Early natural history of prostate cancer linked to disease grade at diagnosis
MedWire News: The time between detection of prostate-specific antigen (PSA) elevation and prostate cancer diagnosis not only varies greatly but can indicate the likely future pathology of the disease, researchers report.
The team found that a longer lead time was significantly associated with a lower risk for high-grade disease.
“Early changes in the prostate are responsible for tumor grade at presentation and the time from screen-detectable disease to clinical diagnosis,” write Caroline Savage, from Memorial Sloan Kettering Cancer Center in New York, USA, and colleagues in the journal Cancer Epidemiology Biomarkers and Prevention.
The study incorporated two cohorts, 1167 men whose PSA was measured at 60 years of age, 132 of whom had prostate cancer, and 4260 men whose PSA was measured at age 51–56 years, 495 of whom had the disease.
In total, 57 of the older and 116 of the younger men had an elevated baseline PSA measurement (3 ng/ml or more).
The median time from PSA elevation to diagnosis was slightly longer in the younger men than the older men, at 12.8 months versus 11.8 months, with wide variation in both age groups.
The researchers evaluated the impact of an elevated PSA on disease pathology, and the potential association between lead time and cancer stage and grade.
Overall, higher PSA levels were significantly associated with shorter lead times in both cohorts. However, the team notes this was due to a small number of patients with very high PSA levels and short lead times.
Savage et al also observed a significant association between longer lead times and lower risk for high-grade disease (Gleason score 7 or higher, or World Health Organisation grade 3) at diagnosis, with odds ratios per 1-year increase in lead time of 0.82 and 0.77 for older and younger men, respectively.
Conversely, no correlations were found between lead time and high-stage disease (T3 or higher) at diagnosis.
“It seems that changes that occur early in the natural history of the disease are associated with the aggressiveness of the cancer, in terms of both how quickly the tumor progresses and how poorly differentiated the disease is at presentation,” they conclude.
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By Sarah Guy