as mentioned in this paper.

Abstract: Early cancer diagnosis is a clinical and research priority of the UK government. Earlier cancer diagnosis should enable identification of cancers at an earlier stage, leading to improved outcomes.1 This must be balanced with the potential physical and psychological harms of over-investigation and over-diagnosis. The ‘two-week wait’ (2WW) referral pathway represents the most common route to cancer diagnosis. However, only 39% of cancer diagnoses were made via 2WW pathways in 2017, while significant proportions of diagnoses are made via other outpatient clinics (32%) or emergency presentation (19%), representing potentially missed diagnostic opportunities.2 Approximately 50% of cancer patients present with non-specific but concerning symptoms of cancer (NSCS).3 Compared to ‘alarm symptoms’ these have low predictive values for cancer and are less indicative of site-specific disease; consequently, they are not reflected in 2WW referral criteria.3 These patients frequently are referred later for specialist investigation and have more advanced disease.4 A principal goal for the new NHS Rapid Diagnostic Centres (RDCs) is to provide a pathway for patients with NSCS to detect cancer earlier, where treatment outcomes are more favourable.1 NHS England aims to provide full population coverage with RDCs by 2024.5 Despite their low predictive value and association with multiple diseases, many NSCS are considered as characteristic warning signs of cancer. These include unexpected weight loss, malaise, unexplained pain, new dyspnoea, and persistently abnormal blood tests.4,6,7 Unexpected weight loss was the most common symptom seen within an RDC pilot (66%) between 2016 and 2018;7 however, it has a relatively low predictive value for cancer.6,8,9 While patients with weight loss in isolation may not warrant further investigation, considering other clinical variables …