The Capio Prostate Cancer Center Model for Prostate Cancer Diagnostics-Real-world Evidence from 2018 to 2022

Background

The Capio Prostate Cancer Center (Capio PCC) in Stockholm, Sweden, adopts a comprehensive diagnostic approach, utilizing prostate-specific antigen (PSA), Stockholm3, and magnetic resonance imaging (MRI) for prostate cancer risk assessment, followed by targeted and systematic biopsies for high-risk cases.

Objective

This study aims to elucidate the clinical process and real-world outcomes of the Capio PCC model for prostate cancer diagnosis at Capio S:t Göran Hospital.

Design setting and participants

Between 2018 and 2022, a cohort of 12 406 men aged 45-75 yr underwent prostate cancer testing, adhering to Capio PCC's structured diagnostic protocol.

Outcome measurements and statistical analysis

We provide a comprehensive description of the Capio PCC model and present results from its implementation, including assessments of PSA, Stockholm3, MRI scans, and biopsies. A comparative analysis is conducted between the diagnostic outcomes obtained at Capio PCC and those obtained at other regions in Sweden.

Results and limitations

The median participant age was 61 yr (interquartile range [IQR]: 55-67), with PSA levels at 1.6 ng/ml (IQR: 0.8-3.3) and Stockholm3 scores at 4 (IQR: 3-11). Among 1064 men (8.6%) undergoing biopsies, 611 (57% of biopsied) were diagnosed with International Society of Urological Pathology grade ≥ 2 cancer. Notably, employing a Stockholm3 ≥ 15 cutoff for biopsy, in lieu of PSA ≥ 3 ng/ml, reduced biopsy recommendations by 43%. For men with PSA levels between 1.5 and 2.9 ng/ml, 360 (12%) exhibited Stockholm3 scores of ≥ 15, with 72 (56% of biopsied) diagnosed with clinically significant prostate cancer. A comparative analysis with national Swedish prostate cancer detection data indicated that the Capio PCC model (vs Sweden) revealed a distribution of 14% (vs 25%) low-risk, 59% (vs 42%) intermediate-risk, and 26% (vs 30%) high-risk and advanced cancers.

Conclusions

This study underscores the effectiveness of the protocol-driven diagnostic process at Capio PCC, enabling earlier detection of intermediate-risk prostate cancer and reducing the need for MRI assessments compared with standard prostate cancer care in Sweden.

Patient summary

At the Capio Prostate Cancer Center, a novel diagnostic approach incorporating prostate-specific antigen, Stockholm3, magnetic resonance imaging, and targeted biopsies has been implemented to enhance prostate cancer testing and diagnosis in Stockholm, Sweden.

Prostate Biopsies Can Be Omitted in Most Patients with a Positive Stockholm3 Test and Negative Prostate Magnetic Resonance Imaging

BACKGROUND

Magnetic resonance imaging (MRI) combined with the Stockholm3 test can be used to inform biopsy decision-making in patients with a suspicion of prostate cancer.

OBJECTIVE

To determine the consequence of omitting biopsies in men with a positive Stockholm3 test and a negative MRI.

DESIGN, SETTING, AND PARTICIPANTS

In a real-life setting, 438 men with a positive Stockholm3 test and a negative MRI underwent systematic biopsies from 2017 to 2020.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The Stockholm3 test result is a percentage risk score with or without a prostate volume cutoff. The main outcomes were the number of clinically significant (Gleason grade group [GG] ≥2) and nonsignificant (GG 1) prostate cancers.

RESULTS AND LIMITATIONS

Median prostate-specific antigen was 4.5 ng/ml (interquartile range 2.8-6.4 ng/ml) and the median age was 69 yr. Systematic biopsies detected grade group (GG) ≥2 disease in 48 men (11%, 95% confidence interval [CI] 8.4-14.2%) and GG 1 disease in 94 men (21.5%, 95% CI 17.9-25.6%). Of 256 patients without a volume cutoff in the test report, GG ≥2 was detected in 37 men (14.5%, 95% CI 10.7-19.3%). Omitting biopsies in patients with a volume cutoff would miss 11 GG ≥2 cases (6%, 95% CI 3.4-10.5%), reduce the number of GG 1 cases detected by 37 (39.4%, 95% CI 30.1-49.5%), and avoid a total of 182 biopsies (41.6%, 95% CI 37.0-46.2%). Limitations include the lack of follow-up data.

