Medium-term outcomes of active surveillance for localised prostate cancer.

BACKGROUND: Active surveillance (AS) aims to allow men with favourable-risk, localised prostate cancer to avoid unnecessary treatment. OBJECTIVE: To describe the clinical outcomes of a prospective study of AS. DESIGN, SETTING, AND PARTICIPANTS: A single-centre, prospective cohort study. Eligibility criteria included histologically proven prostate adenocarcinoma, age 50-80 yr, stage T1/T2, prostate-specific antigen level (PSA) <15 ng/ml, Gleason score (GS) ≤ 3+3 (GS ≤ 3+4 if aged >65 yr), and percent positive biopsy cores (PPC) ≤ 50%. INTERVENTION: Patients were assessed by serum PSA level, and digital rectal examination at 3-mo intervals in year 1, 4-mo intervals in year 2, and at 6-mo intervals thereafter. Transrectal ultrasound-guided prostate biopsy was performed after 18-24 mo and every 2 yr thereafter. Treatment was recommended for PSA velocity (PSAV) >1 ng/ml per year or adverse histology, defined as GS ≥ 4+3 or PPC >50%. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcomes described, using Kaplan-Meier methods, were rate of adverse histology on repeat biopsy, freedom from treatment, biochemical control after deferred treatment, and overall survival. Analyses using Cox regression were performed to determine predictors of deferred treatment and adverse histology. RESULTS AND LIMITATIONS: The study enrolled 471 eligible patients from 2002 to 2011. Median age was 66 yr and median initial PSA value was 6.4 ng/ml. Eighty-eight percent of patients had T1 disease and 93% had GS ≤ 3+3. At median follow-up of 5.7 yr, the 5-yr rate of adverse histology and treatment-free probability was 22% (95% confidence interval [CI], 16-29%) and 70% (95% CI, 65-75%), respectively. There were two deaths from prostate cancer. Predictors of time to adverse histology were GS 7, PSAV >1 ng/ml per year, low ratio of free PSA to total PSA, and PPC >25%. Longer follow-up is needed to confirm the safety of this strategy. CONCLUSIONS: This study demonstrates satisfactory medium-term outcomes for AS in selected men with localised prostate cancer.

Clinical implications of family history of prostate cancer and genetic risk single nucleotide polymorphism (SNP) profiles in an active surveillance cohort.

OBJECTIVES: To explore the potential prognostic role of family history (FH) of prostate cancer and prostate cancer risk single nucleotide polymorphisms (SNPs) in patients undergoing active surveillance (AS) for prostate cancer. This is the first study to date, which has investigated the potential prognostic role of SNP profiles in an AS cohort PATIENTS AND METHODS: FH data were collected from patients in the Royal Marsden Hospital AS study. In all, 39 prostate cancer-risk SNPs identified from published genome wide association studies (GWAS) were genotyped using the Sequenom Platform and TaqMan™ assays from available DNA. The cumulative genetic-risk scores for each patient were then calculated using the weighted effect estimated from previous GWAS (log-additive model). FH status and the genetic-risk scores were assessed against adverse outcomes in AS, time to treatment and adverse histology on repeat biopsy, using univariable and multivariable Cox regression models to address time to treatment; and binary logistic regression to address biopsy upgrade. RESULTS: Of 471 patients, 55 (13.6%) had adverse histology on repeat biopsies and 145 (30.8%) had deferred treatment. On univariate analysis, there was no significant relationship between FH of prostate cancer in any degree of relation, and adverse histology or time to treatment. For risk score analyses, 386 patients' DNA was studied; and there was also no relationship found between the calculated genetic risk scores and adverse histology or time to treatment (P = 0.573 and P = 0.965, respectively). The retrospective study design and the few events were the main limitation of the study. CONCLUSIONS: There is currently insufficient data to support the use of FH status or prostate cancer SNP profile risk scores as prognostic factors in AS and these should not be used to influence management decisions. As more genetic variants are discovered this may change and should be reassessed in multicentre AS cohorts.

Prostate-specific antigen (PSA) kinetics in untreated, localized prostate cancer: PSA velocity vs PSA doubling time.

