Blog from Dr Fiona Walter, Cancer Group, Primary Care Unit
While UK cancer screening programmes currently detect 10-15% of cancers, the remaining patients initially present to primary care or the emergency services. Overall survival for most common cancers in the UK is improving due to treatment strategies, but research suggests that the time taken to appraise symptoms and seek help, management in primary care and access to diagnostic procedures are also key determinants of cancer outcomes. Our work focuses on these areas.
Community symptom awareness campaigns have formed a major component of the UK National Awareness and Early Diagnosis Initiative (NAEDI), and studies examining the impact of the “Be Clear on Cancer” campaigns have begun to show potential effects on presentation and cancer diagnoses. We have two studies currently collecting data which focus on ‘difficult to diagnose’ cancers with poor outcomes. The POSTCARD study is examining patient pathways to diagnosis with oesophageal and gastric cancer, and the BRAcED study is set among patients recently diagnosed with brain cancer. We have recently reported similar studies for melanoma, lung and colorectal cancer, all of which have influenced Public Health England campaigns.
The symptoms of many cancers are common in the community and overlap with prevalent benign conditions. This presents a major challenge for GPs who need to assess the risk, or diagnostic probability, of an underlying cancer, and determine whether further investigation is justified without exposing their patients to the harms of over-diagnosis and over-treatment. We have recently reported the SYMPTOM studies, prospectively collecting data from patients as they are referred with symptoms suspicious of lung, colorectal and pancreatic cancer, plus data from GP and hospital records. These studies highlight that healthcare professionals in both primary and specialist care should have an increased awareness of the risk of cancer among people with comorbid conditions, and beware of misattributing potential cancer symptoms in those with mental health problems.
Recent analyses using large UK general practice databases have led to significant advances in our understanding of the epidemiology of cancer symptoms in primary care. These informed the 2015 NICE guidelines on referral for suspected cancer which apply specific risk thresholds to determine access to fast track referral pathways, and have also underpinned the development of cancer decision support tools embedded in the electronic medical records of general practices. We are researching the implementation of these tools on the diagnosis of melanoma (the MelaTools studies) and oesophageal and gastric cancer (the ECASS trial) in primary care, and will apply these findings to the implementation of novel clinical decision support systems using text mining and artificial intelligence to include epidemiological, clinical and biomarker data.
While understanding the predictors of diagnostic delay at the patient level (e.g. symptoms) is pivotal, insights into contextual factors that may enable or impede appropriate diagnostic decision-making by clinicians can also be critical. Working with Yoryos Lyratzopoulos and other statistical and clinical colleagues in this and other Universities we are examining how factors such as care continuity, the doctors’ gender, age and communication skills may influence decisions about referring or investigating patients, so that interventions can be targeted. Another stream of work is looking for missed diagnostic opportunities in the pathway to diagnosis.
Other strategies for early detection in primary care are also important, including diagnostic biomarkers and novel technology. Working with Rebecca Fitzgerald’s team, we are evaluating the cost-effectiveness and acceptability of the CytoSpongeTM-TFF3 test in primary care to triage patients on long-term treatment with acid suppressants at increased risk of oesophageal cancer. We are keen to collaborate with other academic, clinical and commercial partners to undertake similar evaluations of novel diagnostic approaches in the community setting.
Dr Walter wrote this article for Cambridge Cancer Centre’s Early Detection Network.
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