Renaming Gleason Score 6 Prostate to Noncancer: A Flawed Idea Scientifically and for Patient Care

PI-RADS 3 MRI lesions: Are biopsies still necessary?

INTRODUCTION

A significant proportion of newly diagnosed prostate cancer (PCa) cases are slow growing with a low risk of metastatic progression. There is a lack of data concerning the optimal biopsy regimen for improving diagnosis yield in PI-RADS3 lesions. This study aimed to assess the diagnostic value of current biopsy regimens in PI-RADS 3 lesions and identify clinical predictors to improve clinically significant PCa (csPCa) detection.

METHODS

This retrospective study included patients from two academic centers between 2017 and 2024 who benefitted from prostate biopsies for a PI-RADS 3 lesion. Prostate biopsies were performed via either a transrectal or a transperineal route according to local resources. All patients underwent systematic and targeted cores. Targeted biopsies were performed using MRI-ultrasound fusion software or cognitive fusion. Patients were categorized based on biopsy results: benign, clinically insignificant (insignPCa, i.e. ISUP 1), or csPCa (ISUP≥2). The primary endpoint was to assess the detection rate of csPCa in MRI-targeted biopsies alone and in MRI-targeted+ipsilateral systematic cores in comparison to the gold standard MRI-targeted+systematic biopsies. Then, the percentage of csPCa missed and insignPCa diagnoses avoided were calculated referring to the gold standard MRI-targeted+systematic template.

RESULTS

A total of 163 men with at least one PI-RADS 3 index lesion were identified. Ninety-one (55.8%) lesions were benign, 52 (32%) were insignPCa and 20 (12.3%) were csPCa. Of the 20 patients with csPCa, the diagnosis was made with targeted cores in 12 patients and with systematic cores in 8 patients. If no biopsies were performed, 12.3% of csPCa would have gone undiagnosed. Targeted biopsies alone would have missed 4.9% of csPCa but avoided 24.5% of insignPCa. Targeted biopsies with systematic cores solely performed on the same side as the index lesion would have missed 3.8% of csPCa and avoided 12.9% of insignPCa. We reported no significant differences in detection rate of csPCa between MRI-targeted cores alone vs. the gold standard template (7.4% vs. 12.3%; P=0.9) and between MRI-targeted cores+ipsilateral systematic cores vs. the gold standard template (8.5% vs. 12.3%; P=1.2). At multivariable analysis age, clinical T stage, and mpMRI lesion size were predictors of csPCa.

CONCLUSION

As a small proportion of PI-RADS 3 lesions are associated with csPCa, the value of biopsies is questionable. Targeted biopsies with systematic cores on the same side as the index lesion may improve detection of csPCa and reduce overdiagnosis of indolent CaP. Clinical T stage and lesion size on MRI can potentially predict the presence of clinically significant CaP.

LEVEL OF EVIDENCE: 4

Navigating the evolving diagnostic and therapeutic landscape of low- and intermediate-risk prostate cancer

ABSTRACT

In this nonsystematic review of the literature, we explored the changing landscape of detection and treatment of low- and intermediate-risk prostate cancer (PCa). Through emphasizing improved cancer assessment with histology classification and genomics, we investigated key developments in PCa detection and risk stratification. The pivotal role of prostate magnetic resonance imaging (MRI) in the novel diagnostic pathway is examined, alongside the benefits and drawbacks of MRI-targeted biopsies for detection and tumor characterization. We also delved into treatment options, particularly active surveillance for intermediate-risk PCa. Outcomes are compared between intermediate- and low-risk patients, offering insights into tailored management. Surgical techniques, including Retzius-sparing surgery, precision prostatectomy, and partial prostatectomy for anterior cancer, are appraised. Each technique has the potential to enhance outcomes and minimize complications. Advancements in technology and radiobiology, including computed tomography (CT)/MRI imaging and positron emission tomography (PET) fusion, allow for precise dose adjustment and daily target monitoring with imaging-guided radiotherapy, opening new ways of tailoring patients' treatments. Finally, experimental therapeutic approaches such as focal therapy open new treatment frontiers, although they create new needs in tumor identification and tracking during and after the procedure.

