Is Grade Group 1 (Gleason score 3 + 3 = 6) adenocarcinoma of the prostate really cancer?

Impact of the diagnostic label for a low-risk prostate lesion: protocol for two online factorial randomised experiments

INTRODUCTION

Many types of prostate cancer present minimal risk to a man's lifespan or well-being, but existing terminology makes it difficult for men to distinguish these from high-risk prostate cancers. This study aims to explore whether using an alternative label for low-risk prostate cancer influences management choice and anxiety levels among Australian men and their partners.

METHODS AND ANALYSIS

We will run two separate studies for Australian men and Australian women with a male partner. Both studies are between-subjects factorial (3×2) randomised online hypothetical experiments. Following consent, eligible participants will be randomised 1:1:1 to three labels: 'low-risk prostate cancer, Gleason Group 1', 'low-risk prostate neoplasm' or 'low-risk prostate lesion'. Participants will then undergo a second randomisation step with 1:1 allocation to the provision of detailed information on the benefits and harms of different management choices versus the provision of less detailed information about management choices. The required sample sizes are 1290 men and 1410 women. The primary outcome is the participant choice of their preferred management strategy: no immediate treatment (prostate-specific antigen (PSA)-based monitoring or active surveillance using PSA, MRI, biopsy with delayed treatment for disease progression) versus immediate treatment (prostatectomy or radiation therapy). Secondary outcomes include preferred management choice (from the four options listed above), diagnosis anxiety, management choice anxiety and management choice at a later time point (for participants who initially choose a monitoring strategy).

ETHICS AND DISSEMINATION

Ethics approval has been received from The University of Sydney Human Research Ethics Committee (2023/572). The results of the study will be published in a peer-reviewed medical journal and a plain language summary of the findings will be shared on the Wiser Healthcare publications page http://www.wiserhealthcare.org.au/category/publications/ TRIAL REGISTRATION NUMBERS: Australian New Zealand Clinical Trials Registry (ID 386701 and 386889).

Gleason score 3+3=6 prostatic adenocarcinoma is not benign and the current debate is unhelpful to clinicians and patients

Prostate adenocarcinoma is a common malignancy associated with a significant morbidity and mortality. In both prostate biopsies and radical prostatectomy specimens Gleason scoring informs both treatment and outcome prediction. The current convention is that in needle biopsies, Gleason patterns 3, 4 and 5 are considered to be malignant. Despite this there is debate as to whether or not Gleason score (GS) 3+3=6 should be diagnosed as cancer due to potential over-treatment and the psychological impact on patients. It is apparent that GS 3+3=6 is indolent disease with a low risk of metastasis. However, it does have the histological features of malignancy and is capable of infiltrating the prostate gland, extraprostatic extension, and metastatic spread. Furthermore GS 3+3=6 carcinoma has immunohistochemical and molecular genetic features similar to those of higher grade prostatic carcinoma. If GS 3+3=6 tumour is considered benign, the question arises should a benign label be given to the Gleason pattern 3 component of tumour that includes Gleason patterns of higher grade? This would seem a logical step as GS 3+3=6 cancers and the pattern 3 component in cancers with multiple patterns are morphologically identical. If pattern 3 is considered to be benign, then Gleason scoring would be limited to 4+4=8, 4+5=9, 5+4=9 and 5+5=10 which is clearly inappropriate. The correct strategy to address potential over-treatment of patients with low-grade cancer is clinician and patient education, not the recalibration of Gleason grading to reclassify malignant tumours as benign.

Pituitary adenoma or neuroendocrine tumour: the need for an integrated prognostic classification

In the 2022 fifth edition of the WHO Classification of Endocrine Tumours and of Central Nervous System Tumours, pituitary adenomas are reclassified as neuroendocrine tumours (NETs). This change confers an oncology label to neoplasms that are overwhelmingly benign. A comprehensive clinical classification schema is required to guide prognosis, therapy and outcomes for all patients with pituitary adenomas. Pituitary adenomas and NETs exhibit some morphological and ultrastructural similarities. However, unlike NETs, pituitary adenomas are highly prevalent, yet indolent and rarely become malignant. This Perspective presents the outcomes of an interdisciplinary international workshop that addressed the merit and clinical implications of the classification change of pituitary adenoma to NET. Many non-histological factors provide mechanistic insight and influence the prognosis and treatment of pituitary adenoma. We recommend the development of a comprehensive classification that integrates clinical, genetic, biochemical, radiological, pathological and molecular information for all anterior pituitary neoplasms.

