Active Surveillance for Favorable Risk Prostate Cancer in African Caribbean Men: Results of a Prospective Study

Low-risk prostate lesions: An evidence review to inform discussion on losing the "cancer" label

BACKGROUND

Active surveillance (AS) mitigates harms from overtreatment of low-risk prostate lesions. Recalibration of diagnostic thresholds to redefine which prostate lesions are considered "cancer" and/or adopting alternative diagnostic labels could increase AS uptake and continuation.

METHODS

We searched PubMed and EMBASE to October 2021 for evidence on: (1) clinical outcomes of AS, (2) subclinical prostate cancer at autopsy, (3) reproducibility of histopathological diagnosis, and (4) diagnostic drift. Evidence is presented via narrative synthesis.

RESULTS

AS: one systematic review (13 studies) of men undergoing AS found that prostate cancer-specific mortality was 0%-6% at 15 years. There was eventual termination of AS and conversion to treatment in 45%-66% of men. Four additional cohort studies reported very low rates of metastasis (0%-2.1%) and prostate cancer-specific mortality (0%-0.1%) over follow-up to 15 years. Overall, AS was terminated without medical indication in 1%-9% of men. Subclinical reservoir: 1 systematic review (29 studies) estimated that the subclinical cancer prevalence was 5% at <30 years, and increased nonlinearly to 59% by >79 years. Four additional autopsy studies (mean age: 54-72 years) reported prevalences of 12%-43%. Reproducibility: 1 recent well-conducted study found high reproducibility for low-risk prostate cancer diagnosis, but this was more variable in 7 other studies. Diagnostic drift: 4 studies provided consistent evidence of diagnostic drift, with the most recent (published 2020) reporting that 66% of cases were upgraded and 3% were downgraded when using contemporary diagnostic criteria compared to original diagnoses (1985-1995).

CONCLUSIONS

Evidence collated may inform discussion of diagnostic changes for low-risk prostate lesions.

Active Surveillance for Intermediate-risk Prostate Cancer: A Systematic Review, Meta-analysis, and Metaregression

CONTEXT

Active surveillance (AS) is increasingly selected among patients with localized, intermediate-risk (IR) prostate cancer (PCa). However, the safety and optimal candidate selection for those with IR PCa remain uncertain.

OBJECTIVE

To evaluate treatment-free survival and oncologic outcomes in patients with IR PCa managed with AS and to compare with AS outcomes in low-risk (LR) PCa patients.

EVIDENCE ACQUISITION

A literature search was conducted through February 2022 using PubMed/Medline, Embase, and Web of Science databases. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed to identify eligible studies. The coprimary outcomes were treatment-free, metastasis-free, cancer-specific, and overall survival. A subgroup analysis was planned a priori to explore AS outcomes when limiting inclusion to IR patients with a Gleason grade (GG) of ≤2.

EVIDENCE SYNTHESIS

A total of 25 studies including 29 673 unselected IR patients met our inclusion criteria. The 10-yr treatment-free, metastasis-free, cancer-specific, and overall survival ranged from 19.4% to 69%, 80.8% to 99%, 88.2% to 99%, and 59.4% to 83.9%, respectively. IR patients had similar treatment-free survival to LR patients (risk ratio [RR] 1.16, 95% confidence interval (CI), 0.99-1.36, p = 0.07), but significantly higher risks of metastasis (RR 5.79, 95% CI, 4.61-7.29, p < 0.001), death from PCa (RR 3.93, 95% CI, 2.93-5.27, p < 0.001), and all-cause death (RR 1.44, 95% CI, 1.11-1.86, p = 0.005). In a subgroup analysis of studies including patients with GG ≤2 only (n = 4), treatment-free survival (RR 1.03, 95% CI, 0.62-1.71, p = 0.91) and metastasis-free survival (RR 2.09, 95% CI, 0.75-5.82, p = 0.16) were similar between LR and IR patients. Treatment-free survival was significantly reduced in subgroups of patients with unfavorable IR disease and increased cancer length on biopsy.

CONCLUSIONS

The present systematic review and meta-analysis highlight the need to optimize patient selection for those with IR features. Our findings support limiting the inclusion of IR patients in AS to those with low-volume GG 2 tumor.

PATIENT SUMMARY

Active surveillance is increasingly used in patients with localized, intermediate-risk (IR) prostate cancer. In this population, we have reported higher risks of metastasis and cancer mortality in unselected patients than in patients with low-risk features, underscoring the need to optimize the selection of patients with IR features.

Active surveillance for intermediate-risk prostate cancer in African American and non-Hispanic White men

BACKGROUND

The safety of active surveillance (AS) for African American men compared with non-Hispanic White (White) men with intermediate-risk prostate cancer is unclear.

METHODS

The authors identified patients with modified National Comprehensive Cancer Network favorable ("low-intermediate") and unfavorable ("high-intermediate") intermediate-risk prostate cancer diagnosed between 2001 and 2015 and initially managed with AS in the Veterans Health Administration database. They analyzed definitive treatment, disease progression, metastases, prostate cancer-specific mortality (PCSM), and all-cause mortality by using cumulative incidences and multivariable competing-risks (disease progression, metastasis, and PCSM) or Cox (all-cause mortality) regression.