Does Overgrading on Targeted Biopsy of Magnetic Resonance Imaging-visible Lesions in Prostate Cancer Lead to Overtreatment?

BACKGROUND AND OBJECTIVE

Targeted biopsy of the index prostate cancer (PCa) lesion on multiparametric magnetic resonance imaging (MRI) is effective in reducing the risk of overdiagnosis of indolent PCa. However, it remains to be determined whether MRI-targeted biopsy can lead to a stage shift via overgrading of the index lesion by focusing only on the highest-grade component, and to a subsequent risk of overtreatment. Our aim was to assess whether overgrading on MRI-targeted biopsy may lead to overtreatment, using radical prostatectomy (RP) specimens as the reference standard.

METHODS

Patients with clinically localized PCa who had positive MRI findings (Prostate Imaging-Reporting and Data System [PI-RADS] score ≥3) and Gleason grade group (GG) ≥2 disease detected on MRI-targeted biopsy were retrospectively identified from a prospectively maintained database that records all RP procedures from eight referral centers. Biopsy grade was defined as the highest grade detected. Downgrading was defined as lower GG for the RP specimen than for MRI-targeted biopsy. Overtreatment was defined as downgrading to RP GG 1 for cases with GG ≥2 on biopsy, or to RP low-burden GG 2 for cases with GG ≥3 on biopsy.

KEY FINDINGS AND LIMITATIONS

We included 1020 consecutive biopsy-naïve patients with GG ≥2 PCa on MRI-targeted biopsy in the study. Pathological analysis of RP specimens showed downgrading in 178 patients (17%). The transperineal biopsy route was significantly associated with a lower risk of downgrading (odds ratio 0.364, 95% confidence interval 0.142-0.814; p = 0.022). Among 555 patients with GG 2 on targeted biopsy, only 18 (3.2%) were downgraded to GG 1 on RP. Among 465 patients with GG ≥3 on targeted biopsy, three (0.6%) were downgraded to GG 1 and seven were downgraded to low-burden GG 2 on RP. The overall risk of overtreatment due to targeted biopsy was 2.7% (28/1020).

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our multicenter study revealed no strong evidence that targeted biopsy results could lead to a high risk of overtreatment.

Patients ask and pathologists answer: ten questions around prostate cancer grading

Pathologists have closely collaborated with clinicians, mainly urologists, to update the Gleason grading system to reflect the current practice and approach in prostate cancer diagnosis, prognosis, and treatment. This has led to the development of what is called patient advocacy and patient information. Ten common questions asked by patients to pathologists concerning PCa grading and the answers given by the latter are reported.

Risk of Cancer-related Death for Men with Biopsy Grade Group 1 Prostate Cancer and High-risk Features: A European Multi-institutional Study

International Society of Urological Pathology grade group 1 (GG 1) prostate cancer (PCa) is generally considered insignificant, with recent suggestions that it should even be considered as "noncancerous". We evaluated outcomes for patients with GG 1 PCa on biopsy (bGG 1) and high-risk features (prostate-specific antigen [PSA] >20 ng/ml and/or cT3-4 stage) to challenge the hypothesis that every case of bGG 1 PCa has a benign disease course. We used the multi-institutional EMPaCT database, which includes data for 9508 patients with high-risk PCa undergoing surgery. We included patients with bGG 1 PCa (n = 848) in our analysis and divided them into three groups according to PSA >20 ng/ml, cT3-4 stage, or both. The estimated 10-yr cancer-specific survival (CSS) rate was 96% in the overall population, 88% in the group with both PSA >20 ng/ml and cT3-4 stage, 97% in the group with PSA >20 ng/ml alone, and 98% in the group with cT3-4 stage alone. Similar CSS outcomes were found in subgroups with GG 1 PCa on pathology (n = 502) and with GG 1 on biopsy diagnosed after 2005 (n = 253). Study limitations include the lack of magnetic resonance imaging (MRI) staging and MRI-targeted biopsies. In conclusion, patients with GG 1 and either PSA >20 ng/ml or cT3-4 stage have a low risk of dying from their cancer after surgery. However, patients with GG 1 PCa and both PSA >20 ng/ml and cT3-4 stage are at higher risk of cancer-specific mortality and active treatment should be discussed for this subgroup.