CONCLUSIONS

Systematic biopsies can be omitted in patients with a positive Stockholm3 test and a negative MRI when there is a volume cutoff in the test report. With no volume cutoff, biopsies can be considered with shared decision-making.

PATIENT SUMMARY

When investigated on suspicion of prostate cancer with a positive Stockholm3 test and a negative MRI (magnetic resonance imaging), prostate biopsies are only necessary for a subgroup of patients. This can spare some men from undergoing biopsies and reduce the detection of clinically insignificant cancers.

Cost-Effectiveness of the Stockholm3 Test and Magnetic Resonance Imaging in Prostate Cancer Screening: A Microsimulation Study

BACKGROUND

Stockholm3 is a risk model that combines the prostate-specific antigen (PSA) test, other plasma protein biomarkers, single nucleotide polymorphisms, and clinical variables. The STHLM3-MRI study (NCT03377881) found that the Stockholm3 test with magnetic resonance imaging (MRI) and combined targeted and systematic biopsies maintained the sensitivity for clinically significant cancers, and reduced the number of benign biopsies and clinically insignificant cancers.

OBJECTIVE

To assess the cost-effectiveness of MRI-based screening for prostate cancer using either Stockholm3 as a reflex test or PSA alone.

DESIGN, SETTING, AND PARTICIPANTS

A cost-utility analysis was performed from a lifetime societal perspective using a microsimulation model for men aged 55-69 yr in Sweden. Test characteristics were estimated from the STHLM3-MRI study.

INTERVENTION

No screening and three quadrennial screening strategies, including either PSA ≥3 ng/ml or Stockholm3 with reflex test thresholds of PSA ≥1.5 or 2 ng/ml as criteria for referral to MRI, were performed, and those who were MRI positive had combined targeted and systematic biopsies.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Predictions included the number of tests, cancer incidence and mortality, costs, and quality-adjusted life-years. Uncertainties in key parameters were assessed using sensitivity analyses.

RESULTS AND LIMITATIONS

Compared with no screening, the screening strategies were predicted to reduce prostate cancer deaths by 7-9% across a lifetime. The use of Stockholm3 with PSA ≥2 ng/ml resulted in a 60% reduction in MRI compared with screening using PSA. This Stockholm3 strategy was cost-effective with a probability of 70% at a cost-effectiveness threshold of €47 218 (500 000 Swedish Kronor). As a potential limitation, the economic perspective was specific to Sweden.

CONCLUSIONS

Screening with the Stockholm3 test at a reflex threshold of PSA ≥2 ng/ml and MRI was predicted to be cost-effective in Sweden.

PATIENT SUMMARY

The Stockholm3 test with image-based screening may reduce screening-related harms and costs, while maintaining the health benefits from early detection of prostate cancer.

Identifying Prostate Cancer Among Men with Lower Urinary Tract Symptoms

Background

In men aged above 50 yr, lower urinary tract symptoms (LUTS), benign prostate hyperplasia, and prostate cancer are common urological conditions. Current guidelines for general practitioners frequently recommend prostate-specific antigen (PSA) testing in patients with LUTS for the detection of prostate cancer.

Objective

To assess the performance of PSA, PSA density, and the Stockholm3 blood test for identification of prostate cancer among men with LUTS.

Design, setting, and participants

In this post hoc analysis of a population-based diagnostic trial (STHLM3, n = 58 588), 4588 men aged 50–69 yr, without previous prostate cancer, with International Prostate Symptom Score (IPSS) data, and having PSA ≥ 3 ng/mL were identified. Men with at least moderate LUTS, defined as an IPSS score of ≥8, were included. PSA density and Stockholm3 scores were calculated.

Intervention

Participants underwent 10–12-core systematic prostate biopsies.

Outcome measurements and statistical analysis

The primary outcome was significant prostate cancer (sPCa) defined as International Society of Urological Pathology (ISUP) grade ≥2. Logistic regression analysis adjusted for age and previous biopsy status was performed. The area under the receiver operating characteristic curve (AUC) was calculated, and decision curve analysis was performed.

