Prolaris is a genomic test designed to assess the aggressiveness of prostate cancer by analysing the expression of 31 cell cycle progression (CCP) genes in a tumour sample. This test provides a “Prolaris Score,” which helps predict the likelihood of cancer recurrence and the potential for the tumour to grow and spread. The score can be combined with clinical data (such as PSA levels and Gleason score) to guide treatment decisions. Prolaris is particularly useful in determining whether treatment can be safely deferred or whether immediate treatment is necessary.