Unmet needs in the prediction and detection of metastases in prostate cancer

Abstract

The therapeutic landscape for the treatment of advanced prostate cancer is rapidly evolving, especially for those patients with metastatic castration-resistant prostate cancer (CPRC). Despite advances in therapy options, the diagnostic landscape has remained relatively static, with few guidelines or reviews addressing the optimal timing or methodology for the radiographic detection of metastatic disease. Given recent reports indicating a substantial proportion of patients with CRPC thought to be nonmetastatic (M0) are in fact metastatic (M1), there is now a clear opportunity and need for improvement in detection practices. Herein, we discuss the current status of predicting the presence of metastatic disease, with a particular emphasis on the detection of the M0 to M1 transition. In addition, we review current data on newer imaging technologies that are changing the way metastases are detected. Whether earlier detection of metastatic disease will ultimately improve patient outcomes is unknown, but given that the therapeutic options for those with metastatic and nonmetastatic CPRC vary, there are considerable implications of how and when metastases are detected.

Keywords: Imaging; Lymph nodes; Magnetic resonance imaging; Neoplasm metastasis; Prostatic neoplasms; Radionuclide imaging.

Figure 1.

Distribution of prostate-specific antigen at metastasis to bone on log scale (A) and by years from radical prostatectomy to metastasis (B). Adapted from [25] with permission from Elsevier and the American Urological Association. Abbreviation: PSA, prostate-specific antigen.

Figure 2.

Positive identification of bone metastases with whole-body magnetic resonance imaging versus bone scintigraphy. (A): Bone scintigraphy (anterior-posterior and posterior-anterior views) shows no significant lesion. Coronal T1 (B) and diffusion-weighted (C) magnetic resonance images of the body confirm bone metastases within L3 and the left iliac bone. Reprinted from [65] with permission from Elsevier.