Figure 2A: Log PSA trend and computed tomography (CT) images of a patient with a 100-fold PSA decline on docetaxel-based chemotherapy. Despite very low levels of PSA the patient developed metastatic liver disease. Biopsy revealed small cell carcinoma morphology and negative IHC staining for PSA and AR (Aperio Scanscope, magnification 10x for all images).
Figure 2B: Patient developing widespread liver metastasis on treatment with abiraterone acetate in the presence of PSA stability. The archival primary prostate biopsy shows adenocarcinoma with positive IHC staining for PSA, AR and ERG and FISH confirming an underlying ERG rearrangement. At development of liver metastases in the absence of a rising PSA, a liver biopsy shows adenocarcinoma with negative IHC staining for PSA, AR and ERG despite an underlying ERG gene rearrangement (Aperio Scanscope, magnification 10x for H&E and IHC images, Ariol System for FISH pre-treatment image, magnification 40x; new liver metastasis magnification 20x)