COMMONLY used blood tests can be used to improve the detection of cancer in patients with nonspecific abdominal symptoms, according to recent research.
A population-based cohort study utilised data from the UK Clinical Practice Research Datalink (CPRD), National Cancer Registry, Hospital Episode Statistics, and Index of Multiple Deprivation. The study included patients aged 30 and above who presented with abdominal pain or bloating between January 2007 and October 2016. Positive predictive values (PPV), negative predictive values (NPV), sensitivity, and specificity of 19 abnormal blood tests were assessed within three months of symptom presentation.
Out of 425,549 patients with abdominal pain, 9,427 (2.2%) were diagnosed with cancer within a year. Similarly, out of 52,321 patients with abdominal bloating, 1,148 (2.2%) were diagnosed with cancer in the same timeframe. For patients aged 60 and above, who present with abdominal pain or bloating, the PPV for cancer surpassed the 3% risk threshold recommended by the UK National Institute for Health and Care Excellence (NICE) for urgent cancer referral.
Among the participants, blood tests were performed on 64% of patients with abdominal pain and 70% with bloating. The data showed that in patients aged 30 to 59, certain blood abnormalities significantly raised the cancer risk above the 3% threshold. For instance, in females aged 50 to 59 with abdominal bloating, the cancer risk, initially calculated at 1.6% based on presenting symptoms, sex, and age alone, rose substantially when incorporating blood test results. Specifically, the risk increased to 10% with elevated ferritin, 9% with low albumin, 8% with raised platelets, 6% with raised inflammatory markers, and 4% with anaemia. This demonstrates how blood test results can notably enhance the assessment of cancer risk. Furthermore, incorporating blood test results into cancer risk assessments for abdominal bloating led to 63 additional urgent referrals per 1,000 patients and identified three more cancer cases, marking a 16% relative increase in diagnosis yield.
The results demonstrate that incorporating commonly used blood test results into cancer risk assessments for patients with nonspecific abdominal symptoms can significantly enhance diagnostic accuracy. This approach improves early cancer detection and optimises referral strategies, potentially leading to better patient outcomes.
Katrina Thornber, EMJ
Reference
Rafiq M et al. Predictive value of abnormal blood tests for detecting cancer in primary care patients with nonspecific abdominal symptoms: a population-based cohort study of 477,870 patients in England. PLoS Med. 2024;21(7):e1004426.
