An object of the present invention is to provide a novel determination method which is capable of determining prostate carcinoma with a higher biopsy avoidance rate.
The present invention relates to a method for determining prostate carcinoma, including obtaining a ratio 1 between an amount of a free prostate specific antigen and an amount of a free PSA having an α(2,3) glycan, the free PSA having an α(2,3) glycan being a free prostate specific antigen having a glycan in which a terminal sialic acid residue of the glycan is α(2,3)-linked to a second galactose residue from a terminal of the glycan, in a sample derived from a subject; obtaining a ratio 2 between the ratio 1 and a volume of the prostate of the subject; and determining prostate carcinoma based on the obtained ratio 2.