Objectives Circular RNAs (circRNAs) are RNA transcripts that belong to non‐coding RNAs (ncRNAs), whose implication in human cancers has been recently demonstrated. However, the specific role of multiple circRNAs in breast cancer remains unidentified. Materials and methods Microarray analysis and bioinformatics analysis were applied to select circRNA and miRNA, respectively. The loop structure of circ‐TFF1 was confirmed using RNase R treatment, divergent primer PCR and Sanger sequencing. qRT‐PCR and Western blot were employed for gene expressions. In vitro and in vivo experiments were conducted to assess the function of circ‐TFF1 in biological processes in breast cancer cells. FISH and subcellular separation indicated circ‐TFF1 cellular distribution. Luciferase reporter and RIP assays and Pearson's correlation analysis were performed to evaluate relationships between genes. Results Circ‐TFF1 and TFF1 were both upregulated and positively associated with each other in breast cancer. Knockdown of circ‐TFF1 hindered breast cancer cell proliferation, migration, invasion and EMT in vitro and controlled tumour growth in vivo. Circ‐TFF1 acted as a ceRNA of TFF1 by sponging miR‐326, and its contribution to breast cancer progression was mediated by miR‐326/TFF1 axis. Conclusions Circ‐TFF1 is a facilitator in breast cancer relying on TFF1 by absorbing miR‐326, providing a novel promising target for BC treatment.

In this population-based retrospective study, we aimed to investigate the association between age at diagnosis and prognosis of pancreatic cancer (PC) patients using data from the National Cancer Institute’s Surveillance, Epidemiology, and the End Results database. Different factors for stratification, like race, sex, year of diagnosis, pathological grade, American Joint Committee on Cancer stage, historic stage, and tumour location, were included to compare the survival rates of patients of different age groups, and the five-year survival rate was calculated. Multivariate analysis using Cox regression was performed to control for confounder bias, and the hazard ratio was calculated. In total, 126,066 patients were enrolled in this study. The five-year PC-specific survival of patients aged 20–40 years was almost three times that of patients aged >40 years. Stratified by race, sex, year of diagnosis, pathological grade, clinical stage, and tumour location, a descending trend of survival was observed with an increase in age. On multivariate analysis, the mortality risk of PC patients aged 40–80 years was twice that of patients aged <40 years; however, patients aged >80 years had a mortality risk three times that of patients aged <40 years. The survival rate of PC patients has improved in the last few decades. Age at diagnosis is a significant and negative prognostic factor for PC, and patients diagnosed at a relatively earlier stage had the best survival.

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