Risk stratification of men choosing surveillance for low risk prostate cancer

Active surveillance in prostate cancer: patient selection and triggers for intervention

PURPOSE OF REVIEW

The long-term safety and effectiveness of active surveillance depends on our ability to select appropriate patients and trigger delayed treatment in those who need it, whereas avoiding intervention in those who do not. In this review, we will consider how recent advances have influenced patient selection for active surveillance and review the range of different intervention triggers that have been proposed.

RECENT FINDINGS

Several large surveillance cohort studies have been reported recently showing excellent medium-term outcomes in well selected patients, with approximately a third of patients going on to have deferred treatment. Debate continues on the most appropriate eligibility criteria for active surveillance and what triggers for intervention should be used. There is growing interest in the role of transperineal template biopsies and multiparametric MRI, both for patient selection and in identifying triggers for intervention.

SUMMARY

Active surveillance is a well tolerated treatment option in well selected groups of patients. There is no 'one size fits all' set of criteria for patient selection or triggers for intervention but decisions can be guided by information from histology, prostate-specific antigen kinetics and imaging.

Identifying candidates for active surveillance: an evaluation of the repeat biopsy strategy for men with favorable risk prostate cancer

PURPOSE

Active surveillance is increasingly recommended to reduce overtreatment in men with favorable risk prostate cancer. A repeat confirmatory biopsy has become the standard recommendation for these men to increase the precision of this risk attribution. We investigate the usefulness of this approach by comparing the current practice standard, repeat transrectal ultrasound biopsy, with template prostate mapping.

MATERIALS AND METHODS

A total of 124 men who were attributed a favorable risk prostate cancer status based on transrectal ultrasound guided biopsy and who were considering a policy of active surveillance underwent combined transrectal ultrasound biopsy and template prostate mapping as a confirmatory strategy. Maximum Gleason grade and disease burden were compared between the 2 confirmatory tests.

RESULTS

Depending on the definition used between 8% and 22% of men had prostate cancer reclassified as clinically important by repeat transrectal ultrasound biopsy whereas template guided prostate mapping reclassified the disease in 41% to 85% of the men. Repeat transrectal ultrasound biopsy failed to detect up to 80% of clinically important cancers detected by the reference standard. The sensitivity of repeat transrectal ultrasound biopsy to identify clinically important disease varied from 9% to 24% with the negative predictive value ranging from 23% to 60%.

CONCLUSIONS

When applied to a population of men initially deemed to have favorable risk prostate cancer, transrectal ultrasound biopsy will miss a large proportion of clinically important cancers compared to template guided prostate mapping. The usefulness of repeat transrectal ultrasound biopsy in ruling out clinically important prostate cancer needs to be reconsidered.

Biopsy features associated with prostate cancer progression in active surveillance patients: comparison of three statistical models

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Active surveillance is an established management option for patients with favourable-risk prostate cancer. However, about 25-30% of active surveillance patients demonstrate biopsy progression within the first 3-5 years of follow-up. Although several factors, such as the results of the diagnostic and surveillance biopsies, are known to be associated with the risk of progression, our ability to accurately predict this risk remains limited. Our analysis demonstrated that the overall number of positive cores in the diagnostic and first surveillance biopsies is strongly associated with the risk of progression in active surveillance patients. Furthermore, combined results of diagnostic and first surveillance biopsies provide more information about the probability of progression than they do separately. The most important variable affecting the progression-free survival was the overall number of cores positive for cancer. By 3 years of active surveillance, most of the patients who had four positive cores in the diagnostic and surveillance biopsies progressed, while those who had only one positive core had an excellent prognosis. These findings could be used to improve the accuracy of assessments of the prognosis of patients with low-risk prostate cancer and to help them make informed decisions about their treatment.

OBJECTIVE

To analyse the prognostic importance of information provided by the diagnostic biopsy, the first surveillance biopsy and a combination thereof to identify active surveillance patients with a particularly high risk of progression.

