Impact of Preexisting Schizophrenia Spectrum Disorders on the Receipt of Surgery and Other Treatments for Non-Small Cell Lung Cancer: A Multicenter Nationwide Cohort Study in Japan.

Abstract

Background: Patients with schizophrenia spectrum disorders (SSDs) experience higher cancer mortality than the general population. Disparities in treatments for non-small cell lung cancer (NSCLC) among this population remain underexamined.

Research question: Are patients with SSDs less likely to receive surgery, adjuvant chemotherapy for stage II/IIIA, concurrent chemoradiotherapy for stage III, and systemic therapy for stage IV NSCLC compared with those without psychiatric disorders?

Study design and methods: This retrospective cohort study used national Hospital-Based Cancer Registry data linked to hospital-based administrative data in Japan. It included patients who received initial treatment for NSCLC between 2018 and 2021. Presence of SSDs was defined as a diagnosis using F20 to F29 codes from International Classification of Diseases, 10th Revision. The primary outcome was receipt of surgery for NSCLC. Secondary outcomes were receipt of the following: (1) adjuvant chemotherapy within 180 days in patients with pathologic stage II/IIIA NSCLC; (2) concurrent chemoradiotherapy in clinical stage III NSCLC; and (3) systemic therapy in stage IV NSCLC. Multivariable logistic regression adjusted for age, sex, clinical stage, comorbidities, and functional status was performed.

Results: The final cohort comprised 166,663 patients, 1,346 of whom had SSDs. Patients with SSDs were more likely to be diagnosed at stage IV NSCLC (45.0% vs 31.4%) and less likely to undergo surgery (31.5% vs 49.9%; adjusted OR [aOR], 0.70; 95% CI, 0.57-0.85), receive adjuvant chemotherapy (aOR, 0.31; 95% CI, 0.17-0.57), or receive systemic therapy (aOR, 0.54; 95% CI, 0.45-0.65). No significant difference was observed in concurrent chemoradiotherapy for stage III NSCLC (aOR, 0.99; 95% CI, 0.73-1.34).

Interpretation: Patients with SSDs were less likely to receive surgery and other stage-appropriate treatments for NSCLC, highlighting the need for targeted interventions to promote equitable cancer care for these individuals.