Lung cancer incidence, metastatic disease and mortality in people accessing mental health services: Opportunities for screening

OBJECTIVE: To describe lung cancer incidence, stage and post-diagnosis mortality in people accessing mental health services, focusing on people aged 50-70 targeted by Australia's new lung cancer screening programme. METHODS: Linkage to the New South Wales Cancer Registry identified 39,680 lung cancer notifications from 2011 to 2020. Mental health services contact was defined as public mental health hospital or community care in the 5 years before cancer diagnosis. Measures include the following: (1) incidence standardised for age, sex and disadvantage; (2) odds of metastatic disease at diagnosis, using binary logistic regression; and (3) risk of 12-month post-diagnosis mortality using Cox regression adjusted for age, sex, disadvantage and metastatic disease. RESULTS: People accessing mental health services were younger at diagnosis, had higher lung cancer incidence (adjusted incidence rate ratio = 1.54, 95% confidence interval = 1.47-1.61), risk of metastatic disease (odds ratio = 1.14, 95% confidence interval = 1.03-1.26), 12-month all-cause mortality (hazard ratio = 1.57, 95% confidence interval = 1.49-1.67) and shorter median survival time (mental health: 121 days; other New South Wales residents: 211 days). In the screening-age range, people accessing mental health services had twice the lung cancer incidence (adjusted incidence rate ratio = 2.05, 95% confidence interval = 1.92-2.18) and elevated 12-month mortality (hazard ratio = 1.54, 95% confidence interval = 1.41-1.68). Risks were equally increased in people with non-psychotic disorders and brief care. CONCLUSION: People accessing mental health services in the target age range for lung screening have doubled lung cancer incidence, greater risk of metastatic disease and higher 12-month mortality. Screening should take a broad, transdiagnostic approach, and not be limited to people with diagnoses of schizophrenia or bipolar disorder. Supporting participation in emerging lung screening programmes should be a priority.