OBJECTIVES: To compare the accuracy of prostate-specific antigen (PSA) velocity (PSAV) vs PSA doubling time (DT) for predicting the repeat biopsy results in men with localized prostate cancer on active surveillance (AS), as the utility of PSAV vs PSADT in untreated prostate cancer has not been well studied. PATIENTS AND METHODS: Eligible patients had favourable-risk localized prostate cancer (T1/2a, PSA level or=4, >50% cores positive, or initial Gleason score 3 + 3 upgraded to >or=3 + 4. Using all PSA values for the 2 years preceding repeat biopsy, the PSAV and PSADT were calculated using linear regression and the log-slope method (DT = ln2/slope), respectively. RESULTS: In all, 199 patients were assessable; the median PSAV and PSADT were 0.71 ng/mL/year and 5.29 years, respectively. Fifty-three patients (27%) had adverse histology on repeat biopsy. On univariate analyses, PSAV (P < 0.001) and PSADT (P = 0.019) were associated with adverse histology. The area under the receiver operating characteristic curve for predicting adverse histology was 0.70 and 0.63 for PSAV and PSADT, respectively. The mean difference was 0.07 (95% confidence interval 0.03-0.12; P < 0.001). CONCLUSIONS: PSAV is more accurate than PSADT for predicting adverse histology on repeat biopsies. These data suggest that PSAV should be used in preference to PSADT to describe PSA kinetics in untreated, localized prostate cancer.

Prostate-specific antigen velocity in untreated, localized prostate cancer.

OBJECTIVE: To report the results of a prospective study of active surveillance of untreated prostate cancer, with a focus on baseline predictors of prostate-specific antigen (PSA) velocity, as PSA velocity before treatment is an important predictor of prostate cancer mortality, and patients on active surveillance are monitored for several years to estimate the PSA velocity and thus select patients for radical treatment. PATIENTS AND METHODS: A prospective study of active surveillance for localized prostate cancer opened at the Royal Marsden Hospital in 2002. Eligible patients had clinical stage T1/T2a, N0/Nx, M0/Mx adenocarcinoma of the prostate with a serum PSA level of < 15 ng/mL, a Gleason score of < or = 7 with primary grade < or = 3, and less than half the biopsy cores positive. The PSA velocity before treatment was analysed in relation to baseline clinical characteristics. RESULTS: In all, 237 patients on surveillance were followed for a median of 24 months (median age 67 years; median initial PSA level 6.5 ng/mL; median pretreatment PSA velocity 0.44 ng/mL per year). On multivariate analysis, PSA density (i.e. serum PSA level/prostate volume) was the only significant determinant of PSA velocity (P < 0.001). Patients with a PSA density above or below the median (0.185 ng/mL/mL) had a median (interquartile range) PSA velocity of 0.92 (0.34-1.77) ng/mL per year and 0.35 (-0.06, 0.80) ng/mL per year, respectively. CONCLUSIONS: PSA density, which is readily available at the time of diagnosis, is an independent determinant of PSA velocity in untreated, localized prostate cancer. If this is confirmed, PSA density could be used to inform the often difficult choice between active surveillance and immediate radical treatment.

Predictors of histological disease progression in untreated, localized prostate cancer.

PURPOSE: Active surveillance for early prostate cancer is a policy of close monitoring with radical treatment targeted at cases with evidence of disease progression. There is no consensus on the need for or optimum timing of repeat biopsies as part of active surveillance. MATERIALS AND METHODS: In a prospective cohort study of active surveillance 119 patients with untreated localized prostate cancer (T1/2a), prostate specific antigen less than 15 ng/ml, Gleason score 3 + 4 or less and 50% or less positive cores underwent repeat biopsy after 18 to 24 months. Histological disease progression was defined as primary Gleason grade 4 or greater, greater than 50% positive cores or a Gleason score increase from 6 or less to 7 or greater. The risk of histological disease progression was analyzed with respect to baseline clinical factors. RESULTS: Median patient age was 66 years and median initial prostate specific antigen was 6.6 ng/ml. Histological disease progression was seen in 33 of 119 cases (28%). On multivariate analysis prostate specific antigen density (p = 0.002) and maximum percent involvement of any core (p = 0.04) were significant independent determinants of histological disease progression. Progression was seen in 22 of 40 cases (55%) with prostate specific antigen density 0.2 ng/ml/ml or greater and greater than 15% maximum involvement of any core. Progression was seen in 2 of 33 cases (6%) with prostate specific antigen density less than 0.2 ng/ml/ml and 15% or less maximum involvement of any core. CONCLUSIONS: Repeat biopsy should be an integral part of active surveillance for untreated localized prostate cancer. Immediate repeat biopsy should be considered in patients who elect active surveillance but who have prostate specific antigen density greater than 0.2 ng/ml/ml. These findings must be validated in a cohort of patients with extended biopsies at diagnosis and followup.