B7-H3, unlike PSA, stays attached to the cancer cells, making it a potential therapeutic target.
Mayo Clinic researchers identified an immune molecule, B7-H3, that appears to play a role in prostate cancer development and in predicting cancer recurrence and progression after surgery.
The most notable other prostate biomarkers are prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA), which are useful to diagnose prostate cancer.
However, PSA tends to leave prostate cancer cells and migrate throughout the body, making it a poor target for therapy, but B7-H3 stays attached to the surface of prostate cancer cells and does not appear to migrate, report the researchers.
The team examined tissue from 338 consecutive patients who had cancers confined to the prostate and were treated exclusively with a prostatectomy between 1995 and 1998. All tumors and precancerous tissues displayed B7-H3, but patients with the highest levels of B7-H3 within their prostate tumors were four times more likely to experience cancer progression compared to those with weak levels of B7-H3 within their tumors.
Based on their results, the researchers believe that B7-H3 promotes cancer growth by killing or paralyzing immune cells that are trying to attack the cancer.
“Because B7-H3 is present in all prostate cancer tumors and marked levels predict recurrence, we are able to forecast with much greater certainty the likelihood of cancer progression, regardless of therapeutic intervention,” says Eugene Kwon, M.D., a senior investigator and urologist at Mayo Clinic.
The report appeared in the August 15 issue of Cancer Research.
