OBJECTIVES

This study aims to characterize the specific organ metastatic rates in lung adenocarcinoma (LUAD) patients and identify the prognosis-associated factors.

METHODS

Using the Surveillance, Epidemiology and End Results database, 40 117 patients diagnosed with positive histology as the only primary LUAD were included. We stratified patients by diagnosed year, age, sex, race/ethnicity, marital status, insurance, location, TNM stage, organ-specific metastases, surgery, chemotherapy, and radiation therapy. We performed multivariable logistic and Cox regression to identify the factors associated with the presence of specific organ metastases and prognosis predictors.

RESULTS

For the 40 117 LUAD patients, 43.69%, 26.25%, 19.66%, 10.60%, and 17.89% had specific organ, bone, brain, liver, and lung metastases, respectively. The average survival in patients with organ metastases was 12.19 months, compared to 36.40 months in patients without metastases. In different kinds of metastatic organ cohorts, the longest average survival was 12.60 months in the lung metastases cohort, and the shortest was 8.43 months in liver metastases cohort. In total, 571 patients with metastases received surgery, which was significantly associated with decreased mortality (hazard ratio 1.82, 95% confidence interval 1.65-2.01, p < 0.01). Patients received surgery of lobectomy or extended (251 of 571, 43.96%) displayed the longest average survival (35.16 months); patients (294 of 571, 51.49%) received sub-lobar resection, had the average survival (19.90 months); patients received local tumor destruction (26 of 571, 4.55%) had the shortest average survival (13.73 months).

CONCLUSION

This study provides insights into the specific organ metastatic rates and prognosis in LUAD patients on a population level. These findings suggest that surgery resection should be taken into consideration in the treatment for these LUAD patients.