Systems for providing a probability of prostate cancer risk and/or prostate gland volume, and related methods

A method for determining the probability that a prostate tissue biopsy would contain detectable aggressive prostate cancer, comprising:

• i) obtaining a blood sample of a subject;
• ii) subjecting the blood sample of the subject to one or more immunoassays that measure levels of kallikrein markers comprising free prostate specific antigen (fPSA), intact prostate specific antigen (iPSA), total prostate specific antigen (tPSA) and human kallikrein 2 (hK2);
• iii) determining the probability that a prostate tissue biopsy obtained from the subject would contain detectable aggressive prostate cancer using a logistic regression model with aggressive prostate cancer as the outcome, wherein the logistic regression model is:
• Xβ=β0+β1age+β2tpsa+β3sptpsa1+β4sptpsa2+β5fpsa+β6spfpsa1+β7spfpsa2+β8ipsa+β9hK2+β10dreneg+β11drepos+β12priorbx;
• wherein β0-β12 are weighting coefficients, age is the age of the subject when the blood is obtained, tpsa is concentration of tPSA in ng/mL, fpsa is concentration of fPSA in ng/mL, ipsa is concentration of iPSA in ng/mL, hK2 is concentration of hK2 in ng/mL, sptpsa1 is a first spline term for tPSA, sptpsa2 is a second spline term for tPSA, spfpsa1 is a first spline term for fPSA, spfpsa2 is a second spline term for fPSA, dreneg is a value of 1 if a digital rectal examination has been confirmed as negative or a value of 0 otherwise, drepos is a value of 1 if a digital rectal examination has been confirmed as positive or a value of 0 otherwise, and priorbx is 0 if no prior negative biopsy and 1 if the subject had a prior negative biopsy;
• iv) determining that the probability from step iii) is below a threshold level;
• and
• v) repeating steps i)-iii) at least once;
• wherein the probability from repeated step iii) is above the threshold level, and the method comprises obtaining a prostate tissue biopsy from the subject and analyzing the prostate tissue biopsy to further evaluate presence of aggressive prostate cancer;
• and
• wherein the method further comprises identifying the subject as having aggressive prostate cancer based on the obtained prostate tissue biopsy and treating the identified subject, wherein treatment comprises prostatectomy or radiotherapy.