Background
Prostate cancer is the most frequent cancer in men, with one out of six men being diagnosed during their lifetime. Annually in the U.S. there are:
Approximately 20 million men screened by the Prostate-Specific Antigen (PSA) test
Over 1.3 million prostate biopsy procedures
240,000 newly diagnosed prostate cancer cases
29,000 deaths(3-5)
Although prostate cancer remains one of the deadliest cancers in men, its accurate diagnosis and follow-up remain a challenge and come at a considerable cost to the healthcare system. Approximately $4.4 billion is spent annually on screening, diagnosing and staging, and an additional $9.9 billion is spent annually on treatment of these patients, totaling nearly $15 billion per year on prostate cancer in the U.S. alone. Annually, over $4 billion is spent on pharmaceutical treatment for prostate cancer, which is expected to increase to $8.7 billion by 2019.(6-8)
Under the current standard of care, men with a PSA score that is elevated (i.e., = 4.0 ng/ml) or rising and/or abnormal digital rectal exam (DRE) are considered at high risk for cancer and will often be referred for a prostate biopsy to determine if prostate cancer is present. The standard prostate biopsy procedure takes 10-12 core samples and histopathological review by visual inspection under a microscope remains the gold standard for the diagnosis of prostate cancer. However, this schema actually samples less than 1% of the entire prostate gland and results in limited histopathological analysis. Sampling error is an inherent and well-documented issue with false-negative rates (FNR) of prostate biopsy procedures reported as high as 25-35%
Of the estimated 1.3 million biopsies performed each year, less than a third actually result in a cancer finding, leaving more than 1 million men with a negative biopsy reading but still facing elevated clinical risk factors. Concerns over inconclusive (i.e. false-negative) biopsy results, coupled with the high rate of clinically significant cancer detected upon repeat biopsy, pose a diagnostic dilemma:
43% of patients with negative histopathology on initial biopsy will undergo a repeat biopsy, many also continuing on to 3rd and 4th biopsies
Repeat biopsies are invasive procedures resulting in increased risk of infection and hospitalization
Significant costs associated with unnecessary procedures and associated risks(18-20)
For patients with an initial negative biopsy but with persistently elevated or rising PSA, abnormal DRE or other risk factors, few options are currently available to guide a urologist in determining whether or when an additional biopsy procedure is warranted. Fear of occult (hidden) prostate cancer leads to additional procedures, leading many men to receive 2nd, 3rd and 4th repeat biopsy procedures to rule-out the presence of cancer