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

Abstract

BackgroundDebate 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. ObjectiveTo 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 participantsThis was a population-based observational study using data from the Danish Prostate Registry. Outcome measurements and statistical analysisWe measured the cumulative incidence of curative treatment, endocrine treatment, and cause-specific mortality. Results and limitationsThe 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. ConclusionsGG 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 summaryKey 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.