Researchers have developed a new imaging method that may improve diagnosis, monitoring, and treatment of prostate cancer, according to a new study published in Science Translational Medicine. The study, "Internalization Of Secreted Antigen–Targeted Antibodies By The Neonatal Fc Receptor For Precision Imaging Of The Androgen Receptor Axis,” describes a new cancer-specific antibody that can be tracked using positron emission tomography (PET) scans to provide real-time, accurate images of the tumor, and guide therapy. Prostate cancer is typically diagnosed by assessing prostate-specific antigen (PSA) blood levels based on the theory that PSA levels are a measure of the androgen receptor pathway activation and cancer onset. However, PSA levels may change due to several factors, such as age and type of tumor, making it difficult to assess the real degree of androgen receptor activation. Also, as PSA circulates in the blood, it is not always clear which sites have been affected by the cancer, making it hard to track disease activity outside the prostate. An international research team, led by David Ulmert, MD, at Memorial Sloan Kettering Cancer Center, developed an antibody called 11B6 that targets the hK2 protein. Like PSA, this protein reflects the activation of the androgen receptor, but has the advantage of being located specifically in the prostate. Researchers observed that, when the antibody binds to the protein (11B6-hK2 complex), the complex enters cancer cells, allowing researchers to track down hK2-positive cancer cells.