Transperineal Parallel Biopsy of the Prostate: A New Approach of Tissue Sampling for Precision Medicine

PURPOSE: Through an observational study to present a new approach for obtaining high-quality samples for the targeted therapy of prostate cancer. PATIENTS AND METHODS: Parallel biopsy, which was defined as collecting the tissue from the same site by two biopsies, was performed on patients with elevated PSA. Each tissue was stained by ink to identify the pathological characteristics, including Gleason score and tumor tissue ratio. Kendall tau-b test and intraclass correlation coefficient test were used to compare the consistency between each paired sample. Then, based on the pathology of the biopsies, high-quality tissues would be selected for sequencing, and PyClone model was used to track the clonal evolution. RESULTS: In total, 252 pairs of biopsies were collected. The consistency of Gleason score between each paired biopsy is 0.777 (p<0.01), and the consistency of tumor tissue ratio is 0.853 (p<0.01). With the application of parallel biopsy, on average five nonsynonymous mutations could be identified in patients with castration-resistant prostate cancer. Six out of eight had at least one biology-relevant alteration in patients, guiding further treatment. Meanwhile, clonal evolution was constructed to investigate the progress of tumor. CONCLUSION: Parallel biopsy is a reliable approach to collect high-quality tissue and shows potential application in precision medicine.