RESULTS

The cohort included 1007 men (African Americans, 330 [32.8%]; Whites, 677 [67.2%]) followed for a median of 7.7 years; 773 (76.8%) had low-intermediate-risk disease, and 234 (23.2%) had high-intermediate-risk disease. The 10-year cumulative incidences of definitive treatment were not significantly different (African Americans, 83.5%; 95% confidence interval [CI], 78.5%-88.7%; Whites, 80.6%; 95% CI, 76.6%-84.4%; P = .17). Among those with low-intermediate-risk disease, there were no significant differences in the 10-year cumulative incidences of disease progression (African Americans, 46.8%; 95% CI, 40.0%-53.3%; Whites, 46.9%; 95% CI, 42.1%-51.5%; P = .91), metastasis (African Americans, 7.1%; 95% CI, 3.7%-11.8%; Whites, 10.8%; 95% CI, 7.6%-14.6%; P = .17), or PCSM (African Americans, 3.8%; 95% CI, 1.6%-7.5%; Whites, 3.8%; 95% CI, 2.0%-6.3%; P = .69). In a multivariable regression including the entire cohort, African American race was not associated with increased risks of definitive treatment, disease progression, metastasis, PCSM, or all-cause mortality (all P > .30).

CONCLUSIONS

Outcomes in the Veterans Affairs Health System were similar for African American and White men treated for low-intermediate-risk prostate cancer with AS.

The impact of pretreatment PSA on risk stratification in men with Gleason 6 prostate cancer: Implications for active surveillance

BACKGROUND

There are limited data to support the safety of active surveillance in men with favorable-intermediate risk prostate cancer due only to a prostate specific antigen (PSA) above 10 ng/ml. We therefore evaluated the impact of pretreatment PSA on risk-stratification in men with Gleason 6 prostate cancer.

METHODS

We identified men aged 18 to 75 with cT1-2cN0cM0, pre-treatment PSA < 20 ng/ml, Gleason 6 prostate cancer diagnosed from 2010 to 2016 in the National Cancer Database who underwent radical prostatectomy. The associations of patient and disease features with Gleason score upgrading or adverse pathologic features at prostatectomy were evaluated using logistic regression. To evaluate for non linear relationships between PSA and each outcome, we examined predicted marginal event rates standardized for baseline characteristics with PSA modeled using restricted cubic splines RESULTS: A total of 75,566 patients were included in the cohort. In unadjusted analyses, patients with pretreatment PSA ≥ 10 ng/ml had higher rates of Gleason core upgrading (58.8% vs. 47.9%; P< 0.001) and adverse pathologic features (19.7% vs. 10.0%; P< 0.001) compared to patients with PSA < 10 ng/ml. In multivariable analyses, PSA ≥ 10 ng/ml was associated with statistically significantly increased risks of Gleason score upgrading (OR 1.47;95%CI 1.39 - 1.55) and adverse pathologic features (OR 2.15;95%CI 2.01 - 2.30). When modeled as a non linear continuous covariate, PSA was associated with increased adjusted rates of Gleason score upgrading and adverse pathologic features without a clear dichotomization at a threshold of 10 ng/ml.

CONCLUSION

Higher pretreatment PSA was independently associated with increased risks of Gleason score upgrading and adverse pathologic features at prostatectomy. Flexible modeling of the relationship between PSA and each outcome did not support dichotomization at a threshold of 10 ng/ml. These results can be used to improve patient risk-stratification for active surveillance.

Pathological upgrading and upstaging at radical prostatectomy in Jamaican men with low-risk prostate cancer

Several studies suggest race-based health disparities in men with low-risk prostate cancer (PCa), with African American males having poorer oncological outcomes. We sought to determine the prevalence and predictors of pathological upgrading and upstaging in Jamaican men with low-risk PCa treated with radical prostatectomy (RP). Data on 141 men who met the National Comprehensive Cancer Network criteria for low-risk PCa and underwent RP at a single institution were reviewed. All men had a transrectal ultrasound-guided biopsy. Pre-operative clinical and final pathological data were obtained. Data were summarised as means and standard deviations or percentages as appropriate. Bivariate analyses such as independent samples t-tests and chi-square tables were conducted and logistic regression models were estimated to predict upgrading (>Gleason 6) and upstaging (p ≥ T3). The mean age was 59.5 ± 7.8 years with mean prostate specific antigen (PSA) of 6.6 ± 2 ng/mL. A total of 48.3% of men were upgraded and 11.4% were upstaged. Bivariate analyses indicated that PSA (p = 0.008) and percentage positive cores (p = 0.002) were associated with upgrading. PSA (p = 0.042) and percentage positive cores (p = 0.003) were significantly associated with upstaging. The odds of upgrading increased with increased PSA levels (OR 1.40, 95% CI 1.05-1.87, p = 0.021) or increased percentage positive cores (OR 8.27, 95% CI 2.19-31.16, p = 0.002). The odds of upstaging increased with increased PSA levels (OR 1.4, 95% CI 1.01-1.96, p = 0.046) and with increased percentages positive cores (OR 11.4; 95% CI 2.06-63.09, p = 0.005). Jamaican men with low-risk PCa are at high risk of pathological upgrading and upstaging at RP. These findings should be taken into consideration when discussing treatment options with these patients.

