Characteristics of Cancer Progression on Serial Biopsy in Men on Active Surveillance for Early-stage Prostate Cancer: Implications for Focal Therapy

Abstract

Background: Active surveillance (AS) is a safe and accepted option for managing men with low-risk prostate cancer. Nevertheless, some patients lack confidence in or access to AS. Focal therapy (FT) is a possible alternative to radical treatment for such patients. Objective: We evaluated dominant tumor (DT) progression across serial biopsies to determine whether men on AS could be reasonable candidates for FT. Design, setting, and participants: Men enrolled in AS at University of California, San Francisco between 1996 and 2017 with low/intermediate risk were included. Outcome measurements and statistical analysis: Changes in biopsy grade, volume, and focality of the DT over time were assessed. Focality (good or poor for FT) was defined by the number of cores, laterality, and contiguity of prostate sites containing tumor (based on pathology reports). Candidates (either for targeted/quadrant ablation or for hemigland ablation) were defined based on good focality, grade group (GG) 2, and low-volume disease. Patients were classified as favorable (GG 2 with good focality and concordant multiparametric magnetic resonance imaging [mpMRI]) or unfavorable (poor focality or high-volume disease or discordant mpMRI) for FT at surveillance biopsies. Results and limitations: A total of 1057 men met the inclusion criteria. The median number of biopsies per patient was three (interquartile range 2-4), and 196 patients (18.5%) underwent five or more biopsies. At confirmatory biopsy, 43% remained candidates for FT (67% for targeted/quadrant ablation and 33% for hemigland ablation) and 20% had a negative biopsy. Of the candidates for FT at initial biopsy, 11% had less favorable characteristics at confirmatory biopsy. Among candidates for FT based on both initial and confirmatory biopsies, 70% remained favorable for hemigland ablation at subsequent biopsies. Limitations include retrospective design and mpMRI information only at surveillance biopsy.

Effect of Focal vs Extended Irreversible Electroporation for the Ablation of Localized Low- or Intermediate-Risk Prostate Cancer on Early Oncological Control

“…In fact, for the past 5 years, 51% of patients who underwent focal therapy had Gleason 7 disease, with a stable small proportion of men with Gleason 8 tumor . Because some men with intermediate-risk prostate cancer could still be candidates for active surveillance, focal therapy may be a promising option for those patients with a high risk of cancer progression . In our study, treatment success was not related to the patient volume of the center, indicating that the learning curve for the IRE technique may be short.…”

“…However, each biopsy technique may miss tumors inevitably. One study evaluated the dominant tumor progression across serial biopsies for patients receiving active surveillance, showing that even with MRI-targeted biopsy and additional systematic biopsy, up to 21% unfavorable cancers were detected in the contralateral lobe during follow-up biopsies, which may reflect the limitation of biopsy and also reflects that prostate cancer often presents as a multifocal tumor …”

Racial differences in circulating mitochondria‐derived peptides may contribute to prostate cancer health disparities

“…For example, a recent study of 457 prostate biopsies showed similar AUC when using ExoDx, 4K score and Select MDx (0.849, 0.835, and 0.699, respectively) 32 . Furthermore, in another study, a combined model (MRI and biomarkers) had better predictive ability for detecting high‐grade PC than MRI alone 33 . Thus, tis prior study suggested that MRI alone was not sensitive enough to detect all high‐grade PC and that 4K or ExoDx testing alone could be sufficient when deciding to proceed with biopsy 33 .…”

“…8 32 Furthermore, in another study, a combined model (MRI and biomarkers) had better predictive ability for detecting high-grade PC than MRI alone. 33 Thus, tis prior study suggested that MRI alone was not sensitive enough to detect all highgrade PC and that 4K or ExoDx testing alone could be sufficient when deciding to proceed with biopsy. 33 As such, if our results are validated in future larger studies, the MDPs studied herein may be clinically useful biomarkers to identify which patients with an elevated PSA require a biopsy and which can be safely followed given a very low risk of high-grade PC.…”

Radiomics in prostate cancer: an up-to-date review

“…16 By combining the recent advances in imaging techniques, such as mpMRI prior to the biopsy, 12 performing targeted biopsy (TBx) plus the systematic biopsy of the contralateral lobe can detect approximately 96% of csPCa. [17][18][19][20] Still, there are undiagnosed csPCa that will threaten the life of patients, in part due to heterogeneity of PCa tumors, 20 in part due to spatial 21 alignment of heterogeneous tumor growth and, finally, due to clonal genomic diversity. 4,22,23 To limit the interobserver variability and reader's experience, the Prostate Imaging-Reporting and Data System version 2.1 (PIRADS v2.1) was proposed.…”