Multiplex Biomarkers for Prostate Cancer

DESCRIPTION (provided by applicant): Prostate cancer is the most common malignancy and second-leading cause of cancer deaths among males in the United States, accounting for 1/3 of all new cancers in males with an estimated 232,090 new cases yearly (Jemal, 2005). The mainstay of prostate cancer detection is a blood test for the presence of prostate-specific antigen (PSA). Although testing for PSA has led to earlier cancer detection, the correlation between malignancy and PSA is not strong. A positive test f or PSA signifies that a patient has a 25% chance for cancer, which causes 75% of men to have unnecessary biopsies (Barry, 2001). Conversely, a negative result may actually miss the majority of cancers (Hernandez, 2004). Clearly, more accurate diagnostic te sts are needed to eliminate unneeded treatment as well as better identify the subset of patients that do require treatment. Proteomic analysis has resulted in the discovery of many candidate biomarkers that may supplement or even replace PSA in the diagnos is of prostate cancer (Bradford, 2006). Given that the earlier cancer is detected the better the clinical outcome, and that tumorigenesis involves multiple genetic changes within cells, diagnostic tests that quantify multiple low-abundance cancer-associate d proteins are most desirable. Such tests tend to be more accurate than single target assays and their sensitivity affords the possibility of very early and accurate detection. Fortunately, low abundance biomarkers for prostate cancer have been discovered (Bradford, 2006), but the sensitivity of conventional technology based on ELISA may limit their use in clinical assays. To meet this need, we are developing Prostaplex(tm), a new Multiplexed Real-time Immuno PCR (MRI-PCR) based assay that detects the prese nce of 10 prostate cancer biomarkers. Our methodology is sensitive, reproducible, valid over a large dynamic range, and capable of being multiplexed to dozens or even hundreds of cancer biomarkers. We anticipate that Prostaplex(tm) will result in earlier, more accurate prostate cancer detection and staging than currently available assays. Earlier, more accurate detection will lead to fewer unneeded biopsies, fewer medical procedures for those who do not require them, better cure rates for patients that actu ally have cancer, and better prophylaxis and follow ups for at-risk patients who have not yet developed cancer. PUBLIC HEALTH RELEVANCE:Prostate cancer is the most common malignancy and second-leading cause of cancer deaths among males in the United States , accounting for 1/3 of all new cancers in males with an estimated 232,090 new cases yearly (Jemal, 2005). The mainstay of prostate cancer detection is a blood test for the presence of prostate-specific antigen (PSA). Although testing for PSA has led to ea rlier cancer detection, the correlation between malignancy and PSA is not strong. A positive test for PSA signifies that a patient has a 25% chance for cancer, which causes 75% of men to have unnecessary biopsies (Barry, 2001). Conversely, a negative resul t may actually miss the majority of cancers (Hernandez, 2004). Clearly, more accurate diagnostic tests are needed to eliminate unneeded treatment as well as better identify the subset of patients that do require treatment. Proteomic analysis has resulted i n the discovery of many candidate biomarkers that may supplement or even replace PSA in the diagnosis of prostate cancer (Bradford, 2006). Given that the earlier cancer is detected the better the clinical outcome, and that tumorigenesis involves multiple g enetic changes within cells, diagnostic tests that quantify multiple low-abundance cancer-associated proteins are most desirable. Such tests tend to be more accurate than single target assays and their sensitivity affords the possibility of very early and accurate detection. Fortunately, low abundance biomarkers for prostate cancer have been discovered (Bradford, 2006), but the sensitivity of conventional tec