A method for assessing risk of prostate cancer utilizing both Pro108 and Prostate Specific Antigen (PSA) in combination is provided. Also provided is a method for assessing risk of cancer utilizing Pro108 or specific antibodies to Pro108. Antibodies that bind to Pro108 on a mammalian cell in vivo and compositions comprising an anti-Pro108 antibody and a carrier which can be provided in an article of manufacture or a kit are also provided. An isolated nucleic acid encoding an anti-Pro108 antibody, an expression vector comprising the isolated nucleic acid, cells that produce the anti-Pro108 antibodies and a method of producing the anti-Pro108 antibodies as well as methods for use of the antibodies in killing an Pro108-expressing cancer cell and alleviating or treating an Pro108-expressing cancer in a mammal are also provided.