CPT® Code 81313

PCA3/KLK3 (prostate cancer antigen 3 [non-protein coding]/kallikrein-related peptidase 3 [prostate specific antigen]) ratio (eg, prostate cancer)

The CPT® Code 81313 refers to a specific molecular genetic test that evaluates the ratio of PCA3 (prostate cancer antigen 3) to KLK3 (kallikrein-related peptidase 3, also known as prostate-specific antigen or PSA). This test is particularly relevant for men over the age of 50 who have undergone one or more negative prostate biopsies. The primary purpose of this test is to assist healthcare providers in determining whether a repeat biopsy is necessary. The PCA3 biomarker is a non-protein coding RNA that is often found in higher concentrations in malignant prostate cells compared to benign cells, making it a valuable tool for prostate cancer diagnosis. In contrast, KLK3 (PSA) is produced by both malignant and benign prostate cells, which allows for a comparative analysis between the two markers. The test involves collecting a urine sample after a digital rectal exam (DRE), where the prostate is palpated to assess its condition. The first 20-30 ml of voided urine is then analyzed using quantitative nucleic acid amplification techniques to measure the levels of PCA3 and PSA RNA. The results are expressed as a ratio, providing insights into the likelihood of prostate cancer presence, thereby aiding in risk prediction and prognosis for the patient.