Patient summary

We assessed outcomes for patients diagnosed with low-grade prostate cancer on biopsy who also had one or two factors associated with high risk disease. Men with both of those risk factors had a higher risk of dying from their prostate cancer. Active treatment should be discussed for this subgroup of patients.

Outcomes of Biopsy Grade Group 1 Prostate Cancer Diagnosis in the Danish Population

BACKGROUND

Debate regarding a nomenclature change for grade group 1 (GG 1) prostate cancer to noncancer has been revived, as this could be a powerful tool in reducing the overtreatment of indolent disease.

OBJECTIVE

To describe outcomes for all men diagnosed with GG 1 prostate cancer in the Danish population, with a focus on men followed conservatively.

DESIGN, SETTING, AND PARTICIPANTS

This was a population-based observational study using data from the Danish Prostate Registry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We measured the cumulative incidence of curative treatment, endocrine treatment, and cause-specific mortality.

RESULTS AND LIMITATIONS

The cumulative incidence of endocrine therapy at 10 yr was 5.3% (95% confidence interval [CI] 4.3-6.3%) for men with initial active surveillance and 21% (95% CI 19-23%) for men with initial watchful waiting for localized GG 1. In the GG1 cohort, the prostate cancer-specific mortality rate at 15 yr was 14% (95 CI% 11-16%) for men on watchful waiting, 10% (95 CI% 6.7-14%) for men with prostate-specific antigen <10 ng/ml on watchful waiting, and 16% (95 CI% 13-19%) for men who did not receive curative-intent treatment or histological assessment. The study is limited by the historic nature of the observations over a period during which diagnostic procedures and treatments have evolved.

CONCLUSIONS

GG 1 cancer can lead to disease-specific mortality in men with localized prostate cancer, and changing the nomenclature for all men may lead to undertreatment.

PATIENT SUMMARY

Key opinion leaders have suggested that prostate cancers of Gleason grade group 1 (GG 1) should be renamed as noncancer to reduce overtreatment. The argument is that low-grade cancer does not metastasize. However, our nationwide population-based study showed that death from prostate cancer can occur in some men diagnosed with GG 1 disease. These men should be considered in discussions on changing the name for GG 1 prostate cancer.

The influence of Gleason score ≤ 6 histology on the outcome of high-risk localized prostate cancer after modern radiotherapy

We aimed to retrospectively review outcomes in patients with high-risk prostate cancer and a Gleason score ≤ 6 following modern radiotherapy. We analyzed the outcomes of 1374 patients who had undergone modern radiotherapy, comprising a high-risk low grade [HRLG] group (Gleason score ≤ 6; n = 94) and a high-risk high grade [HRHG] group (Gleason score ≥ 7, n = 1125). We included 955 patients who received brachytherapy with or without external beam radio-therapy (EBRT) and 264 who received modern EBRT (intensity-modulated radiotherapy [IMRT] or stereotactic body radiotherapy [SBRT]). At a median follow-up of 60 (2-177) months, actuarial 5-year biochemical failure-free survival rates were 97.8 and 91.8% (p = 0.017), respectively. The frequency of clinical failure in the HRLG group was less than that in the HRHG group (0% vs 5.4%, p = 0.012). The HRLG group had a better 5-year distant metastasis-free survival than the HRHG group (100% vs 96.0%, p = 0.035). As the HRLG group exhibited no clinical failure and better outcomes than the HRHG group, the HRLG group might potentially be classified as a lower-risk group.

[Early detection of prostate cancer: Towards a new paradigm?]

