Negative first follow-up prostate biopsy on active surveillance is associated with decreased risk of upgrading, suspicion of progression and converting to active treatment

Is Active Surveillance Too Active?

PURPOSE OF REVIEW

Many prostate cancer active surveillance protocols mandate serial monitoring at defined intervals, including but certainly not limited to serum PSA (often every 6 months), clinic visits, prostate multiparametric MRI, and repeat prostate biopsies. The purpose of this article is to evaluate whether current protocols result in excessive testing of patients on active surveillance.

RECENT FINDINGS

Multiple studies have been published in the past several years evaluating the utility of multiparametric MRI, serum biomarkers, and serial prostate biopsy for men on active surveillance. While MRI and serum biomarkers have promise with risk stratification, no studies have demonstrated that periodic prostate biopsy can be safely omitted in active surveillance. Active surveillance for prostate cancer is too active for some men with seemingly low-risk cancer. The use of multiple prostate MRIs or additional biomarkers do not always add to the prediction of higher-grade disease on surveillance biopsy.

Impact of a negative confirmatory biopsy on risk of disease progression among men on active surveillance for prostate cancer

OBJECTIVE

Most prostate cancer active surveillance (AS) protocols suggest a confirmatory biopsy within 12 to 18 months of diagnosis to mitigate the risk of unsampled high-grade disease. We investigate whether the results of confirmatory biopsy impact AS outcomes and could be used to tailor surveillance intensity.

METHODS

We retrospectively reviewed our institutional database of prostate cancer patients managed by AS from 1997 to 2019 who underwent confirmatory biopsy and ≥3 biopsies overall. Biopsy progression was defined as either an increase in grade group or an increase in the proportion of positive biopsy cores to >34% and was compared between patients with a negative vs positive confirmatory biopsy using the Kaplan-Meier method and Cox proportional hazards regression.

RESULTS

We identified 452 patients meeting inclusion criteria for this analysis, of whom 169 (37%) had a negative confirmatory biopsy. With a median follow-up of 6.8 years, 37% of patients progressed to treatment, most commonly due to biopsy progression. A negative confirmatory biopsy was significantly associated with biopsy progression-free survival in multivariable analysis (HR 0.54, 95% CI 0.34-0.88, P = 0.013), adjusting for known clinical and pathologic factors, including use of mpMRI prior to confirmatory biopsy. Negative confirmatory biopsy was also associated with an increased risk of adverse pathologic features at prostatectomy but not with biochemical recurrence among men who ultimately underwent definitive treatment.

CONCLUSIONS

A negative confirmatory biopsy is associated with a lower risk of biopsy progression. While the increased risk of adverse pathology at time of definitive treatment sounds a small cautionary note regarding decreasing surveillance intensity, the majority of such patients have a favorable outcome on AS.

Risk of progression following a negative biopsy in prostate cancer active surveillance

BACKGROUND

Currently, follow-up protocols are applied equally to men on active surveillance (AS) for prostate cancer (PCa) regardless of findings at their initial follow-up biopsy. To determine whether less intensive follow-up is suitable following negative biopsy findings, we assessed the risk of converting to active treatment, any subsequent upgrading, volume progression (>33% positive cores), and serious upgrading (grade group >2) for negative compared with positive findings on initial follow-up biopsy.

METHODS

13,161 men from 24 centres participating in the Global Action Plan Active Surveillance Prostate Cancer [GAP3] consortium database, with baseline grade group ≤2, PSA ≤ 20 ng/mL, cT-stage 1-2, diagnosed after 1995, and ≥1 follow-up biopsy, were included in this study. Risk of converting to treatment was assessed using multivariable mixed-effects survival regression. Odds of volume progression, any upgrading and serious upgrading were assessed using mix-effects binary logistic regression for men with ≥2 surveillance biopsies.

RESULTS

27% of the cohort (n = 3590) had no evidence of PCa at their initial biopsy. Over 50% of subsequent biopsies in this group were also negative. A negative initial biopsy was associated with lower risk of conversion (adjusted hazard ratio: 0.45; 95% confidence interval [CI]: 0.42-0.49), subsequent upgrading (adjusted odds ratio [OR]: 0.52; 95%CI: 0.45-0.62) and serious upgrading (OR: 0.74; 95%CI: 0.59-92). Radiological progression was not assessed due to limited imaging data.

CONCLUSION

Despite heterogeneity in follow-up schedules, findings from this global study indicated reduced risk of converting to treatment, volume progression, any upgrading and serious upgrading among men whose initial biopsy findings were negative compared with positive. Given the low risk of progression and high likelihood of further negative biopsy findings, consideration should be given to decreasing follow-up intensity for this group to reduce unnecessary invasive biopsies.