Untreated Gleason Grade Progression on Serial Biopsies during Prostate Cancer Active Surveillance: Clinical Course and Pathological Outcomes

PURPOSE

We describe the outcomes of patients with low risk localized prostate cancer who were upgraded on a surveillance biopsy while on active surveillance and evaluated whether delayed treatment was associated with adverse outcome.

MATERIALS AND METHODS

We included men in the study with lower risk disease managed initially with active surveillance and upgraded to Gleason score 3+4 or greater. Patient demographics and disease characteristics were compared. Kaplan-Meier curve was used to estimate the treatment-free probability stratified by initial upgrade (3+4 vs 4+3 or greater), Cox regression analysis was used to examine factors associated with treatment and multivariate logistic regression analysis was used to evaluate the factors associated with adverse outcome at surgery.

RESULTS

The final cohort comprised 219 men, with 150 (68%) upgraded to 3+4 and 69 (32%) to 4+3 or greater. Median time to upgrade was 23 months (IQR 11-49). A total of 163 men (74%) sought treatment, the majority (69%) with radical prostatectomy. The treatment-free survival rate at 5 years was 22% for 3+4 and 10% for 4+3 or greater upgrade. Upgrade to 4+3 or greater, higher prostate specific antigen density at diagnosis and shorter time to initial upgrade were associated with treatment. At surgical pathology 34% of cancers were downgraded while 6% were upgraded. Cancer volume at initial upgrade was associated with adverse pathological outcome at surgery (OR 3.33, 95% CI 1.19-9.29, p=0.02).

CONCLUSIONS

After Gleason score upgrade most patients elected treatment with radical prostatectomy. Among men who deferred definitive intervention, few experienced additional upgrading. At radical prostatectomy only 6% of cases were upgraded further and only tumor volume at initial upgrade was significantly associated with adverse pathological outcome.

Updated trends in imaging use in men diagnosed with prostate cancer

BACKGROUND

Previous studies have found persistent overuse of imaging for clinical staging of men with low-risk prostate cancer. We aimed to determine imaging trends in three cohorts of men.

METHODS

We analyzed imaging trends of men with prostate cancer who were a part of Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) (1998-2006), were insured by Medicare (1998-2006), or privately insured (Ingenix database, 2002-2006). The rates of computed tomography (CT), magnetic resonance imaging (MRI) and bone scan (BS) were determined and time trends were analyzed by linear regression. For men in CaPSURE, demographic and clinical predictors of test use were explored using a multivariable regression model.

RESULTS

Since 1998, there was a significant downward trend in BS (16%) use in the CaPSURE cohort (N=5156). There were slight downward trends (2.4 and 1.7%, respectively) in the use of CT and MRI. Among 54 322 Medicare patients, BS, CT and MRI use increased by 2.1, 10.8 and 2.2% and among 16 161 privately insured patients, use increased by 7.9, 8.9 and 3.7%, respectively. In CaPSURE, the use of any imaging test was greater in men with higher-risk disease. In addition, type of insurance and treatment affected the use of imaging tests in this population.

CONCLUSIONS

There is widespread misuse of imaging tests in men with low-risk prostate cancer, particularly for CT. These findings highlight the need for examination of factors that drive decision making with respect to imaging in this setting.

Active surveillance: does serial prostate biopsy increase histological inflammation?

BACKGROUND

Active surveillance (AS) is an appropriate management strategy for men with low-risk prostate cancer. Most protocols recommend repeated prostate biopsy every 12-24 months. The purpose of this paper is to describe histological inflammation patterns in men on AS who underwent serial prostate biopsy for disease monitoring.

METHODS

We reviewed records of men on AS from January 1999 through February 2011 who had a diagnostic plus ≥1 repeat transrectal ultrasound-guided biopsies performed at our institution. The type and degree of inflammatory infiltrate were grossly reviewed and scored for each patient's biopsy by a single pathologist. Relationship of inflammation severity and number of serial biopsies was assessed using a repeated measures mixed model. Unpaired t-test and χ(2)-square analysis assessed variance in degree of inflammation and location of inflammation relative to cancer grade progression defined as Gleason sum increase.

RESULTS

Fifty-six men met study inclusion criteria. Mean age was 62.1 (6.5) years, 71% were stage cT1c, 79% had a PSA level <10 ng ml(-1), and 98% had diagnostic Gleason sum ≤6. A small, statistically significant increase in maximum chronic inflammation (CI) scores with greater number of repeat biopsies was observed. CI scores were not associated with number of biopsies based on upgrade status. The main limitation to our study is our small sample size. Potential unmeasured confounders, such as unreported antibiotic use or symptomatic prostatitis, may have also affected our findings.

CONCLUSIONS

In this pilot study of 56 men on AS for localized prostate cancer, degree of chronic histological inflammation increased with greater number of prostate biopsies, but was not associated with subsequent risk of grade progression.