Prostate cancer (PCa) is a public health issue. The diagnostic strategy for PCa is well codified and assessed by digital rectal examination, PSA testing and multiparametric MRI, which may or may not lead to prostate biopsies. The formal benefit of organized PCa screening, studied more than 10 years ago at an international scale and for all incomers, is not demonstrated. However, diagnostic and therapeutic modalities have evolved since the pivotal studies. The contribution of MRI and targeted biopsies, the widespread use of active surveillance for unsignificant PCa, the improvement of surgical techniques and radiotherapy… have allowed a better selection of patients and strengthened the interest for an individualized approach, reducing the risk of overtreatment. Aiming to enhance coverage and access to screening for the population, the European Commission recently promoted the evaluation of an organized PCa screening strategy, including MRI. The lack of screening programs has become detrimental to the population and must shift towards an early detection policy adapted to the risk of each individual.

The influence of the "cancer" label on perceptions and management decisions for low-grade prostate cancer

BACKGROUND

Grade Group 1 (GG1) prostate cancer should be managed with active surveillance (AS). Global uptake of AS remains disappointingly slow and heterogeneous. Removal of cancer labels has been proposed to reduce GG1 overtreatment. We sought to determine the impact of GG1 disease terminology on individual's perceptions and decision making.

METHODS

Discrete choice experiments were conducted on 3 cohorts: healthy men, canonical partners (partners), and patients with GG1 (patients). Participants reported preferences in a series of vignettes with 2 scenarios each, permuting key opinion leader-endorsed descriptors: biopsy (adenocarcinoma, acinar neoplasm, prostatic acinar neoplasm of low malignant potential [PAN-LMP], prostatic acinar neoplasm of uncertain malignant potential), disease (cancer, neoplasm, tumor, growth), management decision (treatment, AS), and recurrence risk (6%, 3%, 1%, <1%). Influence on scenario selection were estimated by conditional logit models and marginal rates of substitution. Two additional validation vignettes with scenarios portraying identical descriptors except the management options were embedded into the discrete choice experiments.

RESULTS

Across cohorts (194 healthy men, 159 partners, and 159 patients), noncancer labels PAN-LMP or prostatic acinar neoplasm of uncertain malignant potential and neoplasm, tumor, or growth were favored over adenocarcinoma and cancer (P < .01), respectively. Switching adenocarcinoma and cancer labels to PAN-LMP and growth, respectively, increased AS choice by up to 17%: healthy men (15%, 95% confidence interval [CI] = 10% to 20%, from 76% to 91%, P < .001), partners (17%, 95% CI = 12% to 24%, from 65% to 82%, P < .001), and patients (7%, 95% CI = 4% to 12%, from 75% to 82%, P = .063). The main limitation is the theoretical nature of questions perhaps leading to less realistic choices.

CONCLUSIONS

"Cancer" labels negatively affect perceptions and decision making regarding GG1. Relabeling (ie, avoiding word "cancer") increases proclivity for AS and would likely improve public health.

Prostate Adenocarcinoma Grade Group 1: Rationale for Retaining a Cancer Label in the 2022 World Health Organization Classification

We present the rationale for keeping the "cancer" label for grade group 1 (GG1) prostate cancer. Maintaining GG1 as the lowest grade outweighs the potential benefits that a benign designation may bring. Patient and surgeon education on the vital role of active surveillance for GG1 cancers and avoidance of overtreatment should be the focus rather than such a drastic change in nomenclature.

Should grade group 1 prostate cancer be reclassified as "non-cancer"? A pathology community perspective

Overdiagnosis and overtreatment of Grade Group 1 (GG 1) prostate cancer remains a significant health care problem despite of its improved risk assessment and uptake in conservative management. Removing the cancer label from these non-lethal cancers has been proposed as an expedient way to reduce potential physical, psychological and financial harm to patients. Such a nomenclatural change necessitates a multidisciplinary team effort by clinicians and pathologists. Genitourinary Pathology Society recently conducted a survey of its members, gauging their awareness of this controversy and their position on whether GG 1 prostate cancer should be reclassified. Most respondents (196, 81.7%) opposed removing the cancer label from GG 1 cancer, 33 (13.8%) supported a change in nomenclature, while 11 (4.6%) responded that they were uncertain. Of those who supported the reclassification, 17 (51.5%) supported the change for radical prostatectomy only, 4 (12.1%) for biopsy only, and 12 (36.4%) for both biopsy and radical prostatectomy. This survey results highlight the gap between pathologists and clinicians in whether GG 1 prostate cancer should be labeled as "non-cancer," and calls for continued debates and conversations between pathologists and clinicians, and further studies on the biology, diagnostic reproducibility, and ideal management of GG 1 prostate cancer in order to make a more evidence-based decision for patients.

