The objective of this study is to explore the prognostic factors of double primary cancer patients with lung cancer as the first primary cancer (FPC). The Surveillance, Epidemiology, and End Results (SEER) database is a database established by the National Institutes of Research for cancer registration purposes, which collects relatively complete demographic characteristics and clinical data for assessing the epidemiological characteristics of cancer worldwide. Clinical data on patients with a clear histopathological diagnosis of double primary with lung cancer as the FPC were identified and collected from the SEER database from 2010 to 2015. Survival curves were plotted by Kaplan–Meier survival analysis. Independent prognostic factors of patients were analyzed by COX proportional risk model. Clinical data were collected from a total of 9306 patients, including 6516 patients in the modeling group and 2790 patients in the validation group. When we retrieved that the FPC was lung cancer, we found that the most common site of the second primary cancer was located in the respiratory system (54.0%). In addition, the most common site of first primary lung cancer in patients with double primary cancer was the right upper lobe (33.3%). A total of 14 independent prognostic factors were included, and the constructed survival nomogram had high accuracy and clinical applicability. The nomogram established in this study can help to raise awareness of clinical workers and the importance of such diseases, and guide the treatment and follow-up strategies.

Background Long non‐coding RNA (lncRNA) ATB belongs to an active modulator in multiple cancers, but its expression along with potential underlying non‐small cell lung cancer (NSCLC) is obscure. Our study aimed to investigate the role and potential mechanism of LncRNA ATB in NSCLC. Methods LncRNA ATB expression in NSCLC tissues and cell lines was detected by qRT‐PCR. Effects of LncRNA ATB on NSCLC cell proliferation, migration and invasion were assessed by MTS, colony formation and transwell assays. The connection among LncRNA ATB, miR‐200b and fibronectin 1 (FN1) was determined by bioformatics prediction and luciferase reporter assay. Results In this research, upregulation of LncRNA ATB was discovered in NSCLC tissue samples and cell lines. LncRNA ATB was positively related to advanced tumor phase as well as lymph node metastasis. Cell function assays reflected LncRNA ATB expedited NSCLC cells proliferation, migration and invasion. LncRNA ATB promoted fibronectin 1 (FN1) expression via inhibiting miR‐200b. Furthermore, LncRNA ATB depletion suppressed NSCLC cells proliferation, migration and invasion, while miR‐200b inhibitor or pcDNA‐FN1 rescued these effects. Conclusion In summary, our outcomes elucidated that LncRNA ATB/miR‐200b axis expedited NSCLC cells proliferation, migration and invasion by up‐regulating FN1.