Background Survival from lung – and many other – cancers is worse in the UK than other countries. To help address this, the urgency cancer referral (‘two week wait’ (TWW)) was introduced two decades ago. Since then, the proportion of cancers diagnosed as emergencies (which generally have poor prognosis) has declined. There are socio-economic inequalities in lung cancer incidence, survival, and mortality, but whether there are similar inequalities in the route through which patients present for lung cancer diagnosis is unclear. To investigate, this study explored whether clinical and socio-demographic factors are associated with lung cancer routes to diagnosis in England.

Methods Population-based data on 181,763 primary invasive lung cancers (ICD-10 C34.0-C34.9) diagnosed between 1^stJanuary 2012 and 31^st December 2016 were abstracted from the English National Cancer Registrations Database. Multivariable logistic regression examined associations between patients’ demographic and clinical characteristics and likelihood of: (i) emergency presentation (versus all primary care routes); and (ii) TWW presentation versus standard primary care referral. Models included (where appropriate) the following variables: deprivation quintile of area of residence at diagnosis (Index of Multiple Deprivation income domain); sex; age; diagnosis year; ethnic group; rural/urban residence; presence of comorbidities; previous tumours; and tumour histology (small cell lung cancer (SCLC); non-small cell lung cancer (NSCLC)). Sensitivity analyses were performed by histology. Analyses were conducted using Stata (v16.1).

Results Socio-demographic variation in diagnosis routes were observed. 35.2% of patients were diagnosed following emergency presentation. These patients were statistically significantly more likely to be older than 80 years old, female, of non-white ethnicity, resident in areas of greater deprivation, and have a SCLC tumour histology and multiple comorbidities. 43.7% were referred through TWW pathways. These patients were statistically significantly more likely to be aged between 60–80 years old, of white ethnicity, resident in an area of greater deprivation and to have no comorbidities.

Conclusion One third of lung cancers present as emergencies. Routes to diagnosis are subject to distinct socio-demographic patterning. More recent data, particularly covering the pandemic period, is urgently required.

Priority and Relevance Lung cancer is a significant public health problem, with almost 50,000 new diagnoses each year. Strategies for earlier diagnosis are being researched (e.g. blood tests). Policy and practice solutions are needed to ensure equity and timeliness in health service access when lung cancer is suspected.