Analyzing Prostate-Specific Antigen (PSA) trajectories and the impact of COVID-19 on prostate cancer screening and diagnosis in Manitoba

Abstract

Background: Prostate cancer is the most common cancer among Canadian men, yet PSA-based screening remains controversial due to concerns on over diagnosis. Despite this, PSA testing plays a key role in early detection and disease monitoring. While many studies have linked PSA levels to cancer outcomes, few have examined longitudinal PSA trajectories from diagnosis through treatment and recurrence. This study addresses this gap by analyzing PSA trajectories in high-risk men and assessing the impact of the COVID-19 pandemic on PSA screening and prostate cancer diagnosis. Objectives:

Identify distinct PSA trajectories and associated factors; Examine relationships between trajectories and cancer occurrence, aggressiveness, and recurrence; Evaluate COVID-19’s impact on screening and diagnosis.

Methods: The primary cohort included 856 high-risk men aged 40+ in Winnipeg who underwent prostate biopsies in 2019. Longitudinal PSA data (2008–2023), biopsy results, and treatment information were analyzed. For pandemic-related analyses, all PSA tests performed in Manitoba from 2016 to 2023 were considered. Group-based trajectory modeling (GBTM) identified PSA patterns, and model selection was guided by BIC and clinical relevance. Multinomial logistic regression assessed associations between predictors and trajectory classes, while generalized linear models examined links to cancer outcomes. Time-series analysis and Wilcoxon rank sum tests evaluated changes in screening and diagnosis rates across pandemic periods. Results: Five PSA trajectory classes were identified, reflecting varied PSA progression patterns. Classes 1 and 2 (49.4%) showed post-biopsy declines, indicating effective intervention and strong associations with cancer diagnosis, resection, and recurrence. Class 3 (45.6%) exhibited a rebound after initial decline, suggesting partial treatment response. Classes 4 and 5 (5.1%) displayed aggressive or severe disease characteristics. Trajectory class was significantly associated with demographic, clinical, and socioeconomic factors, and with cancer aggressiveness. During the first COVID-19 wave, PSA screening dropped by 41%, with only partial recovery, and biopsy positivity rates increased—suggesting delayed diagnoses. Conclusion: PSA trajectory analysis offers clinically meaningful insight into prostate cancer progression and treatment. The study highlights the need for trajectory-informed screening strategies and the importance of addressing socioeconomic disparities and healthcare disruptions in cancer management.