Prostate cancer visibility on multiparametric magnetic resonance imaging: high Gleason grade and increased tumour volume are not the only important histopathological features

Comparison of Multiparametric MRI-targeted and Systematic Biopsies for Detection of Cribriform and Intraductal Carcinoma Prostate Cancer

Background Intraductal carcinoma (IDC) and invasive cribriform (Cr) subtypes of prostate cancer (PCa) are an indication of aggressiveness, but the evidence regarding whether MRI can be used to detect Cr/IDC-pattern PCa is contradictory. Purpose To compare the detection of Cr/IDC-pattern PCa at multiparametric MRI (mpMRI)-targeted biopsy versus systematic biopsy in biopsy-naive men at risk for PCa. Materials and Methods This study was a secondary analysis of a prospective randomized controlled trial that recruited participants with a clinical suspicion of PCa between April 2017 and November 2019 at five centers. Participants were randomized 1:1 to either the MRI arm or the systematic biopsy arm. Targeted biopsy was performed in participants with a Prostate Imaging Reporting and Data System score of at least 3. MRI features were recorded, and biopsy slides and prostatectomy specimens were reviewed for the presence or absence of Cr/IDC histologic patterns. Comparison of Cr/IDC patterns was performed using generalized linear mixed modeling. Results A total of 453 participants were enrolled, with 226 in the systematic biopsy arm (median age, 65 years [IQR, 59-70 years]; 196 biopsies available for assessment) and 227 in the mpMRI-targeted biopsy arm (median age, 67 years [IQR, 60-72 years]; 132 biopsies available for assessment). Identification of Cr/IDC PCa was lower in the systematic biopsy arm compared with the mpMRI arm (31 of 196 biopsies [16%] vs 33 of 132 biopsies [25%]; P = .01). No evidence of a difference in mean cancer core length (CCL) (11.3 mm ± 4.4 vs 9.7 mm ± 4.5; P = .09), apparent diffusion coefficient (685 µm2/sec ± 178 vs 746 µm2/sec ± 245; P = .52), or dynamic contrast-enhanced positivity (27 [82%] vs 37 [90%]; P = .33) for clinically significant PCa (csPCa) was observed between participants with or without Cr/IDC disease in the MRI arm. Cr/IDC-positive histologic patterns overall had a higher mean CCL compared with Cr/IDC-negative csPCa (11.1 mm ± 4.4 vs 9.2 mm ± 4.1; P = .009). Conclusion MRI-targeted biopsy showed increased detection of Cr/IDC histologic patterns compared with systematic biopsy. Clinical trial registration no. NCT02936258 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Scialpi and Martorana in this issue.

The Added Value of Side-specific Systematic Biopsy in Patients Diagnosed by Magnetic Resonance Imaging-targeted Prostate Biopsy

BACKGROUND

Systematic biopsy (SB) combined with magnetic resonance imaging (MRI)-targeted biopsy is still recommended considering the risk of missing clinically significant prostate cancer (csPCa).

OBJECTIVE

To evaluate the added value in csPCa detection on side-specific SB relative to MRI lesion and to externally validate the Noujeim risk stratification model that predicts the risk of csPCa on distant SB cores relative to the index MRI lesion.

DESIGN, SETTING, AND PARTICIPANTS

Overall, 4841 consecutive patients diagnosed by MRI-targeted biopsy and SB for Prostate Imaging Reporting and Data System score ≥3 lesions were identified from a prospectively maintained database between January 2016 and April 2023 at 15 European referral centers. A total of 2387 patients met the inclusion criteria and were included in the analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

McNemar's test was used to compare the csPCa detection rate between several biopsy strategies including MRI-targeted biopsy, side-specific SB, and a combination of both. Model performance was evaluated in terms of discrimination using area under the receiver operation characteristic curve (AUC), calibration plots, and decision curve analysis. Clinically significant prostate cancer was defined as International Society of Urological Pathology grade group ≥2.

RESULTS AND LIMITATIONS

Overall, the csPCa detection rate was 49%. Considering MRI-targeted biopsy as reference, the added values in terms of csPCa detection were 5.8% (relative increase of 13%), 4.2% (relative increase of 9.8%), and 2.8% (relative increase of 6.1%) for SB, ipsilateral SB, and contralateral SB, respectively. Only 35 patients (1.5%) exclusively had csPCa on contralateral SB (p < 0.001). Considering patients with csPCa on MRI-targeted biopsy and ipsilateral SB, the upgrading rate was 2% (20/961) using contralateral SB (p < 0.001). The Noujeim model exhibited modest performance (AUC of 0.63) when tested using our validation set.

