Diagnosis of lung cancer in primary care: a structured review

Abstract

Background: Lung cancer has the highest cancer incidence and mortality in the UK. Despite this, an individual GP encounters only one new presentation approximately every 8 months, so gains relatively little experience of its diagnosis. This is partly addressed by referral guidelines which aim to help GPs in selection of patients for chest X-ray or referral for specialist investigation.

Objective: The purpose of this study was to review the primary care presenting features of lung cancer, in the light of the UK Referral Guidelines for Suspected Cancer.

Methods: A structured literature review was carried out.

Results: Little research has been undertaken in primary care, and the predictive values for most symptoms are unknown. Approximate likelihood ratios could be calculated for six symptoms or signs: haemoptysis 13; fatigue 5.7; cough 5.3; finger clubbing 3.9; weight loss 2.9; and dyspnoea 1.5-5.7, but none of these figures derived from single primary care studies. Three recommendations for urgent investigation of possible lung cancer in the UK Referral Guidelines are questioned: for unexplained dyspnoea, hoarseness or cervical lymphadenopathy. For all these presentations, other serious diagnoses are more likely.

Conclusion: The UK Guidelines for referral of suspected lung cancer have a weak evidence base.