Prognosis and prognostic factors of lung cancer complications in patients with rheumatoid arthritis.

AIM: To clarify the prognosis and prognostic factors for lung cancer in patients with rheumatoid arthritis (RA).

METHODS: In this retrospective longitudinal study, we investigated the medical records of patients with RA among 1422 patients diagnosed with lung cancer and registered in a hospital-based cancer registry between January 2013 and May 2022. The Kaplan-Meier method and Cox proportional hazards model were used to analyze survival and identify predictive factors.

RESULTS: Of 26 patients with RA complicated with lung cancer (median age, 69 years), the 2-year overall survival rates for stages I-II were 90%-100%, and those for stages III-IV were 20%, respectively. Positivity of anti-citrullinated protein/peptide antibody, smoking history, interstitial lung disease, poorly controlled RA, stage III and IV lung cancer, histological types other than adenocarcinoma and squamous cell carcinoma, and RF ≧ 50 IU/mL were associated with increased mortality. After the surgical resection of stage I and II lung cancer, 5 of the 16 patients experienced cancer recurrence after resumption of RA treatment, and the histology of the recurrent cancers was mostly squamous cell carcinoma.

CONCLUSIONS: Early detection of lung cancer is needed, especially in patients with RA who have a history of smoking, seropositivity, or interstitial lung disease. Even after surgical resection, it should be noted that squamous cell carcinoma is prone to recurrence.