CONCLUSIONS

The added value of contralateral SB was negligible in terms of cancer detection and upgrading rates. The Noujeim model could be included in the decision-making process regarding the appropriate prostate biopsy strategy.

PATIENT SUMMARY

In the present study, we collected a set of patients who underwent magnetic resonance imaging (MRI)-targeted and systematic biopsies for the detection of prostate cancer. We found that biopsies taken at the opposite side of the MRI suspicious lesion have a negligible impact on cancer detection. We also validate a risk stratification model that predicts the risk of cancer on biopsies beyond 10 mm from the initial lesion, which could be used in daily practice to improve the personalization of the prostate biopsy.

Which Prostate Cancers are Undetected by Multiparametric Magnetic Resonance Imaging in Men with Previous Prostate Biopsy? An Analysis from the PICTURE Study

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) has improved risk stratification for suspected prostate cancer in patients following prior biopsy. However, not all significant cancers are detected by mpMRI. The PICTURE study provides the ideal opportunity to investigate cancer undetected by mpMRI owing to the use of 5 mm transperineal template mapping (TTPM) biopsy.

OBJECTIVE

To summarise attributes of cancers systematically undetected by mpMRI in patients with prior biopsy.

DESIGN SETTING AND PARTICIPANTS

PICTURE was a paired-cohort confirmatory study in which men requiring repeat biopsy underwent mpMRI followed by TTPM biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Attributes were compared between cancers detected and undetected by mpMRI at the patient level. Four predefined histopathological thresholds were used as the target condition for TTPM biopsy. Application of prostate-specific antigen density (PSAD) was explored.

RESULTS AND LIMITATIONS

When nonsuspicious mpMRI was defined as Likert score 1-2, 2.9% of patients (3/103; 95% confidence interval [CI] 0.6-8.3%) with definition 1 disease (Gleason ≥ 4 + 3 of any length or maximum cancer core length [MCCL] ≥ 6 mm of any grade) had their cancer not detected by mpMRI. This proportion was 6.5% (11/168; 95% CI 3.3-11%) for definition 2 disease (Gleason ≥ 3 + 4 of any length or MCCL ≥ 4 mm of any grade), 4.8% (7/146; 95% CI 2.0-9.6%) for any amount of Gleason ≥ 3 + 4 cancer, and 9.3% (20/215; 95% CI 5.8-14%) for any cancer. Definition 1 cancers undetected by mpMRI had lower overall Gleason score (p = 0.02) and maximum Gleason score (p = 0.01) compared to cancers detected by mpMRI. Prostate cancers undetected by mpMRI had shorter MCCL than cancers detected by mpMRI for every cancer threshold: definition 1, 6 versus 8 mm (p = 0.02); definition 2, 5 versus 6 mm (p = 0.04); any Gleason ≥ 3 + 4, 5 versus 6 mm (p = 0.03); and any cancer, 3 versus 5 mm (p = 0.0009). A theoretical PSAD threshold of 0.15 ng/ml/ml reduced the proportion of patients with undetected disease on nonsuspicious mpMRI to 0% (0/105; 95% CI 0-3.5%) for definition 1, 0.58% (1/171; 95% CI 0.01-3.2%) for definition 2, and 0% (0/146) for any Gleason ≥ 3 + 4.

CONCLUSIONS

Few significant cancers are undetected by mpMRI in patients requiring repeat prostate biopsy. Undetected tumours are of lower overall and maximum Gleason grade and shorter cancer length compared to cancers detected by mpMRI.

PATIENT SUMMARY

In patients with a previous prostate biopsy, magnetic resonance imaging (MRI) overlooks few prostate cancers, and these tend to be smaller and less aggressive than cancer that is detected.

What to expect from a non-suspicious prostate MRI? A review

BACKGROUND

Many guidelines now recommend multiparametric MRI (mpMRI) prior to an initial or repeat prostate biopsy. However, clinical decision making for men with a non-suspicious mpMRI (Likert or PIRADS score 1-2) varies.

OBJECTIVES

To review the most recent literature to answer three questions. (1) Should we consider systematic biopsy if mpMRI is not suspicious? (2) Are there additional predictive factors that can help decide which patient should have a biopsy? (3) Can the low visibility of some cancers be explained and what are the implications?