MATERIALS AND METHODS

The present study included 161 active surveillance patients who had at least two surveillance biopsies. The first surveillance biopsy was performed within 1 year of the diagnosis. Further surveillance biopsies usually took place every 1-2 years. Progression on the surveillance biopsy was defined as the presence of Gleason 4/5 cancer, > two positive cores or >20% involvement of any core. Cox proportional hazards regression analysis was used to examine the relationship between biopsy characteristics and progression. Three distinct statistical models were built using characteristics of diagnostic biopsies, surveillance biopsies, and a combination thereof. Harrell's c-index was used to quantify the predictive accuracy of each multivariate Cox model.

RESULTS

The median follow-up was 3.6 years; 46 (28.6%) patients progressed. In multivariate analysis the major factor associated with progression was the number of positive cores. The model based on the combined results of diagnostic and first surveillance biopsies was significantly more predictive than the models based on the individual results of each biopsy. Patients with four positive cores in the diagnostic and first surveillance biopsies had estimated 5-year progression rate of 100%.

CONCLUSION

The total number of positive cores in the diagnostic and first surveillance biopsies provides important information about the risk of prostate cancer progression in active surveillance patients.

Differentiation of lethal and non lethal prostate cancer: PSA and PSA isoforms and kinetics

Prostate-specific antigen (PSA) testing for the early diagnosis of prostate cancer has led to a decrease in cancer mortality. However, the high prevalence of low-grade prostate cancer and its long natural history, competing causes of death in older men and treatment patterns of prostate cancer, have led to dramatic overtreatment of the disease. Improved markers of prostate cancer lethality are needed to reduce the overtreatment of prostate cancer that leads to a reduced quality of life without extending life for a high proportion of men. The PSA level prior to treatment is routinely used in multivariable models to predict prostate cancer aggressiveness. PSA isoforms and PSA kinetics have been associated with more aggressive phenotypes, but are not routinely employed as part of prediction tools prior to treatment. PSA kinetics is a valuable marker of lethality post treatment and routinely used in determining the need for salvage therapy.

Effect of treatment with 5-α reductase inhibitors on progression in monitored men with favourable-risk prostate cancer

What's known on the subject? and What does the study add? Finasteride (Proscar) and dutasteride (Avodart) are 5-α reductase inhibitors (5-ARIs) used to treat LUTS in men with benign prostatic enlargement. Because these drugs suppress androgens, the theory has been put forward that 5-ARIs might prevent the development of prostate cancer. Careful analysis of two randomized controlled trials, however, showed that, in the clinical setting, this was not the case, and that these drugs can increase the occurrence of more aggressive high-grade disease. Because of this, the U.S. Food and Drug Administration did not approve 5-ARIs for the primary prevention of prostate cancer and notified healthcare professionals about a change in the 'Warnings and Precautions' for these drugs. Interest remains among some for using 5-ARIs in men diagnosed with very low-risk prostate cancer to delay the progression from clinically indolent disease to clinically significant disease requiring treatment. The present study investigated whether 5-ARI use among men with very low-risk prostate cancer in an active surveillance (AS) programme would reduce the number of cancers reclassified to clinically significant disease on surveillance biopsy. Our results do not support the use of 5-ARIs for slowing or preventing cancer progression in men with low-risk prostate cancer, but do suggest that men with very low-risk prostate cancer who take 5-ARIs for LUTS are unlikely to be at increased risk for the development of high grade disease during AS.

OBJECTIVE

To determine whether 5-α reductase inhibitor (5-ARI) use delays cancer reclassification in an active surveillance (AS) cohort.

PATIENTS AND METHODS

We performed a retrospective study of 587 men enrolled in an AS programme, who had no history of 5-ARI use. Chi-squared and t-tests were used to compare characteristics of 5-ARI users and non-users. Univariable and multivariable proportional hazards models, treating 5-ARI use as a time-dependent covariate, were used to evaluate the influence of 5-ARIs on the risk of a subsequent biopsy no longer meeting criteria for continued AS (i.e. reclassification).

