The long noncoding RNAs (lncRNAs) are non-coding RNAs that are more than 200 nucleotides in length, and one of several types of non-coding RNAs (ncRNAs). The lncRNAs function in diverse biological processes in normal cells, such as cellular differentiation and cell cycle regulation. There is also evidence that some aberrantly regulated lncRNAs function as oncogenes or tumor suppressor genes in various cancers. For example, TTN-AS1 is a lncRNA that binds to titin mRNA (TTN) and has pro-oncogenic effects in many cancers. Overexpression of TTN-AS1 correlates with poor prognosis in breast cancer, lung cancer, digestive system neoplasms, reproductive system cancers, and other cancers. Furthermore, increased TTN-AS1 expression correlates with more advanced pathology and tumor malignancy. In this review, we comprehensively summarize recent studies on the molecular mechanisms of TTN-AS1 regulation and the role of TTN-AS1 in the carcinogenesis and progression of numerous tumors.