Results and limitations

Out of 4588 men, 1544 (34%) reported at least moderate LUTS. The median age was 64 yr, and 11% had undergone a previous prostate biopsy. The Stockholm3 test showed superior discrimination for sPCa to PSA density, which in turn showed superior discrimination to PSA (AUC 0.77 vs 0.70 vs 0.61, p <  0.02). Calibration of the Stockholm3 test was adequate. Performing biopsy only in men with PSA ≥5 ng/mL saved 64% of biopsies, but resulted in missing 52% of detectable sPCa. Recommending biopsy for men with PSA density ≥0.07 resulted in sparing 26% of biopsy procedures and delaying the diagnosis of 12% of sPCa cases, with a 6.1% risk of sPCa among unbiopsied men. Recommending men with Stockholm3 ≥ 0.11 for biopsy resulted in sparing 53% of biopsy procedures and delaying the diagnosis of 20% of sPCa cases, with a 5.1% risk of finding sPCa in unbiopsied men.

Conclusions

PSA density and the Stockholm3 blood test were superior to PSA for the identification of prostate cancer among men with LUTS.

Patient summary

In this analysis of a large Swedish study, we find that the use of prostate-specific antigen (PSA) density or the Stockholm3 blood test instead of only PSA might improve the detection of prostate cancer among men with lower urinary tract symptoms.

Effects of replacing PSA with Stockholm3 for diagnosis of clinically significant prostate cancer in a healthcare system - the Stavanger experience

OBJECTIVE

To describe early experience of replacing PSA with Stockholm3 for detection of prostate cancer in primary care.

DESIGN AND METHODS

Longitudinal observations, comparing outcome measures before and after the implementation of Stockholm3.

SETTING

Stavanger region in Norway with about 370,000 inhabitants, 304 general practitioners (GPs) in 97 primary care clinics, and one hospital.

INTERVENTION

GPs were instructed to use Stockholm3 instead of PSA as standard procedure for diagnosis of prostate cancer.

MAIN OUTCOME MEASURES

Proportion of GP clinics that had ordered a Stockholm3 test. Number of men referred to needle biopsy. Distribution of clinically significant prostate cancer (csPC) (Gleason Score ≥7) and clinically non-significant prostate cancer (cnsPC) (Gleason Score 6), in needle biopsies. Estimation of direct healthcare costs.

RESULTS

Stockholm3 was rapidly implemented as 91% (88/97) of the clinics started to use the test within 14 weeks. After including 4784 tested men, the percentage who would have been referred for prostate needle biopsy was 29.0% (1387/4784) if based on PSA level ≥3ng/ml, and 20.8% (995/4784) if based on Stockholm3 Risk Score (p < 0.000001). The proportion of positive biopsies with csPC increased from 42% (98/233) before to 65% (185/285) after the implementation. Correspondingly, the proportion of cnsPC decreased from 58% (135/233) before to 35% (100/285) after the implementation (p < 0.0017). Direct healthcare costs were estimated to be reduced by 23-28% per tested man.

CONCLUSION

Replacing PSA with Stockholm3 for early detection of prostate cancer in primary care is feasible. Implementation of Stockholm3 resulted in reduced number of referrals for needle-biopsy and a higher proportion of clinically significant prostate cancer findings in performed biopsies. Direct healthcare costs decreased. KEY POINTS A change from PSA to Stockholm3 for the diagnosis of prostate cancer in primary care in the Stavanger region in Norway is described and assessed. •Implementation of a new blood-based test for prostate cancer detection in primary care was feasible. A majority of GP clinics started to use the test within three months. •Implementation of the Stockholm3 test was followed by: -a 28% reduction in number of men referred for urological prostate cancer work-up -an increase in the proportion of clinically significant cancer in performed prostate biopsies from 42 to 65% -an estimated reduction in direct health care costs between 23 and 28%.

Prostate Cancer Diagnostics Using a Combination of the Stockholm3 Blood Test and Multiparametric Magnetic Resonance Imaging

BACKGROUND

More specific diagnostic for prostate cancer is needed to decrease overdetection and number of diagnostic procedures.

OBJECTIVE

To assess the performance of combining a blood-based biomarker panel and magnetic resonance imaging (MRI)-targeted biopsies for prostate cancer detection.

