Liang X, Cheng Y, Zhou W, et al. - Since there is a lack of analysis of the incidence as well as prognosis of lung metastasis (LM) based on primary cancer sites, researchers addressed this topic herein by analyzing cancer patients with LM who were selected from the Surveillance, Epidemiology, and End Results database. There were 1,525,441 cases, of which 47,537 had LM at initial diagnosis. Risk factors for LM, as shown in multivariate logistics regression, included male gender, older age, later T/N stage, unmarried status, and lack of insurance. In bone cancer and in pancreatic cancer, the estimated incidence of LM was 11.91% and 11.19%, respectively. For LM cases, a median survival of 6 months was reported. Findings revealed that a higher hazard ratio (HR) for mortality was evident in patients presenting with LM vs those without LM, except for those with brain tumor. Paying more attention to LM occurrence is recommended, particularly in cases with a significantly elevated HR for mortality, such as those with thyroid cancer, melanoma, and prostate cancer.