Improved lung cancer clinical outcomes in patients with autoimmune rheumatic diseases

PURPOSE: Concomitant autoimmune rheumatic diseases (ARD) can add morbidity and complicate treatment decisions for patients with lung cancer. We evaluated the tumour characteristics at diagnosis and clinical outcomes in lung cancer patients with or without ARD. METHODS: This retrospective cohort study included 10 963 patients with lung cancer, treated at Johns Hopkins. Clinical data including tumour characteristics and outcomes were extracted from the cancer registry. Data on patients’ history of 20 ARD were extracted from the electronic medical record. Logistic regression was used to compare tumour characteristics between those with and without ARD; Kaplan-Meier curves and Cox proportional hazards models were performed to compare survival outcomes. RESULTS: ARD was present in 3.6% of patients (n=454). The mean age at diagnosis was 69 (SD 10) and 68 (SD 12) in patients with and without ARD (p=0.02). Female sex and smoking history were significantly associated with a history of ARD (OR: 1.75, OR: 1.46, p<0.05). Patients with ARD were more likely to be diagnosed with stage 1 lung cancer (36.8% vs 26.9%, p<0.001) and with smaller tumour size (OR: 0.76, p=0.01), controlling for sex, race and histology. Notably, lung cancer patients with ARD had a significantly prolonged median overall survival (OS) (7.11 years vs 1.7 years, p<0.001), independent of stage. CONCLUSION: Patients with ARD and lung cancer had better OS compared with their counterparts, independent of cancer stage and treatments and were less likely to have advanced stage lung cancer at diagnosis. Additional studies are needed to investigate the differential immunological anti-tumour immune activity and genomic variations in patients with and without ARD.