Population-based evaluation of the risk factors and prognosis among renal cell carcinoma patients with initially diagnosed lung metastases.

Objectives: To evaluate risk factors and prognosis of lung metastases in patients with renal cell carcinoma (RCC) based on the Surveillance, Epidemiology, and End Results (SEER) database.

Methods: 56,617 patients with RCC were selected from the SEER database. Based on univariate and multivariate logistic regression, the risk factors for developing lung metastases were derived. 2906 patients were initially diagnosed with lung metastases, and then were used to research the prognostic factors. Multivariable Cox regression analyses were performed for the prediction of cancer-specific mortality.

Results: In total, 2906 RCC patients were initially diagnosed with lung metastases. The prevalence of lung metastases in RCC was approximately 5% with poor survival. Aging, male, other race (American Indian/AK native, Asian Pacific islander) uninsured status, bilateral tumor, collecting duct, higher T stage, local lymph node metastases, higher tumor grade, and evidence of other distant metastases were significantly associated with developing lung metastases at diagnosis. Age >70 years-old, black, female, bilateral tumor, T4 stage, higher tumor grade, local lymph node metastases, collecting duct, and evidence of bone, liver, or brain metastases were related to higher risk of mortality. Blacks and female have lower odds of developing lung metastases at the time of diagnosis both in crude and adjusted logistic regression. Meanwhile, blacks and female showed higher risk of mortality compared with whites and male in Cox regression analyses.

Conclusion: Several factors related to the development and prognosis of lung metastases were revealed, especially black people and female gender have lower risk of developing lung metastatic RCC at initial diagnosis but have higher risk of mortality. These may provide preventive guidelines for the screening and treatment of lung metastases in patients with renal cell carcinoma.