Detecting long non-coding RNA biomarkers in prostate cancer liquid biopsies: Hype or hope?

Abstract

Prostate cancer is a heterogeneous malignancy, with clinical courses widely differing between indolent and aggressive lethal disease. This heterogeneity calls for a more personalized approach towards diagnosis, prognosis, treatment decision, monitoring and follow-up of patients. In this review, we discuss the possibilities and drawbacks of detecting RNA biomarkers in biological fluids to improve disease-specific survival and quality of life. In particular, we examine literature on long non-coding RNAs in blood and urine of prostate cancer patients. We thereby specifically focus on the need for standard operation procedures on many different levels, analytical validation, clinical validation, and assessment of clinical utility. We argue that thorough multi-step validation of putative biomarkers is necessary for successful translation into clinical prostate cancer care. Our recommendations may also prove useful to biomarker research in other cancers.

Fig. 1

Graphical overview of the topics discussed in this review article.

Fig. 2

Heat map constructed from publicly available total RNA sequencing data of lncRNAs known to be involved in prostate cancer. The lncRNAs in light blue were already described in literature to be detectable in liquids. The lncRNAs in dark blue are known to be involved in prostate carcinogenesis, but never before described in liquids.