RESULTS

5-ARI use was initiated in 47 men while on AS. Men using 5-ARIs had larger prostates and higher PSA levels at diagnosis. During 5-ARI use, PSA levels and prostate volume deceased by mean values of 47% and 11%, respectively. Men using 5-ARIs had a mean of 2.5 surveillance biopsies while on the drug. Reclassification occurred in 17% of 5-ARI users compared with 31% of non-users (P = 0.04). Multivariable models (adjusting for age, α-blocker use, PSA level, %free PSA, PSA density, prostate volume and number/percent biopsy core involvement at diagnosis) showed nonsignificant risk reductions for reclassification in 5-ARI users as determined by either tumour extent (hazard ratio [HR] = 0.37 (95% confidence interval [CI] 0.12 to 1.13), P = 0.08) or grade (HR = 0.8 (95% CI 0.25-2.59), P = 0.7).

CONCLUSION

Treatment with 5-ARIs did not significantly alter the outcome of biopsy reclassification by grade in men with very low-risk prostate cancer.

Management of low (favourable)-risk prostate cancer

What's known on the subject? and What does the study add? Most men who are diagnosed with favourable-risk prostate cancer undergo some form of active intervention, despite evidence that treatment will not improve health outcomes for many. The decision to undergo treatment after diagnosis is, in part, related to the inability to precisely determine the long-term risk of harm without treatment. Nevertheless, physicians should consider patient age, overall health, and preferences for living with cancer and the potential side effects of curative treatments, before recommending a management option. This is especially important for older men, given the high level of evidence that those with low-risk disease are unlikely to accrue any benefit from curative intervention. What is known on the subject: Over treatment of favourable-risk prostate cancer is common, especially among older men. What does the study add: A review of the natural history of favourable-risk prostate cancer in the context of choices for management of the disease. • The management of favourable-risk prostate cancer is controversial, and in the absence of controlled trials to inform best practice, choices are driven by personal beliefs with resultant wide variation in practice patterns. • Men with favourable-risk prostate cancer diagnosed today often undergo treatments that will not improve overall health outcomes. • A shared-decision approach for selecting optimal management of favourable-risk disease should account for patient age, overall health, and preferences for living with cancer and the potential side effects of curative treatments.

Active Surveillance Program for Prostate Cancer: An Update of the Johns Hopkins Experience

Purpose

We assessed outcomes of men with prostate cancer enrolled in active surveillance.

Patients and Methods

Since 1995, a total of 769 men diagnosed with prostate cancer have been followed prospectively (median follow-up, 2.7 years; range, 0.01 to 15.0 years) on active surveillance. Enrollment criteria were for very-low-risk cancers, defined by clinical stage (T1c), prostate-specific antigen density < 0.15 ng/mL, and prostate biopsy findings (Gleason score ≤ 6, two or fewer cores with cancer, and ≤ 50% cancer involvement of any core). Curative intervention was recommended on disease reclassification on the basis of biopsy criteria. The primary outcome was survival free of intervention, and secondary outcomes were rates of disease reclassification and exit from the program. Outcomes were compared between men who did and did not meet very-low-risk criteria.

Results

The median survival free of intervention was 6.5 years (range, 0.0 to 15.0 years) after diagnosis, and the proportions of men remaining free of intervention after 2, 5, and 10 years of follow-up were 81%, 59%, and 41%, respectively. Overall, 255 men (33.2%) underwent intervention at a median of 2.2 years (range, 0.6 to 10.2 years) after diagnosis; 188 men (73.7%) underwent intervention on the basis of disease reclassification on biopsy. The proportions of men who underwent curative intervention (P = .026) or had biopsy reclassification (P < .001) were significantly lower in men who met enrollment criteria than in those who did not. There were no prostate cancer deaths.

Conclusion

For carefully selected men, active surveillance with curative intent appears to be a safe alternative to immediate intervention. Limiting surveillance to very-low-risk patients may reduce the frequency of adverse outcomes.

Changes in prostate cancer grade on serial biopsy in men undergoing active surveillance

PURPOSE

Active surveillance is now considered a viable treatment option for men with low-risk prostate cancer. However, little is known regarding changes in Gleason grade on serial biopsies over an extended period of time.

