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

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.

Clinical-Grade Validation of an Autofluorescence Virtual Staining System With Human Experts and a Deep Learning System for Prostate Cancer

The tissue diagnosis of adenocarcinoma and intraductal carcinoma of the prostate includes Gleason grading of tumor morphology on the hematoxylin and eosin stain and immunohistochemistry markers on the prostatic intraepithelial neoplasia-4 stain (CK5/6, P63, and AMACR). In this work, we create an automated system for producing both virtual hematoxylin and eosin and prostatic intraepithelial neoplasia-4 immunohistochemistry stains from unstained prostate tissue using a high-throughput hyperspectral fluorescence microscope and artificial intelligence and machine learning. We demonstrate that the virtual stainer models can produce high-quality images suitable for diagnosis by genitourinary pathologists. Specifically, we validate our system through extensive human review and computational analysis, using a previously validated Gleason scoring model, and an expert panel, on a large data set of test slides. This study extends our previous work on virtual staining from autofluorescence, demonstrates the clinical utility of this technology for prostate cancer, and exemplifies a rigorous standard of qualitative and quantitative evaluation for digital pathology.

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.