Circulating tumor cells (CTCs) are found in the blood of prostate cancer patients. They are representativeof the patients’ tumor and enable an assessment of disease stability or aggressiveness. They also allow for treatment monitoring and for treatment choices. The latter is very important in order to know which patient will respond to which treatment. Our laboratory has successfully isolated CTCs from prostate cancer patient’s blood since 2013 (Awe et al. Transl. Oncology 2013). Using a patented method that we developed, our group has been able to stratify intermediate risk prostate cancer patients into those with stable and those with unstable disease. The latter require treatment, while the former don’t and can be monitored by simply taking a blood sample. We have initiated studies using next generation sequencing of single prostate cancer patient CTCs. This approach identifies mutations in the patient’s CTCs that can help the treating clinician decide which treatments will work for the specific patient. It is another step to personalized medicine for prostate cancer patients. In the current study, we propose the continuation of single cell CTC analysis for high-risk prostate cancer patients in order to identify actionable mutations and allow for patient-specific treatment decisions.