Increased Incidence of Lung Cancer Among Patients With Superficial Transitional Cell Carcinoma: A Potential Risk Cohort for Lung Cancer Screening.

Background: Smoking is a major risk factor for lung cancer (LC) and transitional cell carcinoma of the bladder (TCC). Current recommendations for LC screening do not include TCC as a risk factor for determining screening eligibility. In this study we aimed to evaluate whether TCC patients constitute a population who might benefit from LC screening.

Patients And Methods: The Surveillance, Epidemiology, and End Results 18 database was used to determine the incidence, standardized incidence ratio (SIR), and the average time to diagnosis of LC in patients with localized TCC of the bladder (American Joint Committee on Cancer, sixth edition, stages 0-1).

Results: On the basis of 91,606 patients with localized TCC, The SIR for LC in men was 1.89 (95% confidence interval [CI], 1.8-1.97), significantly different from the risk for all solid tumors. The SIR for LC in women was 2.43 (95% CI, 2.22-2.65), significantly higher than for men. The 5-year incidence of LC was 3.2%, and the 10-year incidence was 5.94%. The average time to diagnosis of LC was 3.4 years, with >80% of LC cases occurring within 5 years of TCC diagnosis.

Conclusion: Patients with localized TCC have a higher incidence of LC than the general population. The risk is significantly increased among women compared with men. Considering this increased risk, patients with early stage TCC might stand to benefit from LC screening. Additional differences were noted between male and female TCC patients, which bear further study.