FIELD: medicine.SUBSTANCE: group of inventions relates to medicine, specifically oncology, and can be used to assess the need for active treatment of a patient with prostate cancer (PCa). Method of the invention includes steps of obtaining a biological sample, analysing therein the category of SNP associated with PCa, (SNPpc), by determining the presence or absence of one or two risk alleles of each of the set of SNPpc, combining data related to said category of SNPpc to obtain a combined value for SNPpc, where the method, when obtaining a combined value for SNPpc, allows a subset of at least 10 % SNPpc from the category of SNPpc to be neglected, where the combined value for SNPpc is formed from data of at least 95 SNPpc, determining the correlation of said combined value for SNPpc with the likelihood of the need for active treatment for the individual. Device of the invention comprises a solid phase with a category of ligands immobilised thereon, which comprises a plurality of different ligands specifically