PATIENTS AND METHODS

Men diagnosed with prostate cancer between 1998 and 2009 who elected active surveillance as initial treatment, with 6 or more months of follow-up and a minimum of six cores at biopsy, were included in analysis. Upgrading and downgrading were defined as an increase or decrease in primary or secondary Gleason score. Means and frequency tables were used to describe patient characteristics, and treatment-free survival rates were determined by life-table product limit estimates.

RESULTS

Three hundred seventy-seven men met inclusion criteria. Mean age at diagnosis was 61.9 years. Fifty-three percent of men had prostate-specific antigen of 6 ng/mL or less, and 94% had Gleason score of 6 or less. A majority of men were cT1 (62%), had less than 33% of biopsy cores involved (80%), and were low risk (77%) at diagnosis. Median number of cores taken at diagnostic biopsy was 13, mean time to follow-up was 18.5 months, and 29% of men had three or more repeat biopsies. Overall, 34% (129 men) were found to have an increase in Gleason grade. The majority of men who experienced an upgrade (81%) did so by their second repeat biopsy.

CONCLUSION

A proportion of men experience an upgrade in Gleason score while undergoing active surveillance. Men who experience early upgrading likely represent initial sampling error, whereas later upgrading may reflect tumor dedifferentiation.

The relationship between prostate specific antigen change and biopsy progression in patients on active surveillance for prostate cancer

PURPOSE

We assessed whether an association exists between a change in prostate specific antigen and biopsy progression in men on active surveillance.

MATERIALS AND METHODS

A cohort of patients undergoing active surveillance for prostate cancer was identified from the urological oncology database at our institution. Multivariate logistic regression was performed to determine whether prostate specific antigen velocity, defined as the change in ln(prostate specific antigen) per year, is associated with biopsy progression, defined as a Gleason upgrade or volume progression on repeat biopsy within 24 months of diagnosis.

RESULTS

A total of 241 men with a mean ± SD age of 61 ± 7 years and mean prostate specific antigen 4.9 ± 2.2 ng/ml met study inclusion criteria. Median time to repeat biopsy was 10 months (IQR 6-13). Biopsy progression developed in 55 men (23%), including a Gleason score upgrade in 46 (19%), greater than 33% positive cores in 11 (5%) and greater than 50% maximum single core positive in 12 (5%). The median prostate specific antigen ratio per year was 1.0 (IQR 0.95-1.03), although 1 man had a ratio of greater than 1.26 (doubled over 3 years) and 7 had a ratio of less than 1/1.26 (halved over 3 years). On multivariate analysis prostate specific antigen doubling within 3 years was associated with a 1.4-fold increase in the odds of biopsy progression (OR 1.4, 95% CI 0.6-3.4, p = 0.46).

CONCLUSIONS

There is little change in prostate specific antigen during the first 24 months of surveillance in men with well staged, low risk prostate cancer. We believe that these findings highlight the importance of repeat biopsy during surveillance.

Risk stratification and validation of prostate specific antigen density as independent predictor of progression in men with low risk prostate cancer during active surveillance

PURPOSE

We assessed risk stratification in patients with low grade prostate cancer managed by active surveillance using a 20-core saturation biopsy technique.

MATERIALS AND METHODS

A total of 135 consecutive patients with low risk prostate cancer were prospectively entered in an active surveillance program in a 10-year period. The study entrance requirement and progression definition followed Epstein criteria using only pathological parameters, ie fewer than 3 positive cores, Gleason score 6 or less and 50% or less of any single core involved. All patients were monitored by restaging 20-core saturation biopsy every 12 to 18 months. A total of 120 patients with at least 1 rebiopsy form the basis of this report.