DESIGN, SETTING, AND PARTICIPANTS

We used a prospective, multicenter, paired diagnostic study design. A total of 532 men aged 45-74 yr referred for prostate cancer workup were included during 2016-2017.

INTERVENTION

Participants underwent blood sampling for analysis of the Stockholm3 test including protein biomarkers, genetic polymorphisms, and clinical variables; 1.5 T MRI; systematic prostate biopsies; and MRI-targeted biopsies to lesions with Prostate Imaging Reporting and Data System version 2 ≥3.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The main outcome was numbers of detected prostate cancer characterized by grade group (GG) and the number of performed biopsies using relative sensitivity (RS).

RESULTS AND LIMITATIONS

Median prostate-specific antigen was 6.3 ng/ml, and mean age was 63.9 yr. Targeted and systematic biopsies detected 170 and 162 GG ≥2 tumors, respectively (RS 1.05; 95% confidence interval [CI] 0.96-1.14). Compared with performing systematic biopsies on all men, performing targeted and systematic biopsies only on men with >10% risk of GG ≥2 cancer, as predicted by the Stockholm3 test, required 62% (95% CI 58-66) of the biopsy procedures and detected 58% (95% CI 48-70) of GG 1 disease, with increased sensitivity for GG ≥2 detection (RS 1.10; 95% CI 1.02-1.17). Performing only targeted biopsies in men with elevated Stockholm3 test altered these results only slightly. Compared with performing systematic and targeted biopsies on all men, performing this only for men with an elevated Stockholm3 test decreased detection of GG ≥2 cancer slightly (RS 0.92; 95% CI 0.88-0.95). Limitations include lacking knowledge of true disease prevalence.

CONCLUSIONS

These findings provide evidence that strategies combining the blood-based Stockholm3 test and MRI-targeted biopsies can be used to inform biopsy decision making.

PATIENT SUMMARY

In this study, 532 men coming for prostate cancer workup underwent blood sampling, and both traditional and magnetic resonance imaging/fusion-guided prostate biopsies. We report that performing targeted biopsies only in men with an elevated risk as assessed by the Stockholm3 test saved biopsies, decreased overdetection, and maintained the number of detected high-grade cancers.

Effects of increasing the PSA cutoff to perform additional biomarker tests before prostate biopsy

Background

Multi-step testing might enhance performance of the prostate cancer diagnostic pipeline. Using PSA >1 ng/ml for first-line risk stratification and the Stockholm 3 Model (S3M) blood-test >10% risk of Gleason Score > 7 prostate cancer to inform biopsy decisions has been suggested. We aimed to determine the effects of changing the PSA cutoff to perform reflex testing with S3M and the subsequent S3M cutoff to recommend prostate biopsy while maintaining the sensitivity to detect Gleason Score ≥ 7 prostate cancer.

Methods

We used data from the prospective, population-based, paired, diagnostic Stockholm 3 (STHLM3) study with participants invited by date of birth from the Swedish Population Register during 2012–2014. All participants underwent testing with PSA and S3M (a combination of plasma protein biomarkers [PSA, free PSA, intact PSA, hK2, MSMB, MIC1], genetic polymorphisms, and clinical variables [age, family, history, previous prostate biopsy, prostate exam]). Of 47,688 men in the STHLM3 main study, we used data from 3133 men with S3M >10% and prostate biopsy data. Logistic regression models were used to calculate prostate cancer detection rates and proportion saved biopsies.

Results

44.2%, 62.5% and 67.9% of the participants had PSA <1, <1.5 and <1.7 ng/ml, respectively. Increasing the PSA cut-off for additional work-up from 1 ng/ml to 1.5 ng/ml would thus save 18.3% of the performed tests, 4.9% of the biopsies and 1.3% (10/765) of Gleason Grade ≥ 7 cancers would be un-detected. By lowering the S3M cutoff to recommend biopsy, sensitivity to high-grade prostate cancer can be restored, to the cost of increasing the number of performed biopsies modestly.

Conclusion

The sensitivity to detect prostate cancer can be maintained when using different PSA cutoffs to perform additional testing. Biomarker cut-offs have implications on number of tests and prostate biopsies performed. A PSA cutoff of 1.5 ng/ml to perform additional testing such as the S3M test might be considered.

Trial registration

ISRCTN84445406.