Comparative analysis of overall survival in non-small cell lung cancer patients with and without different organ metastases

Abstract

Lung cancer is the leading cause of cancer death globally. Non-small cell lung cancer (NSCLC) constitutes more than 80% of all lung cancers, and patients with distant metastasis have much higher mortality. The survival times of NSCLC patients with metastasis have been reported in early studies, however, it remains unclear whether there are variations or patterns in survival times of patients with different metastases. Therefore, we assessed risk factors for distant metastases and the effects of different organ metastasis on overall survival (OS) in patients with NSCLC. Methods: demographics and clinical data of NSCLC patients with and without distant metastasis were collected from the Surveillance, Epidemiology, and End Result (SEER) database between 2010 and 2016. We investigated risk factors for distant metastasis patients and compared the difference in OS of NSCLC patients with different metastatic sites. Results: a total of 3849 patients diagnosed with NSCLC were screened from the SEER database with 41% (1577) of the patients having distant metastasis. During the follow-up period, 3221 (83.7%) patients died and, of all the deceased patients, 2935 (88.4%) died of lung cancer while only 286 (11.6%) died from other diseases or causes. The occurrence of distant metastasis was closely related to the patient’s age, primary tumour site, tumour grade, T stage, N stage, surgery of primary site, radiation therapy, and chemotherapy (p<0.05). Compared to patients without metastasis, whose median OS was 13 months, the median OS of patients with metastasis was 6 months (lung), 5 months (liver), 5 months (bone), 4 months (brain), and 3 months (multiple organs). Conclusions: distant metastasis indicates a poor prognosis in NSCLC patients. There were significant differences in the prognosis of different metastatic sites and the order of their OS from high to low was: no metastasis > lung metastasis, liver metastasis, bone metastasis > brain metastasis, multiple organ metastasis.