Abstract
Background Optimal prostate cancer (PCa) screening strategies will focus on men most likely to have potentially-lethal, localized disease. Age-specific incidence rates (ASIRs) for clinical risk groups could guide risk-stratified screening.
Objective Determine ASIRs and proportions of PCa diagnoses in Norway for modern risk-group and Gleason score categories.
Design, Setting, and Participants All men diagnosed with PCa in Norway in 2014-2017 (n=20,356).
Outcome Measurements and Statistical Analysis Patients were assigned to clinical risk groups: low, favorable-intermediate, unfavorable-intermediate, high, regional, and metastatic, using Gleason score and clinical stage. Associations were assessed between age and (1) Gleason score (including Gleason 3+4 and 4+3) and (2) PCa risk group. Risk-group ASIRs were calculated by multiplying the overall Norwegian ASIR by the proportions observed for each category.
Results Older age was significantly associated with higher Gleason score and more advanced disease. For example, among men aged 55-59, 65-69, 75-79, and 85-89 years, the percentage with Gleason 8-10 disease was 16.5%, 23.4%, 37.2%, and 59.9%, respectively (p<0.001); the percentage with at least high-risk disease was 29.3%, 39.1%, 60.4%, and 90.6%, respectively. Corresponding percentages for low-risk PCa were 24.0%, 17.9%, 10.2%, and 4.1% (p<0.001). The respective maximum ASIRs (per 100,000 men) for low-risk, favorable-intermediate-risk, unfavorable-intermediate-risk, high-risk, regional, and metastatic disease were: 157.1, 183.8, 194.8, 408.3, 172.3, and 330.0; incidence for low-risk and favorable-intermediate-risk PCa peaked before age 70, while more advanced categories peaked after 70. At age 75-79 years, the ASIR of high-risk disease was approximately 6 times greater than at 55-59 years.
Conclusions Risk of clinically-significant, localized PCa increases with age. Healthy older men may be among those most likely to benefit from PCa screening.
Footnotes
Conflicts of Interest: TMS reports grant funding from Varian Medical Systems, unrelated to the present study, and honoraria in the past from WebMD, Inc. for providing medical education materials, unrelated to this work. OAA reports speakers’ honorarium from Lundbeck and is consultant for HealthLytix, Inc. OAA has a patent application (US 20150356243) pending; AMD also applied for this patent application and assigned it to UC San Diego. AMD has stock options in Human Longevity, Inc, and is a founder and equity holder in CorTechs Labs, Inc., and HealthLytix, Inc. AMD reports research funding from General Electric Healthcare, unrelated to the present study. The other authors have no disclosures to report.