Validation of Epstein criteria and development of a nomogram for active surveillance in a contemporary Chinese population

PURPOSE

To evaluate the Epstein criteria for insignificant prostate cancer (CaP) prediction in a contemporary Chinese population, and to develop a risk model with combined clinical and systematic biopsy and targeted biopsy parameters for active surveillance.

METHODS

A total of 249 CaP patients with biopsy Gleason score (GS) of 6 were included. One hundred and one patients were eligible for insignificant CaP on final pathology (GS ≤6 and organ-confined). Diagnostic tests were used to validate the ability of the 2 Epstein criteria. Univariate and multivariate regression analyses were performed to identify predictors of insignificant CaP for the development of predictive models. Receiver operating characteristics analysis was used to select the best model, followed by risk nomogram construction and internal validation.

RESULTS

There were 47 patients met EC1 and 61 met EC2, with pathological upgrading rates of 36% and 41%, respectively, and 70% (71/101) and 64% (65/101) were missed, with areas under the curve of 0.591 and 0.594, respectively. Four prediction models were developed using regression analysis, and model 2 incorporating age, prostate-specific antigen density, maximum percentage of core involvement at systematic biopsy, and percentage of positive cores at targeted biopsy showed the best diagnostic value (area under the curve = 0.731, sensitivity 62.4%, specificity 77.0%) and was used to construct the nomogram. Calibration curves and decision curve analysis demonstrated favorable calibration (mean absolute error 0.048) and clinical benefits of the novel nomogram.

CONCLUSION

The Epstein criteria need to be revised by incorporating targeted biopsy parameters to improve diagnostic performance, and a novel nomogram was developed with better prediction of insignificant CaP.

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.

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.

Grade group 1 prostate cancer on biopsy: are we still missing aggressive disease in the era of image-directed therapy?

PURPOSE

Recently, Eggener et al. reignited a debate consisting to redefine Gleason Grade Group (GGG) 1 prostate cancer (PCa) as a precancerous lesion to reduce overdiagnosis and overtreatment. However, historical cohorts showed that some GGG1-labeled disease at biopsy may be underestimated by the standard PCa diagnostic workup. The aim was to assess whether the risk of adverse features at radical prostatectomy (RP) in selected GGG1 patients still exists in the era of pre-biopsy mpMRI and image-guided biopsies.

METHODS

We retrospectively reviewed our data from a European RP dataset to assess in contemporary patients with GGG1 at mpMRI-targeted biopsy the rate of adverse features at final pathology, defined as ≥ pT3a and/or pN+ and/or GGG ≥ 3.

RESULTS

A total of 419 patients with cT1-T2 cN0 GGG1-PCa were included. At final pathology, 143 (34.1%) patients had adverse features. In multivariate analysis, only unfavorable intermediate-risk/high-risk disease (defined on PSA or stage) was predictive of adverse features (OR 2.45, 95% CI 1.11-5.39, p = 0.02). A significant difference was observed in the 3-year biochemical recurrence-free survival between patients with and without adverse features (93.4 vs 87.8%, p = 0.026). In sensitivity analysis restricted low- and favorable intermediate-risk PCa, 122/383 patients (31.8%) had adverse features and no preoperative factors were statistically associated with this risk.

CONCLUSION

In this European study, we showed that there is still a risk of underestimating GGG1 disease at biopsy despite the routine use of image-guided biopsies. Future studies are warranted to improve the detection of aggressive disease in GGG1-labeled patients by incorporating the latest tools such as genomic testing or radiomics.