Incidence, prognostic factors, and a nomogram of lung metastases at diagnosis: a pan-cancer population-based study

Abstract

Lung metastasis is common and usually associated with poor outcomes in cancer patients. Currently, the epidemiologic and survival data of synchronous lung metastases (SLM) are lacking. We collected 61,493 patients who were diagnosed with lung metastases at the time of primary cancer diagnosis between 2010 and 2017. The age-adjusted incidence of SLM increased from 9.86/100,000 in 2010 to 12.03/100,000 by 2017 [APC: 3.08; 95% CI: 2.30–3.86]. For adults > 35, digestive system cancer is the most common primary site. For younger patients, the top cancers with SLM were more heterogenous. Survival analysis of SLM patients with different primary tumor types suggested that the median OS was the best for the male genital system malignances and the worst for the digestive system malignances. Furthermore, a nomogram comprising age, race, gender, grade, tumor size, N stage and sites was established to predict the 1-/3-/5-year survival probability of patients with SLM, with the C-indexes of 0.628 (95% CI: 0.622–0.634) for the internal validations and 0.620 (95% CI: 0.610–0.630) for the external validations. In conclusion, the incidence of SLM has continued to increase recent years, and a nomogram based on prognostic analysis could accurately quantify the survival rates of patients with SLM.