Defining and Measuring Adherence in Observational Studies Assessing Outcomes of Real-world Active Surveillance for Prostate Cancer: A Systematic Review

CONTEXT

Evidence-based guidelines for active surveillance (AS), a treatment option for men with low-risk prostate cancer, recommend regular follow-up at periodic intervals to monitor disease progression. However, gaps in monitoring can lead to delayed detection of cancer progression, leading to a missed window of curability.

OBJECTIVE

We aimed to identify the extent to which real-world observational studies reported adherence to monitoring protocols among prostate cancer patients on AS. When reported, we sought to characterize definitions of adherence.

EVIDENCE ACQUISITION

We systematically reviewed observational studies assessing outcomes of prostate cancer patients on AS, published before March 22, 2019 in PubMed, Embase, and CENTRAL. Adherence definitions were considered time bound if they included prespecified time and binary if adherence was assessed but did not specify a time interval. We assessed study quality using the Strengthening the Reporting of Observational Studies in Epidemiology checklist.

EVIDENCE SYNTHESIS

Forty-five studies met our inclusion criteria. Eleven studies did not report any data on adherence to AS protocols. Twenty-five studies did not explicitly measure adherence, but provided relevant data (eg, number of patients who received a repeat biopsy). Six studies reported adherence using a time-bound definition, while three studies used a binary definition. Twenty-three studies provided information on patients lost to follow-up.

CONCLUSIONS

Most studies reporting outcomes of patients on AS did not measure or report adherence. When reported, adherence was often not time specific. As some AS patients will benefit from maintaining a window of curability, clinical practices and future studies should track and report adherence and associated factors.

PATIENT SUMMARY

We reviewed real-world observational studies examining outcomes of prostate cancer patients on active surveillance. Most studies did not clearly define or report adherence to monitoring protocols, which is important to consider for appropriate disease management.

Pattern of care of prostate cancer patients across the Martinique: results of a population-based study in the Caribbean

BACKGROUND

The French West-Indies rank first for both prostate cancer incidence and mortality rates. Analyzing diagnostic and therapeutic procedures among patients with prostate cancer, using data from a population-based cancer registry, is essential for cancer surveillance and research strategies.

METHODS

This retrospective observational cohort study was based on data from the Martinique Cancer Registry. Records of 452 patients diagnosed with prostate cancer in 2013 were retrieved from the registry. Data extracted were: socio-demographic and clinical characteristics, circumstances of diagnosis, PSA level at diagnosis, Gleason score and risk of disease progression. Stage at diagnosis and patterns of care among prostate cancer patients were analyzed.

RESULTS

Mean age at diagnosis was 67 ± 8 years; 103 (28.5%) were symptomatic at diagnosis. Digital rectal exam was performed in 406 (93.8%). Clinical stage was available in 385 (85.2%); tumours were localized in 322/385 (83.6%). Overall, 17.9% were at low risk, 36.4% at intermediate and 31.9% at high risk; 13.8% were regional/metastatic cancers. Median PSA level at diagnosis was 8.16 ng/mL (range 1.4-5000 ng/mL). A total of 373 patients (82.5%) received at least one treatment, while 79 (17.5%) had active surveillance or watchful waiting. Among patients treated with more than one therapeutic strategy, the most frequent combination was external radiotherapy with androgen deprivation (n = 102, 22.6%).

CONCLUSIONS

This study provides detailed data regarding the quality of diagnosis and management of patients with prostate cancer in Martinique. Providing data on prostate cancer is essential for the development of high-priority public health measures for the Caribbean.

Racial disparities and considerations for active surveillance of prostate cancer

Active surveillance (AS) for the management of low-risk prostate cancer has been increasing and in the general population appears safe, allowing for a reduction in the harms of prostate cancer screening such as overtreatment. African-American (AA) men have overall worse outcomes from prostate cancer compared to Caucasian-American (CA) men for a variety of socioeconomic, cultural and possibly biologic reasons, thus complicating the use of AS in this population. Strategies for optimizing care and mitigating risk in this population include pursuing close surveillance with steadfast patient compliance, the use of multiparametric MRI with targeted biopsies including the anterior prostate to reduce the risk of undersampling, as well as a judicious and thoughtful incorporation of novel molecular biomarkers for risk stratification. Currently, there exists no direct data to suggest that AS cannot be safely carried out in AA men following an informed discussion and after engaging in shared decision making. Physicians should have a low threshold for consideration of definitive therapy. Additional efforts should be made in increasing the engagement of minority participants in clinical trials, to gain an improved representation of underserved populations in future research.