Quantifying the risk of Hodgkin lymphoma in symptomatic primary care patients aged ≥40 years: A case-control study using electronic records

Abstract

Background: In the UK, approximately five people are diagnosed with Hodgkin lymphoma (HL) daily. One-tenth of diagnoses are in those aged >75 years. Aim: To establish a symptom profile of HL and quantify their risk in primary care patients aged ≥40 years. Design and setting: Matched case-control study using Clinical Practice Research Datalink patient records. Method: Putative clinical features of HL were identified in the year before diagnosis. Results were analysed using conditional logistic regression and positive predictive values (PPVs) calculated for the consulting population. Results: Two-hundred and eighty-three patients aged ≥40 years, diagnosed with HL between 2000 and 2009, and 1237 age, sex, and general practice-matched participants were studied. Six features were independently associated with HL: lymphadenopathy (OR 280, 95% confidence interval [CI] = 25 to 3100), head and neck mass not described as lymphadenopathy (OR 260, 95% CI = 21 to 3200), other mass (OR 12, 95% CI = 4.4 to 35), thrombocytosis (OR 6.0, 95% CI = 2.6 to 14), raised inflammatory markers (OR 5.2, 95% CI = 3.0 to 9.0), and low full blood count (OR 2.8, 95% CI = 1.6 to 4.8). Lymphadenopathy per se has a positive predictive value (PPV) of 5.6% for HL in patients aged ≥60 years. Conclusion: Consistent with secondary care findings, lymphadenopathy is the clinical feature with the highest risk of HL in primary care and warrants urgent investigation.