Cancer is one of the most mortal diseases globally. Although considerable advances in its detection and monitoring have been accomplished over the last decade, simple and continuous cancer monitoring is not a reality, yet. Nowadays, cancer diagnostic is based on image analysis techniques, biopsy and whole blood sample analysis of specific biomarkers. This process is time-consuming and hinders continuous monitoring. Additionally, the use of biomarkers can add some challenges, since there is not an ideal biomarker that can be use in cancer detection. Most of the times, a detection of multiple biomarkers is needed, for a reliable analysis. The lack of sensitivity and specificity of current diagnostic tests are also limitations that need to be taken into account in biomarker detection. Thus, there is an urgent need for new diagnostic technologies, able to produce rapid and reliable early cancer detection and treatment follow-up. Biosensors have been immerging as a promising tool to provide multiplex, increased sensitivity and specificity, and continuous biomarker monitoring. However, biosensors are still being developed in the laboratory, and only few reached clinical trials, therefore their translation to the clinical use is also not a reality. Herein, it will be described the most recent developments in cancer biosensors, discussing their performance on biomarker detection, and their potential for clinical use.