Variation in prostate cancer growth rates in an MRI-based active surveillance cohort
摘要
Understanding tumour growth rates helps optimise screening and active surveillance (AS) schedules. We estimated prostate cancer growth rate accounting for individual variation in a longitudinal AS cohort.
Materials and methodsWe modelled tumour growth in 145 biopsy-confirmed prostate cancer patients undergoing MRI-based AS. Primary lesion volumes were measured longitudinally using planimetry. We compared three mixed-effects models (exponential, Gompertz, and logistic) and investigated relationships between growth rate and clinical characteristics. We estimated the natural trajectory of prostate cancer lesions starting at a single cell to clinical detectability (diameter ≈ 1 cm), with diameters estimated based on spherical volume.
ResultsAll three models fit observed data well; however, only the Gompertz model provided reasonable estimates from a single cell to an MRI-detectable size (diameter ≈ 3 mm). The Gompertz growth parameter (mean = 0.07, range = 0.02–0.15), describing exponential growth deceleration, was positively correlated with: patient age; lesion volume at AS onset; prostate-specific antigen (PSA) level; and PSA density. Lesions with Gleason 3 + 4 had faster volume doubling times than Gleason 3 + 3 lesions (mean = 3.5 and 5.2 years, respectively). On average, it would take 17 years (95% CI [15, 19]) for a lesion to grow from a single cell to an MRI-detectable size and an additional 12 years to reach a clinically detectable size (95% CI [10, 13]). At age 50, 75% of lesions would remain undetectable by MRI.
ConclusionsProstate cancer shows slow growth with large variation between patients, posing a challenge for early detection.
Key Points