Prostate cancer detection and aggressiveness raised in smaller prostates
MedWire News: Men with small prostate volumes and high initial prostate-specific antigen (PSA) levels have a greater risk for cancer detection and aggressive disease than other men, Dutch researchers have discovered.
Prostate biopsy is the standard method for the early detection of prostate cancer, but prostate volume may affect the detection rate on traditional sextant biopsy and current screening protocols may consequently result in missed cases.
To investigate further, Pim van Leeuwen and colleagues from Erasmus University Medical Center in Rotterdam studied 1305 men aged 55–74 years with a PSA level ≥3.0 ng/ml and a negative sextant biopsy at initial screening who were participating in the European Randomized Study of Screening for Prostate Cancer, Rotterdam section.
The men were followed-up for 8 years, and prostate cancer cases detected during follow-up via screening or clinically as interval cancers were examined. Prostate volume at initial screening was assessed in relation to the number of cancers detected during follow-up and the predictors of aggressive cancer, defined as N1 or M1 disease, a PSA >20 ng/ml, and Gleason score >7, were determined.
In all, 11.6% of the men were diagnosed with prostate cancer during follow-up, of whom15.1% had tumors that were classified as aggressive and 32.9% had interval cancers, the team notes in BJU International.
The initial prostate volume for the whole group was 47.4 ml, compared with 43.4 ml among men diagnosed with cancer at the second screening round and 40.0 ml in men diagnosed at the third screening round. On univariate analysis, prostate volume at initial screening was significantly associated with the number of detected cases at the second and third screening rounds, at odds ratios of 0.22 and 0.05, respectively.
Multivariate analysis revealed that all prostate cancers were significantly predicted by log prostate volume, log initial PSA level, and age, at odds ratios of 0.085, 3.213, and 0.957, respectively. The presence of aggressive prostate cancer was significantly predicted by log prostate volume and log initial PSA level, at odds ratios of 0.032 and 70.367, respectively.
The team writes: “In this study we showed that men with a smaller prostate volume, who had, at the initial screening round, an indication for biopsy and a negative biopsy result, were at greater risk of being diagnosed with prostate cancer, and of aggressive prostate cancer, during the 8 years of follow-up.
“This was in contrast with our intuitive assumption which implied that using lateralized sextant biopsies irrespective of prostate volume would result in more missed cancers in larger prostates, due to under-sampling.”
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By Liam Davenport