6810 Identifying early symptoms associated with a diagnosis of childhood, adolescent and young adult cancers: a population-based nested case-control study

Objectives To explore symptoms and symptom combinations associated with a subsequent cancer diagnosis in children, teenagers and young adults (0–24 years) and to establish their timeframe. Methods Using the QResearch Database, a nationally representative primary care database linked to secondary care data and the National Cancer Registry, we carried out an age, sex and general practice matched nested case-control study. Associations between pre-specified symptoms and a subsequent diagnosis of any cancer or selected cancer subtypes were explored using conditional logistic regression. Median diagnostic intervals were used to split symptoms into 'late' and 'early' timeframes to identify relevant early symptoms and symptom combinations. Results 3,125 cases and 50,576 controls were identified from a cohort of 3,424,771 children, teenagers and young adults. We identified 29 associated symptoms overall, of which hemiparesis (OR 90.9 [95%CI 24.7–335.1], PPV=1.6%), testicular swelling (OR 186.7 [95%CI 86.1–404.8], PPV=2.4%) and organomegaly (OR 221.6 [95%CI 28.3–1735.9], PPV=5.4%) had significant positive predictive values. Seventeen symptoms were found to be significant at early stages and limb pain, a known marker of serious illness in children, was a recurrent early symptom across several cancer subtypes. Similar clinical presentations were observed across childhood and young adult cancers. Conclusion Using the largest cohort to date, we provide the most comprehensive study investigating symptoms associated with childhood, teenage and young adult cancers in primary care. To our knowledge, this is the first study to report on symptoms which may be linked to earlier disease stages. We believe this information can be used to improve clinical and public awareness of childhood, teenage and young adult cancers, stratify those at high-risk and ultimately aid earlier diagnosis.