Prostate Cancer Screening with PSA and MRI Followed by Targeted Biopsy Only

BACKGROUND

Screening for prostate cancer is burdened by a high rate of overdiagnosis. The most appropriate algorithm for population-based screening is unknown.

METHODS

We invited 37,887 men who were 50 to 60 years of age to undergo regular prostate-specific antigen (PSA) screening. Participants with a PSA level of 3 ng per milliliter or higher underwent magnetic resonance imaging (MRI) of the prostate; one third of the participants were randomly assigned to a reference group that underwent systematic biopsy as well as targeted biopsy of suspicious lesions shown on MRI. The remaining participants were assigned to the experimental group and underwent MRI-targeted biopsy only. The primary outcome was clinically insignificant prostate cancer, defined as a Gleason score of 3+3. The secondary outcome was clinically significant prostate cancer, defined as a Gleason score of at least 3+4. Safety was also assessed.

RESULTS

Of the men who were invited to undergo screening, 17,980 (47%) participated in the trial. A total of 66 of the 11,986 participants in the experimental group (0.6%) received a diagnosis of clinically insignificant prostate cancer, as compared with 72 of 5994 participants (1.2%) in the reference group, a difference of -0.7 percentage points (95% confidence interval [CI], -1.0 to -0.4; relative risk, 0.46; 95% CI, 0.33 to 0.64; P<0.001). The relative risk of clinically significant prostate cancer in the experimental group as compared with the reference group was 0.81 (95% CI, 0.60 to 1.1). Clinically significant cancer that was detected only by systematic biopsy was diagnosed in 10 participants in the reference group; all cases were of intermediate risk and involved mainly low-volume disease that was managed with active surveillance. Serious adverse events were rare (<0.1%) in the two groups.

CONCLUSIONS

The avoidance of systematic biopsy in favor of MRI-directed targeted biopsy for screening and early detection in persons with elevated PSA levels reduced the risk of overdiagnosis by half at the cost of delaying detection of intermediate-risk tumors in a small proportion of patients. (Funded by Karin and Christer Johansson's Foundation and others; GÖTEBORG-2 ISRCTN Registry number, ISRCTN94604465.).

Clonal relationships of adjacent Gleason pattern 3 and Gleason pattern 5 lesions in Gleason Scores 3+5=8 and 5+3=8

Genomic studies have demonstrated a high level of intra-tumoral heterogeneity in prostate cancer. There is strong evidence suggesting that individual tumor foci can arise as genetically distinct, clonally independent lesions. However, recent studies have also demonstrated that adjacent Gleason pattern (GP) 3 and GP4 lesions can originate from the same clone but follow divergent genetic and morphologic evolution. The clonal relationship of adjacent GP3 and GP5 lesions has thus far not been investigated. Here we analyzed a cohort of 14 cases-11 biopsy and 3 radical prostatectomy specimens-with a Gleason score of 3 + 5 = 8 or 5 + 3 = 8 present in the same biopsy or in a single dominant tumor nodule at radical prostatectomy. Clonal and subclonal relationships between GP3 and GP5 lesions were assessed using genetically validated immunohistochemical assays for ERG, PTEN, and P53. 9/14 (64%) cases showed ERG reactivity in both GP3 and GP5 lesions. Only 1/14 (7%) cases showed a discordant pattern with ERG staining present only in GP3. PTEN expression was lost in 2/14 (14%) cases with perfect concordance between GP5 and GP3. P53 nuclear reactivity was present in 1/14 (7%) case in both GP5 and GP3. This study provides first evidence that the majority of adjacent GP3 and GP5 lesions share driver alterations and are clonally related. In addition, we observed a lower-than-expected rate of PTEN loss in GP5 in the context of Gleason score 3 + 5 = 8 or 5 + 3 = 8 tumors.