SOURCES

A narrative review was performed in Medline databases using two searches with the terms "MRI" and "prostate cancer" and ("diagnosis" or "biopsy") and ("non-suspicious" or "negative" or "invisible"); "prostate cancer MRI visible". References of the selected articles were screened for additional articles.

STUDY SELECTION

Studies published in the last 5 years in English language were assessed for eligibility and selected if data was available to answer one of the three study questions.

RESULTS

Considering clinically significant cancer as ISUP grade≥2, the negative predictive value (NPV) of mpMRI in various settings and populations ranges from 76% to 99%, depending on cancer prevalence and the type of confirmatory reference test used. NPV is higher among patients with prior negative biopsy (88-96%), and lower for active surveillance patients (85-90%). The PSA density (PSAd) with a threshold of PSAd<0.15ng/ml/ml was the most studied and relevant predictive factor used in combination with mpMRI to rule out clinically significant cancer. Finally, mpMRI-invisible tumours appear to differ from a histopathological and genetic point of view, conferring clinical advantage to invisibility.

LIMITATIONS

Most published data come from expert centres and results may not be reproducible in all settings.

CONCLUSION

mpMRI has high diagnostic accuracy and in cases of negative mpMRI, PSA density can be used to determine which patient should have a biopsy. Growing knowledge of the mechanisms and genetics underlying MRI visibility will help develop more accurate risk calculators and biomarkers.

Conspicuity of prostate cancer on multiparametric magnetic resonance imaging: A cross-disciplinary translational hypothesis

Pre-biopsy multiparametric magnetic resonance imaging (mpMRI) has transformed the risk stratification and diagnostic approach for suspected prostate cancer. The majority of clinically significant prostate cancers are visible on pre-biopsy mpMRI, however, there are a subset of significant tumors that are not detected by mpMRI. The radiobiological mechanisms underpinning mpMRI-visibility and invisibility of these cancers remain uncertain. Emerging evidence suggests that mpMRI-visible tumors are enriched with molecular features associated with increased disease aggressivity and poor clinical prognosis, which is supported by short-term endpoints, such as biochemical recurrence following surgery. Furthermore, at the histopathological level, mpMRI-visible tumors appear to exhibit increased architectural and vascular density compared to mpMRI-invisible disease. It seems probable that the genomic, pathological, radiological, and clinical features of mpMRI-visible and mpMRI-invisible prostate cancers are interrelated. Here, we propose a novel cross-disciplinary theory that links genomic and molecular evidence with cellular and histopathological appearances, elucidating both the mpMRI visibility and clinical status of significant prostate cancer.

Genetic Landscape of Prostate Cancer Conspicuity on Multiparametric Magnetic Resonance Imaging: A Systematic Review and Bioinformatic Analysis

Context

Multiparametric magnetic resonance imaging (mpMRI) detects most, but not all, clinically significant prostate cancer. The genetic basis of prostate cancer visibility and invisibility on mpMRI remains uncertain.

Objective

To systematically review the literature on differential gene expression between mpMRI-visible and mpMRI-invisible prostate cancer, and to use bioinformatic analysis to identify enriched processes or cellular components in genes validated in more than one study.

Evidence acquisition

We performed a systematic literature search of the Medline, EMBASE, PubMed, and Cochrane databases up to January 2020 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. The primary endpoint was differential genetic features between mpMRI-visible and mpMRI-invisible tumours. Secondary endpoints were explanatory links between gene function and mpMRI conspicuity, and the prognostic value of differential gene enrichment.

Evidence synthesis

We retrieved 445 articles, of which 32 met the criteria for inclusion. Thematic synthesis from the included studies showed that mpMRI-visible cancer tended towards enrichment of molecular features associated with increased disease aggressivity, including phosphatase and tensin homologue (PTEN) loss and higher genomic classifier scores, such as Oncotype and Decipher. Three of the included studies had accompanying publicly available data suitable for further bioinformatic analysis. An over-representation analysis of these datasets revealed increased expression of genes associated with extracellular matrix components in mpMRI-visible tumours.

Conclusions

Prostate cancer that is visible on mpMRI is generally enriched with molecular features of tumour development and aggressivity, including activation of proliferative signalling, DNA damage, and inflammatory processes. Additionally, there appears to be concordant cellular components and biological processes associated with mpMRI conspicuity, as highlighted by bioinformatic analysis of large genetic datasets.

Patient summary

Prostate cancer that is detected by magnetic resonance imaging (MRI) tends to have genetic features that are associated with more aggressive disease. This suggests that MRI can be used to assess the likelihood of aggressive prostate cancer, based on tumour visibility.