RESULTS

Of the cohort 30% progressed during a median of 2.4 years. Three multivariate analyses were performed. The first analysis used variables only at diagnosis biopsy and revealed that prostate specific antigen density greater than 0.08 ng/ml/cc and prostate cancer family history were significant predictors of progression. When combined in a 3-level risk factor score, they were significant (p = 0.003). The second multivariate analysis considered changes in characteristics between diagnosis biopsy and first rebiopsy. Prostate specific antigen velocity along with prostate specific antigen density and family history highly predicted progression according to a 4-level risk factor score (p <0.0001). The third multivariate analysis validated the previously reported prostate specific antigen density cutoff of 0.08 ng/ml/cc at first rebiopsy as a significant predictor of subsequent progression (HR 3.16, 95% CI 1.12, 8.93; p = 0.03).

CONCLUSIONS

Risk factor stratification can be used to significantly predict the outcome in patients on active surveillance. Prostate specific antigen density 0.08 ng/ml/cc at first rebiopsy was validated as a significant predictor of subsequent progression.

Benign prostatic hyperplasia and prostate cancer: an overview for primary care physicians

Benign prostatic hyperplasia (BPH) and prostate cancer (CaP) are major sources of morbidity in older men. Management of these disorders has evolved considerably in recent years. This article provides a focused overview of BPH and CaP management aimed at primary care physicians. Current literature pertaining to BPH and CaP is reviewed and discussed. The management of BPH has been influenced by the adoption of effective medical therapies; nonetheless, surgical intervention remains a valid option for many men. This can be accomplished with well-established standards such as transurethral resection of the prostate or with minimally invasive techniques. Prostate cancer screening remains controversial despite the recent publication of two large clinical trials. Not all prostate cancers necessarily need to be treated. Robot-assisted prostatectomy is a new and increasingly utilised technique for CaP management, although open radical retropubic prostatectomy is the oncological reference standard. The ageing of the population of the developed world means that primary care physicians will see an increasing number of men with BPH and CaP. Close collaboration between primary care physicians and urologists offers the key to successful management of these disorders.

Careful selection and close monitoring of low-risk prostate cancer patients on active surveillance minimizes the need for treatment

BACKGROUND

With the advent of prostate-specific antigen (PSA) screening and the increase in the number of transrectal ultrasound-guided biopsy cores, there has been a dramatic rise in the incidence of low-risk prostate cancer (LRPC). Because > 97% of men with LRPC are likely to die of something other than prostate cancer, it is critical that patients give thought to whether early curative treatment is the only option at diagnosis.

OBJECTIVE

To identify a group of men with LRPC who may not require initial treatment and monitor them on our active surveillance (AS) protocol, to determine the percentage treated and the outcome and to analyze the quality-of-life data.

DESIGN, SETTING, AND PARTICIPANTS

We defined patients eligible for AS as Gleason ≤ 6, PSA ≤ 10, and two or fewer biopsy cores with ≤ 20% tumor in each core.

MEASUREMENTS

Kaplan Meier analysis was used to predict the 5-year treatment free survival. Logistic regression determined the predictors of treatment. Data on sexual function, continence, and outcome were obtained and analyzed.

RESULTS AND LIMITATIONS

The AS cohort consisted of 230 patients with a mean age of 63.4 yr; 86% remained on AS for a mean follow-up of 44 mo. Thirty-two of the 230 patients (14%) were treated for a mean follow-up of 33 mo. Twelve had a total prostatectomy (TP). The pathologic stage of these patients was similar to initially treated TP patients with LRPC. Fourteen underwent radiation therapy, and six underwent androgen-deprivation therapy. Fifty percent of patients had no tumor on the first rebiopsy, and only 5% of these patients were subsequently treated. PSA doubling time and clinical stage were not predictors of treatment. No patient progressed after treatment. Among the AS patients, 30% had incontinence, yet < 15% were bothered by it. As measured by the Sexual Health Inventory for Men, 49% of patients had, at a minimum, moderate (≤ 16) erectile dysfunction.

CONCLUSIONS

If guidelines for AS are narrowly defined to include only patients with Gleason 6, tumor volume ≤ 20% in one or two biopsy cores, and PSA levels ≤ 10, few patients are likely to require treatment. Progression-free survival of those treated is likely to be equivalent to patients with similar clinical findings treated at diagnosis.