Telomere dysfunction is one of the hallmarks of cancer, which puts telomere-associated genes in a prominent position in oncology. The CTC1-STN1-TEN1 (CST) complex is vital for telomere maintenance and participates in several steps of DNA metabolism, such as repair and replication, essential functions for malignant cells. Despite this, little is known about these genes in cancer biology. Here, using bioinformatics tools, we performed a study in 33 cancer types and over 10,000 TCGA samples analyzing the role of the CST complex in cancer. We obtained the somatic landscape and gene expression patterns of each of the subunits of the complex studied. Furthermore, we show that CST is important for genetic stability and nucleic acid metabolism in cancer. We identify possible interactors, transcription factors, and microRNAs associated with CST and two drugs that may disrupt their pathways. In addition, we show that CST gene expression is associated with cancer survival and recurrence in several tumor types. Finally, we show negative and positive correlations between immune checkpoint genes and CST in different types of cancer. With this work, we corroborate the importance of these genes in cancer biology and open perspectives for their use in other works in the field.