Statistical Issues in Evaluating Prostate-Specific Antigen Test for Aid in Prostate Cancer Detection

• Activity Number: 693
• Type: Contributed
• Date/Time: Thursday, August 13, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Section on Medical Devices and Diagnostics
• Author(s): Kyungsook Kim*
• Companies: FDA
• Keywords: Prostate Specific Antigen test ; Prostate Cancer Detection ; verification bias ; spectrum bias

Abstract

Prostate-specific antigen (PSA) is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in a man's blood (ng/mL). In 1994, the FDA approved the use of the PSA test in conjunction with a digital rectal exam (DRE) to test asymptomatic men for prostate cancer detection. Men who report prostate symptoms often undergo PSA testing (along with a DRE) to help doctors determine the nature of the problem. Although there is no specific normal or abnormal range of PSA in the blood, most doctors considered PSA levels of 4.0 ng/mL and lower as normal. Therefore, if a man had a PSA level above 4.0 ng/mL, doctors would often recommend a prostate biopsy to determine whether prostate cancer was present. Most men with an elevated PSA level turn out not to have prostate cancer; only about 25 percent of men who have a prostate biopsy due to an elevated PSA level actually have prostate cancer. The study design to determine the safety and effectiveness of the PSA device as a prostate cancer diagnostic device has many challenges. In this talk, some statistical challenges and issues in study design, data analysis, and sample size calculation will be discussed.