San Diego, California (UroToday.com): In today’s International Prostate Forum at the 2016 AUA, Dr. David Crawford discussed patient selection and technique for patients who undergo repeat biopsy. He began by discussing challenges in CaP detection, which include improvement of the interpretation of PSA, decreasing the rate of unnecessary biopsies, and enhancement in the risk stratification of newly-diagnosed patients.
Dr. Crawford illustrated 4 “buckets” to aid in these challenges: identifying who to biopsy (aided by PSA, PHI, 4K, SelectMDx), who to re-biopsy (aided by ConfirmMDx, PCA3, 4K), who to offer interventional therapy vs AS (aided by Decipher, OncotypeDx, Prolaris, ProMark), and who to treat or not treat post-prostatectomy (aided by Decipher and Prolaris).
Striking statistics underscore the need for enhancing patient selection for biopsy: 25% will receive a false-negative result, 15% will suffer complications, and 3% of patients will be hospitalized. Moreover, 43% of patients have a repeat biopsy, of which 44% have a second repeat biopsy, of which 43% have an additional biopsy. Meanwhile, more than ½ of cancers found on repeat biopsy are clinically significant.
An algorithm that may improve our ability to detect cancer and risk stratify patients begins with PCP-driven PSA screening and stratification by PSA > vs. < 1.5. Those with higher PSA are referred to a urologist where the test is repeated along with DRE. Those patients with abnormal exam or PSA undergo biopsy, and if negative, they undergo testing with ConfirmMDx, PCA3, 4K, or PHI to aid in the decision to either re-biopsy or defer further investigation. Those with positive biopsies undergo OncotypeDx, ProMark, PTEN/ERG, or Prolaris testing, and KnowError to faciliate stratification by indolent vs aggressive disease. At this point, the decision for active surveillence vs intervention can be determined.
PHI test was shown to improve detection of high grade CaP (AUC 0.707) on rebiopsy compared to PSA alone (AUC=0.551). PCA3 is an FDA-approved urine based test with a score determined by PCA3/PSA mRNA; increasing PCA3 score is correlated with increasing risk of positive biopsy. 4K includes total, free, and intact PSA in addition to hK2. Age, DRE and prior biopsy status are taken into consideration, and the test result provides % risk of having aggressive prostate cancer for an individual patient. ConfirmMDx detects an epigenetic field effect associated with cancer at the DNA level, which provides actionable information to improve patient risk stratification and decisions on repeat biopsy; it facilitates ruling out cancer-free men from undergoing unnecessary repeat biopsy, and rules in those who require repeat biopsies and potential treatment. Pooled analysis of the MATLOC and DOCUMENT trials validate ConfirmMDx and demonstrate a 96% NPV for clinically significant cancers and 90% NPV for all cancers.
Dr. Crawford concluded that we need close collaboration between primary care physicians and urologists to optimize diagnosis, risk stratification, and management of prostate cancer patients. He presented an additional management schema to support this: PCP checks PSA, and if < 1.5, the patient gets it rechecked in 5 years. If > 1.5, the PCP should consider referral to a urologist. At this point, PHI, SelectMD, PCA3, or 4K score should be checked. If considered high risk the patient should undergo TRUS biopsy, followed by ConfirmMDx and possible MP MRI. If low risk, he should continue with routine PSA checks. Patients who are biopsied and are intermediate risk on biopsy should have genomic markers checked to stratify patients for treatment vs AS.
Presented By: David Crawford, MD